DragonFly On-Line Manual Pages

ZSHALL(1) DragonFly General Commands Manual ZSHALL(1)

NAME
zshall - the Z shell meta-man page

OVERVIEW
Because zsh contains many features, the zsh manual has been split into
a number of sections. This manual page includes all the separate
manual pages in the following order:

zsh Zsh overview
zshroadmap Informal introduction to the manual
zshmisc Anything not fitting into the other sections
zshexpn Zsh command and parameter expansion
zshparam Zsh parameters
zshoptions Zsh options
zshbuiltins Zsh built-in functions
zshzle Zsh command line editing
zshcompwid Zsh completion widgets
zshcompsys Zsh completion system
zshcompctl Zsh completion control
zshmodules Zsh loadable modules
zshcalsys Zsh built-in calendar functions
zshtcpsys Zsh built-in TCP functions
zshzftpsys Zsh built-in FTP client
zshcontrib Additional zsh functions and utilities

DESCRIPTION
Zsh is a UNIX command interpreter (shell) usable as an interactive
login shell and as a shell script command processor. Of the standard
shells, zsh most closely resembles ksh but includes many enhancements.
It does not provide compatibility with POSIX or other shells in its
default operating mode: see the section `Compatibility' below.

Zsh has command line editing, builtin spelling correction, programmable
command completion, shell functions (with autoloading), a history
mechanism, and a host of other features.

AUTHOR
Zsh was originally written by Paul Falstad. Zsh is now maintained by
the members of the zsh-workers mailing list <zsh-workers@zsh.org>. The
development is currently coordinated by Peter Stephenson <pws@zsh.org>.
The coordinator can be contacted at <coordinator@zsh.org>, but matters
relating to the code should generally go to the mailing list.

AVAILABILITY
Zsh is available from the following HTTP and anonymous FTP site.

ftp://ftp.zsh.org/pub/
https://www.zsh.org/pub/

The up-to-date source code is available via Git from Sourceforge. See
https://sourceforge.net/projects/zsh/ for details. A summary of
instructions for the archive can be found at
https://zsh.sourceforge.io/.

MAILING LISTS
Zsh has several mailing lists:

<zsh-announce@zsh.org>
Announcements about releases, major changes in the shell and the
monthly posting of the Zsh FAQ. (moderated)

<zsh-users@zsh.org>
User discussions.

<zsh-workers@zsh.org>
Hacking, development, bug reports and patches.

<zsh-security@zsh.org>
Private mailing list (the general public cannot subscribe to it)
for discussing bug reports with security implications, i.e.,
potential vulnerabilities.

If you find a security problem in zsh itself, please mail this
address.

To subscribe or unsubscribe, send mail to the associated administrative
address for the mailing list.

<zsh-announce-subscribe@zsh.org>
<zsh-users-subscribe@zsh.org>
<zsh-workers-subscribe@zsh.org>
<zsh-announce-unsubscribe@zsh.org>
<zsh-users-unsubscribe@zsh.org>
<zsh-workers-unsubscribe@zsh.org>

YOU ONLY NEED TO JOIN ONE OF THE MAILING LISTS AS THEY ARE NESTED. All
submissions to zsh-announce are automatically forwarded to zsh-users.
All submissions to zsh-users are automatically forwarded to
zsh-workers.

If you have problems subscribing/unsubscribing to any of the mailing
lists, send mail to <listmaster@zsh.org>.

The mailing lists are archived; the archives can be accessed via the
administrative addresses listed above. There is also a hypertext
archive available at https://www.zsh.org/mla/.

THE ZSH FAQ
Zsh has a list of Frequently Asked Questions (FAQ), maintained by Peter
Stephenson <pws@zsh.org>. It is regularly posted to the newsgroup
comp.unix.shell and the zsh-announce mailing list. The latest version
can be found at any of the Zsh FTP sites, or at
https://www.zsh.org/FAQ/. The contact address for FAQ-related matters
is <faqmaster@zsh.org>.

THE ZSH WEB PAGE
Zsh has a web page which is located at https://www.zsh.org/. The
contact address for web-related matters is <webmaster@zsh.org>.

THE ZSH USERGUIDE
A userguide is currently in preparation. It is intended to complement
the manual, with explanations and hints on issues where the manual can
be cabbalistic, hierographic, or downright mystifying (for example, the
word `hierographic' does not exist). It can be viewed in its current
state at https://zsh.sourceforge.io/Guide/. At the time of writing,
chapters dealing with startup files and their contents and the new
completion system were essentially complete.

INVOCATION
The following flags are interpreted by the shell when invoked to
determine where the shell will read commands from:

-c Take the first argument as a command to execute, rather than
reading commands from a script or standard input. If any
further arguments are given, the first one is assigned to $0,
rather than being used as a positional parameter.

-i Force shell to be interactive. It is still possible to specify
a script to execute.

-s Force shell to read commands from the standard input. If the -s
flag is not present and an argument is given, the first argument
is taken to be the pathname of a script to execute.

If there are any remaining arguments after option processing, and
neither of the options -c or -s was supplied, the first argument is
taken as the file name of a script containing shell commands to be
executed. If the option PATH_SCRIPT is set, and the file name does not
contain a directory path (i.e. there is no `/' in the name), first the
current directory and then the command path given by the variable PATH
are searched for the script. If the option is not set or the file name
contains a `/' it is used directly.

After the first one or two arguments have been appropriated as
described above, the remaining arguments are assigned to the positional
parameters.

For further options, which are common to invocation and the set
builtin, see zshoptions(1).

The long option `--emulate' followed (in a separate word) by an
emulation mode may be passed to the shell. The emulation modes are
those described for the emulate builtin, see zshbuiltins(1). The
`--emulate' option must precede any other options (which might
otherwise be overridden), but following options are honoured, so may be
used to modify the requested emulation mode. Note that certain extra
steps are taken to ensure a smooth emulation when this option is used
compared with the emulate command within the shell: for example,
variables that conflict with POSIX usage such as path are not defined
within the shell.

Options may be specified by name using the -o option. -o acts like a
single-letter option, but takes a following string as the option name.
For example,

zsh -x -o shwordsplit scr

runs the script scr, setting the XTRACE option by the corresponding
letter `-x' and the SH_WORD_SPLIT option by name. Options may be
turned off by name by using +o instead of -o. -o can be stacked up
with preceding single-letter options, so for example `-xo shwordsplit'
or `-xoshwordsplit' is equivalent to `-x -o shwordsplit'.

Options may also be specified by name in GNU long option style,
`--option-name'. When this is done, `-' characters in the option name
are permitted: they are translated into `_', and thus ignored. So, for
example, `zsh --sh-word-split' invokes zsh with the SH_WORD_SPLIT
option turned on. Like other option syntaxes, options can be turned
off by replacing the initial `-' with a `*'; thus `+-sh-word-split' is
equivalent to `--no-sh-word-split'. Unlike other option syntaxes,
GNU-style long options cannot be stacked with any other options, so for
example `-x-shwordsplit' is an error, rather than being treated like
`-x --shwordsplit'.

The special GNU-style option `--version' is handled; it sends to
standard output the shell's version information, then exits
successfully. `--help' is also handled; it sends to standard output a
list of options that can be used when invoking the shell, then exits
successfully.

Option processing may be finished, allowing following arguments that
start with `-' or `*' to be treated as normal arguments, in two ways.
Firstly, a lone `-' (or `*') as an argument by itself ends option
processing. Secondly, a special option `--' (or `+-'), which may be
specified on its own (which is the standard POSIX usage) or may be
stacked with preceding options (so `-x-' is equivalent to `-x --').
Options are not permitted to be stacked after `--' (so `-x-f' is an
error), but note the GNU-style option form discussed above, where
`--shwordsplit' is permitted and does not end option processing.

Except when the sh/ksh emulation single-letter options are in effect,
the option `-b' (or `+b') ends option processing. `-b' is like `--',
except that further single-letter options can be stacked after the `-b'
and will take effect as normal.

COMPATIBILITY
Zsh tries to emulate sh or ksh when it is invoked as sh or ksh
respectively; more precisely, it looks at the first letter of the name
by which it was invoked, excluding any initial `r' (assumed to stand
for `restricted'), and if that is `b', `s' or `k' it will emulate sh or
ksh. Furthermore, if invoked as su (which happens on certain systems
when the shell is executed by the su command), the shell will try to
find an alternative name from the SHELL environment variable and
perform emulation based on that.

In sh and ksh compatibility modes the following parameters are not
special and not initialized by the shell: ARGC, argv, cdpath, fignore,
fpath, HISTCHARS, mailpath, MANPATH, manpath, path, prompt, PROMPT,
PROMPT2, PROMPT3, PROMPT4, psvar, status.

The usual zsh startup/shutdown scripts are not executed. Login shells
source /etc/profile followed by $HOME/.profile. If the ENV environment
variable is set on invocation, $ENV is sourced after the profile
scripts. The value of ENV is subjected to parameter expansion, command
substitution, and arithmetic expansion before being interpreted as a
pathname. Note that the PRIVILEGED option also affects the execution
of startup files.

The following options are set if the shell is invoked as sh or ksh:
NO_BAD_PATTERN, NO_BANG_HIST, NO_BG_NICE, NO_EQUALS,
NO_FUNCTION_ARGZERO, GLOB_SUBST, NO_GLOBAL_EXPORT, NO_HUP,
INTERACTIVE_COMMENTS, KSH_ARRAYS, NO_MULTIOS, NO_NOMATCH, NO_NOTIFY,
POSIX_BUILTINS, NO_PROMPT_PERCENT, RM_STAR_SILENT, SH_FILE_EXPANSION,
SH_GLOB, SH_OPTION_LETTERS, SH_WORD_SPLIT. Additionally the BSD_ECHO
and IGNORE_BRACES options are set if zsh is invoked as sh. Also, the
KSH_OPTION_PRINT, LOCAL_OPTIONS, PROMPT_BANG, PROMPT_SUBST and
SINGLE_LINE_ZLE options are set if zsh is invoked as ksh.

Please note that, whilst reasonable efforts are taken to address
incompatibilities when they arise, zsh does not guarantee complete
emulation of other shells, nor POSIX compliance. For more information
on the differences between zsh and other shells, please refer to
chapter 2 of the shell FAQ, https://www.zsh.org/FAQ/.

RESTRICTED SHELL
When the basename of the command used to invoke zsh starts with the
letter `r' or the `-r' command line option is supplied at invocation,
the shell becomes restricted. Emulation mode is determined after
stripping the letter `r' from the invocation name. The following are
disabled in restricted mode:

o changing directories with the cd builtin

o changing or unsetting the EGID, EUID, GID, HISTFILE, HISTSIZE,
IFS, LD_AOUT_LIBRARY_PATH, LD_AOUT_PRELOAD, LD_LIBRARY_PATH,
LD_PRELOAD, MODULE_PATH, module_path, PATH, path, SHELL, UID and
USERNAME parameters

o specifying command names containing /

o specifying command pathnames using hash

o redirecting output to files

o using the exec builtin command to replace the shell with another
command

o using jobs -Z to overwrite the shell process' argument and
environment space

o using the ARGV0 parameter to override argv[0] for external
commands

o turning off restricted mode with set +r or unsetopt RESTRICTED

These restrictions are enforced after processing the startup files.
The startup files should set up PATH to point to a directory of
commands which can be safely invoked in the restricted environment.
They may also add further restrictions by disabling selected builtins.

Restricted mode can also be activated any time by setting the
RESTRICTED option. This immediately enables all the restrictions
described above even if the shell still has not processed all startup
files.

A shell Restricted Mode is an outdated way to restrict what users may
do: modern systems have better, safer and more reliable ways to
confine user actions, such as chroot jails, containers and zones.

A restricted shell is very difficult to implement safely. The feature
may be removed in a future version of zsh.

It is important to realise that the restrictions only apply to the
shell, not to the commands it runs (except for some shell builtins).
While a restricted shell can only run the restricted list of commands
accessible via the predefined `PATH' variable, it does not prevent
those commands from running any other command.

As an example, if `env' is among the list of allowed commands, then it
allows the user to run any command as `env' is not a shell builtin
command and can run arbitrary executables.

So when implementing a restricted shell framework it is important to be
fully aware of what actions each of the allowed commands or features
(which may be regarded as modules) can perform.

Many commands can have their behaviour affected by environment
variables. Except for the few listed above, zsh does not restrict the
setting of environment variables.

If a `perl', `python', `bash', or other general purpose interpreted
script it treated as a restricted command, the user can work around the
restriction by setting specially crafted `PERL5LIB', `PYTHONPATH',
`BASHENV' (etc.) environment variables. On GNU systems, any command can
be made to run arbitrary code when performing character set conversion
(including zsh itself) by setting a `GCONV_PATH' environment variable.
Those are only a few examples.

Bear in mind that, contrary to some other shells, `readonly' is not a
security feature in zsh as it can be undone and so cannot be used to
mitigate the above.

A restricted shell only works if the allowed commands are few and
carefully written so as not to grant more access to users than
intended. It is also important to restrict what zsh module the user
may load as some of them, such as `zsh/system', `zsh/mapfile' and
`zsh/files', allow bypassing most of the restrictions.

STARTUP/SHUTDOWN FILES
Commands are first read from /etc/zshenv; this cannot be overridden.
Subsequent behaviour is modified by the RCS and GLOBAL_RCS options; the
former affects all startup files, while the second only affects global
startup files (those shown here with an path starting with a /). If
one of the options is unset at any point, any subsequent startup
file(s) of the corresponding type will not be read. It is also
possible for a file in $ZDOTDIR to re-enable GLOBAL_RCS. Both RCS and
GLOBAL_RCS are set by default.

Commands are then read from $ZDOTDIR/.zshenv. If the shell is a login
shell, commands are read from /etc/zprofile and then
$ZDOTDIR/.zprofile. Then, if the shell is interactive, commands are
read from /etc/zshrc and then $ZDOTDIR/.zshrc. Finally, if the shell
is a login shell, /etc/zlogin and $ZDOTDIR/.zlogin are read.

When a login shell exits, the files $ZDOTDIR/.zlogout and then
/etc/zlogout are read. This happens with either an explicit exit via
the exit or logout commands, or an implicit exit by reading end-of-file
from the terminal. However, if the shell terminates due to exec'ing
another process, the logout files are not read. These are also
affected by the RCS and GLOBAL_RCS options. Note also that the RCS
option affects the saving of history files, i.e. if RCS is unset when
the shell exits, no history file will be saved.

If ZDOTDIR is unset, HOME is used instead. Files listed above as being
in /etc may be in another directory, depending on the installation.

As /etc/zshenv is run for all instances of zsh, it is important that it
be kept as small as possible. In particular, it is a good idea to put
code that does not need to be run for every single shell behind a test
of the form `if [[ -o rcs ]]; then ...' so that it will not be executed
when zsh is invoked with the `-f' option.

Any of these files may be pre-compiled with the zcompile builtin
command (see zshbuiltins(1)). If a compiled file exists (named for the
original file plus the .zwc extension) and it is newer than the
original file, the compiled file will be used instead.

NAME
zshroadmap - informal introduction to the zsh manual The Zsh Manual,
like the shell itself, is large and often complicated. This section of
the manual provides some pointers to areas of the shell that are likely
to be of particular interest to new users, and indicates where in the
rest of the manual the documentation is to be found.

WHEN THE SHELL STARTS
When it starts, the shell reads commands from various files. These can
be created or edited to customize the shell. See the section
Startup/Shutdown Files in zsh(1).

If no personal initialization files exist for the current user, a
function is run to help you change some of the most common settings.
It won't appear if your administrator has disabled the zsh/newuser
module. The function is designed to be self-explanatory. You can run
it by hand with `autoload -Uz zsh-newuser-install; zsh-newuser-install
-f'. See also the section `User Configuration Functions' in
zshcontrib(1).

INTERACTIVE USE
Interaction with the shell uses the builtin Zsh Line Editor, ZLE. This
is described in detail in zshzle(1).

The first decision a user must make is whether to use the Emacs or Vi
editing mode as the keys for editing are substantially different.
Emacs editing mode is probably more natural for beginners and can be
selected explicitly with the command bindkey -e.

A history mechanism for retrieving previously typed lines (most simply
with the Up or Down arrow keys) is available; note that, unlike other
shells, zsh will not save these lines when the shell exits unless you
set appropriate variables, and the number of history lines retained by
default is quite small (30 lines). See the description of the shell
variables (referred to in the documentation as parameters) HISTFILE,
HISTSIZE and SAVEHIST in zshparam(1). Note that it's currently only
possible to read and write files saving history when the shell is
interactive, i.e. it does not work from scripts.

The shell now supports the UTF-8 character set (and also others if
supported by the operating system). This is (mostly) handled
transparently by the shell, but the degree of support in terminal
emulators is variable. There is some discussion of this in the shell
FAQ, https://www.zsh.org/FAQ/. Note in particular that for combining
characters to be handled the option COMBINING_CHARS needs to be set.
Because the shell is now more sensitive to the definition of the
character set, note that if you are upgrading from an older version of
the shell you should ensure that the appropriate variable, either LANG
(to affect all aspects of the shell's operation) or LC_CTYPE (to affect
only the handling of character sets) is set to an appropriate value.
This is true even if you are using a single-byte character set
including extensions of ASCII such as ISO-8859-1 or ISO-8859-15. See
the description of LC_CTYPE in zshparam(1).

Completion
Completion is a feature present in many shells. It allows the user to
type only a part (usually the prefix) of a word and have the shell fill
in the rest. The completion system in zsh is programmable. For
example, the shell can be set to complete email addresses in arguments
to the mail command from your ~/.abook/addressbook; usernames,
hostnames, and even remote paths in arguments to scp, and so on.
Anything that can be written in or glued together with zsh can be the
source of what the line editor offers as possible completions.

Zsh has two completion systems, an old, so called compctl completion
(named after the builtin command that serves as its complete and only
user interface), and a new one, referred to as compsys, organized as
library of builtin and user-defined functions. The two systems differ
in their interface for specifying the completion behavior. The new
system is more customizable and is supplied with completions for many
commonly used commands; it is therefore to be preferred.

The completion system must be enabled explicitly when the shell starts.
For more information see zshcompsys(1).

Extending the line editor
Apart from completion, the line editor is highly extensible by means of
shell functions. Some useful functions are provided with the shell;
they provide facilities such as:

insert-composed-char
composing characters not found on the keyboard

match-words-by-style
configuring what the line editor considers a word when moving or
deleting by word

history-beginning-search-backward-end, etc.
alternative ways of searching the shell history

replace-string, replace-pattern
functions for replacing strings or patterns globally in the
command line

edit-command-line
edit the command line with an external editor.

See the section `ZLE Functions' in zshcontrib(1) for descriptions of
these.

OPTIONS
The shell has a large number of options for changing its behaviour.
These cover all aspects of the shell; browsing the full documentation
is the only good way to become acquainted with the many possibilities.
See zshoptions(1).

PATTERN MATCHING
The shell has a rich set of patterns which are available for file
matching (described in the documentation as `filename generation' and
also known for historical reasons as `globbing') and for use when
programming. These are described in the section `Filename Generation'
in zshexpn(1).

Of particular interest are the following patterns that are not commonly
supported by other systems of pattern matching:

** for matching over multiple directories

| for matching either of two alternatives

~, ^ the ability to exclude patterns from matching when the
EXTENDED_GLOB option is set

(...) glob qualifiers, included in parentheses at the end of the
pattern, which select files by type (such as directories) or
attribute (such as size).

GENERAL COMMENTS ON SYNTAX
Although the syntax of zsh is in ways similar to the Korn shell, and
therefore more remotely to the original UNIX shell, the Bourne shell,
its default behaviour does not entirely correspond to those shells.
General shell syntax is introduced in the section `Shell Grammar' in
zshmisc(1).

One commonly encountered difference is that variables substituted onto
the command line are not split into words. See the description of the
shell option SH_WORD_SPLIT in the section `Parameter Expansion' in
zshexpn(1). In zsh, you can either explicitly request the splitting
(e.g. ${=foo}) or use an array when you want a variable to expand to
more than one word. See the section `Array Parameters' in zshparam(1).

PROGRAMMING
The most convenient way of adding enhancements to the shell is
typically by writing a shell function and arranging for it to be
autoloaded. Functions are described in the section `Functions' in
zshmisc(1). Users changing from the C shell and its relatives should
notice that aliases are less used in zsh as they don't perform argument
substitution, only simple text replacement.

A few general functions, other than those for the line editor described
above, are provided with the shell and are described in zshcontrib(1).
Features include:

promptinit
a prompt theme system for changing prompts easily, see the
section `Prompt Themes'

zsh-mime-setup
a MIME-handling system which dispatches commands according to
the suffix of a file as done by graphical file managers

zcalc a calculator

zargs a version of xargs that makes the find command redundant

zmv a command for renaming files by means of shell patterns.

NAME
zshmisc - everything and then some

SIMPLE COMMANDS & PIPELINES
A simple command is a sequence of optional parameter assignments
followed by blank-separated words, with optional redirections
interspersed. For a description of assignment, see the beginning of
zshparam(1).

The first word is the command to be executed, and the remaining words,
if any, are arguments to the command. If a command name is given, the
parameter assignments modify the environment of the command when it is
executed. The value of a simple command is its exit status, or 128
plus the signal number if terminated by a signal. For example,

echo foo

is a simple command with arguments.

A pipeline is either a simple command, or a sequence of two or more
simple commands where each command is separated from the next by `|' or
`|&'. Where commands are separated by `|', the standard output of the
first command is connected to the standard input of the next. `|&' is
shorthand for `2>&1 |', which connects both the standard output and the
standard error of the command to the standard input of the next. The
value of a pipeline is the value of the last command, unless the
pipeline is preceded by `!' in which case the value is the logical
inverse of the value of the last command. For example,

echo foo | sed 's/foo/bar/'

is a pipeline, where the output (`foo' plus a newline) of the first
command will be passed to the input of the second.

If a pipeline is preceded by `coproc', it is executed as a coprocess; a
two-way pipe is established between it and the parent shell. The shell
can read from or write to the coprocess by means of the `>&p' and `<&p'
redirection operators or with `print -p' and `read -p'. A pipeline
cannot be preceded by both `coproc' and `!'. If job control is active,
the coprocess can be treated in other than input and output as an
ordinary background job.

A sublist is either a single pipeline, or a sequence of two or more
pipelines separated by `&&' or `||'. If two pipelines are separated by
`&&', the second pipeline is executed only if the first succeeds
(returns a zero status). If two pipelines are separated by `||', the
second is executed only if the first fails (returns a nonzero status).
Both operators have equal precedence and are left associative. The
value of the sublist is the value of the last pipeline executed. For
example,

dmesg | grep panic && print yes

is a sublist consisting of two pipelines, the second just a simple
command which will be executed if and only if the grep command returns
a zero status. If it does not, the value of the sublist is that return
status, else it is the status returned by the print (almost certainly
zero).

A list is a sequence of zero or more sublists, in which each sublist is
terminated by `;', `&', `&|', `&!', or a newline. This terminator may
optionally be omitted from the last sublist in the list when the list
appears as a complex command inside `(...)' or `{...}'. When a sublist
is terminated by `;' or newline, the shell waits for it to finish
before executing the next sublist. If a sublist is terminated by a
`&', `&|', or `&!', the shell executes the last pipeline in it in the
background, and does not wait for it to finish (note the difference
from other shells which execute the whole sublist in the background).
A backgrounded pipeline returns a status of zero.

More generally, a list can be seen as a set of any shell commands
whatsoever, including the complex commands below; this is implied
wherever the word `list' appears in later descriptions. For example,
the commands in a shell function form a special sort of list.

PRECOMMAND MODIFIERS
A simple command may be preceded by a precommand modifier, which will
alter how the command is interpreted. These modifiers are shell
builtin commands with the exception of nocorrect which is a reserved
word.

- The command is executed with a `-' prepended to its argv[0]
string.

builtin
The command word is taken to be the name of a builtin command,
rather than a shell function or external command.

command [ -pvV ]
The command word is taken to be the name of an external command,
rather than a shell function or builtin. If the POSIX_BUILTINS
option is set, builtins will also be executed but certain
special properties of them are suppressed. The -p flag causes a
default path to be searched instead of that in $path. With the
-v flag, command is similar to whence and with -V, it is
equivalent to whence -v.

exec [ -cl ] [ -a argv0 ]
The following command together with any arguments is run in
place of the current process, rather than as a sub-process. The
shell does not fork and is replaced. The shell does not invoke
TRAPEXIT, nor does it source zlogout files. The options are
provided for compatibility with other shells.

The -c option clears the environment.

The -l option is equivalent to the - precommand modifier, to
treat the replacement command as a login shell; the command is
executed with a - prepended to its argv[0] string. This flag
has no effect if used together with the -a option.

The -a option is used to specify explicitly the argv[0] string
(the name of the command as seen by the process itself) to be
used by the replacement command and is directly equivalent to
setting a value for the ARGV0 environment variable.

nocorrect
Spelling correction is not done on any of the words. This must
appear before any other precommand modifier, as it is
interpreted immediately, before any parsing is done. It has no
effect in non-interactive shells.

noglob Filename generation (globbing) is not performed on any of the
words.

COMPLEX COMMANDS
A complex command in zsh is one of the following:

if list then list [ elif list then list ] ... [ else list ] fi
The if list is executed, and if it returns a zero exit status,
the then list is executed. Otherwise, the elif list is executed
and if its status is zero, the then list is executed. If each
elif list returns nonzero status, the else list is executed.

for name ... [ in word ... ] term do list done
Expand the list of words, and set the parameter name to each of
them in turn, executing list each time. If the `in word' is
omitted, use the positional parameters instead of the words.

The term consists of one or more newline or ; which terminate
the words, and are optional when the `in word' is omitted.

More than one parameter name can appear before the list of
words. If N names are given, then on each execution of the loop
the next N words are assigned to the corresponding parameters.
If there are more names than remaining words, the remaining
parameters are each set to the empty string. Execution of the
loop ends when there is no remaining word to assign to the first
name. It is only possible for in to appear as the first name in
the list, else it will be treated as marking the end of the
list.

for (( [expr1] ; [expr2] ; [expr3] )) do list done
The arithmetic expression expr1 is evaluated first (see the
section `Arithmetic Evaluation'). The arithmetic expression
expr2 is repeatedly evaluated until it evaluates to zero and
when non-zero, list is executed and the arithmetic expression
expr3 evaluated. If any expression is omitted, then it behaves
as if it evaluated to 1.

while list do list done
Execute the do list as long as the while list returns a zero
exit status.

until list do list done
Execute the do list as long as until list returns a nonzero exit
status.

repeat word do list done
word is expanded and treated as an arithmetic expression, which
must evaluate to a number n. list is then executed n times.

The repeat syntax is disabled by default when the shell starts
in a mode emulating another shell. It can be enabled with the
command `enable -r repeat'

case word in [ [(] pattern [ | pattern ] ... ) list (;;|;&|;|) ] ...
esac Execute the list associated with the first pattern that matches
word, if any. The form of the patterns is the same as that used
for filename generation. See the section `Filename Generation'.

Note further that, unless the SH_GLOB option is set, the whole
pattern with alternatives is treated by the shell as equivalent
to a group of patterns within parentheses, although white space
may appear about the parentheses and the vertical bar and will
be stripped from the pattern at those points. White space may
appear elsewhere in the pattern; this is not stripped. If the
SH_GLOB option is set, so that an opening parenthesis can be
unambiguously treated as part of the case syntax, the expression
is parsed into separate words and these are treated as strict
alternatives (as in other shells).

If the list that is executed is terminated with ;& rather than
;;, the following list is also executed. The rule for the
terminator of the following list ;;, ;& or ;| is applied unless
the esac is reached.

If the list that is executed is terminated with ;| the shell
continues to scan the patterns looking for the next match,
executing the corresponding list, and applying the rule for the
corresponding terminator ;;, ;& or ;|. Note that word is not
re-expanded; all applicable patterns are tested with the same
word.

select name [ in word ... term ] do list done
where term is one or more newline or ; to terminate the words.
Print the set of words, each preceded by a number. If the in
word is omitted, use the positional parameters. The PROMPT3
prompt is printed and a line is read from the line editor if the
shell is interactive and that is active, or else standard input.
If this line consists of the number of one of the listed words,
then the parameter name is set to the word corresponding to this
number. If this line is empty, the selection list is printed
again. Otherwise, the value of the parameter name is set to
null. The contents of the line read from standard input is
saved in the parameter REPLY. list is executed for each
selection until a break or end-of-file is encountered.

( list )
Execute list in a subshell. Traps set by the trap builtin are
reset to their default values while executing list; an exception
is that ignored signals will continue to be ignored if the
option POSIXTRAPS is set.

{ list }
Execute list.

{ try-list } always { always-list }
First execute try-list. Regardless of errors, or break or
continue commands encountered within try-list, execute
always-list. Execution then continues from the result of the
execution of try-list; in other words, any error, or break or
continue command is treated in the normal way, as if always-list
were not present. The two chunks of code are referred to as the
`try block' and the `always block'.

Optional newlines or semicolons may appear after the always;
note, however, that they may not appear between the preceding
closing brace and the always.

An `error' in this context is a condition such as a syntax error
which causes the shell to abort execution of the current
function, script, or list. Syntax errors encountered while the
shell is parsing the code do not cause the always-list to be
executed. For example, an erroneously constructed if block in
try-list would cause the shell to abort during parsing, so that
always-list would not be executed, while an erroneous
substitution such as ${*foo*} would cause a run-time error,
after which always-list would be executed.

An error condition can be tested and reset with the special
integer variable TRY_BLOCK_ERROR. Outside an always-list the
value is irrelevant, but it is initialised to -1. Inside
always-list, the value is 1 if an error occurred in the
try-list, else 0. If TRY_BLOCK_ERROR is set to 0 during the
always-list, the error condition caused by the try-list is
reset, and shell execution continues normally after the end of
always-list. Altering the value during the try-list is not
useful (unless this forms part of an enclosing always block).

Regardless of TRY_BLOCK_ERROR, after the end of always-list the
normal shell status $? is the value returned from try-list.
This will be non-zero if there was an error, even if
TRY_BLOCK_ERROR was set to zero.

The following executes the given code, ignoring any errors it
causes. This is an alternative to the usual convention of
protecting code by executing it in a subshell.

{
# code which may cause an error
} always {
# This code is executed regardless of the error.
(( TRY_BLOCK_ERROR = 0 ))
}
# The error condition has been reset.

When a try block occurs outside of any function, a return or a
exit encountered in try-list does not cause the execution of
always-list. Instead, the shell exits immediately after any
EXIT trap has been executed. Otherwise, a return command
encountered in try-list will cause the execution of always-list,
just like break and continue.

function [ -T ] word ... [ () ] [ term ] { list }
word ... () [ term ] { list }
word ... () [ term ] command
where term is one or more newline or ;. Define a function which
is referenced by any one of word. Normally, only one word is
provided; multiple words are usually only useful for setting
traps. The body of the function is the list between the { and
}. See the section `Functions'.

The options of function have the following meanings:

-T Enable tracing for this function, as though with
functions -T. See the documentation of the -f option to
the typeset builtin, in zshbuiltins(1).

If the option SH_GLOB is set for compatibility with other
shells, then whitespace may appear between the left and right
parentheses when there is a single word; otherwise, the
parentheses will be treated as forming a globbing pattern in
that case.

In any of the forms above, a redirection may appear outside the
function body, for example

func() { ... } 2>&1

The redirection is stored with the function and applied whenever
the function is executed. Any variables in the redirection are
expanded at the point the function is executed, but outside the
function scope.

time [ pipeline ]
The pipeline is executed, and timing statistics are reported on
the standard error in the form specified by the TIMEFMT
parameter. If pipeline is omitted, print statistics about the
shell process and its children.

[[ exp ]]
Evaluates the conditional expression exp and return a zero exit
status if it is true. See the section `Conditional Expressions'
for a description of exp.

ALTERNATE FORMS FOR COMPLEX COMMANDS
Many of zsh's complex commands have alternate forms. These are
non-standard and are likely not to be obvious even to seasoned shell
programmers; they should not be used anywhere that portability of shell
code is a concern.

The short versions below only work if sublist is of the form `{ list }'
or if the SHORT_LOOPS option is set. For the if, while and until
commands, in both these cases the test part of the loop must also be
suitably delimited, such as by `[[ ... ]]' or `(( ... ))', else the end
of the test will not be recognized. For the for, repeat, case and
select commands no such special form for the arguments is necessary,
but the other condition (the special form of sublist or use of the
SHORT_LOOPS option) still applies. The SHORT_REPEAT option is
available to enable the short version only for the repeat command.

if list { list } [ elif list { list } ] ... [ else { list } ]
An alternate form of if. The rules mean that

if [[ -o ignorebraces ]] {
print yes
}

works, but

if true { # Does not work!
print yes
}

does not, since the test is not suitably delimited.

if list sublist
A short form of the alternate if. The same limitations on the
form of list apply as for the previous form.

for name ... ( word ... ) sublist
A short form of for.

for name ... [ in word ... ] term sublist
where term is at least one newline or ;. Another short form of
for.

for (( [expr1] ; [expr2] ; [expr3] )) sublist
A short form of the arithmetic for command.

foreach name ... ( word ... ) list end
Another form of for.

while list { list }
An alternative form of while. Note the limitations on the form
of list mentioned above.

until list { list }
An alternative form of until. Note the limitations on the form
of list mentioned above.

repeat word sublist
This is a short form of repeat.

case word { [ [(] pattern [ | pattern ] ... ) list (;;|;&|;|) ] ... }
An alternative form of case.

select name [ in word ... term ] sublist
where term is at least one newline or ;. A short form of
select.

function word ... [ () ] [ term ] sublist
This is a short form of function.

RESERVED WORDS
The following words are recognized as reserved words when used as the
first word of a command unless quoted or disabled using disable -r:

do done esac then elif else fi for case if while function repeat time
until select coproc nocorrect foreach end ! [[ { } declare export float
integer local readonly typeset

Additionally, `}' is recognized in any position if neither the
IGNORE_BRACES option nor the IGNORE_CLOSE_BRACES option is set.

ERRORS
Certain errors are treated as fatal by the shell: in an interactive
shell, they cause control to return to the command line, and in a
non-interactive shell they cause the shell to be aborted. In older
versions of zsh, a non-interactive shell running a script would not
abort completely, but would resume execution at the next command to be
read from the script, skipping the remainder of any functions or shell
constructs such as loops or conditions; this somewhat illogical
behaviour can be recovered by setting the option CONTINUE_ON_ERROR.

Fatal errors found in non-interactive shells include:

o Failure to parse shell options passed when invoking the shell

o Failure to change options with the set builtin

o Parse errors of all sorts, including failures to parse
mathematical expressions

o Failures to set or modify variable behaviour with typeset,
local, declare, export, integer, float

o Execution of incorrectly positioned loop control structures
(continue, break)

o Attempts to use regular expression with no regular expression
module available

o Disallowed operations when the RESTRICTED options is set

o Failure to create a pipe needed for a pipeline

o Failure to create a multio

o Failure to autoload a module needed for a declared shell feature

o Errors creating command or process substitutions

o Syntax errors in glob qualifiers

o File generation errors where not caught by the option
BAD_PATTERN

o All bad patterns used for matching within case statements

o File generation failures where not caused by NO_MATCH or similar
options

o All file generation errors where the pattern was used to create
a multio

o Memory errors where detected by the shell

o Invalid subscripts to shell variables

o Attempts to assign read-only variables

o Logical errors with variables such as assignment to the wrong
type

o Use of invalid variable names

o Errors in variable substitution syntax

o Failure to convert characters in $'...' expressions

If the POSIX_BUILTINS option is set, more errors associated with shell
builtin commands are treated as fatal, as specified by the POSIX
standard.

COMMENTS
In non-interactive shells, or in interactive shells with the
INTERACTIVE_COMMENTS option set, a word beginning with the third
character of the histchars parameter (`#' by default) causes that word
and all the following characters up to a newline to be ignored.

ALIASING
Every eligible word in the shell input is checked to see if there is an
alias defined for it. If so, it is replaced by the text of the alias
if it is in command position (if it could be the first word of a simple
command), or if the alias is global. If the replacement text ends with
a space, the next word in the shell input is always eligible for
purposes of alias expansion.

It is an error for the function name, word, in the sh-compatible
function definition syntax `word () ...' to be a word that resulted
from alias expansion, unless the ALIAS_FUNC_DEF option is set.

An alias is defined using the alias builtin; global aliases may be
defined using the -g option to that builtin.

A word is defined as:

o Any plain string or glob pattern

o Any quoted string, using any quoting method (note that the
quotes must be part of the alias definition for this to be
eligible)

o Any parameter reference or command substitution

o Any series of the foregoing, concatenated without whitespace or
other tokens between them

o Any reserved word (case, do, else, etc.)

o With global aliasing, any command separator, any redirection
operator, and `(' or `)' when not part of a glob pattern

Alias expansion is done on the shell input before any other expansion
except history expansion. Therefore, if an alias is defined for the
word foo, alias expansion may be avoided by quoting part of the word,
e.g. \foo. Any form of quoting works, although there is nothing to
prevent an alias being defined for the quoted form such as \foo as
well.

In particular, note that quoting must be used when using unalias to
remove global aliases:

% alias -g foo=bar
% unalias foo
unalias: no such hash table element: bar
% unalias \foo
%

When POSIX_ALIASES is set, only plain unquoted strings are eligible for
aliasing. The alias builtin does not reject ineligible aliases, but
they are not expanded.

For use with completion, which would remove an initial backslash
followed by a character that isn't special, it may be more convenient
to quote the word by starting with a single quote, i.e. 'foo;
completion will automatically add the trailing single quote.

Alias difficulties
Although aliases can be used in ways that bend normal shell syntax, not
every string of non-white-space characters can be used as an alias.

Any set of characters not listed as a word above is not a word, hence
no attempt is made to expand it as an alias, no matter how it is
defined (i.e. via the builtin or the special parameter aliases
described in the section THE ZSH/PARAMETER MODULE in zshmodules(1)).
However, as noted in the case of POSIX_ALIASES above, the shell does
not attempt to deduce whether the string corresponds to a word at the
time the alias is created.

For example, an expression containing an = at the start of a command
line is an assignment and cannot be expanded as an alias; a lone = is
not an assignment but can only be set as an alias using the parameter,
as otherwise the = is taken part of the syntax of the builtin command.

It is not presently possible to alias the `((' token that introduces
arithmetic expressions, because until a full statement has been parsed,
it cannot be distinguished from two consecutive `(' tokens introducing
nested subshells. Also, if a separator such as && is aliased, \&&
turns into the two tokens \& and &, each of which may have been aliased
separately. Similarly for \<<, \>|, etc.

There is a commonly encountered problem with aliases illustrated by the
following code:

alias echobar='echo bar'; echobar

This prints a message that the command echobar could not be found.
This happens because aliases are expanded when the code is read in; the
entire line is read in one go, so that when echobar is executed it is
too late to expand the newly defined alias. This is often a problem in
shell scripts, functions, and code executed with `source' or `.'.
Consequently, use of functions rather than aliases is recommended in
non-interactive code.

QUOTING
A character may be quoted (that is, made to stand for itself) by
preceding it with a `\'. `\' followed by a newline is ignored.

A string enclosed between `$'' and `'' is processed the same way as the
string arguments of the print builtin, and the resulting string is
considered to be entirely quoted. A literal `'' character can be
included in the string by using the `\'' escape.

All characters enclosed between a pair of single quotes ('') that is
not preceded by a `$' are quoted. A single quote cannot appear within
single quotes unless the option RC_QUOTES is set, in which case a pair
of single quotes are turned into a single quote. For example,

print ''''

outputs nothing apart from a newline if RC_QUOTES is not set, but one
single quote if it is set.

Inside double quotes (""), parameter and command substitution occur,
and `\' quotes the characters `\', ``', `"', `$', and the first
character of $histchars (default `!').

REDIRECTION
If a command is followed by & and job control is not active, then the
default standard input for the command is the empty file /dev/null.
Otherwise, the environment for the execution of a command contains the
file descriptors of the invoking shell as modified by input/output
specifications.

The following may appear anywhere in a simple command or may precede or
follow a complex command. Expansion occurs before word or digit is
used except as noted below. If the result of substitution on word
produces more than one filename, redirection occurs for each separate
filename in turn.

< word Open file word for reading as standard input. It is an error to
open a file in this fashion if it does not exist.

<> word
Open file word for reading and writing as standard input. If
the file does not exist then it is created.

> word Open file word for writing as standard output. If the file does
not exist then it is created. If the file exists, and the
CLOBBER option is unset, this causes an error; otherwise, it is
truncated to zero length.

>| word
>! word
Same as >, except that the file is truncated to zero length if
it exists, regardless of CLOBBER.

>> word
Open file word for writing in append mode as standard output.
If the file does not exist, and the CLOBBER and APPEND_CREATE
options are both unset, this causes an error; otherwise, the
file is created.

>>| word
>>! word
Same as >>, except that the file is created if it does not
exist, regardless of CLOBBER and APPEND_CREATE.

<<[-] word
The shell input is read up to a line that is the same as word,
or to an end-of-file. No parameter expansion, command
substitution or filename generation is performed on word. The
resulting document, called a here-document, becomes the standard
input.

If any character of word is quoted with single or double quotes
or a `\', no interpretation is placed upon the characters of the
document. Otherwise, parameter and command substitution occurs,
`\' followed by a newline is removed, and `\' must be used to
quote the characters `\', `$', ``' and the first character of
word.

Note that word itself does not undergo shell expansion.
Backquotes in word do not have their usual effect; instead they
behave similarly to double quotes, except that the backquotes
themselves are passed through unchanged. (This information is
given for completeness and it is not recommended that backquotes
be used.) Quotes in the form $'...' have their standard effect
of expanding backslashed references to special characters.

If <<- is used, then all leading tabs are stripped from word and
from the document.

<<< word
Perform shell expansion on word and pass the result to standard
input. This is known as a here-string. Compare the use of word
in here-documents above, where word does not undergo shell
expansion. The result will have a trailing newline after it.

<& number
>& number
The standard input/output is duplicated from file descriptor
number (see dup2(2)).

<& -
>& - Close the standard input/output.

<& p
>& p The input/output from/to the coprocess is moved to the standard
input/output.

>& word
&> word
(Except where `>& word' matches one of the above syntaxes; `&>'
can always be used to avoid this ambiguity.) Redirects both
standard output and standard error (file descriptor 2) in the
manner of `> word'. Note that this does not have the same
effect as `> word 2>&1' in the presence of multios (see the
section below).

>&| word
>&! word
&>| word
&>! word
Redirects both standard output and standard error (file
descriptor 2) in the manner of `>| word'.

>>& word
&>> word
Redirects both standard output and standard error (file
descriptor 2) in the manner of `>> word'.

>>&| word
>>&! word
&>>| word
&>>! word
Redirects both standard output and standard error (file
descriptor 2) in the manner of `>>| word'.

If one of the above is preceded by a digit, then the file descriptor
referred to is that specified by the digit instead of the default 0 or
1. The order in which redirections are specified is significant. The
shell evaluates each redirection in terms of the (file descriptor,
file) association at the time of evaluation. For example:

... 1>fname 2>&1

first associates file descriptor 1 with file fname. It then associates
file descriptor 2 with the file associated with file descriptor 1 (that
is, fname). If the order of redirections were reversed, file
descriptor 2 would be associated with the terminal (assuming file
descriptor 1 had been) and then file descriptor 1 would be associated
with file fname.

The `|&' command separator described in Simple Commands & Pipelines in
zshmisc(1) is a shorthand for `2>&1 |'.

The various forms of process substitution, `<(list)', and `=(list)' for
input and `>(list)' for output, are often used together with
redirection. For example, if word in an output redirection is of the
form `>(list)' then the output is piped to the command represented by
list. See Process Substitution in zshexpn(1).

OPENING FILE DESCRIPTORS USING PARAMETERS
When the shell is parsing arguments to a command, and the shell option
IGNORE_BRACES is not set, a different form of redirection is allowed:
instead of a digit before the operator there is a valid shell
identifier enclosed in braces. The shell will open a new file
descriptor that is guaranteed to be at least 10 and set the parameter
named by the identifier to the file descriptor opened. No whitespace
is allowed between the closing brace and the redirection character.
For example:

... {myfd}>&1

This opens a new file descriptor that is a duplicate of file descriptor
1 and sets the parameter myfd to the number of the file descriptor,
which will be at least 10. The new file descriptor can be written to
using the syntax >&$myfd. The file descriptor remains open in
subshells and forked external executables.

The syntax {varid}>&-, for example {myfd}>&-, may be used to close a
file descriptor opened in this fashion. Note that the parameter given
by varid must previously be set to a file descriptor in this case.

It is an error to open or close a file descriptor in this fashion when
the parameter is readonly. However, it is not an error to read or
write a file descriptor using <&$param or >&$param if param is
readonly.

If the option CLOBBER is unset, it is an error to open a file
descriptor using a parameter that is already set to an open file
descriptor previously allocated by this mechanism. Unsetting the
parameter before using it for allocating a file descriptor avoids the
error.

Note that this mechanism merely allocates or closes a file descriptor;
it does not perform any redirections from or to it. It is usually
convenient to allocate a file descriptor prior to use as an argument to
exec. The syntax does not in any case work when used around complex
commands such as parenthesised subshells or loops, where the opening
brace is interpreted as part of a command list to be executed in the
current shell.

The following shows a typical sequence of allocation, use, and closing
of a file descriptor:

integer myfd
exec {myfd}>~/logs/mylogfile.txt
print This is a log message. >&$myfd
exec {myfd}>&-

Note that the expansion of the variable in the expression >&$myfd
occurs at the point the redirection is opened. This is after the
expansion of command arguments and after any redirections to the left
on the command line have been processed.

MULTIOS
If the user tries to open a file descriptor for writing more than once,
the shell opens the file descriptor as a pipe to a process that copies
its input to all the specified outputs, similar to tee, provided the
MULTIOS option is set, as it is by default. Thus:

date >foo >bar

writes the date to two files, named `foo' and `bar'. Note that a pipe
is an implicit redirection; thus

date >foo | cat

writes the date to the file `foo', and also pipes it to cat.

Note that the shell opens all the files to be used in the multio
process immediately, not at the point they are about to be written.

Note also that redirections are always expanded in order. This happens
regardless of the setting of the MULTIOS option, but with the option in
effect there are additional consequences. For example, the meaning of
the expression >&1 will change after a previous redirection:

date >&1 >output

In the case above, the >&1 refers to the standard output at the start
of the line; the result is similar to the tee command. However,
consider:

date >output >&1

As redirections are evaluated in order, when the >&1 is encountered the
standard output is set to the file output and another copy of the
output is therefore sent to that file. This is unlikely to be what is
intended.

If the MULTIOS option is set, the word after a redirection operator is
also subjected to filename generation (globbing). Thus

: > *

will truncate all files in the current directory, assuming there's at
least one. (Without the MULTIOS option, it would create an empty file
called `*'.) Similarly, you can do

echo exit 0 >> *.sh

If the user tries to open a file descriptor for reading more than once,
the shell opens the file descriptor as a pipe to a process that copies
all the specified inputs to its output in the order specified, provided
the MULTIOS option is set. It should be noted that each file is opened
immediately, not at the point where it is about to be read: this
behaviour differs from cat, so if strictly standard behaviour is
needed, cat should be used instead.

Thus

sort <foo <fubar

or even

sort <f{oo,ubar}

is equivalent to `cat foo fubar | sort'.

Expansion of the redirection argument occurs at the point the
redirection is opened, at the point described above for the expansion
of the variable in >&$myfd.

Note that a pipe is an implicit redirection; thus

cat bar | sort <foo

is equivalent to `cat bar foo | sort' (note the order of the inputs).

If the MULTIOS option is unset, each redirection replaces the previous
redirection for that file descriptor. However, all files redirected to
are actually opened, so

echo Hello > bar > baz

when MULTIOS is unset will truncate `bar', and write `Hello' into
`baz'.

There is a problem when an output multio is attached to an external
program. A simple example shows this:

cat file >file1 >file2
cat file1 file2

Here, it is possible that the second `cat' will not display the full
contents of file1 and file2 (i.e. the original contents of file
repeated twice).

The reason for this is that the multios are spawned after the cat
process is forked from the parent shell, so the parent shell does not
wait for the multios to finish writing data. This means the command as
shown can exit before file1 and file2 are completely written. As a
workaround, it is possible to run the cat process as part of a job in
the current shell:

{ cat file } >file >file2

Here, the {...} job will pause to wait for both files to be written.

REDIRECTIONS WITH NO COMMAND
When a simple command consists of one or more redirection operators and
zero or more parameter assignments, but no command name, zsh can behave
in several ways.

If the parameter NULLCMD is not set or the option CSH_NULLCMD is set,
an error is caused. This is the csh behavior and CSH_NULLCMD is set by
default when emulating csh.

If the option SH_NULLCMD is set, the builtin `:' is inserted as a
command with the given redirections. This is the default when
emulating sh or ksh.

Otherwise, if the parameter NULLCMD is set, its value will be used as a
command with the given redirections. If both NULLCMD and READNULLCMD
are set, then the value of the latter will be used instead of that of
the former when the redirection is an input. The default for NULLCMD
is `cat' and for READNULLCMD is `more'. Thus

< file

shows the contents of file on standard output, with paging if that is a
terminal. NULLCMD and READNULLCMD may refer to shell functions.

COMMAND EXECUTION
If a command name contains no slashes, the shell attempts to locate it.
If there exists a shell function by that name, the function is invoked
as described in the section `Functions'. If there exists a shell
builtin by that name, the builtin is invoked.

Otherwise, the shell searches each element of $path for a directory
containing an executable file by that name.

If execution fails: an error message is printed, and one of the
following values is returned.

127 The search was unsuccessful. The error message is `command not
found: cmd'.
126 The executable file has insufficient permissions, is a directory
or special file, or is not a script and is in a format
unrecognized by the operating system. The exact conditions and
error message are operating system-dependent; see execve(2).

If execution fails because the file is not in executable format, and
the file is not a directory, it is assumed to be a shell script.
/bin/sh is spawned to execute it. If the program is a file beginning
with `#!', the remainder of the first line specifies an interpreter for
the program. The shell will execute the specified interpreter on
operating systems that do not handle this executable format in the
kernel.

If no external command is found but a function
command_not_found_handler exists the shell executes this function with
all command line arguments. The return status of the function becomes
the status of the command. Note that the handler is executed in a
subshell forked to execute an external command, hence changes to
directories, shell parameters, etc. have no effect on the main shell.

FUNCTIONS
Shell functions are defined with the function reserved word or the
special syntax `funcname ()'. Shell functions are read in and stored
internally. Alias names are resolved when the function is read.
Functions are executed like commands with the arguments passed as
positional parameters. (See the section `Command Execution'.)

Functions execute in the same process as the caller and share all files
and present working directory with the caller. A trap on EXIT set
inside a function is executed after the function completes in the
environment of the caller.

The return builtin is used to return from function calls.

Function identifiers can be listed with the functions builtin.
Functions can be undefined with the unfunction builtin.

AUTOLOADING FUNCTIONS
A function can be marked as undefined using the autoload builtin (or
`functions -u' or `typeset -fu'). Such a function has no body. When
the function is first executed, the shell searches for its definition
using the elements of the fpath variable. Thus to define functions for
autoloading, a typical sequence is:

fpath=(~/myfuncs $fpath)
autoload myfunc1 myfunc2 ...

The usual alias expansion during reading will be suppressed if the
autoload builtin or its equivalent is given the option -U. This is
recommended for the use of functions supplied with the zsh
distribution. Note that for functions precompiled with the zcompile
builtin command the flag -U must be provided when the .zwc file is
created, as the corresponding information is compiled into the latter.

For each element in fpath, the shell looks for three possible files,
the newest of which is used to load the definition for the function:

element.zwc
A file created with the zcompile builtin command, which is
expected to contain the definitions for all functions in the
directory named element. The file is treated in the same manner
as a directory containing files for functions and is searched
for the definition of the function. If the definition is not
found, the search for a definition proceeds with the other two
possibilities described below.

If element already includes a .zwc extension (i.e. the extension
was explicitly given by the user), element is searched for the
definition of the function without comparing its age to that of
other files; in fact, there does not need to be any directory
named element without the suffix. Thus including an element
such as `/usr/local/funcs.zwc' in fpath will speed up the search
for functions, with the disadvantage that functions included
must be explicitly recompiled by hand before the shell notices
any changes.

element/function.zwc
A file created with zcompile, which is expected to contain the
definition for function. It may include other function
definitions as well, but those are neither loaded nor executed;
a file found in this way is searched only for the definition of
function.

element/function
A file of zsh command text, taken to be the definition for
function.

In summary, the order of searching is, first, in the parents of
directories in fpath for the newer of either a compiled directory or a
directory in fpath; second, if more than one of these contains a
definition for the function that is sought, the leftmost in the fpath
is chosen; and third, within a directory, the newer of either a
compiled function or an ordinary function definition is used.

If the KSH_AUTOLOAD option is set, or the file contains only a simple
definition of the function, the file's contents will be executed. This
will normally define the function in question, but may also perform
initialization, which is executed in the context of the function
execution, and may therefore define local parameters. It is an error
if the function is not defined by loading the file.

Otherwise, the function body (with no surrounding `funcname() {...}')
is taken to be the complete contents of the file. This form allows the
file to be used directly as an executable shell script. If processing
of the file results in the function being re-defined, the function
itself is not re-executed. To force the shell to perform
initialization and then call the function defined, the file should
contain initialization code (which will be executed then discarded) in
addition to a complete function definition (which will be retained for
subsequent calls to the function), and a call to the shell function,
including any arguments, at the end.

For example, suppose the autoload file func contains

func() { print This is func; }
print func is initialized

then `func; func' with KSH_AUTOLOAD set will produce both messages on
the first call, but only the message `This is func' on the second and
subsequent calls. Without KSH_AUTOLOAD set, it will produce the
initialization message on the first call, and the other message on the
second and subsequent calls.

It is also possible to create a function that is not marked as
autoloaded, but which loads its own definition by searching fpath, by
using `autoload -X' within a shell function. For example, the
following are equivalent:

myfunc() {
autoload -X
}
myfunc args...

and

unfunction myfunc # if myfunc was defined
autoload myfunc
myfunc args...

In fact, the functions command outputs `builtin autoload -X' as the
body of an autoloaded function. This is done so that

eval "$(functions)"

produces a reasonable result. A true autoloaded function can be
identified by the presence of the comment `# undefined' in the body,
because all comments are discarded from defined functions.

To load the definition of an autoloaded function myfunc without
executing myfunc, use:

autoload +X myfunc

ANONYMOUS FUNCTIONS
If no name is given for a function, it is `anonymous' and is handled
specially. Either form of function definition may be used: a `()' with
no preceding name, or a `function' with an immediately following open
brace. The function is executed immediately at the point of definition
and is not stored for future use. The function name is set to
`(anon)'.

Arguments to the function may be specified as words following the
closing brace defining the function, hence if there are none no
arguments (other than $0) are set. This is a difference from the way
other functions are parsed: normal function definitions may be followed
by certain keywords such as `else' or `fi', which will be treated as
arguments to anonymous functions, so that a newline or semicolon is
needed to force keyword interpretation.

Note also that the argument list of any enclosing script or function is
hidden (as would be the case for any other function called at this
point).

Redirections may be applied to the anonymous function in the same
manner as to a current-shell structure enclosed in braces. The main
use of anonymous functions is to provide a scope for local variables.
This is particularly convenient in start-up files as these do not
provide their own local variable scope.

For example,

variable=outside
function {
local variable=inside
print "I am $variable with arguments $*"
} this and that
print "I am $variable"

outputs the following:

I am inside with arguments this and that
I am outside

Note that function definitions with arguments that expand to nothing,
for example `name=; function $name { ... }', are not treated as
anonymous functions. Instead, they are treated as normal function
definitions where the definition is silently discarded.

SPECIAL FUNCTIONS
Certain functions, if defined, have special meaning to the shell.

Hook Functions
For the functions below, it is possible to define an array that has the
same name as the function with `_functions' appended. Any element in
such an array is taken as the name of a function to execute; it is
executed in the same context and with the same arguments and same
initial value of $? as the basic function. For example, if
$chpwd_functions is an array containing the values `mychpwd',
`chpwd_save_dirstack', then the shell attempts to execute the functions
`chpwd', `mychpwd' and `chpwd_save_dirstack', in that order. Any
function that does not exist is silently ignored. A function found by
this mechanism is referred to elsewhere as a hook function. An error
in any function causes subsequent functions not to be run. Note
further that an error in a precmd hook causes an immediately following
periodic function not to run (though it may run at the next
opportunity).

chpwd Executed whenever the current working directory is changed.

periodic
If the parameter PERIOD is set, this function is executed every
$PERIOD seconds, just before a prompt. Note that if multiple
functions are defined using the array periodic_functions only
one period is applied to the complete set of functions, and the
scheduled time is not reset if the list of functions is altered.
Hence the set of functions is always called together.

precmd Executed before each prompt. Note that precommand functions are
not re-executed simply because the command line is redrawn, as
happens, for example, when a notification about an exiting job
is displayed.

preexec
Executed just after a command has been read and is about to be
executed. If the history mechanism is active (regardless of
whether the line was discarded from the history buffer), the
string that the user typed is passed as the first argument,
otherwise it is an empty string. The actual command that will
be executed (including expanded aliases) is passed in two
different forms: the second argument is a single-line,
size-limited version of the command (with things like function
bodies elided); the third argument contains the full text that
is being executed.

zshaddhistory
Executed when a history line has been read interactively, but
before it is executed. The sole argument is the complete
history line (so that any terminating newline will still be
present).

If any of the hook functions returns status 1 (or any non-zero
value other than 2, though this is not guaranteed for future
versions of the shell) the history line will not be saved,
although it lingers in the history until the next line is
executed, allowing you to reuse or edit it immediately.

If any of the hook functions returns status 2 the history line
will be saved on the internal history list, but not written to
the history file. In case of a conflict, the first non-zero
status value is taken.

A hook function may call `fc -p ...' to switch the history
context so that the history is saved in a different file from
that in the global HISTFILE parameter. This is handled
specially: the history context is automatically restored after
the processing of the history line is finished.

The following example function works with one of the options
INC_APPEND_HISTORY or SHARE_HISTORY set, in order that the line
is written out immediately after the history entry is added. It
first adds the history line to the normal history with the
newline stripped, which is usually the correct behaviour. Then
it switches the history context so that the line will be written
to a history file in the current directory.

zshaddhistory() {
print -sr -- ${1%%$'\n'}
fc -p .zsh_local_history
}

zshexit
Executed at the point where the main shell is about to exit
normally. This is not called by exiting subshells, nor when the
exec precommand modifier is used before an external command.
Also, unlike TRAPEXIT, it is not called when functions exit.

Trap Functions
The functions below are treated specially but do not have corresponding
hook arrays.

TRAPNAL
If defined and non-null, this function will be executed whenever
the shell catches a signal SIGNAL, where NAL is a signal name as
specified for the kill builtin. The signal number will be
passed as the first parameter to the function.

If a function of this form is defined and null, the shell and
processes spawned by it will ignore SIGNAL.

The return status from the function is handled specially. If it
is zero, the signal is assumed to have been handled, and
execution continues normally. Otherwise, the shell will behave
as interrupted except that the return status of the trap is
retained.

Programs terminated by uncaught signals typically return the
status 128 plus the signal number. Hence the following causes
the handler for SIGINT to print a message, then mimic the usual
effect of the signal.

TRAPINT() {
print "Caught SIGINT, aborting."
return $(( 128 * $1 ))
}

The functions TRAPZERR, TRAPDEBUG and TRAPEXIT are never
executed inside other traps.

TRAPDEBUG
If the option DEBUG_BEFORE_CMD is set (as it is by default),
executed before each command; otherwise executed after each
command. See the description of the trap builtin in
zshbuiltins(1) for details of additional features provided in
debug traps.

TRAPEXIT
Executed when the shell exits, or when the current function
exits if defined inside a function. The value of $? at the
start of execution is the exit status of the shell or the return
status of the function exiting.

TRAPZERR
Executed whenever a command has a non-zero exit status.
However, the function is not executed if the command occurred in
a sublist followed by `&&' or `||'; only the final command in a
sublist of this type causes the trap to be executed. The
function TRAPERR acts the same as TRAPZERR on systems where
there is no SIGERR (this is the usual case).

The functions beginning `TRAP' may alternatively be defined with the
trap builtin: this may be preferable for some uses. Setting a trap
with one form removes any trap of the other form for the same signal;
removing a trap in either form removes all traps for the same signal.
The forms

TRAPNAL() {
# code
}

('function traps') and

trap '
# code
' NAL

('list traps') are equivalent in most ways, the exceptions being the
following:

o Function traps have all the properties of normal functions,
appearing in the list of functions and being called with their
own function context rather than the context where the trap was
triggered.

o The return status from function traps is special, whereas a
return from a list trap causes the surrounding context to return
with the given status.

o Function traps are not reset within subshells, in accordance
with zsh behaviour; list traps are reset, in accordance with
POSIX behaviour.

JOBS
If the MONITOR option is set, an interactive shell associates a job
with each pipeline. It keeps a table of current jobs, printed by the
jobs command, and assigns them small integer numbers. When a job is
started asynchronously with `&', the shell prints a line to standard
error which looks like:

[1] 1234

indicating that the job which was started asynchronously was job number
1 and had one (top-level) process, whose process ID was 1234.

If a job is started with `&|' or `&!', then that job is immediately
disowned. After startup, it does not have a place in the job table,
and is not subject to the job control features described here.

If you are running a job and wish to do something else you may hit the
key ^Z (control-Z) which sends a TSTP signal to the current job: this
key may be redefined by the susp option of the external stty command.
The shell will then normally indicate that the job has been
`suspended', and print another prompt. You can then manipulate the
state of this job, putting it in the background with the bg command, or
run some other commands and then eventually bring the job back into the
foreground with the foreground command fg. A ^Z takes effect
immediately and is like an interrupt in that pending output and unread
input are discarded when it is typed.

A job being run in the background will suspend if it tries to read from
the terminal.

Note that if the job running in the foreground is a shell function,
then suspending it will have the effect of causing the shell to fork.
This is necessary to separate the function's state from that of the
parent shell performing the job control, so that the latter can return
to the command line prompt. As a result, even if fg is used to
continue the job the function will no longer be part of the parent
shell, and any variables set by the function will not be visible in the
parent shell. Thus the behaviour is different from the case where the
function was never suspended. Zsh is different from many other shells
in this regard.

One additional side effect is that use of disown with a job created by
suspending shell code in this fashion is delayed: the job can only be
disowned once any process started from the parent shell has terminated.
At that point, the disowned job disappears silently from the job list.

The same behaviour is found when the shell is executing code as the
right hand side of a pipeline or any complex shell construct such as
if, for, etc., in order that the entire block of code can be managed as
a single job. Background jobs are normally allowed to produce output,
but this can be disabled by giving the command `stty tostop'. If you
set this tty option, then background jobs will suspend when they try to
produce output like they do when they try to read input.

When a command is suspended and continued later with the fg or wait
builtins, zsh restores tty modes that were in effect when it was
suspended. This (intentionally) does not apply if the command is
continued via `kill -CONT', nor when it is continued with bg.

There are several ways to refer to jobs in the shell. A job can be
referred to by the process ID of any process of the job or by one of
the following:

%number
The job with the given number.
%string
The last job whose command line begins with string.
%?string
The last job whose command line contains string.
%% Current job.
%+ Equivalent to `%%'.
%- Previous job.

The shell learns immediately whenever a process changes state. It
normally informs you whenever a job becomes blocked so that no further
progress is possible. If the NOTIFY option is not set, it waits until
just before it prints a prompt before it informs you. All such
notifications are sent directly to the terminal, not to the standard
output or standard error.

When the monitor mode is on, each background job that completes
triggers any trap set for CHLD.

When you try to leave the shell while jobs are running or suspended,
you will be warned that `You have suspended (running) jobs'. You may
use the jobs command to see what they are. If you do this or
immediately try to exit again, the shell will not warn you a second
time; the suspended jobs will be terminated, and the running jobs will
be sent a SIGHUP signal, if the HUP option is set.

To avoid having the shell terminate the running jobs, either use the
nohup(1) command or the disown builtin.

SIGNALS
The INT and QUIT signals for an invoked command are ignored if the
command is followed by `&' and the MONITOR option is not active. The
shell itself always ignores the QUIT signal. Otherwise, signals have
the values inherited by the shell from its parent (but see the TRAPNAL
special functions in the section `Functions').

Certain jobs are run asynchronously by the shell other than those
explicitly put into the background; even in cases where the shell would
usually wait for such jobs, an explicit exit command or exit due to the
option ERR_EXIT will cause the shell to exit without waiting. Examples
of such asynchronous jobs are process substitution, see the section
PROCESS SUBSTITUTION in the zshexpn(1) manual page, and the handler
processes for multios, see the section MULTIOS in the zshmisc(1) manual
page.

ARITHMETIC EVALUATION
The shell can perform integer and floating point arithmetic, either
using the builtin let, or via a substitution of the form $((...)). For
integers, the shell is usually compiled to use 8-byte precision where
this is available, otherwise precision is 4 bytes. This can be tested,
for example, by giving the command `print - $(( 12345678901 ))'; if the
number appears unchanged, the precision is at least 8 bytes. Floating
point arithmetic always uses the `double' type with whatever
corresponding precision is provided by the compiler and the library.

The let builtin command takes arithmetic expressions as arguments; each
is evaluated separately. Since many of the arithmetic operators, as
well as spaces, require quoting, an alternative form is provided: for
any command which begins with a `((', all the characters until a
matching `))' are treated as a double-quoted expression and arithmetic
expansion performed as for an argument of let. More precisely,
`((...))' is equivalent to `let "..."'. The return status is 0 if the
arithmetic value of the expression is non-zero, 1 if it is zero, and 2
if an error occurred.

For example, the following statement

(( val = 2 * 1 ))

is equivalent to

let "val = 2 * 1"

both assigning the value 3 to the shell variable val and returning a
zero status.

Integers can be in bases other than 10. A leading `0x' or `0X' denotes
hexadecimal and a leading `0b' or `0B' binary. Integers may also be of
the form `base#n', where base is a decimal number between two and
thirty-six representing the arithmetic base and n is a number in that
base (for example, `16#ff' is 255 in hexadecimal). The base# may also
be omitted, in which case base 10 is used. For backwards compatibility
the form `[base]n' is also accepted.

An integer expression or a base given in the form `base#n' may contain
underscores (`_') after the leading digit for visual guidance; these
are ignored in computation. Examples are 1_000_000 or 0xffff_ffff
which are equivalent to 1000000 and 0xffffffff respectively.

It is also possible to specify a base to be used for output in the form
`[#base]', for example `[#16]'. This is used when outputting
arithmetical substitutions or when assigning to scalar parameters, but
an explicitly defined integer or floating point parameter will not be
affected. If an integer variable is implicitly defined by an
arithmetic expression, any base specified in this way will be set as
the variable's output arithmetic base as if the option `-i base' to the
typeset builtin had been used. The expression has no precedence and if
it occurs more than once in a mathematical expression, the last
encountered is used. For clarity it is recommended that it appear at
the beginning of an expression. As an example:

typeset -i 16 y
print $(( [#8] x = 32, y = 32 ))
print $x $y

outputs first `8#40', the rightmost value in the given output base, and
then `8#40 16#20', because y has been explicitly declared to have
output base 16, while x (assuming it does not already exist) is
implicitly typed by the arithmetic evaluation, where it acquires the
output base 8.

The base may be replaced or followed by an underscore, which may itself
be followed by a positive integer (if it is missing the value 3 is
used). This indicates that underscores should be inserted into the
output string, grouping the number for visual clarity. The following
integer specifies the number of digits to group together. For example:

setopt cbases
print $(( [#16_4] 65536 ** 2 ))

outputs `0x1_0000_0000'.

The feature can be used with floating point numbers, in which case the
base must be omitted; grouping is away from the decimal point. For
example,

zmodload zsh/mathfunc
print $(( [#_] sqrt(1e7) ))

outputs `3_162.277_660_168_379_5' (the number of decimal places shown
may vary).

If the C_BASES option is set, hexadecimal numbers are output in the
standard C format, for example `0xFF' instead of the usual `16#FF'. If
the option OCTAL_ZEROES is also set (it is not by default), octal
numbers will be treated similarly and hence appear as `077' instead of
`8#77'. This option has no effect on the output of bases other than
hexadecimal and octal, and these formats are always understood on
input.

When an output base is specified using the `[#base]' syntax, an
appropriate base prefix will be output if necessary, so that the value
output is valid syntax for input. If the # is doubled, for example
`[##16]', then no base prefix is output.

Floating point constants are recognized by the presence of a decimal
point or an exponent. The decimal point may be the first character of
the constant, but the exponent character e or E may not, as it will be
taken for a parameter name. All numeric parts (before and after the
decimal point and in the exponent) may contain underscores after the
leading digit for visual guidance; these are ignored in computation.

An arithmetic expression uses nearly the same syntax and associativity
of expressions as in C.

In the native mode of operation, the following operators are supported
(listed in decreasing order of precedence):

* - ! ~ ++ --
unary plus/minus, logical NOT, complement,
{pre,post}{in,de}crement
<< >> bitwise shift left, right
& bitwise AND
^ bitwise XOR
| bitwise OR
** exponentiation
* / % multiplication, division, modulus (remainder)
* - addition, subtraction
< > <= >=
comparison
== != equality and inequality
&& logical AND
|| ^^ logical OR, XOR
? : ternary operator
= += -= *= /= %= &= ^= |= <<= >>= &&= ||= ^^= **=
assignment
, comma operator

The operators `&&', `||', `&&=', and `||=' are short-circuiting, and
only one of the latter two expressions in a ternary operator is
evaluated. Note the precedence of the bitwise AND, OR, and XOR
operators.

With the option C_PRECEDENCES the precedences (but no other properties)
of the operators are altered to be the same as those in most other
languages that support the relevant operators:

* - ! ~ ++ --
unary plus/minus, logical NOT, complement,
{pre,post}{in,de}crement
** exponentiation
* / % multiplication, division, modulus (remainder)
* - addition, subtraction
<< >> bitwise shift left, right
< > <= >=
comparison
== != equality and inequality
& bitwise AND
^ bitwise XOR
| bitwise OR
&& logical AND
^^ logical XOR
|| logical OR
? : ternary operator
= += -= *= /= %= &= ^= |= <<= >>= &&= ||= ^^= **=
assignment
, comma operator

Note the precedence of exponentiation in both cases is below that of
unary operators, hence `-3**2' evaluates as `9', not `-9'. Use
parentheses where necessary: `-(3**2)'. This is for compatibility with
other shells.

Mathematical functions can be called with the syntax `func(args)',
where the function decides if the args is used as a string or a
comma-separated list of arithmetic expressions. The shell currently
defines no mathematical functions by default, but the module
zsh/mathfunc may be loaded with the zmodload builtin to provide
standard floating point mathematical functions.

An expression of the form `##x' where x is any character sequence such
as `a', `^A', or `\M-\C-x' gives the value of this character and an
expression of the form `#name' gives the value of the first character
of the contents of the parameter name. Character values are according
to the character set used in the current locale; for multibyte
character handling the option MULTIBYTE must be set. Note that this
form is different from `$#name', a standard parameter substitution
which gives the length of the parameter name. `#\' is accepted instead
of `##', but its use is deprecated.

Named parameters and subscripted arrays can be referenced by name
within an arithmetic expression without using the parameter expansion
syntax. For example,

((val2 = val1 * 2))

assigns twice the value of $val1 to the parameter named val2.

An internal integer representation of a named parameter can be
specified with the integer builtin. Arithmetic evaluation is performed
on the value of each assignment to a named parameter declared integer
in this manner. Assigning a floating point number to an integer
results in rounding towards zero.

Likewise, floating point numbers can be declared with the float
builtin; there are two types, differing only in their output format, as
described for the typeset builtin. The output format can be bypassed
by using arithmetic substitution instead of the parameter substitution,
i.e. `${float}' uses the defined format, but `$((float))' uses a
generic floating point format.

Promotion of integer to floating point values is performed where
necessary. In addition, if any operator which requires an integer
(`&', `|', `^', `<<', `>>' and their equivalents with assignment) is
given a floating point argument, it will be silently rounded towards
zero except for `~' which rounds down.

Users should beware that, in common with many other programming
languages but not software designed for calculation, the evaluation of
an expression in zsh is taken a term at a time and promotion of
integers to floating point does not occur in terms only containing
integers. A typical result of this is that a division such as 6/8 is
truncated, in this being rounded towards 0. The FORCE_FLOAT shell
option can be used in scripts or functions where floating point
evaluation is required throughout.

Scalar variables can hold integer or floating point values at different
times; there is no memory of the numeric type in this case.

If a variable is first assigned in a numeric context without previously
being declared, it will be implicitly typed as integer or float and
retain that type either until the type is explicitly changed or until
the end of the scope. This can have unforeseen consequences. For
example, in the loop

for (( f = 0; f < 1; f += 0.1 )); do
# use $f
done

if f has not already been declared, the first assignment will cause it
to be created as an integer, and consequently the operation `f += 0.1'
will always cause the result to be truncated to zero, so that the loop
will fail. A simple fix would be to turn the initialization into `f =
0.0'. It is therefore best to declare numeric variables with explicit
types.

CONDITIONAL EXPRESSIONS
A conditional expression is used with the [[ compound command to test
attributes of files and to compare strings. Each expression can be
constructed from one or more of the following unary or binary
expressions:

-a file
true if file exists.

-b file
true if file exists and is a block special file.

-c file
true if file exists and is a character special file.

-d file
true if file exists and is a directory.

-e file
true if file exists.

-f file
true if file exists and is a regular file.

-g file
true if file exists and has its setgid bit set.

-h file
true if file exists and is a symbolic link.

-k file
true if file exists and has its sticky bit set.

-n string
true if length of string is non-zero.

-o option
true if option named option is on. option may be a single
character, in which case it is a single letter option name.
(See the section `Specifying Options'.)

When no option named option exists, and the POSIX_BUILTINS
option hasn't been set, return 3 with a warning. If that option
is set, return 1 with no warning.

-p file
true if file exists and is a FIFO special file (named pipe).

-r file
true if file exists and is readable by current process.

-s file
true if file exists and has size greater than zero.

-t fd true if file descriptor number fd is open and associated with a
terminal device. (note: fd is not optional)

-u file
true if file exists and has its setuid bit set.

-v varname
true if shell variable varname is set.

-w file
true if file exists and is writable by current process.

-x file
true if file exists and is executable by current process. If
file exists and is a directory, then the current process has
permission to search in the directory.

-z string
true if length of string is zero.

-L file
true if file exists and is a symbolic link.

-O file
true if file exists and is owned by the effective user ID of
this process.

-G file
true if file exists and its group matches the effective group ID
of this process.

-S file
true if file exists and is a socket.

-N file
true if file exists and its access time is not newer than its
modification time.

file1 -nt file2
true if file1 exists and is newer than file2.

file1 -ot file2
true if file1 exists and is older than file2.

file1 -ef file2
true if file1 and file2 exist and refer to the same file.

string = pattern
string == pattern
true if string matches pattern. The two forms are exactly
equivalent. The `=' form is the traditional shell syntax (and
hence the only one generally used with the test and [ builtins);
the `==' form provides compatibility with other sorts of
computer language.

string != pattern
true if string does not match pattern.

string =~ regexp
true if string matches the regular expression regexp. If the
option RE_MATCH_PCRE is set regexp is tested as a PCRE regular
expression using the zsh/pcre module, else it is tested as a
POSIX extended regular expression using the zsh/regex module.
Upon successful match, some variables will be updated; no
variables are changed if the matching fails.

If the option BASH_REMATCH is not set the scalar parameter MATCH
is set to the substring that matched the pattern and the integer
parameters MBEGIN and MEND to the index of the start and end,
respectively, of the match in string, such that if string is
contained in variable var the expression `${var[$MBEGIN,$MEND]}'
is identical to `$MATCH'. The setting of the option KSH_ARRAYS
is respected. Likewise, the array match is set to the
substrings that matched parenthesised subexpressions and the
arrays mbegin and mend to the indices of the start and end
positions, respectively, of the substrings within string. The
arrays are not set if there were no parenthesised
subexpressions. For example, if the string `a short string' is
matched against the regular expression `s(...)t', then (assuming
the option KSH_ARRAYS is not set) MATCH, MBEGIN and MEND are
`short', 3 and 7, respectively, while match, mbegin and mend are
single entry arrays containing the strings `hor', `4' and `6',
respectively.

If the option BASH_REMATCH is set the array BASH_REMATCH is set
to the substring that matched the pattern followed by the
substrings that matched parenthesised subexpressions within the
pattern.

string1 < string2
true if string1 comes before string2 based on ASCII value of
their characters.

string1 > string2
true if string1 comes after string2 based on ASCII value of
their characters.

exp1 -eq exp2
true if exp1 is numerically equal to exp2. Note that for purely
numeric comparisons use of the ((...)) builtin described in the
section `ARITHMETIC EVALUATION' is more convenient than
conditional expressions.

exp1 -ne exp2
true if exp1 is numerically not equal to exp2.

exp1 -lt exp2
true if exp1 is numerically less than exp2.

exp1 -gt exp2
true if exp1 is numerically greater than exp2.

exp1 -le exp2
true if exp1 is numerically less than or equal to exp2.

exp1 -ge exp2
true if exp1 is numerically greater than or equal to exp2.

( exp )
true if exp is true.

! exp true if exp is false.

exp1 && exp2
true if exp1 and exp2 are both true.

exp1 || exp2
true if either exp1 or exp2 is true.

For compatibility, if there is a single argument that is not
syntactically significant, typically a variable, the condition is
treated as a test for whether the expression expands as a string of
non-zero length. In other words, [[ $var ]] is the same as [[ -n $var
]]. It is recommended that the second, explicit, form be used where
possible.

Normal shell expansion is performed on the file, string and pattern
arguments, but the result of each expansion is constrained to be a
single word, similar to the effect of double quotes.

Filename generation is not performed on any form of argument to
conditions. However, it can be forced in any case where normal shell
expansion is valid and when the option EXTENDED_GLOB is in effect by
using an explicit glob qualifier of the form (#q) at the end of the
string. A normal glob qualifier expression may appear between the `q'
and the closing parenthesis; if none appears the expression has no
effect beyond causing filename generation. The results of filename
generation are joined together to form a single word, as with the
results of other forms of expansion.

This special use of filename generation is only available with the [[
syntax. If the condition occurs within the [ or test builtin commands
then globbing occurs instead as part of normal command line expansion
before the condition is evaluated. In this case it may generate
multiple words which are likely to confuse the syntax of the test
command.

For example,

[[ -n file*(#qN) ]]

produces status zero if and only if there is at least one file in the
current directory beginning with the string `file'. The globbing
qualifier N ensures that the expression is empty if there is no
matching file.

Pattern metacharacters are active for the pattern arguments; the
patterns are the same as those used for filename generation, see
zshexpn(1), but there is no special behaviour of `/' nor initial dots,
and no glob qualifiers are allowed.

In each of the above expressions, if file is of the form `/dev/fd/n',
where n is an integer, then the test applied to the open file whose
descriptor number is n, even if the underlying system does not support
the /dev/fd directory.

In the forms which do numeric comparison, the expressions exp undergo
arithmetic expansion as if they were enclosed in $((...)).

For example, the following:

[[ ( -f foo || -f bar ) && $report = y* ]] && print File exists.

tests if either file foo or file bar exists, and if so, if the value of
the parameter report begins with `y'; if the complete condition is
true, the message `File exists.' is printed.

EXPANSION OF PROMPT SEQUENCES
Prompt sequences undergo a special form of expansion. This type of
expansion is also available using the -P option to the print builtin.

If the PROMPT_SUBST option is set, the prompt string is first subjected
to parameter expansion, command substitution and arithmetic expansion.
See zshexpn(1).

Certain escape sequences may be recognised in the prompt string.

If the PROMPT_BANG option is set, a `!' in the prompt is replaced by
the current history event number. A literal `!' may then be
represented as `!!'.

If the PROMPT_PERCENT option is set, certain escape sequences that
start with `%' are expanded. Many escapes are followed by a single
character, although some of these take an optional integer argument
that should appear between the `%' and the next character of the
sequence. More complicated escape sequences are available to provide
conditional expansion.

SIMPLE PROMPT ESCAPES
Special characters
%% A `%'.

%) A `)'.

Login information
%l The line (tty) the user is logged in on, without `/dev/' prefix.
If the name starts with `/dev/tty', that prefix is stripped.

%M The full machine hostname.

%m The hostname up to the first `.'. An integer may follow the `%'
to specify how many components of the hostname are desired.
With a negative integer, trailing components of the hostname are
shown.

%n $USERNAME.

%y The line (tty) the user is logged in on, without `/dev/' prefix.
This does not treat `/dev/tty' names specially.

Shell state
%# A `#' if the shell is running with privileges, a `%' if not.
Equivalent to `%(!.#.%%)'. The definition of `privileged', for
these purposes, is that either the effective user ID is zero,
or, if POSIX.1e capabilities are supported, that at least one
capability is raised in either the Effective or Inheritable
capability vectors.

%? The return status of the last command executed just before the
prompt.

%_ The status of the parser, i.e. the shell constructs (like `if'
and `for') that have been started on the command line. If given
an integer number that many strings will be printed; zero or
negative or no integer means print as many as there are. This
is most useful in prompts PS2 for continuation lines and PS4 for
debugging with the XTRACE option; in the latter case it will
also work non-interactively.

%^ The status of the parser in reverse. This is the same as `%_'
other than the order of strings. It is often used in RPS2.

%d
%/ Current working directory. If an integer follows the `%', it
specifies a number of trailing components of the current working
directory to show; zero means the whole path. A negative
integer specifies leading components, i.e. %-1d specifies the
first component.

%~ As %d and %/, but if the current working directory starts with
$HOME, that part is replaced by a `~'. Furthermore, if it has a
named directory as its prefix, that part is replaced by a `~'
followed by the name of the directory, but only if the result is
shorter than the full path; see Dynamic and Static named
directories in zshexpn(1).

%e Evaluation depth of the current sourced file, shell function, or
eval. This is incremented or decremented every time the value
of %N is set or reverted to a previous value, respectively.
This is most useful for debugging as part of $PS4.

%h
%! Current history event number.

%i The line number currently being executed in the script, sourced
file, or shell function given by %N. This is most useful for
debugging as part of $PS4.

%I The line number currently being executed in the file %x. This
is similar to %i, but the line number is always a line number in
the file where the code was defined, even if the code is a shell
function.

%j The number of jobs.

%L The current value of $SHLVL.

%N The name of the script, sourced file, or shell function that zsh
is currently executing, whichever was started most recently. If
there is none, this is equivalent to the parameter $0. An
integer may follow the `%' to specify a number of trailing path
components to show; zero means the full path. A negative
integer specifies leading components.

%x The name of the file containing the source code currently being
executed. This behaves as %N except that function and eval
command names are not shown, instead the file where they were
defined.

%c
%.
%C Trailing component of the current working directory. An integer
may follow the `%' to get more than one component. Unless `%C'
is used, tilde contraction is performed first. These are
deprecated as %c and %C are equivalent to %1~ and %1/,
respectively, while explicit positive integers have the same
effect as for the latter two sequences.

Date and time
%D The date in yy-mm-dd format.

%T Current time of day, in 24-hour format.

%t
%@ Current time of day, in 12-hour, am/pm format.

%* Current time of day in 24-hour format, with seconds.

%w The date in day-dd format.

%W The date in mm/dd/yy format.

%D{string}
string is formatted using the strftime function. See
strftime(3) for more details. Various zsh extensions provide
numbers with no leading zero or space if the number is a single
digit:

%f a day of the month
%K the hour of the day on the 24-hour clock
%L the hour of the day on the 12-hour clock

In addition, if the system supports the POSIX gettimeofday
system call, %. provides decimal fractions of a second since the
epoch with leading zeroes. By default three decimal places are
provided, but a number of digits up to 9 may be given following
the %; hence %6. outputs microseconds, and %9. outputs
nanoseconds. (The latter requires a nanosecond-precision
clock_gettime; systems lacking this will return a value
multiplied by the appropriate power of 10.) A typical example
of this is the format `%D{%H:%M:%S.%.}'.

The GNU extension %N is handled as a synonym for %9..

Additionally, the GNU extension that a `-' between the % and the
format character causes a leading zero or space to be stripped
is handled directly by the shell for the format characters d, f,
H, k, l, m, M, S and y; any other format characters are provided
to the system's strftime(3) with any leading `-' present, so the
handling is system dependent. Further GNU (or other) extensions
are also passed to strftime(3) and may work if the system
supports them.

Visual effects
%B (%b)
Start (stop) boldface mode.

%E Clear to end of line.

%U (%u)
Start (stop) underline mode.

%S (%s)
Start (stop) standout mode.

%F (%f)
Start (stop) using a different foreground colour, if supported
by the terminal. The colour may be specified two ways: either
as a numeric argument, as normal, or by a sequence in braces
following the %F, for example %F{red}. In the latter case the
values allowed are as described for the fg zle_highlight
attribute; see Character Highlighting in zshzle(1). This means
that numeric colours are allowed in the second format also.

%K (%k)
Start (stop) using a different bacKground colour. The syntax is
identical to that for %F and %f.

%{...%}
Include a string as a literal escape sequence. The string
within the braces should not change the cursor position. Brace
pairs can nest.

A positive numeric argument between the % and the { is treated
as described for %G below.

%G Within a %{...%} sequence, include a `glitch': that is, assume
that a single character width will be output. This is useful
when outputting characters that otherwise cannot be correctly
handled by the shell, such as the alternate character set on
some terminals. The characters in question can be included
within a %{...%} sequence together with the appropriate number
of %G sequences to indicate the correct width. An integer
between the `%' and `G' indicates a character width other than
one. Hence %{seq%2G%} outputs seq and assumes it takes up the
width of two standard characters.

Multiple uses of %G accumulate in the obvious fashion; the
position of the %G is unimportant. Negative integers are not
handled.

Note that when prompt truncation is in use it is advisable to
divide up output into single characters within each %{...%}
group so that the correct truncation point can be found.

CONDITIONAL SUBSTRINGS IN PROMPTS
%v The value of the first element of the psvar array parameter.
Following the `%' with an integer gives that element of the
array. Negative integers count from the end of the array.

%(x.true-text.false-text)
Specifies a ternary expression. The character following the x
is arbitrary; the same character is used to separate the text
for the `true' result from that for the `false' result. This
separator may not appear in the true-text, except as part of a
%-escape sequence. A `)' may appear in the false-text as `%)'.
true-text and false-text may both contain arbitrarily-nested
escape sequences, including further ternary expressions.

The left parenthesis may be preceded or followed by a positive
integer n, which defaults to zero. A negative integer will be
multiplied by -1, except as noted below for `l'. The test
character x may be any of the following:

! True if the shell is running with privileges.
# True if the effective uid of the current process is n.
? True if the exit status of the last command was n.
_ True if at least n shell constructs were started.
C
/ True if the current absolute path has at least n elements
relative to the root directory, hence / is counted as 0
elements.
c
.
~ True if the current path, with prefix replacement, has at
least n elements relative to the root directory, hence /
is counted as 0 elements.
D True if the month is equal to n (January = 0).
d True if the day of the month is equal to n.
e True if the evaluation depth is at least n.
g True if the effective gid of the current process is n.
j True if the number of jobs is at least n.
L True if the SHLVL parameter is at least n.
l True if at least n characters have already been printed
on the current line. When n is negative, true if at
least abs(n) characters remain before the opposite margin
(thus the left margin for RPROMPT).
S True if the SECONDS parameter is at least n.
T True if the time in hours is equal to n.
t True if the time in minutes is equal to n.
v True if the array psvar has at least n elements.
V True if element n of the array psvar is set and
non-empty.
w True if the day of the week is equal to n (Sunday = 0).

%<string<
%>string>
%[xstring]
Specifies truncation behaviour for the remainder of the prompt
string. The third, deprecated, form is equivalent to
`%xstringx', i.e. x may be `<' or `>'. The string will be
displayed in place of the truncated portion of any string; note
this does not undergo prompt expansion.

The numeric argument, which in the third form may appear
immediately after the `[', specifies the maximum permitted
length of the various strings that can be displayed in the
prompt. In the first two forms, this numeric argument may be
negative, in which case the truncation length is determined by
subtracting the absolute value of the numeric argument from the
number of character positions remaining on the current prompt
line. If this results in a zero or negative length, a length of
1 is used. In other words, a negative argument arranges that
after truncation at least n characters remain before the right
margin (left margin for RPROMPT).

The forms with `<' truncate at the left of the string, and the
forms with `>' truncate at the right of the string. For
example, if the current directory is `/home/pike', the prompt
`%8<..<%/' will expand to `..e/pike'. In this string, the
terminating character (`<', `>' or `]'), or in fact any
character, may be quoted by a preceding `\'; note when using
print -P, however, that this must be doubled as the string is
also subject to standard print processing, in addition to any
backslashes removed by a double quoted string: the worst case
is therefore `print -P "%<\\\\<<..."'.

If the string is longer than the specified truncation length, it
will appear in full, completely replacing the truncated string.

The part of the prompt string to be truncated runs to the end of
the string, or to the end of the next enclosing group of the
`%(' construct, or to the next truncation encountered at the
same grouping level (i.e. truncations inside a `%(' are
separate), which ever comes first. In particular, a truncation
with argument zero (e.g., `%<<') marks the end of the range of
the string to be truncated while turning off truncation from
there on. For example, the prompt `%10<...<%~%<<%# ' will print
a truncated representation of the current directory, followed by
a `%' or `#', followed by a space. Without the `%<<', those two
characters would be included in the string to be truncated.
Note that `%-0<<' is not equivalent to `%<<' but specifies that
the prompt is truncated at the right margin.

Truncation applies only within each individual line of the
prompt, as delimited by embedded newlines (if any). If the
total length of any line of the prompt after truncation is
greater than the terminal width, or if the part to be truncated
contains embedded newlines, truncation behavior is undefined and
may change in a future version of the shell. Use
`%-n(l.true-text.false-text)' to remove parts of the prompt when
the available space is less than n.

NAME
zshexpn - zsh expansion and substitution

DESCRIPTION
The following types of expansions are performed in the indicated order
in five steps:

History Expansion
This is performed only in interactive shells.

Alias Expansion
Aliases are expanded immediately before the command line is
parsed as explained under Aliasing in zshmisc(1).

Process Substitution
Parameter Expansion
Command Substitution
Arithmetic Expansion
Brace Expansion
These five are performed in left-to-right fashion. On each
argument, any of the five steps that are needed are performed
one after the other. Hence, for example, all the parts of
parameter expansion are completed before command substitution is
started. After these expansions, all unquoted occurrences of
the characters `\',`'' and `"' are removed.

Filename Expansion
If the SH_FILE_EXPANSION option is set, the order of expansion
is modified for compatibility with sh and ksh. In that case
filename expansion is performed immediately after alias
expansion, preceding the set of five expansions mentioned above.

Filename Generation
This expansion, commonly referred to as globbing, is always done
last.

The following sections explain the types of expansion in detail.

HISTORY EXPANSION
History expansion allows you to use words from previous command lines
in the command line you are typing. This simplifies spelling
corrections and the repetition of complicated commands or arguments.

Immediately before execution, each command is saved in the history
list, the size of which is controlled by the HISTSIZE parameter. The
one most recent command is always retained in any case. Each saved
command in the history list is called a history event and is assigned a
number, beginning with 1 (one) when the shell starts up. The history
number that you may see in your prompt (see EXPANSION OF PROMPT
SEQUENCES in zshmisc(1)) is the number that is to be assigned to the
next command.

Overview
A history expansion begins with the first character of the histchars
parameter, which is `!' by default, and may occur anywhere on the
command line, including inside double quotes (but not inside single
quotes '...' or C-style quotes $'...' nor when escaped with a
backslash).

The first character is followed by an optional event designator (see
the section `Event Designators') and then an optional word designator
(the section `Word Designators'); if neither of these designators is
present, no history expansion occurs.

Input lines containing history expansions are echoed after being
expanded, but before any other expansions take place and before the
command is executed. It is this expanded form that is recorded as the
history event for later references.

History expansions do not nest.

By default, a history reference with no event designator refers to the
same event as any preceding history reference on that command line; if
it is the only history reference in a command, it refers to the
previous command. However, if the option CSH_JUNKIE_HISTORY is set,
then every history reference with no event specification always refers
to the previous command.

For example, `!' is the event designator for the previous command, so
`!!:1' always refers to the first word of the previous command, and
`!!$' always refers to the last word of the previous command. With
CSH_JUNKIE_HISTORY set, then `!:1' and `!$' function in the same manner
as `!!:1' and `!!$', respectively. Conversely, if CSH_JUNKIE_HISTORY
is unset, then `!:1' and `!$' refer to the first and last words,
respectively, of the same event referenced by the nearest other history
reference preceding them on the current command line, or to the
previous command if there is no preceding reference.

The character sequence `^foo^bar' (where `^' is actually the second
character of the histchars parameter) repeats the last command,
replacing the string foo with bar. More precisely, the sequence
`^foo^bar^' is synonymous with `!!:s^foo^bar^', hence other modifiers
(see the section `Modifiers') may follow the final `^'. In particular,
`^foo^bar^:G' performs a global substitution.

If the shell encounters the character sequence `!"' in the input, the
history mechanism is temporarily disabled until the current list (see
zshmisc(1)) is fully parsed. The `!"' is removed from the input, and
any subsequent `!' characters have no special significance.

A less convenient but more comprehensible form of command history
support is provided by the fc builtin.

Event Designators
An event designator is a reference to a command-line entry in the
history list. In the list below, remember that the initial `!' in each
item may be changed to another character by setting the histchars
parameter.

! Start a history expansion, except when followed by a blank,
newline, `=' or `('. If followed immediately by a word
designator (see the section `Word Designators'), this forms a
history reference with no event designator (see the section
`Overview').

!! Refer to the previous command. By itself, this expansion
repeats the previous command.

!n Refer to command-line n.

!-n Refer to the current command-line minus n.

!str Refer to the most recent command starting with str.

!?str[?]
Refer to the most recent command containing str. The trailing
`?' is necessary if this reference is to be followed by a
modifier or followed by any text that is not to be considered
part of str.

!# Refer to the current command line typed in so far. The line is
treated as if it were complete up to and including the word
before the one with the `!#' reference.

!{...} Insulate a history reference from adjacent characters (if
necessary).

Word Designators
A word designator indicates which word or words of a given command line
are to be included in a history reference. A `:' usually separates the
event specification from the word designator. It may be omitted only
if the word designator begins with a `^', `$', `*', `-' or `%'. Word
designators include:

0 The first input word (command).
n The nth argument.
^ The first argument. That is, 1.
$ The last argument.
% The word matched by (the most recent) ?str search.
x-y A range of words; x defaults to 0.
* All the arguments, or a null value if there are none.
x* Abbreviates `x-$'.
x- Like `x*' but omitting word $.

Note that a `%' word designator works only when used in one of `!%',
`!:%' or `!?str?:%', and only when used after a !? expansion (possibly
in an earlier command). Anything else results in an error, although
the error may not be the most obvious one.

Modifiers
After the optional word designator, you can add a sequence of one or
more of the following modifiers, each preceded by a `:'. These
modifiers also work on the result of filename generation and parameter
expansion, except where noted.

a Turn a file name into an absolute path: prepends the current
directory, if necessary; remove `.' path segments; and remove
`..' path segments and the segments that immediately precede
them.

This transformation is agnostic about what is in the filesystem,
i.e. is on the logical, not the physical directory. It takes
place in the same manner as when changing directories when
neither of the options CHASE_DOTS or CHASE_LINKS is set. For
example, `/before/here/../after' is always transformed to
`/before/after', regardless of whether `/before/here' exists or
what kind of object (dir, file, symlink, etc.) it is.

A Turn a file name into an absolute path as the `a' modifier does,
and then pass the result through the realpath(3) library
function to resolve symbolic links.

Note: on systems that do not have a realpath(3) library
function, symbolic links are not resolved, so on those systems
`a' and `A' are equivalent.

Note: foo:A and realpath(foo) are different on some inputs. For
realpath(foo) semantics, see the `P` modifier.

c Resolve a command name into an absolute path by searching the
command path given by the PATH variable. This does not work for
commands containing directory parts. Note also that this does
not usually work as a glob qualifier unless a file of the same
name is found in the current directory.

e Remove all but the part of the filename extension following the
`.'; see the definition of the filename extension in the
description of the r modifier below. Note that according to
that definition the result will be empty if the string ends with
a `.'.

h [ digits ]
Remove a trailing pathname component, shortening the path by one
directory level: this is the `head' of the pathname. This works
like `dirname'. If the h is followed immediately (with no
spaces or other separator) by any number of decimal digits, and
the value of the resulting number is non-zero, that number of
leading components is preserved instead of the final component
being removed. In an absolute path the leading `/' is the first
component, so, for example, if var=/my/path/to/something, then
${var:h3} substitutes /my/path. Consecutive `/'s are treated
the same as a single `/'. In parameter substitution, digits may
only be used if the expression is in braces, so for example the
short form substitution $var:h2 is treated as ${var:h}2, not as
${var:h2}. No restriction applies to the use of digits in
history substitution or globbing qualifiers. If more components
are requested than are present, the entire path is substituted
(so this does not trigger a `failed modifier' error in history
expansion).

l Convert the words to all lowercase.

p Print the new command but do not execute it. Only works with
history expansion.

P Turn a file name into an absolute path, like realpath(3). The
resulting path will be absolute, will refer to the same
directory entry as the input filename, and none of its
components will be symbolic links or equal to `.' or `..'.

Unlike realpath(3), non-existent trailing components are
permitted and preserved.

q Quote the substituted words, escaping further substitutions.
Works with history expansion and parameter expansion, though for
parameters it is only useful if the resulting text is to be
re-evaluated such as by eval.

Q Remove one level of quotes from the substituted words.

r Remove a filename extension leaving the root name. Strings with
no filename extension are not altered. A filename extension is
a `.' followed by any number of characters (including zero) that
are neither `.' nor `/' and that continue to the end of the
string. For example, the extension of `foo.orig.c' is `.c', and
`dir.c/foo' has no extension.

s/l/r[/]
Substitute r for l as described below. The substitution is done
only for the first string that matches l. For arrays and for
filename generation, this applies to each word of the expanded
text. See below for further notes on substitutions.

The forms `gs/l/r' and `s/l/r/:G' perform global substitution,
i.e. substitute every occurrence of r for l. Note that the g or
:G must appear in exactly the position shown.

See further notes on this form of substitution below.

& Repeat the previous s substitution. Like s, may be preceded
immediately by a g. In parameter expansion the & must appear
inside braces, and in filename generation it must be quoted with
a backslash.

t [ digits ]
Remove all leading pathname components, leaving the final
component (tail). This works like `basename'. Any trailing
slashes are first removed. Decimal digits are handled as
described above for (h), but in this case that number of
trailing components is preserved instead of the default 1; 0 is
treated the same as 1.

u Convert the words to all uppercase.

x Like q, but break into words at whitespace. Does not work with
parameter expansion.

The s/l/r/ substitution works as follows. By default the left-hand
side of substitutions are not patterns, but character strings. Any
character can be used as the delimiter in place of `/'. A backslash
quotes the delimiter character. The character `&', in the
right-hand-side r, is replaced by the text from the left-hand-side l.
The `&' can be quoted with a backslash. A null l uses the previous
string either from the previous l or from the contextual scan string s
from `!?s'. You can omit the rightmost delimiter if a newline
immediately follows r; the rightmost `?' in a context scan can
similarly be omitted. Note the same record of the last l and r is
maintained across all forms of expansion.

Note that if a `&' is used within glob qualifiers an extra backslash is
needed as a & is a special character in this case.

Also note that the order of expansions affects the interpretation of l
and r. When used in a history expansion, which occurs before any other
expansions, l and r are treated as literal strings (except as explained
for HIST_SUBST_PATTERN below). When used in parameter expansion, the
replacement of r into the parameter's value is done first, and then any
additional process, parameter, command, arithmetic, or brace references
are applied, which may evaluate those substitutions and expansions more
than once if l appears more than once in the starting value. When used
in a glob qualifier, any substitutions or expansions are performed once
at the time the qualifier is parsed, even before the `:s' expression
itself is divided into l and r sides.

If the option HIST_SUBST_PATTERN is set, l is treated as a pattern of
the usual form described in the section FILENAME GENERATION below.
This can be used in all the places where modifiers are available; note,
however, that in globbing qualifiers parameter substitution has already
taken place, so parameters in the replacement string should be quoted
to ensure they are replaced at the correct time. Note also that
complicated patterns used in globbing qualifiers may need the extended
glob qualifier notation (#q:s/.../.../) in order for the shell to
recognize the expression as a glob qualifier. Further, note that bad
patterns in the substitution are not subject to the NO_BAD_PATTERN
option so will cause an error.

When HIST_SUBST_PATTERN is set, l may start with a # to indicate that
the pattern must match at the start of the string to be substituted,
and a % may appear at the start or after an # to indicate that the
pattern must match at the end of the string to be substituted. The %
or # may be quoted with two backslashes.

For example, the following piece of filename generation code with the
EXTENDED_GLOB option:

print -r -- *.c(#q:s/#%(#b)s(*).c/'S${match[1]}.C'/)

takes the expansion of *.c and applies the glob qualifiers in the
(#q...) expression, which consists of a substitution modifier anchored
to the start and end of each word (#%). This turns on backreferences
((#b)), so that the parenthesised subexpression is available in the
replacement string as ${match[1]}. The replacement string is quoted so
that the parameter is not substituted before the start of filename
generation.

The following f, F, w and W modifiers work only with parameter
expansion and filename generation. They are listed here to provide a
single point of reference for all modifiers.

f Repeats the immediately (without a colon) following modifier
until the resulting word doesn't change any more.

F:expr:
Like f, but repeats only n times if the expression expr
evaluates to n. Any character can be used instead of the `:';
if `(', `[', or `{' is used as the opening delimiter, the
closing delimiter should be ')', `]', or `}', respectively.

w Makes the immediately following modifier work on each word in
the string.

W:sep: Like w but words are considered to be the parts of the string
that are separated by sep. Any character can be used instead of
the `:'; opening parentheses are handled specially, see above.

PROCESS SUBSTITUTION
Each part of a command argument that takes the form `<(list)',
`>(list)' or `=(list)' is subject to process substitution. The
expression may be preceded or followed by other strings except that, to
prevent clashes with commonly occurring strings and patterns, the last
form must occur at the start of a command argument, and the forms are
only expanded when first parsing command or assignment arguments.
Process substitutions may be used following redirection operators; in
this case, the substitution must appear with no trailing string.

Note that `<<(list)' is not a special syntax; it is equivalent to `<
<(list)', redirecting standard input from the result of process
substitution. Hence all the following documentation applies. The
second form (with the space) is recommended for clarity.

In the case of the < or > forms, the shell runs the commands in list as
a subprocess of the job executing the shell command line. If the
system supports the /dev/fd mechanism, the command argument is the name
of the device file corresponding to a file descriptor; otherwise, if
the system supports named pipes (FIFOs), the command argument will be a
named pipe. If the form with > is selected then writing on this
special file will provide input for list. If < is used, then the file
passed as an argument will be connected to the output of the list
process. For example,

paste <(cut -f1 file1) <(cut -f3 file2) |
tee >(process1) >(process2) >/dev/null

cuts fields 1 and 3 from the files file1 and file2 respectively, pastes
the results together, and sends it to the processes process1 and
process2.

If =(...) is used instead of <(...), then the file passed as an
argument will be the name of a temporary file containing the output of
the list process. This may be used instead of the < form for a program
that expects to lseek (see lseek(2)) on the input file.

There is an optimisation for substitutions of the form =(<<<arg), where
arg is a single-word argument to the here-string redirection <<<. This
form produces a file name containing the value of arg after any
substitutions have been performed. This is handled entirely within the
current shell. This is effectively the reverse of the special form
$(<arg) which treats arg as a file name and replaces it with the file's
contents.

The = form is useful as both the /dev/fd and the named pipe
implementation of <(...) have drawbacks. In the former case, some
programmes may automatically close the file descriptor in question
before examining the file on the command line, particularly if this is
necessary for security reasons such as when the programme is running
setuid. In the second case, if the programme does not actually open
the file, the subshell attempting to read from or write to the pipe
will (in a typical implementation, different operating systems may have
different behaviour) block for ever and have to be killed explicitly.
In both cases, the shell actually supplies the information using a
pipe, so that programmes that expect to lseek (see lseek(2)) on the
file will not work.

Also note that the previous example can be more compactly and
efficiently written (provided the MULTIOS option is set) as:

paste <(cut -f1 file1) <(cut -f3 file2) > >(process1) > >(process2)

The shell uses pipes instead of FIFOs to implement the latter two
process substitutions in the above example.

There is an additional problem with >(process); when this is attached
to an external command, the parent shell does not wait for process to
finish and hence an immediately following command cannot rely on the
results being complete. The problem and solution are the same as
described in the section MULTIOS in zshmisc(1). Hence in a simplified
version of the example above:

paste <(cut -f1 file1) <(cut -f3 file2) > >(process)

(note that no MULTIOS are involved), process will be run asynchronously
as far as the parent shell is concerned. The workaround is:

{ paste <(cut -f1 file1) <(cut -f3 file2) } > >(process)

The extra processes here are spawned from the parent shell which will
wait for their completion.

Another problem arises any time a job with a substitution that requires
a temporary file is disowned by the shell, including the case where
`&!' or `&|' appears at the end of a command containing a substitution.
In that case the temporary file will not be cleaned up as the shell no
longer has any memory of the job. A workaround is to use a subshell,
for example,

(mycmd =(myoutput)) &!

as the forked subshell will wait for the command to finish then remove
the temporary file.

A general workaround to ensure a process substitution endures for an
appropriate length of time is to pass it as a parameter to an anonymous
shell function (a piece of shell code that is run immediately with
function scope). For example, this code:

() {
print File $1:
cat $1
} =(print This be the verse)

outputs something resembling the following

File /tmp/zsh6nU0kS:
This be the verse

The temporary file created by the process substitution will be deleted
when the function exits.

PARAMETER EXPANSION
The character `$' is used to introduce parameter expansions. See
zshparam(1) for a description of parameters, including arrays,
associative arrays, and subscript notation to access individual array
elements.

Note in particular the fact that words of unquoted parameters are not
automatically split on whitespace unless the option SH_WORD_SPLIT is
set; see references to this option below for more details. This is an
important difference from other shells. However, as in other shells,
null words are elided from unquoted parameters' expansions.

With default options, after the assignments:

array=("first word" "" "third word")
scalar="only word"

then $array substitutes two words, `first word' and `third word', and
$scalar substitutes a single word `only word'. Note that second
element of array was elided. Scalar parameters can be elided too if
their value is null (empty). To avoid elision, use quoting as follows:
"$scalar" for scalars and "${array[@]}" or "${(@)array}" for arrays.
(The last two forms are equivalent.)

Parameter expansions can involve flags, as in `${(@kv)aliases}', and
other operators, such as `${PREFIX:-"/usr/local"}'. Parameter
expansions can also be nested. These topics will be introduced below.
The full rules are complicated and are noted at the end.

In the expansions discussed below that require a pattern, the form of
the pattern is the same as that used for filename generation; see the
section `Filename Generation'. Note that these patterns, along with
the replacement text of any substitutions, are themselves subject to
parameter expansion, command substitution, and arithmetic expansion.
In addition to the following operations, the colon modifiers described
in the section `Modifiers' in the section `History Expansion' can be
applied: for example, ${i:s/foo/bar/} performs string substitution on
the expansion of parameter $i.

In the following descriptions, `word' refers to a single word
substituted on the command line, not necessarily a space delimited
word.

${name}
The value, if any, of the parameter name is substituted. The
braces are required if the expansion is to be followed by a
letter, digit, or underscore that is not to be interpreted as
part of name. In addition, more complicated forms of
substitution usually require the braces to be present;
exceptions, which only apply if the option KSH_ARRAYS is not
set, are a single subscript or any colon modifiers appearing
after the name, or any of the characters `^', `=', `~', `#' or
`*' appearing before the name, all of which work with or without
braces.

If name is an array parameter, and the KSH_ARRAYS option is not
set, then the value of each element of name is substituted, one
element per word. Otherwise, the expansion results in one word
only; with KSH_ARRAYS, this is the first element of an array.
No field splitting is done on the result unless the
SH_WORD_SPLIT option is set. See also the flags = and
s:string:.

${+name}
If name is the name of a set parameter `1' is substituted,
otherwise `0' is substituted.

${name-word}
${name:-word}
If name is set, or in the second form is non-null, then
substitute its value; otherwise substitute word. In the second
form name may be omitted, in which case word is always
substituted.

${name*word}
${name:+word}
If name is set, or in the second form is non-null, then
substitute word; otherwise substitute nothing.

${name=word}
${name:=word}
${name::=word}
In the first form, if name is unset then set it to word; in the
second form, if name is unset or null then set it to word; and
in the third form, unconditionally set name to word. In all
forms, the value of the parameter is then substituted.

${name?word}
${name:?word}
In the first form, if name is set, or in the second form if name
is both set and non-null, then substitute its value; otherwise,
print word and exit from the shell. Interactive shells instead
return to the prompt. If word is omitted, then a standard
message is printed.

In any of the above expressions that test a variable and substitute an
alternate word, note that you can use standard shell quoting in the
word value to selectively override the splitting done by the
SH_WORD_SPLIT option and the = flag, but not splitting by the s:string:
flag.

In the following expressions, when name is an array and the
substitution is not quoted, or if the `(@)' flag or the name[@] syntax
is used, matching and replacement is performed on each array element
separately.

${name#pattern}
${name##pattern}
If the pattern matches the beginning of the value of name, then
substitute the value of name with the matched portion deleted;
otherwise, just substitute the value of name. In the first
form, the smallest matching pattern is preferred; in the second
form, the largest matching pattern is preferred.

${name%pattern}
${name%%pattern}
If the pattern matches the end of the value of name, then
substitute the value of name with the matched portion deleted;
otherwise, just substitute the value of name. In the first
form, the smallest matching pattern is preferred; in the second
form, the largest matching pattern is preferred.

${name:#pattern}
If the pattern matches the value of name, then substitute the
empty string; otherwise, just substitute the value of name. If
name is an array the matching array elements are removed (use
the `(M)' flag to remove the non-matched elements).

${name:|arrayname}
If arrayname is the name (N.B., not contents) of an array
variable, then any elements contained in arrayname are removed
from the substitution of name. If the substitution is scalar,
either because name is a scalar variable or the expression is
quoted, the elements of arrayname are instead tested against the
entire expression.

${name:*arrayname}
Similar to the preceding substitution, but in the opposite
sense, so that entries present in both the original substitution
and as elements of arrayname are retained and others removed.

${name:^arrayname}
${name:^^arrayname}
Zips two arrays, such that the output array is twice as long as
the shortest (longest for `:^^') of name and arrayname, with the
elements alternatingly being picked from them. For `:^', if one
of the input arrays is longer, the output will stop when the end
of the shorter array is reached. Thus,

a=(1 2 3 4); b=(a b); print ${a:^b}

will output `1 a 2 b'. For `:^^', then the input is repeated
until all of the longer array has been used up and the above
will output `1 a 2 b 3 a 4 b'.

Either or both inputs may be a scalar, they will be treated as
an array of length 1 with the scalar as the only element. If
either array is empty, the other array is output with no extra
elements inserted.

Currently the following code will output `a b' and `1' as two
separate elements, which can be unexpected. The second print
provides a workaround which should continue to work if this is
changed.

a=(a b); b=(1 2); print -l "${a:^b}"; print -l "${${a:^b}}"

${name:offset}
${name:offset:length}
This syntax gives effects similar to parameter subscripting in
the form $name[start,end], but is compatible with other shells;
note that both offset and length are interpreted differently
from the components of a subscript.

If offset is non-negative, then if the variable name is a scalar
substitute the contents starting offset characters from the
first character of the string, and if name is an array
substitute elements starting offset elements from the first
element. If length is given, substitute that many characters or
elements, otherwise the entire rest of the scalar or array.

A positive offset is always treated as the offset of a character
or element in name from the first character or element of the
array (this is different from native zsh subscript notation).
Hence 0 refers to the first character or element regardless of
the setting of the option KSH_ARRAYS.

A negative offset counts backwards from the end of the scalar or
array, so that -1 corresponds to the last character or element,
and so on.

When positive, length counts from the offset position toward the
end of the scalar or array. When negative, length counts back
from the end. If this results in a position smaller than
offset, a diagnostic is printed and nothing is substituted.

The option MULTIBYTE is obeyed, i.e. the offset and length count
multibyte characters where appropriate.

offset and length undergo the same set of shell substitutions as
for scalar assignment; in addition, they are then subject to
arithmetic evaluation. Hence, for example

print ${foo:3}
print ${foo: 1 * 2}
print ${foo:$(( 1 * 2))}
print ${foo:$(echo 1 * 2)}

all have the same effect, extracting the string starting at the
fourth character of $foo if the substitution would otherwise
return a scalar, or the array starting at the fourth element if
$foo would return an array. Note that with the option
KSH_ARRAYS $foo always returns a scalar (regardless of the use
of the offset syntax) and a form such as ${foo[*]:3} is required
to extract elements of an array named foo.

If offset is negative, the - may not appear immediately after
the : as this indicates the ${name:-word} form of substitution.
Instead, a space may be inserted before the -. Furthermore,
neither offset nor length may begin with an alphabetic character
or & as these are used to indicate history-style modifiers. To
substitute a value from a variable, the recommended approach is
to precede it with a $ as this signifies the intention
(parameter substitution can easily be rendered unreadable);
however, as arithmetic substitution is performed, the expression
${var: offs} does work, retrieving the offset from $offs.

For further compatibility with other shells there is a special
case for array offset 0. This usually accesses the first
element of the array. However, if the substitution refers to
the positional parameter array, e.g. $@ or $*, then offset 0
instead refers to $0, offset 1 refers to $1, and so on. In
other words, the positional parameter array is effectively
extended by prepending $0. Hence ${*:0:1} substitutes $0 and
${*:1:1} substitutes $1.

${name/pattern/repl}
${name//pattern/repl}
${name:/pattern/repl}
Replace the longest possible match of pattern in the expansion
of parameter name by string repl. The first form replaces just
the first occurrence, the second form all occurrences, and the
third form replaces only if pattern matches the entire string.
Both pattern and repl are subject to double-quoted substitution,
so that expressions like ${name/$opat/$npat} will work, but obey
the usual rule that pattern characters in $opat are not treated
specially unless either the option GLOB_SUBST is set, or $opat
is instead substituted as ${~opat}.

The pattern may begin with a `#', in which case the pattern must
match at the start of the string, or `%', in which case it must
match at the end of the string, or `#%' in which case the
pattern must match the entire string. The repl may be an empty
string, in which case the final `/' may also be omitted. To
quote the final `/' in other cases it should be preceded by a
single backslash; this is not necessary if the `/' occurs inside
a substituted parameter. Note also that the `#', `%' and `#%
are not active if they occur inside a substituted parameter,
even at the start.

If, after quoting rules apply, ${name} expands to an array, the
replacements act on each element individually. Note also the
effect of the I and S parameter expansion flags below; however,
the flags M, R, B, E and N are not useful.

For example,

foo="twinkle twinkle little star" sub="t*e" rep="spy"
print ${foo//${~sub}/$rep}
print ${(S)foo//${~sub}/$rep}

Here, the `~' ensures that the text of $sub is treated as a
pattern rather than a plain string. In the first case, the
longest match for t*e is substituted and the result is `spy
star', while in the second case, the shortest matches are taken
and the result is `spy spy lispy star'.

${#spec}
If spec is one of the above substitutions, substitute the length
in characters of the result instead of the result itself. If
spec is an array expression, substitute the number of elements
of the result. This has the side-effect that joining is skipped
even in quoted forms, which may affect other sub-expressions in
spec. Note that `^', `=', and `~', below, must appear to the
left of `#' when these forms are combined.

If the option POSIX_IDENTIFIERS is not set, and spec is a simple
name, then the braces are optional; this is true even for
special parameters so e.g. $#- and $#* take the length of the
string $- and the array $* respectively. If POSIX_IDENTIFIERS
is set, then braces are required for the # to be treated in this
fashion.

${^spec}
${^^spec}
Turn on the RC_EXPAND_PARAM option for the evaluation of spec;
if the `^' is doubled, turn it off. When this option is set,
array expansions of the form foo${xx}bar, where the parameter xx
is set to (a b c), are substituted with `fooabar foobbar
foocbar' instead of the default `fooa b cbar'. Note that an
empty array will therefore cause all arguments to be removed.

Internally, each such expansion is converted into the equivalent
list for brace expansion. E.g., ${^var} becomes
{$var[1],$var[2],...}, and is processed as described in the
section `Brace Expansion' below: note, however, the expansion
happens immediately, with any explicit brace expansion happening
later. If word splitting is also in effect the $var[N] may
themselves be split into different list elements.

${=spec}
${==spec}
Perform word splitting using the rules for SH_WORD_SPLIT during
the evaluation of spec, but regardless of whether the parameter
appears in double quotes; if the `=' is doubled, turn it off.
This forces parameter expansions to be split into separate words
before substitution, using IFS as a delimiter. This is done by
default in most other shells.

Note that splitting is applied to word in the assignment forms
of spec before the assignment to name is performed. This
affects the result of array assignments with the A flag.

${~spec}
${~~spec}
Turn on the GLOB_SUBST option for the evaluation of spec; if the
`~' is doubled, turn it off. When this option is set, the
string resulting from the expansion will be interpreted as a
pattern anywhere that is possible, such as in filename expansion
and filename generation and pattern-matching contexts like the
right hand side of the `=' and `!=' operators in conditions.

In nested substitutions, note that the effect of the ~ applies
to the result of the current level of substitution. A
surrounding pattern operation on the result may cancel it.
Hence, for example, if the parameter foo is set to *,
${~foo//\*/*.c} is substituted by the pattern *.c, which may be
expanded by filename generation, but ${${~foo}//\*/*.c}
substitutes to the string *.c, which will not be further
expanded.

If a ${...} type parameter expression or a $(...) type command
substitution is used in place of name above, it is expanded first and
the result is used as if it were the value of name. Thus it is
possible to perform nested operations: ${${foo#head}%tail} substitutes
the value of $foo with both `head' and `tail' deleted. The form with
$(...) is often useful in combination with the flags described next;
see the examples below. Each name or nested ${...} in a parameter
expansion may also be followed by a subscript expression as described
in Array Parameters in zshparam(1).

Note that double quotes may appear around nested expressions, in which
case only the part inside is treated as quoted; for example,
${(f)"$(foo)"} quotes the result of $(foo), but the flag `(f)' (see
below) is applied using the rules for unquoted expansions. Note
further that quotes are themselves nested in this context; for example,
in "${(@f)"$(foo)"}", there are two sets of quotes, one surrounding the
whole expression, the other (redundant) surrounding the $(foo) as
before.

Parameter Expansion Flags
If the opening brace is directly followed by an opening parenthesis,
the string up to the matching closing parenthesis will be taken as a
list of flags. In cases where repeating a flag is meaningful, the
repetitions need not be consecutive; for example, `(q%q%q)' means the
same thing as the more readable `(%%qqq)'. The following flags are
supported:

# Evaluate the resulting words as numeric expressions and
interpret these as character codes. Output the corresponding
characters. Note that this form is entirely distinct from use
of the # without parentheses.

If the MULTIBYTE option is set and the number is greater than
127 (i.e. not an ASCII character) it is treated as a Unicode
character.

% Expand all % escapes in the resulting words in the same way as
in prompts (see EXPANSION OF PROMPT SEQUENCES in zshmisc(1)). If
this flag is given twice, full prompt expansion is done on the
resulting words, depending on the setting of the PROMPT_PERCENT,
PROMPT_SUBST and PROMPT_BANG options.

@ In double quotes, array elements are put into separate words.
E.g., `"${(@)foo}"' is equivalent to `"${foo[@]}"' and
`"${(@)foo[1,2]}"' is the same as `"$foo[1]" "$foo[2]"'. This
is distinct from field splitting by the f, s or z flags, which
still applies within each array element.

A Convert the substitution into an array expression, even if it
otherwise would be scalar. This has lower precedence than
subscripting, so one level of nested expansion is required in
order that subscripts apply to array elements. Thus
${${(A)name}[1]} yields the full value of name when name is
scalar.

This assigns an array parameter with `${...=...}', `${...:=...}'
or `${...::=...}'. If this flag is repeated (as in `AA'),
assigns an associative array parameter. Assignment is made
before sorting or padding; if field splitting is active, the
word part is split before assignment. The name part may be a
subscripted range for ordinary arrays; when assigning an
associative array, the word part must be converted to an array,
for example by using `${(AA)=name=...}' to activate field
splitting.

Surrounding context such as additional nesting or use of the
value in a scalar assignment may cause the array to be joined
back into a single string again.

a Sort in array index order; when combined with `O' sort in
reverse array index order. Note that `a' is therefore
equivalent to the default but `Oa' is useful for obtaining an
array's elements in reverse order.

b Quote with backslashes only characters that are special to
pattern matching. This is useful when the contents of the
variable are to be tested using GLOB_SUBST, including the
${~...} switch.

Quoting using one of the q family of flags does not work for
this purpose since quotes are not stripped from non-pattern
characters by GLOB_SUBST. In other words,

pattern=${(q)str}
[[ $str = ${~pattern} ]]

works if $str is `a*b' but not if it is `a b', whereas

pattern=${(b)str}
[[ $str = ${~pattern} ]]

is always true for any possible value of $str.

c With ${#name}, count the total number of characters in an array,
as if the elements were concatenated with spaces between them.
This is not a true join of the array, so other expressions used
with this flag may have an effect on the elements of the array
before it is counted.

C Capitalize the resulting words. `Words' in this case refers to
sequences of alphanumeric characters separated by
non-alphanumerics, not to words that result from field
splitting.

D Assume the string or array elements contain directories and
attempt to substitute the leading part of these by names. The
remainder of the path (the whole of it if the leading part was
not substituted) is then quoted so that the whole string can be
used as a shell argument. This is the reverse of `~'
substitution: see the section FILENAME EXPANSION below.

e Perform single word shell expansions, namely parameter
expansion, command substitution and arithmetic expansion, on the
result. Such expansions can be nested but too deep recursion may
have unpredictable effects.

f Split the result of the expansion at newlines. This is a
shorthand for `ps:\n:'.

F Join the words of arrays together using newline as a separator.
This is a shorthand for `pj:\n:'.

g:opts:
Process escape sequences like the echo builtin when no options
are given (g::). With the o option, octal escapes don't take a
leading zero. With the c option, sequences like `^X' are also
processed. With the e option, processes `\M-t' and similar
sequences like the print builtin. With both of the o and e
options, behaves like the print builtin except that in none of
these modes is `\c' interpreted.

i Sort case-insensitively. May be combined with `n' or `O'.

k If name refers to an associative array, substitute the keys
(element names) rather than the values of the elements. Used
with subscripts (including ordinary arrays), force indices or
keys to be substituted even if the subscript form refers to
values. However, this flag may not be combined with subscript
ranges. With the KSH_ARRAYS option a subscript `[*]' or `[@]'
is needed to operate on the whole array, as usual.

L Convert all letters in the result to lower case.

n Sort decimal integers numerically; if the first differing
characters of two test strings are not digits, sorting is
lexical. `*' and `-' are not treated specially; they are
treated as any other non-digit. Integers with more initial
zeroes are sorted before those with fewer or none. Hence the
array `foo+24 foo1 foo02 foo2 foo3 foo20 foo23' is sorted into
the order shown. May be combined with `i' or `O'.

- As n, but a leading minus sign indicates a negative decimal
integer. A leading minus sign not followed by an integer does
not trigger numeric sorting. Note that `*' signs are not
handled specially (this may change in the future).

o Sort the resulting words in ascending order; if this appears on
its own the sorting is lexical and case-sensitive (unless the
locale renders it case-insensitive). Sorting in ascending order
is the default for other forms of sorting, so this is ignored if
combined with `a', `i', `n' or `-'.

O Sort the resulting words in descending order; `O' without `a',
`i', `n' or `-' sorts in reverse lexical order. May be combined
with `a', `i', `n' or `-' to reverse the order of sorting.

P This forces the value of the parameter name to be interpreted as
a further parameter name, whose value will be used where
appropriate. Note that flags set with one of the typeset family
of commands (in particular case transformations) are not applied
to the value of name used in this fashion.

If used with a nested parameter or command substitution, the
result of that will be taken as a parameter name in the same
way. For example, if you have `foo=bar' and `bar=baz', the
strings ${(P)foo}, ${(P)${foo}}, and ${(P)$(echo bar)} will be
expanded to `baz'.

Likewise, if the reference is itself nested, the expression with
the flag is treated as if it were directly replaced by the
parameter name. It is an error if this nested substitution
produces an array with more than one word. For example, if
`name=assoc' where the parameter assoc is an associative array,
then `${${(P)name}[elt]}' refers to the element of the
associative subscripted `elt'.

q Quote characters that are special to the shell in the resulting
words with backslashes; unprintable or invalid characters are
quoted using the $'\NNN' form, with separate quotes for each
octet.

If this flag is given twice, the resulting words are quoted in
single quotes and if it is given three times, the words are
quoted in double quotes; in these forms no special handling of
unprintable or invalid characters is attempted. If the flag is
given four times, the words are quoted in single quotes preceded
by a $. Note that in all three of these forms quoting is done
unconditionally, even if this does not change the way the
resulting string would be interpreted by the shell.

If a q- is given (only a single q may appear), a minimal form of
single quoting is used that only quotes the string if needed to
protect special characters. Typically this form gives the most
readable output.

If a q+ is given, an extended form of minimal quoting is used
that causes unprintable characters to be rendered using $'...'.
This quoting is similar to that used by the output of values by
the typeset family of commands.

Q Remove one level of quotes from the resulting words.

t Use a string describing the type of the parameter where the
value of the parameter would usually appear. This string
consists of keywords separated by hyphens (`-'). The first
keyword in the string describes the main type, it can be one of
`scalar', `array', `integer', `float' or `association'. The
other keywords describe the type in more detail:

local for local parameters

left for left justified parameters

right_blanks
for right justified parameters with leading blanks

right_zeros
for right justified parameters with leading zeros

lower for parameters whose value is converted to all lower case
when it is expanded

upper for parameters whose value is converted to all upper case
when it is expanded

readonly
for readonly parameters

tag for tagged parameters

tied for parameters tied to another parameter in the manner of
PATH (colon-separated list) and path (array), whether
these are special parameters or user-defined with
`typeset -T'

export for exported parameters

unique for arrays which keep only the first occurrence of
duplicated values

hide for parameters with the `hide' flag

hideval
for parameters with the `hideval' flag

special
for special parameters defined by the shell

u Expand only the first occurrence of each unique word.

U Convert all letters in the result to upper case.

v Used with k, substitute (as two consecutive words) both the key
and the value of each associative array element. Used with
subscripts, force values to be substituted even if the subscript
form refers to indices or keys.

V Make any special characters in the resulting words visible.

w With ${#name}, count words in arrays or strings; the s flag may
be used to set a word delimiter.

W Similar to w with the difference that empty words between
repeated delimiters are also counted.

X With this flag, parsing errors occurring with the Q, e and #
flags or the pattern matching forms such as `${name#pattern}'
are reported. Without the flag, errors are silently ignored.

z Split the result of the expansion into words using shell parsing
to find the words, i.e. taking into account any quoting in the
value. Comments are not treated specially but as ordinary
strings, similar to interactive shells with the
INTERACTIVE_COMMENTS option unset (however, see the Z flag below
for related options)

Note that this is done very late, even later than the `(s)'
flag. So to access single words in the result use nested
expansions as in `${${(z)foo}[2]}'. Likewise, to remove the
quotes in the resulting words use `${(Q)${(z)foo}}'.

0 Split the result of the expansion on null bytes. This is a
shorthand for `ps:\0:'.

The following flags (except p) are followed by one or more arguments as
shown. Any character, or the matching pairs `(...)', `{...}', `[...]',
or `<...>', may be used in place of a colon as delimiters, but note
that when a flag takes more than one argument, a matched pair of
delimiters must surround each argument.

p Recognize the same escape sequences as the print builtin in
string arguments to any of the flags described below that follow
this argument.

Alternatively, with this option string arguments may be in the
form $var in which case the value of the variable is
substituted. Note this form is strict; the string argument does
not undergo general parameter expansion.

For example,

sep=:
val=a:b:c
print ${(ps.$sep.)val}

splits the variable on a :.

~ Strings inserted into the expansion by any of the flags below
are to be treated as patterns. This applies to the string
arguments of flags that follow ~ within the same set of
parentheses. Compare with ~ outside parentheses, which forces
the entire substituted string to be treated as a pattern.
Hence, for example,

[[ "?" = ${(~j.|.)array} ]]

treats `|' as a pattern and succeeds if and only if $array
contains the string `?' as an element. The ~ may be repeated to
toggle the behaviour; its effect only lasts to the end of the
parenthesised group.

j:string:
Join the words of arrays together using string as a separator.
Note that this occurs before field splitting by the s:string:
flag or the SH_WORD_SPLIT option.

l:expr::string1::string2:
Pad the resulting words on the left. Each word will be
truncated if required and placed in a field expr characters
wide.

The arguments :string1: and :string2: are optional; neither, the
first, or both may be given. Note that the same pairs of
delimiters must be used for each of the three arguments. The
space to the left will be filled with string1 (concatenated as
often as needed) or spaces if string1 is not given. If both
string1 and string2 are given, string2 is inserted once directly
to the left of each word, truncated if necessary, before string1
is used to produce any remaining padding.

If either of string1 or string2 is present but empty, i.e. there
are two delimiters together at that point, the first character
of $IFS is used instead.

If the MULTIBYTE option is in effect, the flag m may also be
given, in which case widths will be used for the calculation of
padding; otherwise individual multibyte characters are treated
as occupying one unit of width.

If the MULTIBYTE option is not in effect, each byte in the
string is treated as occupying one unit of width.

Control characters are always assumed to be one unit wide; this
allows the mechanism to be used for generating repetitions of
control characters.

m Only useful together with one of the flags l or r or with the #
length operator when the MULTIBYTE option is in effect. Use the
character width reported by the system in calculating how much
of the string it occupies or the overall length of the string.
Most printable characters have a width of one unit, however
certain Asian character sets and certain special effects use
wider characters; combining characters have zero width.
Non-printable characters are arbitrarily counted as zero width;
how they would actually be displayed will vary.

If the m is repeated, the character either counts zero (if it
has zero width), else one. For printable character strings this
has the effect of counting the number of glyphs (visibly
separate characters), except for the case where combining
characters themselves have non-zero width (true in certain
alphabets).

r:expr::string1::string2:
As l, but pad the words on the right and insert string2
immediately to the right of the string to be padded.

Left and right padding may be used together. In this case the
strategy is to apply left padding to the first half width of
each of the resulting words, and right padding to the second
half. If the string to be padded has odd width the extra
padding is applied on the left.

s:string:
Force field splitting at the separator string. Note that a
string of two or more characters means that all of them must
match in sequence; this differs from the treatment of two or
more characters in the IFS parameter. See also the = flag and
the SH_WORD_SPLIT option. An empty string may also be given in
which case every character will be a separate element.

For historical reasons, the usual behaviour that empty array
elements are retained inside double quotes is disabled for
arrays generated by splitting; hence the following:

line="one::three"
print -l "${(s.:.)line}"

produces two lines of output for one and three and elides the
empty field. To override this behaviour, supply the `(@)' flag
as well, i.e. "${(@s.:.)line}".

Z:opts:
As z but takes a combination of option letters between a
following pair of delimiter characters. With no options the
effect is identical to z. The following options are available:

(Z+c+) causes comments to be parsed as a string and retained;
any field in the resulting array beginning with an
unquoted comment character is a comment.

(Z+C+) causes comments to be parsed and removed. The rule for
comments is standard: anything between a word starting
with the third character of $HISTCHARS, default #, up to
the next newline is a comment.

(Z+n+) causes unquoted newlines to be treated as ordinary
whitespace, else they are treated as if they are shell
code delimiters and converted to semicolons.

Options are combined within the same set of delimiters, e.g.
(Z+Cn+).

_:flags:
The underscore (_) flag is reserved for future use. As of this
revision of zsh, there are no valid flags; anything following an
underscore, other than an empty pair of delimiters, is treated
as an error, and the flag itself has no effect.

The following flags are meaningful with the ${...#...} or ${...%...}
forms. The S, I, and * flags may also be used with the ${.../...}
forms.

S With # or ##, search for the match that starts closest to the
start of the string (a `substring match'). Of all matches at a
particular position, # selects the shortest and ## the longest:

% str="aXbXc"
% echo ${(S)str#X*}
abXc
% echo ${(S)str##X*}
a
%

With % or %%, search for the match that starts closest to the
end of the string:

% str="aXbXc"
% echo ${(S)str%X*}
aXbc
% echo ${(S)str%%X*}
aXb
%

(Note that % and %% don't search for the match that ends closest
to the end of the string, as one might expect.)

With substitution via ${.../...} or ${...//...}, specifies
non-greedy matching, i.e. that the shortest instead of the
longest match should be replaced:

% str="abab"
% echo ${str/*b/_}
_
% echo ${(S)str/*b/_}
_ab
%

I:expr:
Search the exprth match (where expr evaluates to a number).
This only applies when searching for substrings, either with the
S flag, or with ${.../...} (only the exprth match is
substituted) or ${...//...} (all matches from the exprth on are
substituted). The default is to take the first match.

The exprth match is counted such that there is either one or
zero matches from each starting position in the string, although
for global substitution matches overlapping previous
replacements are ignored. With the ${...%...} and ${...%%...}
forms, the starting position for the match moves backwards from
the end as the index increases, while with the other forms it
moves forward from the start.

Hence with the string
which switch is the right switch for Ipswich?
substitutions of the form ${(SI:N:)string#w*ch} as N increases
from 1 will match and remove `which', `witch', `witch' and
`wich'; the form using `##' will match and remove `which switch
is the right switch for Ipswich', `witch is the right switch for
Ipswich', `witch for Ipswich' and `wich'. The form using `%'
will remove the same matches as for `#', but in reverse order,
and the form using `%%' will remove the same matches as for `##'
in reverse order.

* Enable EXTENDED_GLOB for substitution via ${.../...} or
${...//...}. Note that `**' does not disable extendedglob.

B Include the index of the beginning of the match in the result.

E Include the index one character past the end of the match in the
result (note this is inconsistent with other uses of parameter
index).

M Include the matched portion in the result.

N Include the length of the match in the result.

R Include the unmatched portion in the result (the Rest).

Rules
Here is a summary of the rules for substitution; this assumes that
braces are present around the substitution, i.e. ${...}. Some
particular examples are given below. Note that the Zsh Development
Group accepts no responsibility for any brain damage which may occur
during the reading of the following rules.

1. Nested substitution
If multiple nested ${...} forms are present, substitution is
performed from the inside outwards. At each level, the
substitution takes account of whether the current value is a
scalar or an array, whether the whole substitution is in double
quotes, and what flags are supplied to the current level of
substitution, just as if the nested substitution were the
outermost. The flags are not propagated up to enclosing
substitutions; the nested substitution will return either a
scalar or an array as determined by the flags, possibly adjusted
for quoting. All the following steps take place where
applicable at all levels of substitution.

Note that, unless the `(P)' flag is present, the flags and any
subscripts apply directly to the value of the nested
substitution; for example, the expansion ${${foo}} behaves
exactly the same as ${foo}. When the `(P)' flag is present in a
nested substitution, the other substitution rules are applied to
the value before it is interpreted as a name, so ${${(P)foo}}
may differ from ${(P)foo}.

At each nested level of substitution, the substituted words
undergo all forms of single-word substitution (i.e. not filename
generation), including command substitution, arithmetic
expansion and filename expansion (i.e. leading ~ and =). Thus,
for example, ${${:-=cat}:h} expands to the directory where the
cat program resides. (Explanation: the internal substitution
has no parameter but a default value =cat, which is expanded by
filename expansion to a full path; the outer substitution then
applies the modifier :h and takes the directory part of the
path.)

2. Internal parameter flags
Any parameter flags set by one of the typeset family of
commands, in particular the -L, -R, -Z, -u and -l options for
padding and capitalization, are applied directly to the
parameter value. Note these flags are options to the command,
e.g. `typeset -Z'; they are not the same as the flags used
within parameter substitutions.

At the outermost level of substitution, the `(P)' flag (rule 4.)
ignores these transformations and uses the unmodified value of
the parameter as the name to be replaced. This is usually the
desired behavior because padding may make the value
syntactically illegal as a parameter name, but if capitalization
changes are desired, use the ${${(P)foo}} form (rule 25.).

3. Parameter subscripting
If the value is a raw parameter reference with a subscript, such
as ${var[3]}, the effect of subscripting is applied directly to
the parameter. Subscripts are evaluated left to right;
subsequent subscripts apply to the scalar or array value yielded
by the previous subscript. Thus if var is an array,
${var[1][2]} is the second character of the first word, but
${var[2,4][2]} is the entire third word (the second word of the
range of words two through four of the original array). Any
number of subscripts may appear. Flags such as `(k)' and `(v)'
which alter the result of subscripting are applied.

4. Parameter name replacement
At the outermost level of nesting only, the `(P)' flag is
applied. This treats the value so far as a parameter name
(which may include a subscript expression) and replaces that
with the corresponding value. This replacement occurs later if
the `(P)' flag appears in a nested substitution.

If the value so far names a parameter that has internal flags
(rule 2.), those internal flags are applied to the new value
after replacement.

5. Double-quoted joining
If the value after this process is an array, and the
substitution appears in double quotes, and neither an `(@)' flag
nor a `#' length operator is present at the current level, then
words of the value are joined with the first character of the
parameter $IFS, by default a space, between each word (single
word arrays are not modified). If the `(j)' flag is present,
that is used for joining instead of $IFS.

6. Nested subscripting
Any remaining subscripts (i.e. of a nested substitution) are
evaluated at this point, based on whether the value is an array
or a scalar. As with 3., multiple subscripts can appear. Note
that ${foo[2,4][2]} is thus equivalent to ${${foo[2,4]}[2]} and
also to "${${(@)foo[2,4]}[2]}" (the nested substitution returns
an array in both cases), but not to "${${foo[2,4]}[2]}" (the
nested substitution returns a scalar because of the quotes).

7. Modifiers
Any modifiers, as specified by a trailing `#', `%', `/'
(possibly doubled) or by a set of modifiers of the form `:...'
(see the section `Modifiers' in the section `History
Expansion'), are applied to the words of the value at this
level.

8. Character evaluation
Any `(#)' flag is applied, evaluating the result so far
numerically as a character.

9. Length
Any initial `#' modifier, i.e. in the form ${#var}, is used to
evaluate the length of the expression so far.

10. Forced joining
If the `(j)' flag is present, or no `(j)' flag is present but
the string is to be split as given by rule 11., and joining did
not take place at rule 5., any words in the value are joined
together using the given string or the first character of $IFS
if none. Note that the `(F)' flag implicitly supplies a string
for joining in this manner.

11. Simple word splitting
If one of the `(s)' or `(f)' flags are present, or the `='
specifier was present (e.g. ${=var}), the word is split on
occurrences of the specified string, or (for = with neither of
the two flags present) any of the characters in $IFS.

If no `(s)', `(f)' or `=' was given, but the word is not quoted
and the option SH_WORD_SPLIT is set, the word is split on
occurrences of any of the characters in $IFS. Note this step,
too, takes place at all levels of a nested substitution.

12. Case modification
Any case modification from one of the flags `(L)', `(U)' or
`(C)' is applied.

13. Escape sequence replacement
First any replacements from the `(g)' flag are performed, then
any prompt-style formatting from the `(%)' family of flags is
applied.

14. Quote application
Any quoting or unquoting using `(q)' and `(Q)' and related flags
is applied.

15. Directory naming
Any directory name substitution using `(D)' flag is applied.

16. Visibility enhancement
Any modifications to make characters visible using the `(V)'
flag are applied.

17. Lexical word splitting
If the '(z)' flag or one of the forms of the '(Z)' flag is
present, the word is split as if it were a shell command line,
so that quotation marks and other metacharacters are used to
decide what constitutes a word. Note this form of splitting is
entirely distinct from that described by rule 11.: it does not
use $IFS, and does not cause forced joining.

18. Uniqueness
If the result is an array and the `(u)' flag was present,
duplicate elements are removed from the array.

19. Ordering
If the result is still an array and one of the `(o)' or `(O)'
flags was present, the array is reordered.

20. RC_EXPAND_PARAM
At this point the decision is made whether any resulting array
elements are to be combined element by element with surrounding
text, as given by either the RC_EXPAND_PARAM option or the `^'
flag.

21. Re-evaluation
Any `(e)' flag is applied to the value, forcing it to be
re-examined for new parameter substitutions, but also for
command and arithmetic substitutions.

22. Padding
Any padding of the value by the `(l.fill.)' or `(r.fill.)' flags
is applied.

23. Semantic joining
In contexts where expansion semantics requires a single word to
result, all words are rejoined with the first character of IFS
between. So in `${(P)${(f)lines}}' the value of ${lines} is
split at newlines, but then must be joined again before the
`(P)' flag can be applied.

If a single word is not required, this rule is skipped.

24. Empty argument removal
If the substitution does not appear in double quotes, any
resulting zero-length argument, whether from a scalar or an
element of an array, is elided from the list of arguments
inserted into the command line.

Strictly speaking, the removal happens later as the same happens
with other forms of substitution; the point to note here is
simply that it occurs after any of the above parameter
operations.

25. Nested parameter name replacement
If the `(P)' flag is present and rule 4. has not applied, the
value so far is treated as a parameter name (which may include a
subscript expression) and replaced with the corresponding value,
with internal flags (rule 2.) applied to the new value.

Examples
The flag f is useful to split a double-quoted substitution line by
line. For example, ${(f)"$(<file)"} substitutes the contents of file
divided so that each line is an element of the resulting array.
Compare this with the effect of $(<file) alone, which divides the file
up by words, or the same inside double quotes, which makes the entire
content of the file a single string.

The following illustrates the rules for nested parameter expansions.
Suppose that $foo contains the array (bar baz):

"${(@)${foo}[1]}"
This produces the result b. First, the inner substitution
"${foo}", which has no array (@) flag, produces a single word
result "bar baz". The outer substitution "${(@)...[1]}" detects
that this is a scalar, so that (despite the `(@)' flag) the
subscript picks the first character.

"${${(@)foo}[1]}"
This produces the result `bar'. In this case, the inner
substitution "${(@)foo}" produces the array `(bar baz)'. The
outer substitution "${...[1]}" detects that this is an array and
picks the first word. This is similar to the simple case
"${foo[1]}".

As an example of the rules for word splitting and joining, suppose $foo
contains the array `(ax1 bx1)'. Then

${(s/x/)foo}
produces the words `a', `1 b' and `1'.

${(j/x/s/x/)foo}
produces `a', `1', `b' and `1'.

${(s/x/)foo%%1*}
produces `a' and ` b' (note the extra space). As substitution
occurs before either joining or splitting, the operation first
generates the modified array (ax bx), which is joined to give
"ax bx", and then split to give `a', ` b' and `'. The final
empty string will then be elided, as it is not in double quotes.

COMMAND SUBSTITUTION
A command enclosed in parentheses preceded by a dollar sign, like
`$(...)', or quoted with grave accents, like ``...`', is replaced with
its standard output, with any trailing newlines deleted. If the
substitution is not enclosed in double quotes, the output is broken
into words using the IFS parameter.

The substitution `$(cat foo)' may be replaced by the faster `$(<foo)'.
In this case foo undergoes single word shell expansions (parameter
expansion, command substitution and arithmetic expansion), but not
filename generation.

If the option GLOB_SUBST is set, the result of any unquoted command
substitution, including the special form just mentioned, is eligible
for filename generation.

ARITHMETIC EXPANSION
A string of the form `$[exp]' or `$((exp))' is substituted with the
value of the arithmetic expression exp. exp is subjected to parameter
expansion, command substitution and arithmetic expansion before it is
evaluated. See the section `Arithmetic Evaluation'.

BRACE EXPANSION
A string of the form `foo{xx,yy,zz}bar' is expanded to the individual
words `fooxxbar', `fooyybar' and `foozzbar'. Left-to-right order is
preserved. This construct may be nested. Commas may be quoted in
order to include them literally in a word.

An expression of the form `{n1..n2}', where n1 and n2 are integers, is
expanded to every number between n1 and n2 inclusive. If either number
begins with a zero, all the resulting numbers will be padded with
leading zeroes to that minimum width, but for negative numbers the -
character is also included in the width. If the numbers are in
decreasing order the resulting sequence will also be in decreasing
order.

An expression of the form `{n1..n2..n3}', where n1, n2, and n3 are
integers, is expanded as above, but only every n3th number starting
from n1 is output. If n3 is negative the numbers are output in reverse
order, this is slightly different from simply swapping n1 and n2 in the
case that the step n3 doesn't evenly divide the range. Zero padding
can be specified in any of the three numbers, specifying it in the
third can be useful to pad for example `{-99..100..01}' which is not
possible to specify by putting a 0 on either of the first two numbers
(i.e. pad to two characters).

An expression of the form `{c1..c2}', where c1 and c2 are single
characters (which may be multibyte characters), is expanded to every
character in the range from c1 to c2 in whatever character sequence is
used internally. For characters with code points below 128 this is US
ASCII (this is the only case most users will need). If any intervening
character is not printable, appropriate quotation is used to render it
printable. If the character sequence is reversed, the output is in
reverse order, e.g. `{d..a}' is substituted as `d c b a'.

If a brace expression matches none of the above forms, it is left
unchanged, unless the option BRACE_CCL (an abbreviation for `brace
character class') is set. In that case, it is expanded to a list of
the individual characters between the braces sorted into the order of
the characters in the ASCII character set (multibyte characters are not
currently handled). The syntax is similar to a [...] expression in
filename generation: `-' is treated specially to denote a range of
characters, but `^' or `!' as the first character is treated normally.
For example, `{abcdef0-9}' expands to 16 words 0 1 2 3 4 5 6 7 8 9 a b
c d e f.

Note that brace expansion is not part of filename generation
(globbing); an expression such as */{foo,bar} is split into two
separate words */foo and */bar before filename generation takes place.
In particular, note that this is liable to produce a `no match' error
if either of the two expressions does not match; this is to be
contrasted with */(foo|bar), which is treated as a single pattern but
otherwise has similar effects.

To combine brace expansion with array expansion, see the ${^spec} form
described in the section `Parameter Expansion' above.

FILENAME EXPANSION
Each word is checked to see if it begins with an unquoted `~'. If it
does, then the word up to a `/', or the end of the word if there is no
`/', is checked to see if it can be substituted in one of the ways
described here. If so, then the `~' and the checked portion are
replaced with the appropriate substitute value.

A `~' by itself is replaced by the value of $HOME. A `~' followed by a
`*' or a `-' is replaced by current or previous working directory,
respectively.

A `~' followed by a number is replaced by the directory at that
position in the directory stack. `~0' is equivalent to `~+', and `~1'
is the top of the stack. `~+' followed by a number is replaced by the
directory at that position in the directory stack. `~+0' is equivalent
to `~+', and `~+1' is the top of the stack. `~-' followed by a number
is replaced by the directory that many positions from the bottom of the
stack. `~-0' is the bottom of the stack. The PUSHD_MINUS option
exchanges the effects of `~+' and `~-' where they are followed by a
number.

Dynamic named directories
If the function zsh_directory_name exists, or the shell variable
zsh_directory_name_functions exists and contains an array of function
names, then the functions are used to implement dynamic directory
naming. The functions are tried in order until one returns status
zero, so it is important that functions test whether they can handle
the case in question and return an appropriate status.

A `~' followed by a string namstr in unquoted square brackets is
treated specially as a dynamic directory name. Note that the first
unquoted closing square bracket always terminates namstr. The shell
function is passed two arguments: the string n (for name) and namstr.
It should either set the array reply to a single element which is the
directory corresponding to the name and return status zero (executing
an assignment as the last statement is usually sufficient), or it
should return status non-zero. In the former case the element of reply
is used as the directory; in the latter case the substitution is deemed
to have failed. If all functions fail and the option NOMATCH is set,
an error results.

The functions defined as above are also used to see if a directory can
be turned into a name, for example when printing the directory stack or
when expanding %~ in prompts. In this case each function is passed two
arguments: the string d (for directory) and the candidate for dynamic
naming. The function should either return non-zero status, if the
directory cannot be named by the function, or it should set the array
reply to consist of two elements: the first is the dynamic name for the
directory (as would appear within `~[...]'), and the second is the
prefix length of the directory to be replaced. For example, if the
trial directory is /home/myname/src/zsh and the dynamic name for
/home/myname/src (which has 16 characters) is s, then the function sets

reply=(s 16)

The directory name so returned is compared with possible static names
for parts of the directory path, as described below; it is used if the
prefix length matched (16 in the example) is longer than that matched
by any static name.

It is not a requirement that a function implements both n and d calls;
for example, it might be appropriate for certain dynamic forms of
expansion not to be contracted to names. In that case any call with
the first argument d should cause a non-zero status to be returned.

The completion system calls `zsh_directory_name c' followed by
equivalent calls to elements of the array zsh_directory_name_functions,
if it exists, in order to complete dynamic names for directories. The
code for this should be as for any other completion function as
described in zshcompsys(1).

As a working example, here is a function that expands any dynamic names
beginning with the string p: to directories below /home/pws/perforce.
In this simple case a static name for the directory would be just as
effective.

zsh_directory_name() {
emulate -L zsh
setopt extendedglob
local -a match mbegin mend
if [[ $1 = d ]]; then
# turn the directory into a name
if [[ $2 = (#b)(/home/pws/perforce/)([^/]##)* ]]; then
typeset -ga reply
reply=(p:$match[2] $(( ${#match[1]} * ${#match[2]} )) )
else
return 1
fi
elif [[ $1 = n ]]; then
# turn the name into a directory
[[ $2 != (#b)p:(?*) ]] && return 1
typeset -ga reply
reply=(/home/pws/perforce/$match[1])
elif [[ $1 = c ]]; then
# complete names
local expl
local -a dirs
dirs=(/home/pws/perforce/*(/:t))
dirs=(p:${^dirs})
_wanted dynamic-dirs expl 'dynamic directory' compadd -S\] -a dirs
return
else
return 1
fi
return 0
}

Static named directories
A `~' followed by anything not already covered consisting of any number
of alphanumeric characters or underscore (`_'), hyphen (`-'), or dot
(`.') is looked up as a named directory, and replaced by the value of
that named directory if found. Named directories are typically home
directories for users on the system. They may also be defined if the
text after the `~' is the name of a string shell parameter whose value
begins with a `/'. Note that trailing slashes will be removed from the
path to the directory (though the original parameter is not modified).

It is also possible to define directory names using the -d option to
the hash builtin.

When the shell prints a path (e.g. when expanding %~ in prompts or when
printing the directory stack), the path is checked to see if it has a
named directory as its prefix. If so, then the prefix portion is
replaced with a `~' followed by the name of the directory. The shorter
of the two ways of referring to the directory is used, i.e. either the
directory name or the full path; the name is used if they are the same
length. The parameters $PWD and $OLDPWD are never abbreviated in this
fashion.

`=' expansion
If a word begins with an unquoted `=' and the EQUALS option is set, the
remainder of the word is taken as the name of a command. If a command
exists by that name, the word is replaced by the full pathname of the
command.

Notes
Filename expansion is performed on the right hand side of a parameter
assignment, including those appearing after commands of the typeset
family. In this case, the right hand side will be treated as a
colon-separated list in the manner of the PATH parameter, so that a `~'
or an `=' following a `:' is eligible for expansion. All such
behaviour can be disabled by quoting the `~', the `=', or the whole
expression (but not simply the colon); the EQUALS option is also
respected.

If the option MAGIC_EQUAL_SUBST is set, any unquoted shell argument in
the form `identifier=expression' becomes eligible for file expansion as
described in the previous paragraph. Quoting the first `=' also
inhibits this.

FILENAME GENERATION
If a word contains an unquoted instance of one of the characters `*',
`(', `|', `<', `[', or `?', it is regarded as a pattern for filename
generation, unless the GLOB option is unset. If the EXTENDED_GLOB
option is set, the `^' and `#' characters also denote a pattern;
otherwise they are not treated specially by the shell.

The word is replaced with a list of sorted filenames that match the
pattern. If no matching pattern is found, the shell gives an error
message, unless the NULL_GLOB option is set, in which case the word is
deleted; or unless the NOMATCH option is unset, in which case the word
is left unchanged.

In filename generation, the character `/' must be matched explicitly;
also, a `.' must be matched explicitly at the beginning of a pattern or
after a `/', unless the GLOB_DOTS option is set. No filename
generation pattern matches the files `.' or `..'. In other instances
of pattern matching, the `/' and `.' are not treated specially.

Glob Operators
* Matches any string, including the null string.

? Matches any character.

[...] Matches any of the enclosed characters. Ranges of characters
can be specified by separating two characters by a `-'. A `-'
or `]' may be matched by including it as the first character in
the list. There are also several named classes of characters,
in the form `[:name:]' with the following meanings. The first
set use the macros provided by the operating system to test for
the given character combinations, including any modifications
due to local language settings, see ctype(3):

[:alnum:]
The character is alphanumeric

[:alpha:]
The character is alphabetic

[:ascii:]
The character is 7-bit, i.e. is a single-byte character
without the top bit set.

[:blank:]
The character is a blank character

[:cntrl:]
The character is a control character

[:digit:]
The character is a decimal digit

[:graph:]
The character is a printable character other than
whitespace

[:lower:]
The character is a lowercase letter

[:print:]
The character is printable

[:punct:]
The character is printable but neither alphanumeric nor
whitespace

[:space:]
The character is whitespace

[:upper:]
The character is an uppercase letter

[:xdigit:]
The character is a hexadecimal digit

Another set of named classes is handled internally by the shell
and is not sensitive to the locale:

[:IDENT:]
The character is allowed to form part of a shell
identifier, such as a parameter name; this test respects
the POSIX_IDENTIFIERS option

[:IFS:]
The character is used as an input field separator, i.e.
is contained in the IFS parameter

[:IFSSPACE:]
The character is an IFS white space character; see the
documentation for IFS in the zshparam(1) manual page.

[:INCOMPLETE:]
Matches a byte that starts an incomplete multibyte
character. Note that there may be a sequence of more
than one bytes that taken together form the prefix of a
multibyte character. To test for a potentially
incomplete byte sequence, use the pattern
`[[:INCOMPLETE:]]*'. This will never match a sequence
starting with a valid multibyte character.

[:INVALID:]
Matches a byte that does not start a valid multibyte
character. Note this may be a continuation byte of an
incomplete multibyte character as any part of a multibyte
string consisting of invalid and incomplete multibyte
characters is treated as single bytes.

[:WORD:]
The character is treated as part of a word; this test is
sensitive to the value of the WORDCHARS parameter

Note that the square brackets are additional to those enclosing
the whole set of characters, so to test for a single
alphanumeric character you need `[[:alnum:]]'. Named character
sets can be used alongside other types, e.g. `[[:alpha:]0-9]'.

[^...]
[!...] Like [...], except that it matches any character which is not in
the given set.

<[x]-[y]>
Matches any number in the range x to y, inclusive. Either of
the numbers may be omitted to make the range open-ended; hence
`<->' matches any number. To match individual digits, the [...]
form is more efficient.

Be careful when using other wildcards adjacent to patterns of
this form; for example, <0-9>* will actually match any number
whatsoever at the start of the string, since the `<0-9>' will
match the first digit, and the `*' will match any others. This
is a trap for the unwary, but is in fact an inevitable
consequence of the rule that the longest possible match always
succeeds. Expressions such as `<0-9>[^[:digit:]]*' can be used
instead.

(...) Matches the enclosed pattern. This is used for grouping. If
the KSH_GLOB option is set, then a `@', `*', `*', `?' or `!'
immediately preceding the `(' is treated specially, as detailed
below. The option SH_GLOB prevents bare parentheses from being
used in this way, though the KSH_GLOB option is still available.

Note that grouping cannot extend over multiple directories: it
is an error to have a `/' within a group (this only applies for
patterns used in filename generation). There is one exception:
a group of the form (pat/)# appearing as a complete path segment
can match a sequence of directories. For example, foo/(a*/)#bar
matches foo/bar, foo/any/bar, foo/any/anyother/bar, and so on.

x|y Matches either x or y. This operator has lower precedence than
any other. The `|' character must be within parentheses, to
avoid interpretation as a pipeline. The alternatives are tried
in order from left to right.

^x (Requires EXTENDED_GLOB to be set.) Matches anything except the
pattern x. This has a higher precedence than `/', so `^foo/bar'
will search directories in `.' except `./foo' for a file named
`bar'.

x~y (Requires EXTENDED_GLOB to be set.) Match anything that matches
the pattern x but does not match y. This has lower precedence
than any operator except `|', so `*/*~foo/bar' will search for
all files in all directories in `.' and then exclude `foo/bar'
if there was such a match. Multiple patterns can be excluded by
`foo~bar~baz'. In the exclusion pattern (y), `/' and `.' are
not treated specially the way they usually are in globbing.

x# (Requires EXTENDED_GLOB to be set.) Matches zero or more
occurrences of the pattern x. This operator has high
precedence; `12#' is equivalent to `1(2#)', rather than `(12)#'.
It is an error for an unquoted `#' to follow something which
cannot be repeated; this includes an empty string, a pattern
already followed by `##', or parentheses when part of a KSH_GLOB
pattern (for example, `!(foo)#' is invalid and must be replaced
by `*(!(foo))').

x## (Requires EXTENDED_GLOB to be set.) Matches one or more
occurrences of the pattern x. This operator has high
precedence; `12##' is equivalent to `1(2##)', rather than
`(12)##'. No more than two active `#' characters may appear
together. (Note the potential clash with glob qualifiers in the
form `1(2##)' which should therefore be avoided.)

ksh-like Glob Operators
If the KSH_GLOB option is set, the effects of parentheses can be
modified by a preceding `@', `*', `*', `?' or `!'. This character need
not be unquoted to have special effects, but the `(' must be.

@(...) Match the pattern in the parentheses. (Like `(...)'.)

*(...) Match any number of occurrences. (Like `(...)#', except that
recursive directory searching is not supported.)

+(...) Match at least one occurrence. (Like `(...)##', except that
recursive directory searching is not supported.)

?(...) Match zero or one occurrence. (Like `(|...)'.)

!(...) Match anything but the expression in parentheses. (Like
`(^(...))'.)

Precedence
The precedence of the operators given above is (highest) `^', `/', `~',
`|' (lowest); the remaining operators are simply treated from left to
right as part of a string, with `#' and `##' applying to the shortest
possible preceding unit (i.e. a character, `?', `[...]', `<...>', or a
parenthesised expression). As mentioned above, a `/' used as a
directory separator may not appear inside parentheses, while a `|' must
do so; in patterns used in other contexts than filename generation (for
example, in case statements and tests within `[[...]]'), a `/' is not
special; and `/' is also not special after a `~' appearing outside
parentheses in a filename pattern.

Globbing Flags
There are various flags which affect any text to their right up to the
end of the enclosing group or to the end of the pattern; they require
the EXTENDED_GLOB option. All take the form (#X) where X may have one
of the following forms:

i Case insensitive: upper or lower case characters in the pattern
match upper or lower case characters.

l Lower case characters in the pattern match upper or lower case
characters; upper case characters in the pattern still only
match upper case characters.

I Case sensitive: locally negates the effect of i or l from that
point on.

b Activate backreferences for parenthesised groups in the pattern;
this does not work in filename generation. When a pattern with
a set of active parentheses is matched, the strings matched by
the groups are stored in the array $match, the indices of the
beginning of the matched parentheses in the array $mbegin, and
the indices of the end in the array $mend, with the first
element of each array corresponding to the first parenthesised
group, and so on. These arrays are not otherwise special to the
shell. The indices use the same convention as does parameter
substitution, so that elements of $mend and $mbegin may be used
in subscripts; the KSH_ARRAYS option is respected. Sets of
globbing flags are not considered parenthesised groups; only the
first nine active parentheses can be referenced.

For example,

foo="a_string_with_a_message"
if [[ $foo = (a|an)_(#b)(*) ]]; then
print ${foo[$mbegin[1],$mend[1]]}
fi

prints `string_with_a_message'. Note that the first set of
parentheses is before the (#b) and does not create a
backreference.

Backreferences work with all forms of pattern matching other
than filename generation, but note that when performing matches
on an entire array, such as ${array#pattern}, or a global
substitution, such as ${param//pat/repl}, only the data for the
last match remains available. In the case of global
replacements this may still be useful. See the example for the
m flag below.

The numbering of backreferences strictly follows the order of
the opening parentheses from left to right in the pattern
string, although sets of parentheses may be nested. There are
special rules for parentheses followed by `#' or `##'. Only the
last match of the parenthesis is remembered: for example, in `[[
abab = (#b)([ab])# ]]', only the final `b' is stored in
match[1]. Thus extra parentheses may be necessary to match the
complete segment: for example, use `X((ab|cd)#)Y' to match a
whole string of either `ab' or `cd' between `X' and `Y', using
the value of $match[1] rather than $match[2].

If the match fails none of the parameters is altered, so in some
cases it may be necessary to initialise them beforehand. If
some of the backreferences fail to match -- which happens if
they are in an alternate branch which fails to match, or if they
are followed by # and matched zero times -- then the matched
string is set to the empty string, and the start and end indices
are set to -1.

Pattern matching with backreferences is slightly slower than
without.

B Deactivate backreferences, negating the effect of the b flag
from that point on.

cN,M The flag (#cN,M) can be used anywhere that the # or ## operators
can be used except in the expressions `(*/)#' and `(*/)##' in
filename generation, where `/' has special meaning; it cannot be
combined with other globbing flags and a bad pattern error
occurs if it is misplaced. It is equivalent to the form {N,M}
in regular expressions. The previous character or group is
required to match between N and M times, inclusive. The form
(#cN) requires exactly N matches; (#c,M) is equivalent to
specifying N as 0; (#cN,) specifies that there is no maximum
limit on the number of matches.

m Set references to the match data for the entire string matched;
this is similar to backreferencing and does not work in filename
generation. The flag must be in effect at the end of the
pattern, i.e. not local to a group. The parameters $MATCH,
$MBEGIN and $MEND will be set to the string matched and to the
indices of the beginning and end of the string, respectively.
This is most useful in parameter substitutions, as otherwise the
string matched is obvious.

For example,

arr=(veldt jynx grimps waqf zho buck)
print ${arr//(#m)[aeiou]/${(U)MATCH}}

forces all the matches (i.e. all vowels) into uppercase,
printing `vEldt jynx grImps wAqf zhO bUck'.

Unlike backreferences, there is no speed penalty for using match
references, other than the extra substitutions required for the
replacement strings in cases such as the example shown.

M Deactivate the m flag, hence no references to match data will be
created.

anum Approximate matching: num errors are allowed in the string
matched by the pattern. The rules for this are described in the
next subsection.

s, e Unlike the other flags, these have only a local effect, and each
must appear on its own: `(#s)' and `(#e)' are the only valid
forms. The `(#s)' flag succeeds only at the start of the test
string, and the `(#e)' flag succeeds only at the end of the test
string; they correspond to `^' and `$' in standard regular
expressions. They are useful for matching path segments in
patterns other than those in filename generation (where path
segments are in any case treated separately). For example,
`*((#s)|/)test((#e)|/)*' matches a path segment `test' in any of
the following strings: test, test/at/start, at/end/test,
in/test/middle.

Another use is in parameter substitution; for example
`${array/(#s)A*Z(#e)}' will remove only elements of an array
which match the complete pattern `A*Z'. There are other ways of
performing many operations of this type, however the combination
of the substitution operations `/' and `//' with the `(#s)' and
`(#e)' flags provides a single simple and memorable method.

Note that assertions of the form `(^(#s))' also work, i.e. match
anywhere except at the start of the string, although this
actually means `anything except a zero-length portion at the
start of the string'; you need to use `(""~(#s))' to match a
zero-length portion of the string not at the start.

q A `q' and everything up to the closing parenthesis of the
globbing flags are ignored by the pattern matching code. This
is intended to support the use of glob qualifiers, see below.
The result is that the pattern `(#b)(*).c(#q.)' can be used both
for globbing and for matching against a string. In the former
case, the `(#q.)' will be treated as a glob qualifier and the
`(#b)' will not be useful, while in the latter case the `(#b)'
is useful for backreferences and the `(#q.)' will be ignored.
Note that colon modifiers in the glob qualifiers are also not
applied in ordinary pattern matching.

u Respect the current locale in determining the presence of
multibyte characters in a pattern, provided the shell was
compiled with MULTIBYTE_SUPPORT. This overrides the MULTIBYTE
option; the default behaviour is taken from the option. Compare
U. (Mnemonic: typically multibyte characters are from Unicode
in the UTF-8 encoding, although any extension of ASCII supported
by the system library may be used.)

U All characters are considered to be a single byte long. The
opposite of u. This overrides the MULTIBYTE option.

For example, the test string fooxx can be matched by the pattern
(#i)FOOXX, but not by (#l)FOOXX, (#i)FOO(#I)XX or ((#i)FOOX)X. The
string (#ia2)readme specifies case-insensitive matching of readme with
up to two errors.

When using the ksh syntax for grouping both KSH_GLOB and EXTENDED_GLOB
must be set and the left parenthesis should be preceded by @. Note
also that the flags do not affect letters inside [...] groups, in other
words (#i)[a-z] still matches only lowercase letters. Finally, note
that when examining whole paths case-insensitively every directory must
be searched for all files which match, so that a pattern of the form
(#i)/foo/bar/... is potentially slow.

Approximate Matching
When matching approximately, the shell keeps a count of the errors
found, which cannot exceed the number specified in the (#anum) flags.
Four types of error are recognised:

1. Different characters, as in fooxbar and fooybar.

2. Transposition of characters, as in banana and abnana.

3. A character missing in the target string, as with the pattern
road and target string rod.

4. An extra character appearing in the target string, as with stove
and strove.

Thus, the pattern (#a3)abcd matches dcba, with the errors occurring by
using the first rule twice and the second once, grouping the string as
[d][cb][a] and [a][bc][d].

Non-literal parts of the pattern must match exactly, including
characters in character ranges: hence (#a1)??? matches strings of
length four, by applying rule 4 to an empty part of the pattern, but
not strings of length two, since all the ? must match. Other
characters which must match exactly are initial dots in filenames
(unless the GLOB_DOTS option is set), and all slashes in filenames, so
that a/bc is two errors from ab/c (the slash cannot be transposed with
another character). Similarly, errors are counted separately for
non-contiguous strings in the pattern, so that (ab|cd)ef is two errors
from aebf.

When using exclusion via the ~ operator, approximate matching is
treated entirely separately for the excluded part and must be activated
separately. Thus, (#a1)README~READ_ME matches READ.ME but not READ_ME,
as the trailing READ_ME is matched without approximation. However,
(#a1)README~(#a1)READ_ME does not match any pattern of the form READ?ME
as all such forms are now excluded.

Apart from exclusions, there is only one overall error count; however,
the maximum errors allowed may be altered locally, and this can be
delimited by grouping. For example, (#a1)cat((#a0)dog)fox allows one
error in total, which may not occur in the dog section, and the pattern
(#a1)cat(#a0)dog(#a1)fox is equivalent. Note that the point at which
an error is first found is the crucial one for establishing whether to
use approximation; for example, (#a1)abc(#a0)xyz will not match
abcdxyz, because the error occurs at the `x', where approximation is
turned off.

Entire path segments may be matched approximately, so that
`(#a1)/foo/d/is/available/at/the/bar' allows one error in any path
segment. This is much less efficient than without the (#a1), however,
since every directory in the path must be scanned for a possible
approximate match. It is best to place the (#a1) after any path
segments which are known to be correct.

Recursive Globbing
A pathname component of the form `(foo/)#' matches a path consisting of
zero or more directories matching the pattern foo.

As a shorthand, `**/' is equivalent to `(*/)#'; note that this
therefore matches files in the current directory as well as
subdirectories. Thus:

ls -ld -- (*/)#bar

ls -ld -- **/bar

does a recursive directory search for files named `bar' (potentially
including the file `bar' in the current directory). This form does not
follow symbolic links; the alternative form `***/' does, but is
otherwise identical. Neither of these can be combined with other forms
of globbing within the same path segment; in that case, the `*'
operators revert to their usual effect.

Even shorter forms are available when the option GLOB_STAR_SHORT is
set. In that case if no / immediately follows a ** or *** they are
treated as if both a / plus a further * are present. Hence:

setopt GLOBSTARSHORT
ls -ld -- **.c

is equivalent to

ls -ld -- **/*.c

Glob Qualifiers
Patterns used for filename generation may end in a list of qualifiers
enclosed in parentheses. The qualifiers specify which filenames that
otherwise match the given pattern will be inserted in the argument
list.

If the option BARE_GLOB_QUAL is set, then a trailing set of parentheses
containing no `|' or `(' characters (or `~' if it is special) is taken
as a set of glob qualifiers. A glob subexpression that would normally
be taken as glob qualifiers, for example `(^x)', can be forced to be
treated as part of the glob pattern by doubling the parentheses, in
this case producing `((^x))'.

If the option EXTENDED_GLOB is set, a different syntax for glob
qualifiers is available, namely `(#qx)' where x is any of the same glob
qualifiers used in the other format. The qualifiers must still appear
at the end of the pattern. However, with this syntax multiple glob
qualifiers may be chained together. They are treated as a logical AND
of the individual sets of flags. Also, as the syntax is unambiguous,
the expression will be treated as glob qualifiers just as long any
parentheses contained within it are balanced; appearance of `|', `(' or
`~' does not negate the effect. Note that qualifiers will be
recognised in this form even if a bare glob qualifier exists at the end
of the pattern, for example `*(#q*)(.)' will recognise executable
regular files if both options are set; however, mixed syntax should
probably be avoided for the sake of clarity. Note that within
conditions using the `[[' form the presence of a parenthesised
expression (#q...) at the end of a string indicates that globbing
should be performed; the expression may include glob qualifiers, but it
is also valid if it is simply (#q). This does not apply to the right
hand side of pattern match operators as the syntax already has special
significance.

A qualifier may be any one of the following:

/ directories

F `full' (i.e. non-empty) directories. Note that the opposite
sense (^F) expands to empty directories and all non-directories.
Use (/^F) for empty directories.

. plain files

@ symbolic links

= sockets

p named pipes (FIFOs)

* executable plain files (0100 or 0010 or 0001)

% device files (character or block special)

%b block special files

%c character special files

r owner-readable files (0400)

w owner-writable files (0200)

x owner-executable files (0100)

A group-readable files (0040)

I group-writable files (0020)

E group-executable files (0010)

R world-readable files (0004)

W world-writable files (0002)

X world-executable files (0001)

s setuid files (04000)

S setgid files (02000)

t files with the sticky bit (01000)

fspec files with access rights matching spec. This spec may be a octal
number optionally preceded by a `=', a `*', or a `-'. If none of
these characters is given, the behavior is the same as for `='.
The octal number describes the mode bits to be expected, if
combined with a `=', the value given must match the file-modes
exactly, with a `*', at least the bits in the given number must
be set in the file-modes, and with a `-', the bits in the number
must not be set. Giving a `?' instead of a octal digit anywhere
in the number ensures that the corresponding bits in the
file-modes are not checked, this is only useful in combination
with `='.

If the qualifier `f' is followed by any other character anything
up to the next matching character (`[', `{', and `<' match `]',
`}', and `>' respectively, any other character matches itself)
is taken as a list of comma-separated sub-specs. Each sub-spec
may be either an octal number as described above or a list of
any of the characters `u', `g', `o', and `a', followed by a `=',
a `*', or a `-', followed by a list of any of the characters
`r', `w', `x', `s', and `t', or an octal digit. The first list
of characters specify which access rights are to be checked. If
a `u' is given, those for the owner of the file are used, if a
`g' is given, those of the group are checked, a `o' means to
test those of other users, and the `a' says to test all three
groups. The `=', `*', and `-' again says how the modes are to be
checked and have the same meaning as described for the first
form above. The second list of characters finally says which
access rights are to be expected: `r' for read access, `w' for
write access, `x' for the right to execute the file (or to
search a directory), `s' for the setuid and setgid bits, and `t'
for the sticky bit.

Thus, `*(f70?)' gives the files for which the owner has read,
write, and execute permission, and for which other group members
have no rights, independent of the permissions for other users.
The pattern `*(f-100)' gives all files for which the owner does
not have execute permission, and `*(f:gu+w,o-rx:)' gives the
files for which the owner and the other members of the group
have at least write permission, and for which other users don't
have read or execute permission.

estring
*cmd The string will be executed as shell code. The filename will be
included in the list if and only if the code returns a zero
status (usually the status of the last command).

In the first form, the first character after the `e' will be
used as a separator and anything up to the next matching
separator will be taken as the string; `[', `{', and `<' match
`]', `}', and `>', respectively, while any other character
matches itself. Note that expansions must be quoted in the
string to prevent them from being expanded before globbing is
done. string is then executed as shell code. The string
globqual is appended to the array zsh_eval_context the duration
of execution.

During the execution of string the filename currently being
tested is available in the parameter REPLY; the parameter may be
altered to a string to be inserted into the list instead of the
original filename. In addition, the parameter reply may be set
to an array or a string, which overrides the value of REPLY. If
set to an array, the latter is inserted into the command line
word by word.

For example, suppose a directory contains a single file
`lonely'. Then the expression `*(e:'reply=(${REPLY}{1,2})':)'
will cause the words `lonely1' and `lonely2' to be inserted into
the command line. Note the quoting of string.

The form *cmd has the same effect, but no delimiters appear
around cmd. Instead, cmd is taken as the longest sequence of
characters following the * that are alphanumeric or underscore.
Typically cmd will be the name of a shell function that contains
the appropriate test. For example,

nt() { [[ $REPLY -nt $NTREF ]] }
NTREF=reffile
ls -ld -- *(+nt)

lists all files in the directory that have been modified more
recently than reffile.

ddev files on the device dev

l[-|*]ct
files having a link count less than ct (-), greater than ct (*),
or equal to ct

U files owned by the effective user ID

G files owned by the effective group ID

uid files owned by user ID id if that is a number. Otherwise, id
specifies a user name: the character after the `u' will be taken
as a separator and the string between it and the next matching
separator will be taken as a user name. The starting separators
`[', `{', and `<' match the final separators `]', `}', and `>',
respectively; any other character matches itself. The selected
files are those owned by this user. For example, `u:foo:' or
`u[foo]' selects files owned by user `foo'.

gid like uid but with group IDs or names

a[Mwhms][-|*]n
files accessed exactly n days ago. Files accessed within the
last n days are selected using a negative value for n (-n).
Files accessed more than n days ago are selected by a positive n
value (*n). Optional unit specifiers `M', `w', `h', `m' or `s'
(e.g. `ah5') cause the check to be performed with months (of 30
days), weeks, hours, minutes or seconds instead of days,
respectively. An explicit `d' for days is also allowed.

Any fractional part of the difference between the access time
and the current part in the appropriate units is ignored in the
comparison. For instance, `echo *(ah-5)' would echo files
accessed within the last five hours, while `echo *(ah+5)' would
echo files accessed at least six hours ago, as times strictly
between five and six hours are treated as five hours.

m[Mwhms][-|*]n
like the file access qualifier, except that it uses the file
modification time.

c[Mwhms][-|*]n
like the file access qualifier, except that it uses the file
inode change time.

L[*|-]n
files less than n bytes (-), more than n bytes (*), or exactly n
bytes in length.

If this flag is directly followed by a size specifier `k' (`K'),
`m' (`M'), or `p' (`P') (e.g. `Lk-50') the check is performed
with kilobytes, megabytes, or blocks (of 512 bytes) instead.
(On some systems additional specifiers are available for
gigabytes, `g' or `G', and terabytes, `t' or `T'.) If a size
specifier is used a file is regarded as "exactly" the size if
the file size rounded up to the next unit is equal to the test
size. Hence `*(Lm1)' matches files from 1 byte up to 1 Megabyte
inclusive. Note also that the set of files "less than" the test
size only includes files that would not match the equality test;
hence `*(Lm-1)' only matches files of zero size.

^ negates all qualifiers following it

- toggles between making the qualifiers work on symbolic links
(the default) and the files they point to, if any; any symbolic
link for whose target the `stat' system call fails (whatever the
cause of the failure) is treated as a file in its own right

M sets the MARK_DIRS option for the current pattern

T appends a trailing qualifier mark to the filenames, analogous to
the LIST_TYPES option, for the current pattern (overrides M)

N sets the NULL_GLOB option for the current pattern

D sets the GLOB_DOTS option for the current pattern

n sets the NUMERIC_GLOB_SORT option for the current pattern

Yn enables short-circuit mode: the pattern will expand to at most n
filenames. If more than n matches exist, only the first n
matches in directory traversal order will be considered.

Implies oN when no oc qualifier is used.

oc specifies how the names of the files should be sorted. The
following values of c sort in the following ways:

n By name.
L By the size (length) of the files.
l By number of links.
a By time of last access, youngest first.
m By time of last modification, youngest first.
c By time of last inode change, youngest first.
d By directories: files in subdirectories appear before
those in the current directory at each level of the
search -- this is best combined with other criteria, for
example `odon' to sort on names for files within the same
directory.
N No sorting is performed.
estring
*cmd Sort by shell code (see below).

Note that the modifiers ^ and - are used, so `*(^-oL)' gives a
list of all files sorted by file size in descending order,
following any symbolic links. Unless oN is used, multiple order
specifiers may occur to resolve ties.

The default sorting is n (by name) unless the Y glob qualifier
is used, in which case it is N (unsorted).

oe and o+ are special cases; they are each followed by shell
code, delimited as for the e glob qualifier and the * glob
qualifier respectively (see above). The code is executed for
each matched file with the parameter REPLY set to the name of
the file on entry and globsort appended to zsh_eval_context.
The code should modify the parameter REPLY in some fashion. On
return, the value of the parameter is used instead of the file
name as the string on which to sort. Unlike other sort
operators, oe and o+ may be repeated, but note that the maximum
number of sort operators of any kind that may appear in any glob
expression is 12.

Oc like `o', but sorts in descending order; i.e. `*(^oc)' is the
same as `*(Oc)' and `*(^Oc)' is the same as `*(oc)'; `Od' puts
files in the current directory before those in subdirectories at
each level of the search.

[beg[,end]]
specifies which of the matched filenames should be included in
the returned list. The syntax is the same as for array
subscripts. beg and the optional end may be mathematical
expressions. As in parameter subscripting they may be negative
to make them count from the last match backward. E.g.:
`*(-OL[1,3])' gives a list of the names of the three largest
files.

Pstring
The string will be prepended to each glob match as a separate
word. string is delimited in the same way as arguments to the e
glob qualifier described above. The qualifier can be repeated;
the words are prepended separately so that the resulting command
line contains the words in the same order they were given in the
list of glob qualifiers.

A typical use for this is to prepend an option before all
occurrences of a file name; for example, the pattern `*(P:-f:)'
produces the command line arguments `-f file1 -f file2 ...'

If the modifier ^ is active, then string will be appended
instead of prepended. Prepending and appending is done
independently so both can be used on the same glob expression;
for example by writing `*(P:foo:^P:bar:^P:baz:)' which produces
the command line arguments `foo baz file1 bar ...'

More than one of these lists can be combined, separated by commas. The
whole list matches if at least one of the sublists matches (they are
`or'ed, the qualifiers in the sublists are `and'ed). Some qualifiers,
however, affect all matches generated, independent of the sublist in
which they are given. These are the qualifiers `M', `T', `N', `D',
`n', `o', `O' and the subscripts given in brackets (`[...]').

If a `:' appears in a qualifier list, the remainder of the expression
in parenthesis is interpreted as a modifier (see the section
`Modifiers' in the section `History Expansion'). Each modifier must be
introduced by a separate `:'. Note also that the result after
modification does not have to be an existing file. The name of any
existing file can be followed by a modifier of the form `(:...)' even
if no actual filename generation is performed, although note that the
presence of the parentheses causes the entire expression to be
subjected to any global pattern matching options such as NULL_GLOB.
Thus:

ls -ld -- *(-/)

lists all directories and symbolic links that point to directories, and

ls -ld -- *(-@)

lists all broken symbolic links, and

ls -ld -- *(%W)

lists all world-writable device files in the current directory, and

ls -ld -- *(W,X)

lists all files in the current directory that are world-writable or
world-executable, and

print -rC1 /tmp/foo*(u0^@:t)

outputs the basename of all root-owned files beginning with the string
`foo' in /tmp, ignoring symlinks, and

ls -ld -- *.*~(lex|parse).[ch](^D^l1)

lists all files having a link count of one whose names contain a dot
(but not those starting with a dot, since GLOB_DOTS is explicitly
switched off) except for lex.c, lex.h, parse.c and parse.h.

print -rC1 b*.pro(#q:s/pro/shmo/)(#q.:s/builtin/shmiltin/)

demonstrates how colon modifiers and other qualifiers may be chained
together. The ordinary qualifier `.' is applied first, then the colon
modifiers in order from left to right. So if EXTENDED_GLOB is set and
the base pattern matches the regular file builtin.pro, the shell will
print `shmiltin.shmo'.

NAME
zshparam - zsh parameters

DESCRIPTION
A parameter has a name, a value, and a number of attributes. A name
may be any sequence of alphanumeric characters and underscores, or the
single characters `*', `@', `#', `?', `-', `$', or `!'. A parameter
whose name begins with an alphanumeric or underscore is also referred
to as a variable.

The attributes of a parameter determine the type of its value, often
referred to as the parameter type or variable type, and also control
other processing that may be applied to the value when it is
referenced. The value type may be a scalar (a string, an integer, or a
floating point number), an array (indexed numerically), or an
associative array (an unordered set of name-value pairs, indexed by
name, also referred to as a hash).

Named scalar parameters may have the exported, -x, attribute, to copy
them into the process environment, which is then passed from the shell
to any new processes that it starts. Exported parameters are called
environment variables. The shell also imports environment variables at
startup time and automatically marks the corresponding parameters as
exported. Some environment variables are not imported for reasons of
security or because they would interfere with the correct operation of
other shell features.

Parameters may also be special, that is, they have a predetermined
meaning to the shell. Special parameters cannot have their type
changed or their readonly attribute turned off, and if a special
parameter is unset, then later recreated, the special properties will
be retained.

To declare the type of a parameter, or to assign a string or numeric
value to a scalar parameter, use the typeset builtin.

The value of a scalar parameter may also be assigned by writing:

name=value

In scalar assignment, value is expanded as a single string, in which
the elements of arrays are joined together; filename expansion is not
performed unless the option GLOB_ASSIGN is set.

When the integer attribute, -i, or a floating point attribute, -E or
-F, is set for name, the value is subject to arithmetic evaluation.
Furthermore, by replacing `=' with `+=', a parameter can be incremented
or appended to. See the section `Array Parameters' and Arithmetic
Evaluation (in zshmisc(1)) for additional forms of assignment.

Note that assignment may implicitly change the attributes of a
parameter. For example, assigning a number to a variable in arithmetic
evaluation may change its type to integer or float, and with
GLOB_ASSIGN assigning a pattern to a variable may change its type to an
array.

To reference the value of a parameter, write `$name' or `${name}'. See
Parameter Expansion in zshexpn(1) for complete details. That section
also explains the effect of the difference between scalar and array
assignment on parameter expansion.

ARRAY PARAMETERS
To assign an array value, write one of:

set -A name value ...
name=(value ...)
name=([key]=value ...)

If no parameter name exists, an ordinary array parameter is created.
If the parameter name exists and is a scalar, it is replaced by a new
array.

In the third form, key is an expression that will be evaluated in
arithmetic context (in its simplest form, an integer) that gives the
index of the element to be assigned with value. In this form any
elements not explicitly mentioned that come before the largest index to
which a value is assigned are assigned an empty string. The indices
may be in any order. Note that this syntax is strict: [ and ]= must
not be quoted, and key may not consist of the unquoted string ]=, but
is otherwise treated as a simple string. The enhanced forms of
subscript expression that may be used when directly subscripting a
variable name, described in the section `Array Subscripts' below, are
not available.

The syntaxes with and without the explicit key may be mixed. An
implicit key is deduced by incrementing the index from the previously
assigned element. Note that it is not treated as an error if latter
assignments in this form overwrite earlier assignments.

For example, assuming the option KSH_ARRAYS is not set, the following:

array=(one [3]=three four)

causes the array variable array to contain four elements one, an empty
string, three and four, in that order.

In the forms where only value is specified, full command line expansion
is performed.

In the [key]=value form, both key and value undergo all forms of
expansion allowed for single word shell expansions (this does not
include filename generation); these are as performed by the parameter
expansion flag (e) as described in zshexpn(1). Nested parentheses may
surround value and are included as part of the value, which is joined
into a plain string; this differs from ksh which allows the values
themselves to be arrays. A future version of zsh may support that. To
cause the brackets to be interpreted as a character class for filename
generation, and therefore to treat the resulting list of files as a set
of values, quote the equal sign using any form of quoting. Example:

name=([a-z]'='*)

To append to an array without changing the existing values, use one of
the following:

name+=(value ...)
name+=([key]=value ...)

In the second form key may specify an existing index as well as an
index off the end of the old array; any existing value is overwritten
by value. Also, it is possible to use [key]+=value to append to the
existing value at that index.

Within the parentheses on the right hand side of either form of the
assignment, newlines and semicolons are treated the same as white
space, separating individual values. Any consecutive sequence of such
characters has the same effect.

Ordinary array parameters may also be explicitly declared with:

typeset -a name

Associative arrays must be declared before assignment, by using:

typeset -A name

When name refers to an associative array, the list in an assignment is
interpreted as alternating keys and values:

set -A name key value ...
name=(key value ...)
name=([key]=value ...)

Note that only one of the two syntaxes above may be used in any given
assignment; the forms may not be mixed. This is unlike the case of
numerically indexed arrays.

Every key must have a value in this case. Note that this assigns to
the entire array, deleting any elements that do not appear in the list.
The append syntax may also be used with an associative array:

name+=(key value ...)
name+=([key]=value ...)

This adds a new key/value pair if the key is not already present, and
replaces the value for the existing key if it is. In the second form
it is also possible to use [key]+=value to append to the existing value
at that key. Expansion is performed identically to the corresponding
forms for normal arrays, as described above.

To create an empty array (including associative arrays), use one of:

set -A name
name=()

Array Subscripts
Individual elements of an array may be selected using a subscript. A
subscript of the form `[exp]' selects the single element exp, where exp
is an arithmetic expression which will be subject to arithmetic
expansion as if it were surrounded by `$((...))'. The elements are
numbered beginning with 1, unless the KSH_ARRAYS option is set in which
case they are numbered from zero.

Subscripts may be used inside braces used to delimit a parameter name,
thus `${foo[2]}' is equivalent to `$foo[2]'. If the KSH_ARRAYS option
is set, the braced form is the only one that works, as bracketed
expressions otherwise are not treated as subscripts.

If the KSH_ARRAYS option is not set, then by default accesses to an
array element with a subscript that evaluates to zero return an empty
string, while an attempt to write such an element is treated as an
error. For backward compatibility the KSH_ZERO_SUBSCRIPT option can be
set to cause subscript values 0 and 1 to be equivalent; see the
description of the option in zshoptions(1).

The same subscripting syntax is used for associative arrays, except
that no arithmetic expansion is applied to exp. However, the parsing
rules for arithmetic expressions still apply, which affects the way
that certain special characters must be protected from interpretation.
See Subscript Parsing below for details.

A subscript of the form `[*]' or `[@]' evaluates to all elements of an
array; there is no difference between the two except when they appear
within double quotes. `"$foo[*]"' evaluates to `"$foo[1] $foo[2]
..."', whereas `"$foo[@]"' evaluates to `"$foo[1]" "$foo[2]" ...'. For
associative arrays, `[*]' or `[@]' evaluate to all the values, in no
particular order. Note that this does not substitute the keys; see the
documentation for the `k' flag under Parameter Expansion Flags in
zshexpn(1) for complete details. When an array parameter is referenced
as `$name' (with no subscript) it evaluates to `$name[*]', unless the
KSH_ARRAYS option is set in which case it evaluates to `${name[0]}'
(for an associative array, this means the value of the key `0', which
may not exist even if there are values for other keys).

A subscript of the form `[exp1,exp2]' selects all elements in the range
exp1 to exp2, inclusive. (Associative arrays are unordered, and so do
not support ranges.) If one of the subscripts evaluates to a negative
number, say -n, then the nth element from the end of the array is used.
Thus `$foo[-3]' is the third element from the end of the array foo, and
`$foo[1,-1]' is the same as `$foo[*]'.

Subscripting may also be performed on non-array values, in which case
the subscripts specify a substring to be extracted. For example, if
FOO is set to `foobar', then `echo $FOO[2,5]' prints `ooba'. Note that
some forms of subscripting described below perform pattern matching,
and in that case the substring extends from the start of the match of
the first subscript to the end of the match of the second subscript.
For example,

string="abcdefghijklm"
print ${string[(r)d?,(r)h?]}

prints `defghi'. This is an obvious generalisation of the rule for
single-character matches. For a single subscript, only a single
character is referenced (not the range of characters covered by the
match).

Note that in substring operations the second subscript is handled
differently by the r and R subscript flags: the former takes the
shortest match as the length and the latter the longest match. Hence
in the former case a * at the end is redundant while in the latter case
it matches the whole remainder of the string. This does not affect the
result of the single subscript case as here the length of the match is
irrelevant.

Array Element Assignment
A subscript may be used on the left side of an assignment like so:

name[exp]=value

In this form of assignment the element or range specified by exp is
replaced by the expression on the right side. An array (but not an
associative array) may be created by assignment to a range or element.
Arrays do not nest, so assigning a parenthesized list of values to an
element or range changes the number of elements in the array, shifting
the other elements to accommodate the new values. (This is not
supported for associative arrays.)

This syntax also works as an argument to the typeset command:

typeset "name[exp]"=value

The value may not be a parenthesized list in this case; only
single-element assignments may be made with typeset. Note that quotes
are necessary in this case to prevent the brackets from being
interpreted as filename generation operators. The noglob precommand
modifier could be used instead.

To delete an element of an ordinary array, assign `()' to that element.
To delete an element of an associative array, use the unset command:

unset "name[exp]"

Subscript Flags
If the opening bracket, or the comma in a range, in any subscript
expression is directly followed by an opening parenthesis, the string
up to the matching closing one is considered to be a list of flags, as
in `name[(flags)exp]'.

The flags s, n and b take an argument; the delimiter is shown below as
`:', but any character, or the matching pairs `(...)', `{...}',
`[...]', or `<...>', may be used, but note that `<...>' can only be
used if the subscript is inside a double quoted expression or a
parameter substitution enclosed in braces as otherwise the expression
is interpreted as a redirection.

The flags currently understood are:

w If the parameter subscripted is a scalar then this flag makes
subscripting work on words instead of characters. The default
word separator is whitespace. When combined with the i or I
flag, the effect is to produce the index of the first character
of the first/last word which matches the given pattern; note
that a failed match in this case always yields 0.

s:string:
This gives the string that separates words (for use with the w
flag). The delimiter character : is arbitrary; see above.

p Recognize the same escape sequences as the print builtin in the
string argument of a subsequent `s' flag.

f If the parameter subscripted is a scalar then this flag makes
subscripting work on lines instead of characters, i.e. with
elements separated by newlines. This is a shorthand for
`pws:\n:'.

r Reverse subscripting: if this flag is given, the exp is taken as
a pattern and the result is the first matching array element,
substring or word (if the parameter is an array, if it is a
scalar, or if it is a scalar and the `w' flag is given,
respectively). The subscript used is the number of the matching
element, so that pairs of subscripts such as `$foo[(r)??,3]' and
`$foo[(r)??,(r)f*]' are possible if the parameter is not an
associative array. If the parameter is an associative array,
only the value part of each pair is compared to the pattern, and
the result is that value.

If a search through an ordinary array failed, the search sets
the subscript to one past the end of the array, and hence
${array[(r)pattern]} will substitute the empty string. Thus the
success of a search can be tested by using the (i) flag, for
example (assuming the option KSH_ARRAYS is not in effect):

[[ ${array[(i)pattern]} -le ${#array} ]]

If KSH_ARRAYS is in effect, the -le should be replaced by -lt.

R Like `r', but gives the last match. For associative arrays,
gives all possible matches. May be used for assigning to
ordinary array elements, but not for assigning to associative
arrays. On failure, for normal arrays this has the effect of
returning the element corresponding to subscript 0; this is
empty unless one of the options KSH_ARRAYS or KSH_ZERO_SUBSCRIPT
is in effect.

Note that in subscripts with both `r' and `R' pattern characters
are active even if they were substituted for a parameter
(regardless of the setting of GLOB_SUBST which controls this
feature in normal pattern matching). The flag `e' can be added
to inhibit pattern matching. As this flag does not inhibit
other forms of substitution, care is still required; using a
parameter to hold the key has the desired effect:

key2='original key'
print ${array[(Re)$key2]}

i Like `r', but gives the index of the match instead; this may not
be combined with a second argument. On the left side of an
assignment, behaves like `r'. For associative arrays, the key
part of each pair is compared to the pattern, and the first
matching key found is the result. On failure substitutes the
length of the array plus one, as discussed under the description
of `r', or the empty string for an associative array.

Note: Although `i' may be applied to a scalar substitution to
find the offset of a substring, the results are likely to be
misleading when searching within substitutions that yield an
empty string, or when searching for the empty substring.

I Like `i', but gives the index of the last match, or all possible
matching keys in an associative array. On failure substitutes
0, or the empty string for an associative array. This flag is
best when testing for values or keys that do not exist.

Note: If the option KSH_ARRAYS is in effect and no match is
found, the result is indistinguishable from the case when the
first element of the array matches.

k If used in a subscript on an associative array, this flag causes
the keys to be interpreted as patterns, and returns the value
for the first key found where exp is matched by the key. Note
this could be any such key as no ordering of associative arrays
is defined. This flag does not work on the left side of an
assignment to an associative array element. If used on another
type of parameter, this behaves like `r'.

K On an associative array this is like `k' but returns all values
where exp is matched by the keys. On other types of parameters
this has the same effect as `R'.

n:expr:
If combined with `r', `R', `i' or `I', makes them give the nth
or nth last match (if expr evaluates to n). This flag is
ignored when the array is associative. The delimiter character
: is arbitrary; see above.

b:expr:
If combined with `r', `R', `i' or `I', makes them begin at the
nth or nth last element, word, or character (if expr evaluates
to n). This flag is ignored when the array is associative. The
delimiter character : is arbitrary; see above.

e This flag causes any pattern matching that would be performed on
the subscript to use plain string matching instead. Hence
`${array[(re)*]}' matches only the array element whose value is
*. Note that other forms of substitution such as parameter
substitution are not inhibited.

This flag can also be used to force * or @ to be interpreted as
a single key rather than as a reference to all values. It may
be used for either purpose on the left side of an assignment.

See Parameter Expansion Flags (zshexpn(1)) for additional ways to
manipulate the results of array subscripting.

Subscript Parsing
This discussion applies mainly to associative array key strings and to
patterns used for reverse subscripting (the `r', `R', `i', etc. flags),
but it may also affect parameter substitutions that appear as part of
an arithmetic expression in an ordinary subscript.

To avoid subscript parsing limitations in assignments to associative
array elements, use the append syntax:

aa+=('key with "*strange*" characters' 'value string')

The basic rule to remember when writing a subscript expression is that
all text between the opening `[' and the closing `]' is interpreted as
if it were in double quotes (see zshmisc(1)). However, unlike double
quotes which normally cannot nest, subscript expressions may appear
inside double-quoted strings or inside other subscript expressions (or
both!), so the rules have two important differences.

The first difference is that brackets (`[' and `]') must appear as
balanced pairs in a subscript expression unless they are preceded by a
backslash (`\'). Therefore, within a subscript expression (and unlike
true double-quoting) the sequence `\[' becomes `[', and similarly `\]'
becomes `]'. This applies even in cases where a backslash is not
normally required; for example, the pattern `[^[]' (to match any
character other than an open bracket) should be written `[^\[]' in a
reverse-subscript pattern. However, note that `\[^\[\]' and even
`\[^[]' mean the same thing, because backslashes are always stripped
when they appear before brackets!

The same rule applies to parentheses (`(' and `)') and braces (`{' and
`}'): they must appear either in balanced pairs or preceded by a
backslash, and backslashes that protect parentheses or braces are
removed during parsing. This is because parameter expansions may be
surrounded by balanced braces, and subscript flags are introduced by
balanced parentheses.

The second difference is that a double-quote (`"') may appear as part
of a subscript expression without being preceded by a backslash, and
therefore that the two characters `\"' remain as two characters in the
subscript (in true double-quoting, `\"' becomes `"'). However, because
of the standard shell quoting rules, any double-quotes that appear must
occur in balanced pairs unless preceded by a backslash. This makes it
more difficult to write a subscript expression that contains an odd
number of double-quote characters, but the reason for this difference
is so that when a subscript expression appears inside true
double-quotes, one can still write `\"' (rather than `\\\"') for `"'.

To use an odd number of double quotes as a key in an assignment, use
the typeset builtin and an enclosing pair of double quotes; to refer to
the value of that key, again use double quotes:

typeset -A aa
typeset "aa[one\"two\"three\"quotes]"=QQQ
print "$aa[one\"two\"three\"quotes]"

It is important to note that the quoting rules do not change when a
parameter expansion with a subscript is nested inside another subscript
expression. That is, it is not necessary to use additional backslashes
within the inner subscript expression; they are removed only once, from
the innermost subscript outwards. Parameters are also expanded from
the innermost subscript first, as each expansion is encountered left to
right in the outer expression.

A further complication arises from a way in which subscript parsing is
not different from double quote parsing. As in true double-quoting,
the sequences `\*', and `\@' remain as two characters when they appear
in a subscript expression. To use a literal `*' or `@' as an
associative array key, the `e' flag must be used:

typeset -A aa
aa[(e)*]=star
print $aa[(e)*]

A last detail must be considered when reverse subscripting is
performed. Parameters appearing in the subscript expression are first
expanded and then the complete expression is interpreted as a pattern.
This has two effects: first, parameters behave as if GLOB_SUBST were on
(and it cannot be turned off); second, backslashes are interpreted
twice, once when parsing the array subscript and again when parsing the
pattern. In a reverse subscript, it's necessary to use four
backslashes to cause a single backslash to match literally in the
pattern. For complex patterns, it is often easiest to assign the
desired pattern to a parameter and then refer to that parameter in the
subscript, because then the backslashes, brackets, parentheses, etc.,
are seen only when the complete expression is converted to a pattern.
To match the value of a parameter literally in a reverse subscript,
rather than as a pattern, use `${(q)name}' (see zshexpn(1)) to quote
the expanded value.

Note that the `k' and `K' flags are reverse subscripting for an
ordinary array, but are not reverse subscripting for an associative
array! (For an associative array, the keys in the array itself are
interpreted as patterns by those flags; the subscript is a plain string
in that case.)

One final note, not directly related to subscripting: the numeric names
of positional parameters (described below) are parsed specially, so for
example `$2foo' is equivalent to `${2}foo'. Therefore, to use
subscript syntax to extract a substring from a positional parameter,
the expansion must be surrounded by braces; for example, `${2[3,5]}'
evaluates to the third through fifth characters of the second
positional parameter, but `$2[3,5]' is the entire second parameter
concatenated with the filename generation pattern `[3,5]'.

POSITIONAL PARAMETERS
The positional parameters provide access to the command-line arguments
of a shell function, shell script, or the shell itself; see the section
`Invocation', and also the section `Functions'. The parameter n, where
n is a number, is the nth positional parameter. The parameter `$0' is
a special case, see the section `Parameters Set By The Shell'.

The parameters *, @ and argv are arrays containing all the positional
parameters; thus `$argv[n]', etc., is equivalent to simply `$n'. Note
that the options KSH_ARRAYS or KSH_ZERO_SUBSCRIPT apply to these arrays
as well, so with either of those options set, `${argv[0]}' is
equivalent to `$1' and so on.

Positional parameters may be changed after the shell or function starts
by using the set builtin, by assigning to the argv array, or by direct
assignment of the form `n=value' where n is the number of the
positional parameter to be changed. This also creates (with empty
values) any of the positions from 1 to n that do not already have
values. Note that, because the positional parameters form an array, an
array assignment of the form `n=(value ...)' is allowed, and has the
effect of shifting all the values at positions greater than n by as
many positions as necessary to accommodate the new values.

LOCAL PARAMETERS
Shell function executions delimit scopes for shell parameters.
(Parameters are dynamically scoped.) The typeset builtin, and its
alternative forms declare, integer, local and readonly (but not
export), can be used to declare a parameter as being local to the
innermost scope.

When a parameter is read or assigned to, the innermost existing
parameter of that name is used. (That is, the local parameter hides
any less-local parameter.) However, assigning to a non-existent
parameter, or declaring a new parameter with export, causes it to be
created in the outermost scope.

Local parameters disappear when their scope ends. unset can be used to
delete a parameter while it is still in scope; any outer parameter of
the same name remains hidden.

Special parameters may also be made local; they retain their special
attributes unless either the existing or the newly-created parameter
has the -h (hide) attribute. This may have unexpected effects: there
is no default value, so if there is no assignment at the point the
variable is made local, it will be set to an empty value (or zero in
the case of integers). The following:

typeset PATH=/new/directory:$PATH

is valid for temporarily allowing the shell or programmes called from
it to find the programs in /new/directory inside a function.

Note that the restriction in older versions of zsh that local
parameters were never exported has been removed.

PARAMETERS SET BY THE SHELL
In the parameter lists that follow, the mark `<S>' indicates that the
parameter is special. `<Z>' indicates that the parameter does not
exist when the shell initializes in sh or ksh emulation mode.

The parameters `!', `#', `*', `-', `?', `@', `$', `ARGC', `HISTCMD',
`LINENO', `PPID', `status', `TTYIDLE', `zsh_eval_context',
`ZSH_EVAL_CONTEXT', and `ZSH_SUBSHELL' are read-only and thus cannot be
restored by the user, so they are not output by `typeset -p'. This
also applies to many read-only parameters loaded from modules.

The following parameters are automatically set by the shell:

! <S> The process ID of the last command started in the background
with &, put into the background with the bg builtin, or spawned
with coproc.

# <S> The number of positional parameters in decimal. Note that some
confusion may occur with the syntax $#param which substitutes
the length of param. Use ${#} to resolve ambiguities. In
particular, the sequence `$#-...' in an arithmetic expression is
interpreted as the length of the parameter -, q.v.

ARGC <S> <Z>
Same as #.

$ <S> The process ID of this shell, set when the shell initializes.
Processes forked from the shell without executing a new program,
such as command substitutions and commands grouped with (...),
are subshells that duplicate the current shell, and thus
substitute the same value for $$ as their parent shell.

- <S> Flags supplied to the shell on invocation or by the set or
setopt commands.

* <S> An array containing the positional parameters.

argv <S> <Z>
Same as *. Assigning to argv changes the local positional
parameters, but argv is not itself a local parameter. Deleting
argv with unset in any function deletes it everywhere, although
only the innermost positional parameter array is deleted (so *
and @ in other scopes are not affected).

@ <S> Same as argv[@], even when argv is not set.

? <S> The exit status returned by the last command.

0 <S> The name used to invoke the current shell, or as set by the -c
command line option upon invocation. If the FUNCTION_ARGZERO
option is set, $0 is set upon entry to a shell function to the
name of the function, and upon entry to a sourced script to the
name of the script, and reset to its previous value when the
function or script returns.

status <S> <Z>
Same as ?.

pipestatus <S> <Z>
An array containing the exit statuses returned by all commands
in the last pipeline.

_ <S> The last argument of the previous command. Also, this parameter
is set in the environment of every command executed to the full
pathname of the command.

CPUTYPE
The machine type (microprocessor class or machine model), as
determined at run time.

EGID <S>
The effective group ID of the shell process. If you have
sufficient privileges, you may change the effective group ID of
the shell process by assigning to this parameter. Also
(assuming sufficient privileges), you may start a single command
with a different effective group ID by `(EGID=gid; command)'

If this is made local, it is not implicitly set to 0, but may be
explicitly set locally.

EUID <S>
The effective user ID of the shell process. If you have
sufficient privileges, you may change the effective user ID of
the shell process by assigning to this parameter. Also
(assuming sufficient privileges), you may start a single command
with a different effective user ID by `(EUID=uid; command)'

If this is made local, it is not implicitly set to 0, but may be
explicitly set locally.

ERRNO <S>
The value of errno (see errno(3)) as set by the most recently
failed system call. This value is system dependent and is
intended for debugging purposes. It is also useful with the
zsh/system module which allows the number to be turned into a
name or message.

To use this parameter, it must first be assigned a value
(typically 0 (zero)). It is initially unset for scripting
compatibility.

FUNCNEST <S>
Integer. If greater than or equal to zero, the maximum nesting
depth of shell functions. When it is exceeded, an error is
raised at the point where a function is called. The default
value is determined when the shell is configured, but is
typically 500. Increasing the value increases the danger of a
runaway function recursion causing the shell to crash. Setting
a negative value turns off the check.

GID <S>
The real group ID of the shell process. If you have sufficient
privileges, you may change the group ID of the shell process by
assigning to this parameter. Also (assuming sufficient
privileges), you may start a single command under a different
group ID by `(GID=gid; command)'

If this is made local, it is not implicitly set to 0, but may be
explicitly set locally.

HISTCMD
The current history event number in an interactive shell, in
other words the event number for the command that caused
$HISTCMD to be read. If the current history event modifies the
history, HISTCMD changes to the new maximum history event
number.

HOST The current hostname.

LINENO <S>
The line number of the current line within the current script,
sourced file, or shell function being executed, whichever was
started most recently. Note that in the case of shell functions
the line number refers to the function as it appeared in the
original definition, not necessarily as displayed by the
functions builtin.

LOGNAME
If the corresponding variable is not set in the environment of
the shell, it is initialized to the login name corresponding to
the current login session. This parameter is exported by default
but this can be disabled using the typeset builtin. The value
is set to the string returned by the getlogin(3) system call if
that is available.

MACHTYPE
The machine type (microprocessor class or machine model), as
determined at compile time.

OLDPWD The previous working directory. This is set when the shell
initializes and whenever the directory changes.

OPTARG <S>
The value of the last option argument processed by the getopts
command.

OPTIND <S>
The index of the last option argument processed by the getopts
command.

OSTYPE The operating system, as determined at compile time.

PPID <S>
The process ID of the parent of the shell, set when the shell
initializes. As with $$, the value does not change in subshells
created as a duplicate of the current shell.

PWD The present working directory. This is set when the shell
initializes and whenever the directory changes.

RANDOM <S>
A pseudo-random integer from 0 to 32767, newly generated each
time this parameter is referenced. The random number generator
can be seeded by assigning a numeric value to RANDOM.

The values of RANDOM form an intentionally-repeatable
pseudo-random sequence; subshells that reference RANDOM will
result in identical pseudo-random values unless the value of
RANDOM is referenced or seeded in the parent shell in between
subshell invocations.

SECONDS <S>
The number of seconds since shell invocation. If this parameter
is assigned a value, then the value returned upon reference will
be the value that was assigned plus the number of seconds since
the assignment.

Unlike other special parameters, the type of the SECONDS
parameter can be changed using the typeset command. The type
may be changed only to one of the floating point types or back
to integer. For example, `typeset -F SECONDS' causes the value
to be reported as a floating point number. The value is
available to microsecond accuracy, although the shell may show
more or fewer digits depending on the use of typeset. See the
documentation for the builtin typeset in zshbuiltins(1) for more
details.

SHLVL <S>
Incremented by one each time a new shell is started.

signals
An array containing the names of the signals. Note that with
the standard zsh numbering of array indices, where the first
element has index 1, the signals are offset by 1 from the signal
number used by the operating system. For example, on typical
Unix-like systems HUP is signal number 1, but is referred to as
$signals[2]. This is because of EXIT at position 1 in the
array, which is used internally by zsh but is not known to the
operating system.

TRY_BLOCK_ERROR <S>
In an always block, indicates whether the preceding list of code
caused an error. The value is 1 to indicate an error, 0
otherwise. It may be reset, clearing the error condition. See
Complex Commands in zshmisc(1)

TRY_BLOCK_INTERRUPT <S>
This variable works in a similar way to TRY_BLOCK_ERROR, but
represents the status of an interrupt from the signal SIGINT,
which typically comes from the keyboard when the user types ^C.
If set to 0, any such interrupt will be reset; otherwise, the
interrupt is propagated after the always block.

Note that it is possible that an interrupt arrives during the
execution of the always block; this interrupt is also
propagated.

TTY The name of the tty associated with the shell, if any.

TTYIDLE <S>
The idle time of the tty associated with the shell in seconds or
-1 if there is no such tty.

UID <S>
The real user ID of the shell process. If you have sufficient
privileges, you may change the user ID of the shell by assigning
to this parameter. Also (assuming sufficient privileges), you
may start a single command under a different user ID by
`(UID=uid; command)'

If this is made local, it is not implicitly set to 0, but may be
explicitly set locally.

USERNAME <S>
The username corresponding to the real user ID of the shell
process. If you have sufficient privileges, you may change the
username (and also the user ID and group ID) of the shell by
assigning to this parameter. Also (assuming sufficient
privileges), you may start a single command under a different
username (and user ID and group ID) by `(USERNAME=username;
command)'

VENDOR The vendor, as determined at compile time.

zsh_eval_context <S> <Z> (ZSH_EVAL_CONTEXT <S>)
An array (colon-separated list) indicating the context of shell
code that is being run. Each time a piece of shell code that is
stored within the shell is executed a string is temporarily
appended to the array to indicate the type of operation that is
being performed. Read in order the array gives an indication of
the stack of operations being performed with the most immediate
context last.

Note that the variable does not give information on syntactic
context such as pipelines or subshells. Use $ZSH_SUBSHELL to
detect subshells.

The context is one of the following:
cmdarg Code specified by the -c option to the command line that
invoked the shell.

cmdsubst
Command substitution using the `...` or $(...) construct.

equalsubst
File substitution using the =(...) construct.

eval Code executed by the eval builtin.

evalautofunc
Code executed with the KSH_AUTOLOAD mechanism in order to
define an autoloaded function.

fc Code from the shell history executed by the -e option to
the fc builtin.

file Lines of code being read directly from a file, for
example by the source builtin.

filecode
Lines of code being read from a .zwc file instead of
directly from the source file.

globqual
Code executed by the e or * glob qualifier.

globsort
Code executed to order files by the o glob qualifier.

insubst
File substitution using the <(...) construct.

loadautofunc
Code read directly from a file to define an autoloaded
function.

outsubst
File substitution using the >(...) construct.

sched Code executed by the sched builtin.

shfunc A shell function.

stty Code passed to stty by the STTY environment variable.
Normally this is passed directly to the system's stty
command, so this value is unlikely to be seen in
practice.

style Code executed as part of a style retrieved by the zstyle
builtin from the zsh/zutil module.

toplevel
The highest execution level of a script or interactive
shell.

trap Code executed as a trap defined by the trap builtin.
Traps defined as functions have the context shfunc. As
traps are asynchronous they may have a different
hierarchy from other code.

zpty Code executed by the zpty builtin from the zsh/zpty
module.

zregexparse-guard
Code executed as a guard by the zregexparse command from
the zsh/zutil module.

zregexparse-action
Code executed as an action by the zregexparse command
from the zsh/zutil module.

ZSH_ARGZERO
If zsh was invoked to run a script, this is the name of the
script. Otherwise, it is the name used to invoke the current
shell. This is the same as the value of $0 when the
POSIX_ARGZERO option is set, but is always available.

ZSH_EXECUTION_STRING
If the shell was started with the option -c, this contains the
argument passed to the option. Otherwise it is not set.

ZSH_NAME
Expands to the basename of the command used to invoke this
instance of zsh.

ZSH_PATCHLEVEL
The output of `git describe --tags --long' for the zsh
repository used to build the shell. This is most useful in
order to keep track of versions of the shell during development
between releases; hence most users should not use it and should
instead rely on $ZSH_VERSION.

zsh_scheduled_events
See the section `The zsh/sched Module' in zshmodules(1).

ZSH_SCRIPT
If zsh was invoked to run a script, this is the name of the
script, otherwise it is unset.

ZSH_SUBSHELL
Readonly integer. Initially zero, incremented each time the
shell forks to create a subshell for executing code. Hence
`(print $ZSH_SUBSHELL)' and `print $(print $ZSH_SUBSHELL)'
output 1, while `( (print $ZSH_SUBSHELL) )' outputs 2.

ZSH_VERSION
The version number of the release of zsh.

PARAMETERS USED BY THE SHELL
The following parameters are used by the shell. Again, `<S>' indicates
that the parameter is special and `<Z>' indicates that the parameter
does not exist when the shell initializes in sh or ksh emulation mode.

In cases where there are two parameters with an upper- and lowercase
form of the same name, such as path and PATH, the lowercase form is an
array and the uppercase form is a scalar with the elements of the array
joined together by colons. These are similar to tied parameters
created via `typeset -T'. The normal use for the colon-separated form
is for exporting to the environment, while the array form is easier to
manipulate within the shell. Note that unsetting either of the pair
will unset the other; they retain their special properties when
recreated, and recreating one of the pair will recreate the other.

ARGV0 If exported, its value is used as the argv[0] of external
commands. Usually used in constructs like `ARGV0=emacs
nethack'.

BAUD The rate in bits per second at which data reaches the terminal.
The line editor will use this value in order to compensate for a
slow terminal by delaying updates to the display until
necessary. If the parameter is unset or the value is zero the
compensation mechanism is turned off. The parameter is not set
by default.

This parameter may be profitably set in some circumstances, e.g.
for slow modems dialing into a communications server, or on a
slow wide area network. It should be set to the baud rate of
the slowest part of the link for best performance.

cdpath <S> <Z> (CDPATH <S>)
An array (colon-separated list) of directories specifying the
search path for the cd command.

COLUMNS <S>
The number of columns for this terminal session. Used for
printing select lists and for the line editor.

CORRECT_IGNORE
If set, is treated as a pattern during spelling correction. Any
potential correction that matches the pattern is ignored. For
example, if the value is `_*' then completion functions (which,
by convention, have names beginning with `_') will never be
offered as spelling corrections. The pattern does not apply to
the correction of file names, as applied by the CORRECT_ALL
option (so with the example just given files beginning with `_'
in the current directory would still be completed).

CORRECT_IGNORE_FILE
If set, is treated as a pattern during spelling correction of
file names. Any file name that matches the pattern is never
offered as a correction. For example, if the value is `.*' then
dot file names will never be offered as spelling corrections.
This is useful with the CORRECT_ALL option.

DIRSTACKSIZE
The maximum size of the directory stack, by default there is no
limit. If the stack gets larger than this, it will be truncated
automatically. This is useful with the AUTO_PUSHD option.

ENV If the ENV environment variable is set when zsh is invoked as sh
or ksh, $ENV is sourced after the profile scripts. The value of
ENV is subjected to parameter expansion, command substitution,
and arithmetic expansion before being interpreted as a pathname.
Note that ENV is not used unless the shell is interactive and
zsh is emulating sh or ksh.

FCEDIT The default editor for the fc builtin. If FCEDIT is not set,
the parameter EDITOR is used; if that is not set either, a
builtin default, usually vi, is used.

fignore <S> <Z> (FIGNORE <S>)
An array (colon separated list) containing the suffixes of files
to be ignored during filename completion. However, if
completion only generates files with suffixes in this list, then
these files are completed anyway.

fpath <S> <Z> (FPATH <S>)
An array (colon separated list) of directories specifying the
search path for function definitions. This path is searched
when a function with the -u attribute is referenced. If an
executable file is found, then it is read and executed in the
current environment.

histchars <S>
Three characters used by the shell's history and lexical
analysis mechanism. The first character signals the start of a
history expansion (default `!'). The second character signals
the start of a quick history substitution (default `^'). The
third character is the comment character (default `#').

The characters must be in the ASCII character set; any attempt
to set histchars to characters with a locale-dependent meaning
will be rejected with an error message.

HISTCHARS <S> <Z>
Same as histchars. (Deprecated.)

HISTFILE
The file to save the history in when an interactive shell exits.
If unset, the history is not saved.

HISTORY_IGNORE
If set, is treated as a pattern at the time history files are
written. Any potential history entry that matches the pattern
is skipped. For example, if the value is `fc *' then commands
that invoke the interactive history editor are never written to
the history file.

Note that HISTORY_IGNORE defines a single pattern: to specify
alternatives use the `(first|second|...)' syntax.

Compare the HIST_NO_STORE option or the zshaddhistory hook,
either of which would prevent such commands from being added to
the interactive history at all. If you wish to use
HISTORY_IGNORE to stop history being added in the first place,
you can define the following hook:

zshaddhistory() {
emulate -L zsh
## uncomment if HISTORY_IGNORE
## should use EXTENDED_GLOB syntax
# setopt extendedglob
[[ $1 != ${~HISTORY_IGNORE} ]]
}

HISTSIZE <S>
The maximum number of events stored in the internal history
list. If you use the HIST_EXPIRE_DUPS_FIRST option, setting
this value larger than the SAVEHIST size will give you the
difference as a cushion for saving duplicated history events.

If this is made local, it is not implicitly set to 0, but may be
explicitly set locally.

HOME <S>
The default argument for the cd command. This is not set
automatically by the shell in sh, ksh or csh emulation, but it
is typically present in the environment anyway, and if it
becomes set it has its usual special behaviour.

IFS <S>
Internal field separators (by default space, tab, newline and
NUL), that are used to separate words which result from command
or parameter expansion and words read by the read builtin. Any
characters from the set space, tab and newline that appear in
the IFS are called IFS white space. One or more IFS white space
characters or one non-IFS white space character together with
any adjacent IFS white space character delimit a field. If an
IFS white space character appears twice consecutively in the
IFS, this character is treated as if it were not an IFS white
space character.

If the parameter is unset, the default is used. Note this has a
different effect from setting the parameter to an empty string.

KEYBOARD_HACK
This variable defines a character to be removed from the end of
the command line before interpreting it (interactive shells
only). It is intended to fix the problem with keys placed
annoyingly close to return and replaces the SUNKEYBOARDHACK
option which did this for backquotes only. Should the chosen
character be one of singlequote, doublequote or backquote, there
must also be an odd number of them on the command line for the
last one to be removed.

For backward compatibility, if the SUNKEYBOARDHACK option is
explicitly set, the value of KEYBOARD_HACK reverts to backquote.
If the option is explicitly unset, this variable is set to
empty.

KEYTIMEOUT
The time the shell waits, in hundredths of seconds, for another
key to be pressed when reading bound multi-character sequences.

LANG <S>
This variable determines the locale category for any category
not specifically selected via a variable starting with `LC_'.

LC_ALL <S>
This variable overrides the value of the `LANG' variable and the
value of any of the other variables starting with `LC_'.

LC_COLLATE <S>
This variable determines the locale category for character
collation information within ranges in glob brackets and for
sorting.

LC_CTYPE <S>
This variable determines the locale category for character
handling functions. If the MULTIBYTE option is in effect this
variable or LANG should contain a value that reflects the
character set in use, even if it is a single-byte character set,
unless only the 7-bit subset (ASCII) is used. For example, if
the character set is ISO-8859-1, a suitable value might be
en_US.iso88591 (certain Linux distributions) or en_US.ISO8859-1
(MacOS).

LC_MESSAGES <S>
This variable determines the language in which messages should
be written. Note that zsh does not use message catalogs.

LC_NUMERIC <S>
This variable affects the decimal point character and thousands
separator character for the formatted input/output functions and
string conversion functions. Note that zsh ignores this setting
when parsing floating point mathematical expressions.

LC_TIME <S>
This variable determines the locale category for date and time
formatting in prompt escape sequences.

LINES <S>
The number of lines for this terminal session. Used for
printing select lists and for the line editor.

LISTMAX
In the line editor, the number of matches to list without asking
first. If the value is negative, the list will be shown if it
spans at most as many lines as given by the absolute value. If
set to zero, the shell asks only if the top of the listing would
scroll off the screen.

MAIL If this parameter is set and mailpath is not set, the shell
looks for mail in the specified file.

MAILCHECK
The interval in seconds between checks for new mail.

mailpath <S> <Z> (MAILPATH <S>)
An array (colon-separated list) of filenames to check for new
mail. Each filename can be followed by a `?' and a message that
will be printed. The message will undergo parameter expansion,
command substitution and arithmetic expansion with the variable
$_ defined as the name of the file that has changed. The
default message is `You have new mail'. If an element is a
directory instead of a file the shell will recursively check
every file in every subdirectory of the element.

manpath <S> <Z> (MANPATH <S> <Z>)
An array (colon-separated list) whose value is not used by the
shell. The manpath array can be useful, however, since setting
it also sets MANPATH, and vice versa.

match
mbegin
mend Arrays set by the shell when the b globbing flag is used in
pattern matches. See the subsection Globbing flags in the
documentation for Filename Generation in zshexpn(1).

MATCH
MBEGIN
MEND Set by the shell when the m globbing flag is used in pattern
matches. See the subsection Globbing flags in the documentation
for Filename Generation in zshexpn(1).

module_path <S> <Z> (MODULE_PATH <S>)
An array (colon-separated list) of directories that zmodload
searches for dynamically loadable modules. This is initialized
to a standard pathname, usually
`/usr/local/lib/zsh/$ZSH_VERSION'. (The `/usr/local/lib' part
varies from installation to installation.) For security reasons,
any value set in the environment when the shell is started will
be ignored.

These parameters only exist if the installation supports dynamic
module loading.

NULLCMD <S>
The command name to assume if a redirection is specified with no
command. Defaults to cat. For sh/ksh behavior, change this to
:. For csh-like behavior, unset this parameter; the shell will
print an error message if null commands are entered.

path <S> <Z> (PATH <S>)
An array (colon-separated list) of directories to search for
commands. When this parameter is set, each directory is scanned
and all files found are put in a hash table.

POSTEDIT <S>
This string is output whenever the line editor exits. It
usually contains termcap strings to reset the terminal.

PROMPT <S> <Z>
PROMPT2 <S> <Z>
PROMPT3 <S> <Z>
PROMPT4 <S> <Z>
Same as PS1, PS2, PS3 and PS4, respectively.

prompt <S> <Z>
Same as PS1.

PROMPT_EOL_MARK
When the PROMPT_CR and PROMPT_SP options are set, the
PROMPT_EOL_MARK parameter can be used to customize how the end
of partial lines are shown. This parameter undergoes prompt
expansion, with the PROMPT_PERCENT option set. If not set, the
default behavior is equivalent to the value `%B%S%#%s%b'.

PS1 <S>
The primary prompt string, printed before a command is read. It
undergoes a special form of expansion before being displayed;
see EXPANSION OF PROMPT SEQUENCES in zshmisc(1). The default is
`%m%# '.

PS2 <S>
The secondary prompt, printed when the shell needs more
information to complete a command. It is expanded in the same
way as PS1. The default is `%_> ', which displays any shell
constructs or quotation marks which are currently being
processed.

PS3 <S>
Selection prompt used within a select loop. It is expanded in
the same way as PS1. The default is `?# '.

PS4 <S>
The execution trace prompt. Default is `+%N:%i> ', which
displays the name of the current shell structure and the line
number within it. In sh or ksh emulation, the default is `* '.

psvar <S> <Z> (PSVAR <S>)
An array (colon-separated list) whose elements can be used in
PROMPT strings. Setting psvar also sets PSVAR, and vice versa.

READNULLCMD <S>
The command name to assume if a single input redirection is
specified with no command. Defaults to more.

REPORTMEMORY
If nonnegative, commands whose maximum resident set size
(roughly speaking, main memory usage) in kilobytes is greater
than this value have timing statistics reported. The format
used to output statistics is the value of the TIMEFMT parameter,
which is the same as for the REPORTTIME variable and the time
builtin; note that by default this does not output memory usage.
Appending " max RSS %M" to the value of TIMEFMT causes it to
output the value that triggered the report. If REPORTTIME is
also in use, at most a single report is printed for both
triggers. This feature requires the getrusage() system call,
commonly supported by modern Unix-like systems.

REPORTTIME
If nonnegative, commands whose combined user and system
execution times (measured in seconds) are greater than this
value have timing statistics printed for them. Output is
suppressed for commands executed within the line editor,
including completion; commands explicitly marked with the time
keyword still cause the summary to be printed in this case.

REPLY This parameter is reserved by convention to pass string values
between shell scripts and shell builtins in situations where a
function call or redirection are impossible or undesirable. The
read builtin and the select complex command may set REPLY, and
filename generation both sets and examines its value when
evaluating certain expressions. Some modules also employ REPLY
for similar purposes.

reply As REPLY, but for array values rather than strings.

RPROMPT <S>
RPS1 <S>
This prompt is displayed on the right-hand side of the screen
when the primary prompt is being displayed on the left. This
does not work if the SINGLE_LINE_ZLE option is set. It is
expanded in the same way as PS1.

RPROMPT2 <S>
RPS2 <S>
This prompt is displayed on the right-hand side of the screen
when the secondary prompt is being displayed on the left. This
does not work if the SINGLE_LINE_ZLE option is set. It is
expanded in the same way as PS2.

SAVEHIST
The maximum number of history events to save in the history
file.

If this is made local, it is not implicitly set to 0, but may be
explicitly set locally.

SPROMPT <S>
The prompt used for spelling correction. The sequence `%R'
expands to the string which presumably needs spelling
correction, and `%r' expands to the proposed correction. All
other prompt escapes are also allowed.

The actions available at the prompt are [nyae]:
n (`no') (default)
Discard the correction and run the command.
y (`yes')
Make the correction and run the command.
a (`abort')
Discard the entire command line without running it.
e (`edit')
Resume editing the command line.

STTY If this parameter is set in a command's environment, the shell
runs the stty command with the value of this parameter as
arguments in order to set up the terminal before executing the
command. The modes apply only to the command, and are reset when
it finishes or is suspended. If the command is suspended and
continued later with the fg or wait builtins it will see the
modes specified by STTY, as if it were not suspended. This
(intentionally) does not apply if the command is continued via
`kill -CONT'. STTY is ignored if the command is run in the
background, or if it is in the environment of the shell but not
explicitly assigned to in the input line. This avoids running
stty at every external command by accidentally exporting it.
Also note that STTY should not be used for window size
specifications; these will not be local to the command.

If the parameter is set and empty, all of the above applies
except that stty is not run. This can be useful as a way to
freeze the tty around a single command, blocking its changes to
tty settings, similar to the ttyctl builtin.

TERM <S>
The type of terminal in use. This is used when looking up
termcap sequences. An assignment to TERM causes zsh to
re-initialize the terminal, even if the value does not change
(e.g., `TERM=$TERM'). It is necessary to make such an
assignment upon any change to the terminal definition database
or terminal type in order for the new settings to take effect.

TERMINFO <S>
A reference to your terminfo database, used by the `terminfo'
library when the system has it; see terminfo(5). If set, this
causes the shell to reinitialise the terminal, making the
workaround `TERM=$TERM' unnecessary.

TERMINFO_DIRS <S>
A colon-seprarated list of terminfo databases, used by the
`terminfo' library when the system has it; see terminfo(5). This
variable is only used by certain terminal libraries, in
particular ncurses; see terminfo(5) to check support on your
system. If set, this causes the shell to reinitialise the
terminal, making the workaround `TERM=$TERM' unnecessary. Note
that unlike other colon-separated arrays this is not tied to a
zsh array.

TIMEFMT
The format of process time reports with the time keyword. The
default is `%J %U user %S system %P cpu %*E total'. Recognizes
the following escape sequences, although not all may be
available on all systems, and some that are available may not be
useful:

%% A `%'.
%U CPU seconds spent in user mode.
%S CPU seconds spent in kernel mode.
%E Elapsed time in seconds.
%P The CPU percentage, computed as 100*(%U+%S)/%E.
%W Number of times the process was swapped.
%X The average amount in (shared) text space used in
kilobytes.
%D The average amount in (unshared) data/stack space used in
kilobytes.
%K The total space used (%X+%D) in kilobytes.
%M The maximum memory the process had in use at any time in
kilobytes.
%F The number of major page faults (page needed to be
brought from disk).
%R The number of minor page faults.
%I The number of input operations.
%O The number of output operations.
%r The number of socket messages received.
%s The number of socket messages sent.
%k The number of signals received.
%w Number of voluntary context switches (waits).
%c Number of involuntary context switches.
%J The name of this job.

A star may be inserted between the percent sign and flags
printing time (e.g., `%*E'); this causes the time to be printed
in `hh:mm:ss.ttt' format (hours and minutes are only printed if
they are not zero). Alternatively, `m' or `u' may be used
(e.g., `%mE') to produce time output in milliseconds or
microseconds, respectively.

TMOUT If this parameter is nonzero, the shell will receive an ALRM
signal if a command is not entered within the specified number
of seconds after issuing a prompt. If there is a trap on
SIGALRM, it will be executed and a new alarm is scheduled using
the value of the TMOUT parameter after executing the trap. If
no trap is set, and the idle time of the terminal is not less
than the value of the TMOUT parameter, zsh terminates.
Otherwise a new alarm is scheduled to TMOUT seconds after the
last keypress.

TMPPREFIX
A pathname prefix which the shell will use for all temporary
files. Note that this should include an initial part for the
file name as well as any directory names. The default is
`/tmp/zsh'.

TMPSUFFIX
A filename suffix which the shell will use for temporary files
created by process substitutions (e.g., `=(list)'). Note that
the value should include a leading dot `.' if intended to be
interpreted as a file extension. The default is not to append
any suffix, thus this parameter should be assigned only when
needed and then unset again.

WORDCHARS <S>
A list of non-alphanumeric characters considered part of a word
by the line editor.

ZBEEP If set, this gives a string of characters, which can use all the
same codes as the bindkey command as described in the zsh/zle
module entry in zshmodules(1), that will be output to the
terminal instead of beeping. This may have a visible instead of
an audible effect; for example, the string `\e[?5h\e[?5l' on a
vt100 or xterm will have the effect of flashing reverse video on
and off (if you usually use reverse video, you should use the
string `\e[?5l\e[?5h' instead). This takes precedence over the
NOBEEP option.

ZDOTDIR
The directory to search for shell startup files (.zshrc, etc),
if not $HOME.

zle_bracketed_paste
Many terminal emulators have a feature that allows applications
to identify when text is pasted into the terminal rather than
being typed normally. For ZLE, this means that special
characters such as tabs and newlines can be inserted instead of
invoking editor commands. Furthermore, pasted text forms a
single undo event and if the region is active, pasted text will
replace the region.

This two-element array contains the terminal escape sequences
for enabling and disabling the feature. These escape sequences
are used to enable bracketed paste when ZLE is active and
disable it at other times. Unsetting the parameter has the
effect of ensuring that bracketed paste remains disabled.

zle_highlight
An array describing contexts in which ZLE should highlight the
input text. See Character Highlighting in zshzle(1).

ZLE_LINE_ABORTED
This parameter is set by the line editor when an error occurs.
It contains the line that was being edited at the point of the
error. `print -zr -- $ZLE_LINE_ABORTED' can be used to recover
the line. Only the most recent line of this kind is remembered.

ZLE_REMOVE_SUFFIX_CHARS
ZLE_SPACE_SUFFIX_CHARS
These parameters are used by the line editor. In certain
circumstances suffixes (typically space or slash) added by the
completion system will be removed automatically, either because
the next editing command was not an insertable character, or
because the character was marked as requiring the suffix to be
removed.

These variables can contain the sets of characters that will
cause the suffix to be removed. If ZLE_REMOVE_SUFFIX_CHARS is
set, those characters will cause the suffix to be removed; if
ZLE_SPACE_SUFFIX_CHARS is set, those characters will cause the
suffix to be removed and replaced by a space.

If ZLE_REMOVE_SUFFIX_CHARS is not set, the default behaviour is
equivalent to:

ZLE_REMOVE_SUFFIX_CHARS=$' \t\n;&|'

If ZLE_REMOVE_SUFFIX_CHARS is set but is empty, no characters
have this behaviour. ZLE_SPACE_SUFFIX_CHARS takes precedence,
so that the following:

ZLE_SPACE_SUFFIX_CHARS=$'&|'

causes the characters `&' and `|' to remove the suffix but to
replace it with a space.

To illustrate the difference, suppose that the option
AUTO_REMOVE_SLASH is in effect and the directory DIR has just
been completed, with an appended /, following which the user
types `&'. The default result is `DIR&'. With
ZLE_REMOVE_SUFFIX_CHARS set but without including `&' the result
is `DIR/&'. With ZLE_SPACE_SUFFIX_CHARS set to include `&' the
result is `DIR &'.

Note that certain completions may provide their own suffix
removal or replacement behaviour which overrides the values
described here. See the completion system documentation in
zshcompsys(1).

ZLE_RPROMPT_INDENT <S>
If set, used to give the indentation between the right hand side
of the right prompt in the line editor as given by RPS1 or
RPROMPT and the right hand side of the screen. If not set, the
value 1 is used.

Typically this will be used to set the value to 0 so that the
prompt appears flush with the right hand side of the screen.
This is not the default as many terminals do not handle this
correctly, in particular when the prompt appears at the extreme
bottom right of the screen. Recent virtual terminals are more
likely to handle this case correctly. Some experimentation is
necessary.

NAME
zshoptions - zsh options

SPECIFYING OPTIONS
Options are primarily referred to by name. These names are case
insensitive and underscores are ignored. For example, `allexport' is
equivalent to `A__lleXP_ort'.

The sense of an option name may be inverted by preceding it with `no',
so `setopt No_Beep' is equivalent to `unsetopt beep'. This inversion
can only be done once, so `nonobeep' is not a synonym for `beep'.
Similarly, `tify' is not a synonym for `nonotify' (the inversion of
`notify').

Some options also have one or more single letter names. There are two
sets of single letter options: one used by default, and another used to
emulate sh/ksh (used when the SH_OPTION_LETTERS option is set). The
single letter options can be used on the shell command line, or with
the set, setopt and unsetopt builtins, as normal Unix options preceded
by `-'.

The sense of the single letter options may be inverted by using `*'
instead of `-'. Some of the single letter option names refer to an
option being off, in which case the inversion of that name refers to
the option being on. For example, `+n' is the short name of `exec',
and `-n' is the short name of its inversion, `noexec'.

In strings of single letter options supplied to the shell at startup,
trailing whitespace will be ignored; for example the string `-f '
will be treated just as `-f', but the string `-f i' is an error. This
is because many systems which implement the `#!' mechanism for calling
scripts do not strip trailing whitespace.

It is possible for options to be set within a function scope. See the
description of the option LOCAL_OPTIONS below.

DESCRIPTION OF OPTIONS
In the following list, options set by default in all emulations are
marked <D>; those set by default only in csh, ksh, sh, or zsh
emulations are marked <C>, <K>, <S>, <Z> as appropriate. When listing
options (by `setopt', `unsetopt', `set -o' or `set +o'), those turned
on by default appear in the list prefixed with `no'. Hence (unless
KSH_OPTION_PRINT is set), `setopt' shows all options whose settings are
changed from the default.

Changing Directories
AUTO_CD (-J)
If a command is issued that can't be executed as a normal
command, and the command is the name of a directory, perform the
cd command to that directory. This option is only applicable if
the option SHIN_STDIN is set, i.e. if commands are being read
from standard input. The option is designed for interactive
use; it is recommended that cd be used explicitly in scripts to
avoid ambiguity.

AUTO_PUSHD (-N)
Make cd push the old directory onto the directory stack.

CDABLE_VARS (-T)
If the argument to a cd command (or an implied cd with the
AUTO_CD option set) is not a directory, and does not begin with
a slash, try to expand the expression as if it were preceded by
a `~' (see the section `Filename Expansion').

CD_SILENT
Never print the working directory after a cd (whether explicit
or implied with the AUTO_CD option set). cd normally prints the
working directory when the argument given to it was -, a stack
entry, or the name of a directory found under CDPATH. Note that
this is distinct from pushd's stack-printing behaviour, which is
controlled by PUSHD_SILENT. This option overrides the
printing-related effects of POSIX_CD.

CHASE_DOTS
When changing to a directory containing a path segment `..'
which would otherwise be treated as canceling the previous
segment in the path (in other words, `foo/..' would be removed
from the path, or if `..' is the first part of the path, the
last part of the current working directory would be removed),
instead resolve the path to the physical directory. This option
is overridden by CHASE_LINKS.

For example, suppose /foo/bar is a link to the directory
/alt/rod. Without this option set, `cd /foo/bar/..' changes to
/foo; with it set, it changes to /alt. The same applies if the
current directory is /foo/bar and `cd ..' is used. Note that
all other symbolic links in the path will also be resolved.

CHASE_LINKS (-w)
Resolve symbolic links to their true values when changing
directory. This also has the effect of CHASE_DOTS, i.e. a `..'
path segment will be treated as referring to the physical
parent, even if the preceding path segment is a symbolic link.

POSIX_CD <K> <S>
Modifies the behaviour of cd, chdir and pushd commands to make
them more compatible with the POSIX standard. The behaviour with
the option unset is described in the documentation for the cd
builtin in zshbuiltins(1). If the option is set, the shell does
not test for directories beneath the local directory (`.') until
after all directories in cdpath have been tested, and the cd and
chdir commands do not recognise arguments of the form `{*|-}n'
as directory stack entries.

Also, if the option is set, the conditions under which the shell
prints the new directory after changing to it are modified. It
is no longer restricted to interactive shells (although printing
of the directory stack with pushd is still limited to
interactive shells); and any use of a component of CDPATH,
including a `.' but excluding an empty component that is
otherwise treated as `.', causes the directory to be printed.

PUSHD_IGNORE_DUPS
Don't push multiple copies of the same directory onto the
directory stack.

PUSHD_MINUS
Exchanges the meanings of `*' and `-' when used with a number to
specify a directory in the stack.

PUSHD_SILENT (-E)
Do not print the directory stack after pushd or popd.

PUSHD_TO_HOME (-D)
Have pushd with no arguments act like `pushd $HOME'.

Completion
ALWAYS_LAST_PROMPT <D>
If unset, key functions that list completions try to return to
the last prompt if given a numeric argument. If set these
functions try to return to the last prompt if given no numeric
argument.

ALWAYS_TO_END
If a completion is performed with the cursor within a word, and
a full completion is inserted, the cursor is moved to the end of
the word. That is, the cursor is moved to the end of the word
if either a single match is inserted or menu completion is
performed.

AUTO_LIST (-9) <D>
Automatically list choices on an ambiguous completion.

AUTO_MENU <D>
Automatically use menu completion after the second consecutive
request for completion, for example by pressing the tab key
repeatedly. This option is overridden by MENU_COMPLETE.

AUTO_NAME_DIRS
Any parameter that is set to the absolute name of a directory
immediately becomes a name for that directory, that will be used
by the `%~' and related prompt sequences, and will be available
when completion is performed on a word starting with `~'.
(Otherwise, the parameter must be used in the form `~param'
first.)

AUTO_PARAM_KEYS <D>
If a parameter name was completed and a following character
(normally a space) automatically inserted, and the next
character typed is one of those that have to come directly after
the name (like `}', `:', etc.), the automatically added
character is deleted, so that the character typed comes
immediately after the parameter name. Completion in a brace
expansion is affected similarly: the added character is a `,',
which will be removed if `}' is typed next.

AUTO_PARAM_SLASH <D>
If a parameter is completed whose content is the name of a
directory, then add a trailing slash instead of a space.

AUTO_REMOVE_SLASH <D>
When the last character resulting from a completion is a slash
and the next character typed is a word delimiter, a slash, or a
character that ends a command (such as a semicolon or an
ampersand), remove the slash.

BASH_AUTO_LIST
On an ambiguous completion, automatically list choices when the
completion function is called twice in succession. This takes
precedence over AUTO_LIST. The setting of LIST_AMBIGUOUS is
respected. If AUTO_MENU is set, the menu behaviour will then
start with the third press. Note that this will not work with
MENU_COMPLETE, since repeated completion calls immediately cycle
through the list in that case.

COMPLETE_ALIASES
Prevents aliases on the command line from being internally
substituted before completion is attempted. The effect is to
make the alias a distinct command for completion purposes.

COMPLETE_IN_WORD
If unset, the cursor is set to the end of the word if completion
is started. Otherwise it stays there and completion is done from
both ends.

GLOB_COMPLETE
When the current word has a glob pattern, do not insert all the
words resulting from the expansion but generate matches as for
completion and cycle through them like MENU_COMPLETE. The
matches are generated as if a `*' was added to the end of the
word, or inserted at the cursor when COMPLETE_IN_WORD is set.
This actually uses pattern matching, not globbing, so it works
not only for files but for any completion, such as options, user
names, etc.

Note that when the pattern matcher is used, matching control
(for example, case-insensitive or anchored matching) cannot be
used. This limitation only applies when the current word
contains a pattern; simply turning on the GLOB_COMPLETE option
does not have this effect.

HASH_LIST_ALL <D>
Whenever a command completion or spelling correction is
attempted, make sure the entire command path is hashed first.
This makes the first completion slower but avoids false reports
of spelling errors.

LIST_AMBIGUOUS <D>
This option works when AUTO_LIST or BASH_AUTO_LIST is also set.
If there is an unambiguous prefix to insert on the command line,
that is done without a completion list being displayed; in other
words, auto-listing behaviour only takes place when nothing
would be inserted. In the case of BASH_AUTO_LIST, this means
that the list will be delayed to the third call of the function.

LIST_BEEP <D>
Beep on an ambiguous completion. More accurately, this forces
the completion widgets to return status 1 on an ambiguous
completion, which causes the shell to beep if the option BEEP is
also set; this may be modified if completion is called from a
user-defined widget.

LIST_PACKED
Try to make the completion list smaller (occupying less lines)
by printing the matches in columns with different widths.

LIST_ROWS_FIRST
Lay out the matches in completion lists sorted horizontally,
that is, the second match is to the right of the first one, not
under it as usual.

LIST_TYPES (-X) <D>
When listing files that are possible completions, show the type
of each file with a trailing identifying mark.

MENU_COMPLETE (-Y)
On an ambiguous completion, instead of listing possibilities or
beeping, insert the first match immediately. Then when
completion is requested again, remove the first match and insert
the second match, etc. When there are no more matches, go back
to the first one again. reverse-menu-complete may be used to
loop through the list in the other direction. This option
overrides AUTO_MENU.

REC_EXACT (-S)
If the string on the command line exactly matches one of the
possible completions, it is accepted, even if there is another
completion (i.e. that string with something else added) that
also matches.

Expansion and Globbing
BAD_PATTERN (+2) <C> <Z>
If a pattern for filename generation is badly formed, print an
error message. (If this option is unset, the pattern will be
left unchanged.)

BARE_GLOB_QUAL <Z>
In a glob pattern, treat a trailing set of parentheses as a
qualifier list, if it contains no `|', `(' or (if special) `~'
characters. See the section `Filename Generation'.

BRACE_CCL
Expand expressions in braces which would not otherwise undergo
brace expansion to a lexically ordered list of all the
characters. See the section `Brace Expansion'.

CASE_GLOB <D>
Make globbing (filename generation) sensitive to case. Note
that other uses of patterns are always sensitive to case. If
the option is unset, the presence of any character which is
special to filename generation will cause case-insensitive
matching. For example, cvs(/) can match the directory CVS owing
to the presence of the globbing flag (unless the option
BARE_GLOB_QUAL is unset).

CASE_MATCH <D>
Make regular expressions using the zsh/regex module (including
matches with =~) sensitive to case.

CASE_PATHS
If CASE_PATHS is not set (the default), CASE_GLOB affects the
interpretation of every path component, whenever a special
character appears in any component. When CASE_PATHS is set,
file path components that do not contain special filename
generation characters are always sensitive to case, thus
restricting NO_CASE_GLOB to components that contain globbing
characters.

Note that if the filesystem itself is not sensitive to case,
then CASE_PATHS has no effect.

CSH_NULL_GLOB <C>
If a pattern for filename generation has no matches, delete the
pattern from the argument list; do not report an error unless
all the patterns in a command have no matches. Overrides
NOMATCH.

EQUALS <Z>
Perform = filename expansion. (See the section `Filename
Expansion'.)

EXTENDED_GLOB
Treat the `#', `~' and `^' characters as part of patterns for
filename generation, etc. (An initial unquoted `~' always
produces named directory expansion.)

FORCE_FLOAT
Constants in arithmetic evaluation will be treated as floating
point even without the use of a decimal point; the values of
integer variables will be converted to floating point when used
in arithmetic expressions. Integers in any base will be
converted.

GLOB (+F, ksh: +f) <D>
Perform filename generation (globbing). (See the section
`Filename Generation'.)

GLOB_ASSIGN <C>
If this option is set, filename generation (globbing) is
performed on the right hand side of scalar parameter assignments
of the form `name=pattern (e.g. `foo=*'). If the result has
more than one word the parameter will become an array with those
words as arguments. This option is provided for backwards
compatibility only: globbing is always performed on the right
hand side of array assignments of the form `name=(value)' (e.g.
`foo=(*)') and this form is recommended for clarity; with this
option set, it is not possible to predict whether the result
will be an array or a scalar.

GLOB_DOTS (-4)
Do not require a leading `.' in a filename to be matched
explicitly.

GLOB_STAR_SHORT
When this option is set and the default zsh-style globbing is in
effect, the pattern `**/*' can be abbreviated to `**' and the
pattern `***/*' can be abbreviated to ***. Hence `**.c' finds a
file ending in .c in any subdirectory, and `***.c' does the same
while also following symbolic links. A / immediately after the
`**' or `***' forces the pattern to be treated as the
unabbreviated form.

GLOB_SUBST <C> <K> <S>
Treat any characters resulting from parameter expansion as being
eligible for filename expansion and filename generation, and any
characters resulting from command substitution as being eligible
for filename generation. Braces (and commas in between) do not
become eligible for expansion.

HIST_SUBST_PATTERN
Substitutions using the :s and :& history modifiers are
performed with pattern matching instead of string matching.
This occurs wherever history modifiers are valid, including glob
qualifiers and parameters. See the section `Modifiers' in
zshexpn(1).

IGNORE_BRACES (-I) <S>
Do not perform brace expansion. For historical reasons this
also includes the effect of the IGNORE_CLOSE_BRACES option.

IGNORE_CLOSE_BRACES
When neither this option nor IGNORE_BRACES is set, a sole close
brace character `}' is syntactically significant at any point on
a command line. This has the effect that no semicolon or
newline is necessary before the brace terminating a function or
current shell construct. When either option is set, a closing
brace is syntactically significant only in command position.
Unlike IGNORE_BRACES, this option does not disable brace
expansion.

For example, with both options unset a function may be defined
in the following fashion:

args() { echo $# }

while if either option is set, this does not work and something
equivalent to the following is required:

args() { echo $#; }

KSH_GLOB <K>
In pattern matching, the interpretation of parentheses is
affected by a preceding `@', `*', `*', `?' or `!'. See the
section `Filename Generation'.

MAGIC_EQUAL_SUBST
All unquoted arguments of the form `anything=expression'
appearing after the command name have filename expansion (that
is, where expression has a leading `~' or `=') performed on
expression as if it were a parameter assignment. The argument
is not otherwise treated specially; it is passed to the command
as a single argument, and not used as an actual parameter
assignment. For example, in echo foo=~/bar:~/rod, both
occurrences of ~ would be replaced. Note that this happens
anyway with typeset and similar statements.

This option respects the setting of the KSH_TYPESET option. In
other words, if both options are in effect, arguments looking
like assignments will not undergo word splitting.

MARK_DIRS (-8, ksh: -X)
Append a trailing `/' to all directory names resulting from
filename generation (globbing).

MULTIBYTE <D>
Respect multibyte characters when found in strings. When this
option is set, strings are examined using the system library to
determine how many bytes form a character, depending on the
current locale. This affects the way characters are counted in
pattern matching, parameter values and various delimiters.

The option is on by default if the shell was compiled with
MULTIBYTE_SUPPORT; otherwise it is off by default and has no
effect if turned on.

If the option is off a single byte is always treated as a single
character. This setting is designed purely for examining
strings known to contain raw bytes or other values that may not
be characters in the current locale. It is not necessary to
unset the option merely because the character set for the
current locale does not contain multibyte characters.

The option does not affect the shell's editor, which always
uses the locale to determine multibyte characters. This is
because the character set displayed by the terminal emulator is
independent of shell settings.

NOMATCH (+3) <C> <Z>
If a pattern for filename generation has no matches, print an
error, instead of leaving it unchanged in the argument list.
This also applies to file expansion of an initial `~' or `='.

NULL_GLOB (-G)
If a pattern for filename generation has no matches, delete the
pattern from the argument list instead of reporting an error.
Overrides NOMATCH.

NUMERIC_GLOB_SORT
If numeric filenames are matched by a filename generation
pattern, sort the filenames numerically rather than
lexicographically.

RC_EXPAND_PARAM (-P)
Array expansions of the form `foo${xx}bar', where the parameter
xx is set to (a b c), are substituted with `fooabar foobbar
foocbar' instead of the default `fooa b cbar'. Note that an
empty array will therefore cause all arguments to be removed.

REMATCH_PCRE
If set, regular expression matching with the =~ operator will
use Perl-Compatible Regular Expressions from the PCRE library.
(The zsh/pcre module must be available.) If not set, regular
expressions will use the extended regexp syntax provided by the
system libraries.

SH_GLOB <K> <S>
Disables the special meaning of `(', `|', `)' and '<' for
globbing the result of parameter and command substitutions, and
in some other places where the shell accepts patterns. If
SH_GLOB is set but KSH_GLOB is not, the shell allows the
interpretation of subshell expressions enclosed in parentheses
in some cases where there is no space before the opening
parenthesis, e.g. !(true) is interpreted as if there were a
space after the !. This option is set by default if zsh is
invoked as sh or ksh.

UNSET (+u, ksh: +u) <K> <S> <Z>
Treat unset parameters as if they were empty when substituting,
and as if they were zero when reading their values in arithmetic
expansion and arithmetic commands. Otherwise they are treated
as an error.

WARN_CREATE_GLOBAL
Print a warning message when a global parameter is created in a
function by an assignment or in math context. This often
indicates that a parameter has not been declared local when it
should have been. Parameters explicitly declared global from
within a function using typeset -g do not cause a warning. Note
that there is no warning when a local parameter is assigned to
in a nested function, which may also indicate an error.

WARN_NESTED_VAR
Print a warning message when an existing parameter from an
enclosing function scope, or global, is set in a function by an
assignment or in math context. Assignment to shell special
parameters does not cause a warning. This is the companion to
WARN_CREATE_GLOBAL as in this case the warning is only printed
when a parameter is not created. Where possible, use of typeset
-g to set the parameter suppresses the error, but note that this
needs to be used every time the parameter is set. To restrict
the effect of this option to a single function scope, use
`functions -W'.

For example, the following code produces a warning for the
assignment inside the function nested as that overrides the
value within toplevel

toplevel() {
local foo="in fn"
nested
}
nested() {
foo="in nested"
}
setopt warn_nested_var
toplevel

History
APPEND_HISTORY <D>
If this is set, zsh sessions will append their history list to
the history file, rather than replace it. Thus, multiple
parallel zsh sessions will all have the new entries from their
history lists added to the history file, in the order that they
exit. The file will still be periodically re-written to trim it
when the number of lines grows 20% beyond the value specified by
$SAVEHIST (see also the HIST_SAVE_BY_COPY option).

BANG_HIST (+K) <C> <Z>
Perform textual history expansion, csh-style, treating the
character `!' specially.

EXTENDED_HISTORY <C>
Save each command's beginning timestamp (in seconds since the
epoch) and the duration (in seconds) to the history file. The
format of this prefixed data is:

`: <beginning time>:<elapsed seconds>;<command>'.

HIST_ALLOW_CLOBBER
Add `|' to output redirections in the history. This allows
history references to clobber files even when CLOBBER is unset.

HIST_BEEP <D>
Beep in ZLE when a widget attempts to access a history entry
which isn't there.

HIST_EXPIRE_DUPS_FIRST
If the internal history needs to be trimmed to add the current
command line, setting this option will cause the oldest history
event that has a duplicate to be lost before losing a unique
event from the list. You should be sure to set the value of
HISTSIZE to a larger number than SAVEHIST in order to give you
some room for the duplicated events, otherwise this option will
behave just like HIST_IGNORE_ALL_DUPS once the history fills up
with unique events.

HIST_FCNTL_LOCK
When writing out the history file, by default zsh uses ad-hoc
file locking to avoid known problems with locking on some
operating systems. With this option locking is done by means of
the system's fcntl call, where this method is available. On
recent operating systems this may provide better performance, in
particular avoiding history corruption when files are stored on
NFS.

HIST_FIND_NO_DUPS
When searching for history entries in the line editor, do not
display duplicates of a line previously found, even if the
duplicates are not contiguous.

HIST_IGNORE_ALL_DUPS
If a new command line being added to the history list duplicates
an older one, the older command is removed from the list (even
if it is not the previous event).

HIST_IGNORE_DUPS (-h)
Do not enter command lines into the history list if they are
duplicates of the previous event.

HIST_IGNORE_SPACE (-g)
Remove command lines from the history list when the first
character on the line is a space, or when one of the expanded
aliases contains a leading space. Only normal aliases (not
global or suffix aliases) have this behaviour. Note that the
command lingers in the internal history until the next command
is entered before it vanishes, allowing you to briefly reuse or
edit the line. If you want to make it vanish right away without
entering another command, type a space and press return.

HIST_LEX_WORDS
By default, shell history that is read in from files is split
into words on all white space. This means that arguments with
quoted whitespace are not correctly handled, with the
consequence that references to words in history lines that have
been read from a file may be inaccurate. When this option is
set, words read in from a history file are divided up in a
similar fashion to normal shell command line handling. Although
this produces more accurately delimited words, if the size of
the history file is large this can be slow. Trial and error is
necessary to decide.

HIST_NO_FUNCTIONS
Remove function definitions from the history list. Note that
the function lingers in the internal history until the next
command is entered before it vanishes, allowing you to briefly
reuse or edit the definition.

HIST_NO_STORE
Remove the history (fc -l) command from the history list when
invoked. Note that the command lingers in the internal history
until the next command is entered before it vanishes, allowing
you to briefly reuse or edit the line.

HIST_REDUCE_BLANKS
Remove superfluous blanks from each command line being added to
the history list.

HIST_SAVE_BY_COPY <D>
When the history file is re-written, we normally write out a
copy of the file named $HISTFILE.new and then rename it over the
old one. However, if this option is unset, we instead truncate
the old history file and write out the new version in-place. If
one of the history-appending options is enabled, this option
only has an effect when the enlarged history file needs to be
re-written to trim it down to size. Disable this only if you
have special needs, as doing so makes it possible to lose
history entries if zsh gets interrupted during the save.

When writing out a copy of the history file, zsh preserves the
old file's permissions and group information, but will refuse to
write out a new file if it would change the history file's
owner.

HIST_SAVE_NO_DUPS
When writing out the history file, older commands that duplicate
newer ones are omitted.

HIST_VERIFY
Whenever the user enters a line with history expansion, don't
execute the line directly; instead, perform history expansion
and reload the line into the editing buffer.

INC_APPEND_HISTORY
This option works like APPEND_HISTORY except that new history
lines are added to the $HISTFILE incrementally (as soon as they
are entered), rather than waiting until the shell exits. The
file will still be periodically re-written to trim it when the
number of lines grows 20% beyond the value specified by
$SAVEHIST (see also the HIST_SAVE_BY_COPY option).

INC_APPEND_HISTORY_TIME
This option is a variant of INC_APPEND_HISTORY in which, where
possible, the history entry is written out to the file after the
command is finished, so that the time taken by the command is
recorded correctly in the history file in EXTENDED_HISTORY
format. This means that the history entry will not be available
immediately from other instances of the shell that are using the
same history file.

This option is only useful if INC_APPEND_HISTORY and
SHARE_HISTORY are turned off. The three options should be
considered mutually exclusive.

SHARE_HISTORY <K>

This option both imports new commands from the history file, and
also causes your typed commands to be appended to the history
file (the latter is like specifying INC_APPEND_HISTORY, which
should be turned off if this option is in effect). The history
lines are also output with timestamps ala EXTENDED_HISTORY
(which makes it easier to find the spot where we left off
reading the file after it gets re-written).

By default, history movement commands visit the imported lines
as well as the local lines, but you can toggle this on and off
with the set-local-history zle binding. It is also possible to
create a zle widget that will make some commands ignore imported
commands, and some include them.

If you find that you want more control over when commands get
imported, you may wish to turn SHARE_HISTORY off,
INC_APPEND_HISTORY or INC_APPEND_HISTORY_TIME (see above) on,
and then manually import commands whenever you need them using
`fc -RI'.

Initialisation
ALL_EXPORT (-a, ksh: -a)
All parameters subsequently defined are automatically exported.

GLOBAL_EXPORT <Z>
If this option is set, passing the -x flag to the builtins
declare, float, integer, readonly and typeset (but not local)
will also set the -g flag; hence parameters exported to the
environment will not be made local to the enclosing function,
unless they were already or the flag +g is given explicitly. If
the option is unset, exported parameters will be made local in
just the same way as any other parameter.

This option is set by default for backward compatibility; it is
not recommended that its behaviour be relied upon. Note that
the builtin export always sets both the -x and -g flags, and
hence its effect extends beyond the scope of the enclosing
function; this is the most portable way to achieve this
behaviour.

GLOBAL_RCS (+d) <D>
If this option is unset, the startup files /etc/zprofile,
/etc/zshrc, /etc/zlogin and /etc/zlogout will not be run. It
can be disabled and re-enabled at any time, including inside
local startup files (.zshrc, etc.).

RCS (+f) <D>
After /etc/zshenv is sourced on startup, source the .zshenv,
/etc/zprofile, .zprofile, /etc/zshrc, .zshrc, /etc/zlogin,
.zlogin, and .zlogout files, as described in the section
`Files'. If this option is unset, the /etc/zshenv file is still
sourced, but any of the others will not be; it can be set at any
time to prevent the remaining startup files after the currently
executing one from being sourced.

Input/Output
ALIASES <D>
Expand aliases.

CLOBBER (+C, ksh: +C) <D>
Allows `>' redirection to truncate existing files. Otherwise
`>!' or `>|' must be used to truncate a file.

If the option is not set, and the option APPEND_CREATE is also
not set, `>>!' or `>>|' must be used to create a file. If
either option is set, `>>' may be used.

CLOBBER_EMPTY
This option is only used if the option CLOBBER is not set: note
that it is set by default.

If this option is set, then regular files of zero length may be
ovewritten (`clobbered'). Note that it is possible another
process has written to the file between this test and use of the
file by the current process. This option should therefore not
be used in cases where files to be clobbered may be written to
asynchronously.

CORRECT (-0)
Try to correct the spelling of commands. Note that, when the
HASH_LIST_ALL option is not set or when some directories in the
path are not readable, this may falsely report spelling errors
the first time some commands are used.

The shell variable CORRECT_IGNORE may be set to a pattern to
match words that will never be offered as corrections.

CORRECT_ALL (-O)
Try to correct the spelling of all arguments in a line.

The shell variable CORRECT_IGNORE_FILE may be set to a pattern
to match file names that will never be offered as corrections.

DVORAK Use the Dvorak keyboard instead of the standard qwerty keyboard
as a basis for examining spelling mistakes for the CORRECT and
CORRECT_ALL options and the spell-word editor command.

FLOW_CONTROL <D>
If this option is unset, output flow control via start/stop
characters (usually assigned to ^S/^Q) is disabled in the
shell's editor.

IGNORE_EOF (-7)
Do not exit on end-of-file. Require the use of exit or logout
instead. However, ten consecutive EOFs will cause the shell to
exit anyway, to avoid the shell hanging if its tty goes away.

Also, if this option is set and the Zsh Line Editor is used,
widgets implemented by shell functions can be bound to EOF
(normally Control-D) without printing the normal warning
message. This works only for normal widgets, not for completion
widgets.

INTERACTIVE_COMMENTS (-k) <K> <S>
Allow comments even in interactive shells.

HASH_CMDS <D>
Note the location of each command the first time it is executed.
Subsequent invocations of the same command will use the saved
location, avoiding a path search. If this option is unset, no
path hashing is done at all. However, when CORRECT is set,
commands whose names do not appear in the functions or aliases
hash tables are hashed in order to avoid reporting them as
spelling errors.

HASH_DIRS <D>
Whenever a command name is hashed, hash the directory containing
it, as well as all directories that occur earlier in the path.
Has no effect if neither HASH_CMDS nor CORRECT is set.

HASH_EXECUTABLES_ONLY
When hashing commands because of HASH_CMDS, check that the file
to be hashed is actually an executable. This option is unset by
default as if the path contains a large number of commands, or
consists of many remote files, the additional tests can take a
long time. Trial and error is needed to show if this option is
beneficial.

MAIL_WARNING (-U)
Print a warning message if a mail file has been accessed since
the shell last checked.

PATH_DIRS (-Q)
Perform a path search even on command names with slashes in
them. Thus if `/usr/local/bin' is in the user's path, and he or
she types `X11/xinit', the command `/usr/local/bin/X11/xinit'
will be executed (assuming it exists). Commands explicitly
beginning with `/', `./' or `../' are not subject to the path
search. This also applies to the `.' and source builtins.

Note that subdirectories of the current directory are always
searched for executables specified in this form. This takes
place before any search indicated by this option, and regardless
of whether `.' or the current directory appear in the command
search path.

PATH_SCRIPT <K> <S>
If this option is not set, a script passed as the first
non-option argument to the shell must contain the name of the
file to open. If this option is set, and the script does not
specify a directory path, the script is looked for first in the
current directory, then in the command path. See the section
INVOCATION in zsh(1).

PRINT_EIGHT_BIT
Print eight bit characters literally in completion lists, etc.
This option is not necessary if your system correctly returns
the printability of eight bit characters (see ctype(3)).

PRINT_EXIT_VALUE (-1)
Print the exit value of programs with non-zero exit status.
This is only available at the command line in interactive
shells.

RC_QUOTES
Allow the character sequence `''' to signify a single quote
within singly quoted strings. Note this does not apply in
quoted strings using the format $'...', where a backslashed
single quote can be used.

RM_STAR_SILENT (-H) <K> <S>
Do not query the user before executing `rm *' or `rm path/*'.

RM_STAR_WAIT
If querying the user before executing `rm *' or `rm path/*',
first wait ten seconds and ignore anything typed in that time.
This avoids the problem of reflexively answering `yes' to the
query when one didn't really mean it. The wait and query can
always be avoided by expanding the `*' in ZLE (with tab).

SHORT_LOOPS <C> <Z>
Allow the short forms of for, repeat, select, if, and function
constructs.

SHORT_REPEAT
Allow the short form repeat as SHORT_LOOPS but without enabling
it for the other constructs.

SUN_KEYBOARD_HACK (-L)
If a line ends with a backquote, and there are an odd number of
backquotes on the line, ignore the trailing backquote. This is
useful on some keyboards where the return key is too small, and
the backquote key lies annoyingly close to it. As an
alternative the variable KEYBOARD_HACK lets you choose the
character to be removed.

Job Control
AUTO_CONTINUE
With this option set, stopped jobs that are removed from the job
table with the disown builtin command are automatically sent a
CONT signal to make them running.

AUTO_RESUME (-W)
Treat single word simple commands without redirection as
candidates for resumption of an existing job.

BG_NICE (-6) <C> <Z>
Run all background jobs at a lower priority. This option is set
by default.

CHECK_JOBS <Z>
Report the status of background and suspended jobs before
exiting a shell with job control; a second attempt to exit the
shell will succeed. NO_CHECK_JOBS is best used only in
combination with NO_HUP, else such jobs will be killed
automatically.

The check is omitted if the commands run from the previous
command line included a `jobs' command, since it is assumed the
user is aware that there are background or suspended jobs. A
`jobs' command run from one of the hook functions defined in the
section SPECIAL FUNCTIONS in zshmisc(1) is not counted for this
purpose.

CHECK_RUNNING_JOBS <Z>
Check for both running and suspended jobs when CHECK_JOBS is
enabled. When this option is disabled, zsh checks only for
suspended jobs, which matches the default behavior of bash.

This option has no effect unless CHECK_JOBS is set.

HUP <Z>
Send the HUP signal to running jobs when the shell exits.

LONG_LIST_JOBS (-R)
Print job notifications in the long format by default.

MONITOR (-m, ksh: -m)
Allow job control. Set by default in interactive shells.

NOTIFY (-5, ksh: -b) <Z>
Report the status of background jobs immediately, rather than
waiting until just before printing a prompt.

POSIX_JOBS <K> <S>
This option makes job control more compliant with the POSIX
standard.

When the option is not set, the MONITOR option is unset on entry
to subshells, so that job control is no longer active. When the
option is set, the MONITOR option and job control remain active
in the subshell, but note that the subshell has no access to
jobs in the parent shell.

When the option is not set, jobs put in the background or
foreground with bg or fg are displayed with the same information
that would be reported by jobs. When the option is set, only
the text is printed. The output from jobs itself is not
affected by the option.

When the option is not set, job information from the parent
shell is saved for output within a subshell (for example, within
a pipeline). When the option is set, the output of jobs is
empty until a job is started within the subshell.

In previous versions of the shell, it was necessary to enable
POSIX_JOBS in order for the builtin command wait to return the
status of background jobs that had already exited. This is no
longer the case.

Prompting
PROMPT_BANG <K>
If set, `!' is treated specially in prompt expansion. See
EXPANSION OF PROMPT SEQUENCES in zshmisc(1).

PROMPT_CR (+V) <D>
Print a carriage return just before printing a prompt in the
line editor. This is on by default as multi-line editing is
only possible if the editor knows where the start of the line
appears.

PROMPT_SP <D>
Attempt to preserve a partial line (i.e. a line that did not end
with a newline) that would otherwise be covered up by the
command prompt due to the PROMPT_CR option. This works by
outputting some cursor-control characters, including a series of
spaces, that should make the terminal wrap to the next line when
a partial line is present (note that this is only successful if
your terminal has automatic margins, which is typical).

When a partial line is preserved, by default you will see an
inverse+bold character at the end of the partial line: a `%'
for a normal user or a `#' for root. If set, the shell
parameter PROMPT_EOL_MARK can be used to customize how the end
of partial lines are shown.

NOTE: if the PROMPT_CR option is not set, enabling this option
will have no effect. This option is on by default.

PROMPT_PERCENT <C> <Z>
If set, `%' is treated specially in prompt expansion. See
EXPANSION OF PROMPT SEQUENCES in zshmisc(1).

PROMPT_SUBST <K> <S>
If set, parameter expansion, command substitution and arithmetic
expansion are performed in prompts. Substitutions within
prompts do not affect the command status.

TRANSIENT_RPROMPT
Remove any right prompt from display when accepting a command
line. This may be useful with terminals with other cut/paste
methods.

Scripts and Functions
ALIAS_FUNC_DEF <S>
By default, zsh does not allow the definition of functions using
the `name ()' syntax if name was expanded as an alias: this
causes an error. This is usually the desired behaviour, as
otherwise the combination of an alias and a function based on
the same definition can easily cause problems.

When this option is set, aliases can be used for defining
functions.

For example, consider the following definitions as they might
occur in a startup file.

alias foo=bar
foo() {
print This probably does not do what you expect.
}

Here, foo is expanded as an alias to bar before the () is
encountered, so the function defined would be named bar. By
default this is instead an error in native mode. Note that
quoting any part of the function name, or using the keyword
function, avoids the problem, so is recommended when the
function name can also be an alias.

C_BASES
Output hexadecimal numbers in the standard C format, for example
`0xFF' instead of the usual `16#FF'. If the option OCTAL_ZEROES
is also set (it is not by default), octal numbers will be
treated similarly and hence appear as `077' instead of `8#77'.
This option has no effect on the choice of the output base, nor
on the output of bases other than hexadecimal and octal. Note
that these formats will be understood on input irrespective of
the setting of C_BASES.

C_PRECEDENCES
This alters the precedence of arithmetic operators to be more
like C and other programming languages; the section ARITHMETIC
EVALUATION in zshmisc(1) has an explicit list.

DEBUG_BEFORE_CMD <D>
Run the DEBUG trap before each command; otherwise it is run
after each command. Setting this option mimics the behaviour of
ksh 93; with the option unset the behaviour is that of ksh 88.

ERR_EXIT (-e, ksh: -e)
If a command has a non-zero exit status, execute the ZERR trap,
if set, and exit. This is disabled while running initialization
scripts.

The behaviour is also disabled inside DEBUG traps. In this case
the option is handled specially: it is unset on entry to the
trap. If the option DEBUG_BEFORE_CMD is set, as it is by
default, and the option ERR_EXIT is found to have been set on
exit, then the command for which the DEBUG trap is being
executed is skipped. The option is restored after the trap
exits.

Non-zero status in a command list containing && or || is ignored
for commands not at the end of the list. Hence

false && true

does not trigger exit.

Exiting due to ERR_EXIT has certain interactions with
asynchronous jobs noted in the section JOBS in zshmisc(1).

ERR_RETURN
If a command has a non-zero exit status, return immediately from
the enclosing function. The logic is similar to that for
ERR_EXIT, except that an implicit return statement is executed
instead of an exit. This will trigger an exit at the outermost
level of a non-interactive script.

Normally this option inherits the behaviour of ERR_EXIT that
code followed by `&&' `||' does not trigger a return. Hence in
the following:

summit || true

no return is forced as the combined effect always has a zero
return status.

Note. however, that if summit in the above example is itself a
function, code inside it is considered separately: it may force
a return from summit (assuming the option remains set within
summit), but not from the enclosing context. This behaviour is
different from ERR_EXIT which is unaffected by function scope.

EVAL_LINENO <Z>
If set, line numbers of expressions evaluated using the builtin
eval are tracked separately of the enclosing environment. This
applies both to the parameter LINENO and the line number output
by the prompt escape %i. If the option is set, the prompt
escape %N will output the string `(eval)' instead of the script
or function name as an indication. (The two prompt escapes are
typically used in the parameter PS4 to be output when the option
XTRACE is set.) If EVAL_LINENO is unset, the line number of the
surrounding script or function is retained during the
evaluation.

EXEC (+n, ksh: +n) <D>
Do execute commands. Without this option, commands are read and
checked for syntax errors, but not executed. This option cannot
be turned off in an interactive shell, except when `-n' is
supplied to the shell at startup.

FUNCTION_ARGZERO <C> <Z>
When executing a shell function or sourcing a script, set $0
temporarily to the name of the function/script. Note that
toggling FUNCTION_ARGZERO from on to off (or off to on) does not
change the current value of $0. Only the state upon entry to
the function or script has an effect. Compare POSIX_ARGZERO.

LOCAL_LOOPS
When this option is not set, the effect of break and continue
commands may propagate outside function scope, affecting loops
in calling functions. When the option is set in a calling
function, a break or a continue that is not caught within a
called function (regardless of the setting of the option within
that function) produces a warning and the effect is cancelled.

LOCAL_OPTIONS <K>
If this option is set at the point of return from a shell
function, most options (including this one) which were in force
upon entry to the function are restored; options that are not
restored are PRIVILEGED and RESTRICTED. Otherwise, only this
option, and the LOCAL_LOOPS, XTRACE and PRINT_EXIT_VALUE options
are restored. Hence if this is explicitly unset by a shell
function the other options in force at the point of return will
remain so. A shell function can also guarantee itself a known
shell configuration with a formulation like `emulate -L zsh';
the -L activates LOCAL_OPTIONS.

LOCAL_PATTERNS
If this option is set at the point of return from a shell
function, the state of pattern disables, as set with the builtin
command `disable -p', is restored to what it was when the
function was entered. The behaviour of this option is similar
to the effect of LOCAL_OPTIONS on options; hence `emulate -L sh'
(or indeed any other emulation with the -L option) activates
LOCAL_PATTERNS.

LOCAL_TRAPS <K>
If this option is set when a signal trap is set inside a
function, then the previous status of the trap for that signal
will be restored when the function exits. Note that this option
must be set prior to altering the trap behaviour in a function;
unlike LOCAL_OPTIONS, the value on exit from the function is
irrelevant. However, it does not need to be set before any
global trap for that to be correctly restored by a function.
For example,

unsetopt localtraps
trap - INT
fn() { setopt localtraps; trap '' INT; sleep 3; }

will restore normal handling of SIGINT after the function exits.

MULTI_FUNC_DEF <Z>
Allow definitions of multiple functions at once in the form `fn1
fn2...()'; if the option is not set, this causes a parse error.
Definition of multiple functions with the function keyword is
always allowed. Multiple function definitions are not often
used and can cause obscure errors.

MULTIOS <Z>
Perform implicit tees or cats when multiple redirections are
attempted (see the section `Redirection').

OCTAL_ZEROES <S>
Interpret any integer constant beginning with a 0 as octal, per
IEEE Std 1003.2-1992 (ISO 9945-2:1993). This is not enabled by
default as it causes problems with parsing of, for example, date
and time strings with leading zeroes.

Sequences of digits indicating a numeric base such as the `08'
component in `08#77' are always interpreted as decimal,
regardless of leading zeroes.

PIPE_FAIL
By default, when a pipeline exits the exit status recorded by
the shell and returned by the shell variable $? reflects that of
the rightmost element of a pipeline. If this option is set, the
exit status instead reflects the status of the rightmost element
of the pipeline that was non-zero, or zero if all elements
exited with zero status.

SOURCE_TRACE
If set, zsh will print an informational message announcing the
name of each file it loads. The format of the output is similar
to that for the XTRACE option, with the message <sourcetrace>.
A file may be loaded by the shell itself when it starts up and
shuts down (Startup/Shutdown Files) or by the use of the
`source' and `dot' builtin commands.

TYPESET_SILENT
If this is unset, executing any of the `typeset' family of
commands with no options and a list of parameters that have no
values to be assigned but already exist will display the value
of the parameter. If the option is set, they will only be shown
when parameters are selected with the `-m' option. The option
`-p' is available whether or not the option is set.

TYPESET_TO_UNSET <K> <S>
When declaring a new parameter with any of the `typeset' family
of related commands, the parameter remains unset unless and
until a value is explicity assigned to it, either in the
`typeset' command itself or as a later assignment statement.

VERBOSE (-v, ksh: -v)
Print shell input lines as they are read.

XTRACE (-x, ksh: -x)
Print commands and their arguments as they are executed. The
output is preceded by the value of $PS4, formatted as described
in the section EXPANSION OF PROMPT SEQUENCES in zshmisc(1).

Shell Emulation
APPEND_CREATE <K> <S>
This option only applies when NO_CLOBBER (-C) is in effect.

If this option is not set, the shell will report an error when a
append redirection (>>) is used on a file that does not already
exists (the traditional zsh behaviour of NO_CLOBBER). If the
option is set, no error is reported (POSIX behaviour).

BASH_REMATCH
When set, matches performed with the =~ operator will set the
BASH_REMATCH array variable, instead of the default MATCH and
match variables. The first element of the BASH_REMATCH array
will contain the entire matched text and subsequent elements
will contain extracted substrings. This option makes more sense
when KSH_ARRAYS is also set, so that the entire matched portion
is stored at index 0 and the first substring is at index 1.
Without this option, the MATCH variable contains the entire
matched text and the match array variable contains substrings.

BSD_ECHO <S>
Make the echo builtin compatible with the BSD echo(1) command.
This disables backslashed escape sequences in echo strings
unless the -e option is specified.

CONTINUE_ON_ERROR
If a fatal error is encountered (see the section ERRORS in
zshmisc(1)), and the code is running in a script, the shell will
resume execution at the next statement in the script at the top
level, in other words outside all functions or shell constructs
such as loops and conditions. This mimics the behaviour of
interactive shells, where the shell returns to the line editor
to read a new command; it was the normal behaviour in versions
of zsh before 5.0.1.

CSH_JUNKIE_HISTORY <C>
A history reference without an event specifier will always refer
to the previous command. Without this option, such a history
reference refers to the same event as the previous history
reference on the current command line, defaulting to the
previous command.

CSH_JUNKIE_LOOPS <C>
Allow loop bodies to take the form `list; end' instead of `do
list; done'.

CSH_JUNKIE_QUOTES <C>
Changes the rules for single- and double-quoted text to match
that of csh. These require that embedded newlines be preceded
by a backslash; unescaped newlines will cause an error message.
In double-quoted strings, it is made impossible to escape `$',
``' or `"' (and `\' itself no longer needs escaping). Command
substitutions are only expanded once, and cannot be nested.

CSH_NULLCMD <C>
Do not use the values of NULLCMD and READNULLCMD when running
redirections with no command. This make such redirections fail
(see the section `Redirection').

KSH_ARRAYS <K> <S>
Emulate ksh array handling as closely as possible. If this
option is set, array elements are numbered from zero, an array
parameter without subscript refers to the first element instead
of the whole array, and braces are required to delimit a
subscript (`${path[2]}' rather than just `$path[2]') or to apply
modifiers to any parameter (`${PWD:h}' rather than `$PWD:h').

KSH_AUTOLOAD <K> <S>
Emulate ksh function autoloading. This means that when a
function is autoloaded, the corresponding file is merely
executed, and must define the function itself. (By default, the
function is defined to the contents of the file. However, the
most common ksh-style case - of the file containing only a
simple definition of the function - is always handled in the
ksh-compatible manner.)

KSH_OPTION_PRINT <K>
Alters the way options settings are printed: instead of separate
lists of set and unset options, all options are shown, marked
`on' if they are in the non-default state, `off' otherwise.

KSH_TYPESET
This option is now obsolete: a better appropximation to the
behaviour of other shells is obtained with the reserved word
interface to declare, export, float, integer, local, readonly
and typeset. Note that the option is only applied when the
reserved word interface is not in use.

Alters the way arguments to the typeset family of commands,
including declare, export, float, integer, local and readonly,
are processed. Without this option, zsh will perform normal
word splitting after command and parameter expansion in
arguments of an assignment; with it, word splitting does not
take place in those cases.

KSH_ZERO_SUBSCRIPT
Treat use of a subscript of value zero in array or string
expressions as a reference to the first element, i.e. the
element that usually has the subscript 1. Ignored if KSH_ARRAYS
is also set.

If neither this option nor KSH_ARRAYS is set, accesses to an
element of an array or string with subscript zero return an
empty element or string, while attempts to set element zero of
an array or string are treated as an error. However, attempts
to set an otherwise valid subscript range that includes zero
will succeed. For example, if KSH_ZERO_SUBSCRIPT is not set,

array[0]=(element)

is an error, while

array[0,1]=(element)

is not and will replace the first element of the array.

This option is for compatibility with older versions of the
shell and is not recommended in new code.

POSIX_ALIASES <K> <S>
When this option is set, reserved words are not candidates for
alias expansion: it is still possible to declare any of them as
an alias, but the alias will never be expanded. Reserved words
are described in the section RESERVED WORDS in zshmisc(1).

Alias expansion takes place while text is being read; hence when
this option is set it does not take effect until the end of any
function or other piece of shell code parsed as one unit. Note
this may cause differences from other shells even when the
option is in effect. For example, when running a command with
`zsh -c', or even `zsh -o posixaliases -c', the entire command
argument is parsed as one unit, so aliases defined within the
argument are not available even in later lines. If in doubt,
avoid use of aliases in non-interactive code.

POSIX_ARGZERO
This option may be used to temporarily disable FUNCTION_ARGZERO
and thereby restore the value of $0 to the name used to invoke
the shell (or as set by the -c command line option). For
compatibility with previous versions of the shell, emulations
use NO_FUNCTION_ARGZERO instead of POSIX_ARGZERO, which may
result in unexpected scoping of $0 if the emulation mode is
changed inside a function or script. To avoid this, explicitly
enable POSIX_ARGZERO in the emulate command:

emulate sh -o POSIX_ARGZERO

Note that NO_POSIX_ARGZERO has no effect unless FUNCTION_ARGZERO
was already enabled upon entry to the function or script.

POSIX_BUILTINS <K> <S>
When this option is set the command builtin can be used to
execute shell builtin commands. Parameter assignments specified
before shell functions and special builtins are kept after the
command completes unless the special builtin is prefixed with
the command builtin. Special builtins are ., :, break,
continue, declare, eval, exit, export, integer, local, readonly,
return, set, shift, source, times, trap and unset.

In addition, various error conditions associated with the above
builtins or exec cause a non-interactive shell to exit and an
interactive shell to return to its top-level processing.

Furthermore, functions and shell builtins are not executed after
an exec prefix; the command to be executed must be an external
command found in the path.

Furthermore, the getopts builtin behaves in a POSIX-compatible
fashion in that the associated variable OPTIND is not made local
to functions, and its value is calculated differently to match
other shells.

Moreover, the warning and special exit code from [[ -o
non_existent_option ]] are suppressed.

POSIX_IDENTIFIERS <K> <S>
When this option is set, only the ASCII characters a to z, A to
Z, 0 to 9 and _ may be used in identifiers (names of shell
parameters and modules).

In addition, setting this option limits the effect of parameter
substitution with no braces, so that the expression $# is
treated as the parameter $# even if followed by a valid
parameter name. When it is unset, zsh allows expressions of the
form $#name to refer to the length of $name, even for special
variables, for example in expressions such as $#- and $#*.

Another difference is that with the option set assignment to an
unset variable in arithmetic context causes the variable to be
created as a scalar rather than a numeric type. So after `unset
t; (( t = 3 ))'. without POSIX_IDENTIFIERS set t has integer
type, while with it set it has scalar type.

When the option is unset and multibyte character support is
enabled (i.e. it is compiled in and the option MULTIBYTE is
set), then additionally any alphanumeric characters in the local
character set may be used in identifiers. Note that scripts and
functions written with this feature are not portable, and also
that both options must be set before the script or function is
parsed; setting them during execution is not sufficient as the
syntax variable=value has already been parsed as a command
rather than an assignment.

If multibyte character support is not compiled into the shell
this option is ignored; all octets with the top bit set may be
used in identifiers. This is non-standard but is the
traditional zsh behaviour.

POSIX_STRINGS <K> <S>
This option affects processing of quoted strings. Currently it
only affects the behaviour of null characters, i.e. character 0
in the portable character set corresponding to US ASCII.

When this option is not set, null characters embedded within
strings of the form $'...' are treated as ordinary characters.
The entire string is maintained within the shell and output to
files where necessary, although owing to restrictions of the
library interface the string is truncated at the null character
in file names, environment variables, or in arguments to
external programs.

When this option is set, the $'...' expression is truncated at
the null character. Note that remaining parts of the same
string beyond the termination of the quotes are not truncated.

For example, the command line argument a$'b\0c'd is treated with
the option off as the characters a, b, null, c, d, and with the
option on as the characters a, b, d.

POSIX_TRAPS <K> <S>
When this option is set, the usual zsh behaviour of executing
traps for EXIT on exit from shell functions is suppressed. In
that case, manipulating EXIT traps always alters the global trap
for exiting the shell; the LOCAL_TRAPS option is ignored for the
EXIT trap.

Also, a return statement executed in a trap with no argument
passes back from the function the value from the surrounding
context, not from code executed within the trap.

Furthermore, if a trap is set to be ignored, this state persists
when a subshell is entered. Without the option, the trap would
be reset to its default state at this point.

SH_FILE_EXPANSION <K> <S>
Perform filename expansion (e.g., ~ expansion) before parameter
expansion, command substitution, arithmetic expansion and brace
expansion. If this option is unset, it is performed after brace
expansion, so things like `~$USERNAME' and `~{pfalstad,rc}' will
work.

SH_NULLCMD <K> <S>
Do not use the values of NULLCMD and READNULLCMD when doing
redirections, use `:' instead (see the section `Redirection').

SH_OPTION_LETTERS <K> <S>
If this option is set the shell tries to interpret single letter
options (which are used with set and setopt) like ksh does.
This also affects the value of the - special parameter.

SH_WORD_SPLIT (-y) <K> <S>
Causes field splitting to be performed on unquoted parameter
expansions. Note that this option has nothing to do with word
splitting. (See zshexpn(1).)

TRAPS_ASYNC
While waiting for a program to exit, handle signals and run
traps immediately. Otherwise the trap is run after a child
process has exited. Note this does not affect the point at
which traps are run for any case other than when the shell is
waiting for a child process.

Shell State
INTERACTIVE (-i, ksh: -i)
This is an interactive shell. This option is set upon
initialisation if the standard input is a tty and commands are
being read from standard input. (See the discussion of
SHIN_STDIN.) This heuristic may be overridden by specifying a
state for this option on the command line. The value of this
option can only be changed via flags supplied at invocation of
the shell. It cannot be changed once zsh is running.

LOGIN (-l, ksh: -l)
This is a login shell. If this option is not explicitly set,
the shell becomes a login shell if the first character of the
argv[0] passed to the shell is a `-'.

PRIVILEGED (-p, ksh: -p)
Turn on privileged mode. Typically this is used when script is
to be run with elevated privileges. This should be done as
follows directly with the -p option to zsh so that it takes
effect during startup.

#!/bin/zsh -p

The option is enabled automatically on startup if the effective
user (group) ID is not equal to the real user (group) ID. In
this case, turning the option off causes the effective user and
group IDs to be set to the real user and group IDs. Be aware
that if that fails the shell may be running with different IDs
than was intended so a script should check for failure and act
accordingly, for example:

unsetopt privileged || exit

The PRIVILEGED option disables sourcing user startup files. If
zsh is invoked as `sh' or `ksh' with this option set,
/etc/suid_profile is sourced (after /etc/profile on interactive
shells). Sourcing ~/.profile is disabled and the contents of the
ENV variable is ignored. This option cannot be changed using the
-m option of setopt and unsetopt, and changing it inside a
function always changes it globally regardless of the
LOCAL_OPTIONS option.

RESTRICTED (-r)
Enables restricted mode. This option cannot be changed using
unsetopt, and setting it inside a function always changes it
globally regardless of the LOCAL_OPTIONS option. See the
section `Restricted Shell'.

SHIN_STDIN (-s, ksh: -s)
Commands are being read from the standard input. Commands are
read from standard input if no command is specified with -c and
no file of commands is specified. If SHIN_STDIN is set
explicitly on the command line, any argument that would
otherwise have been taken as a file to run will instead be
treated as a normal positional parameter. Note that setting or
unsetting this option on the command line does not necessarily
affect the state the option will have while the shell is running
- that is purely an indicator of whether or not commands are
actually being read from standard input. The value of this
option can only be changed via flags supplied at invocation of
the shell. It cannot be changed once zsh is running.

SINGLE_COMMAND (-t, ksh: -t)
If the shell is reading from standard input, it exits after a
single command has been executed. This also makes the shell
non-interactive, unless the INTERACTIVE option is explicitly set
on the command line. The value of this option can only be
changed via flags supplied at invocation of the shell. It
cannot be changed once zsh is running.

Zle
BEEP (+B) <D>
Beep on error in ZLE.

COMBINING_CHARS
Assume that the terminal displays combining characters
correctly. Specifically, if a base alphanumeric character is
followed by one or more zero-width punctuation characters,
assume that the zero-width characters will be displayed as
modifications to the base character within the same width. Not
all terminals handle this. If this option is not set,
zero-width characters are displayed separately with special
mark-up.

If this option is set, the pattern test [[:WORD:]] matches a
zero-width punctuation character on the assumption that it will
be used as part of a word in combination with a word character.
Otherwise the base shell does not handle combining characters
specially.

EMACS If ZLE is loaded, turning on this option has the equivalent
effect of `bindkey -e'. In addition, the VI option is unset.
Turning it off has no effect. The option setting is not
guaranteed to reflect the current keymap. This option is
provided for compatibility; bindkey is the recommended
interface.

OVERSTRIKE
Start up the line editor in overstrike mode.

SINGLE_LINE_ZLE (-M) <K>
Use single-line command line editing instead of multi-line.

Note that although this is on by default in ksh emulation it
only provides superficial compatibility with the ksh line editor
and reduces the effectiveness of the zsh line editor. As it has
no effect on shell syntax, many users may wish to disable this
option when using ksh emulation interactively.

VI If ZLE is loaded, turning on this option has the equivalent
effect of `bindkey -v'. In addition, the EMACS option is unset.
Turning it off has no effect. The option setting is not
guaranteed to reflect the current keymap. This option is
provided for compatibility; bindkey is the recommended
interface.

ZLE (-Z)
Use the zsh line editor. Set by default in interactive shells
connected to a terminal.

OPTION ALIASES
Some options have alternative names. These aliases are never used for
output, but can be used just like normal option names when specifying
options to the shell.

BRACE_EXPAND
NO_IGNORE_BRACES (ksh and bash compatibility)

DOT_GLOB
GLOB_DOTS (bash compatibility)

HASH_ALL
HASH_CMDS (bash compatibility)

HIST_APPEND
APPEND_HISTORY (bash compatibility)

HIST_EXPAND
BANG_HIST (bash compatibility)

LOG NO_HIST_NO_FUNCTIONS (ksh compatibility)

MAIL_WARN
MAIL_WARNING (bash compatibility)

ONE_CMD
SINGLE_COMMAND (bash compatibility)

PHYSICAL
CHASE_LINKS (ksh and bash compatibility)

PROMPT_VARS
PROMPT_SUBST (bash compatibility)

STDIN SHIN_STDIN (ksh compatibility)

TRACK_ALL
HASH_CMDS (ksh compatibility)

SINGLE LETTER OPTIONS
Default set
-0 CORRECT
-1 PRINT_EXIT_VALUE
-2 NO_BAD_PATTERN
-3 NO_NOMATCH
-4 GLOB_DOTS
-5 NOTIFY
-6 BG_NICE
-7 IGNORE_EOF
-8 MARK_DIRS
-9 AUTO_LIST
-B NO_BEEP
-C NO_CLOBBER
-D PUSHD_TO_HOME
-E PUSHD_SILENT
-F NO_GLOB
-G NULL_GLOB
-H RM_STAR_SILENT
-I IGNORE_BRACES
-J AUTO_CD
-K NO_BANG_HIST
-L SUN_KEYBOARD_HACK
-M SINGLE_LINE_ZLE
-N AUTO_PUSHD
-O CORRECT_ALL
-P RC_EXPAND_PARAM
-Q PATH_DIRS
-R LONG_LIST_JOBS
-S REC_EXACT
-T CDABLE_VARS
-U MAIL_WARNING
-V NO_PROMPT_CR
-W AUTO_RESUME
-X LIST_TYPES
-Y MENU_COMPLETE
-Z ZLE
-a ALL_EXPORT
-e ERR_EXIT
-f NO_RCS
-g HIST_IGNORE_SPACE
-h HIST_IGNORE_DUPS
-i INTERACTIVE
-k INTERACTIVE_COMMENTS
-l LOGIN
-m MONITOR
-n NO_EXEC
-p PRIVILEGED
-r RESTRICTED
-s SHIN_STDIN
-t SINGLE_COMMAND
-u NO_UNSET
-v VERBOSE
-w CHASE_LINKS
-x XTRACE
-y SH_WORD_SPLIT

sh/ksh emulation set
-C NO_CLOBBER
-T TRAPS_ASYNC
-X MARK_DIRS
-a ALL_EXPORT
-b NOTIFY
-e ERR_EXIT
-f NO_GLOB
-i INTERACTIVE
-l LOGIN
-m MONITOR
-n NO_EXEC
-p PRIVILEGED
-r RESTRICTED
-s SHIN_STDIN
-t SINGLE_COMMAND
-u NO_UNSET
-v VERBOSE
-x XTRACE

Also note
-A Used by set for setting arrays
-b Used on the command line to specify end of option processing
-c Used on the command line to specify a single command
-m Used by setopt for pattern-matching option setting
-o Used in all places to allow use of long option names
-s Used by set to sort positional parameters

NAME
zshbuiltins - zsh built-in commands

SHELL BUILTIN COMMANDS
Some shell builtin commands take options as described in individual
entries; these are often referred to in the list below as `flags' to
avoid confusion with shell options, which may also have an effect on
the behaviour of builtin commands. In this introductory section,
`option' always has the meaning of an option to a command that should
be familiar to most command line users.

Typically, options are single letters preceded by a hyphen (-).
Options that take an argument accept it either immediately following
the option letter or after white space, for example `print -C3 {1..9}'
or `print -C 3 {1..9}' are equivalent. Arguments to options are not
the same as arguments to the command; the documentation indicates which
is which. Options that do not take an argument may be combined in a
single word, for example `print -rca -- *' and `print -r -c -a -- *'
are equivalent.

Some shell builtin commands also take options that begin with `*'
instead of `-'. The list below makes clear which commands these are.

Options (together with their individual arguments, if any) must appear
in a group before any non-option arguments; once the first non-option
argument has been found, option processing is terminated.

All builtin commands other than `echo' and precommand modifiers, even
those that have no options, can be given the argument `--' to terminate
option processing. This indicates that the following words are
non-option arguments, but is otherwise ignored. This is useful in
cases where arguments to the command may begin with `-'. For
historical reasons, most builtin commands (including `echo') also
recognize a single `-' in a separate word for this purpose; note that
this is less standard and use of `--' is recommended.

- simple command
See the section `Precommand Modifiers' in zshmisc(1).

. file [ arg ... ]
Read commands from file and execute them in the current shell
environment.

If file does not contain a slash, or if PATH_DIRS is set, the
shell looks in the components of $path to find the directory
containing file. Files in the current directory are not read
unless `.' appears somewhere in $path. If a file named
`file.zwc' is found, is newer than file, and is the compiled
form (created with the zcompile builtin) of file, then commands
are read from that file instead of file.

If any arguments arg are given, they become the positional
parameters; the old positional parameters are restored when the
file is done executing. However, if no arguments are given, the
positional parameters remain those of the calling context, and
no restoring is done.

If file was not found the return status is 127; if file was
found but contained a syntax error the return status is 126;
else the return status is the exit status of the last command
executed.

: [ arg ... ]
This command does nothing, although normal argument expansions
is performed which may have effects on shell parameters. A zero
exit status is returned.

alias [ {*|-}gmrsL ] [ name[=value] ... ]
For each name with a corresponding value, define an alias with
that value. A trailing space in value causes the next word to
be checked for alias expansion. If the -g flag is present,
define a global alias; global aliases are expanded even if they
do not occur in command position:

% perldoc --help 2>&1 | grep 'built-in functions'
-f Search Perl built-in functions
% alias -g HG='--help 2>&1 | grep'
% perldoc HG 'built-in functions'
-f Search Perl built-in functions

If the -s flag is present, define a suffix alias: if the command
word on a command line is in the form `text.name', where text is
any non-empty string, it is replaced by the text `value
text.name'. Note that name is treated as a literal string, not
a pattern. A trailing space in value is not special in this
case. For example,

alias -s ps='gv --'

will cause the command `*.ps' to be expanded to `gv -- *.ps'.
As alias expansion is carried out earlier than globbing, the
`*.ps' will then be expanded. Suffix aliases constitute a
different name space from other aliases (so in the above example
it is still possible to create an alias for the command ps) and
the two sets are never listed together.

For each name with no value, print the value of name, if any.
With no arguments, print all currently defined aliases other
than suffix aliases. If the -m flag is given the arguments are
taken as patterns (they should be quoted to preserve them from
being interpreted as glob patterns), and the aliases matching
these patterns are printed. When printing aliases and one of
the -g, -r or -s flags is present, restrict the printing to
global, regular or suffix aliases, respectively; a regular alias
is one which is neither a global nor a suffix alias. Using `*'
instead of `-', or ending the option list with a single `*',
prevents the values of the aliases from being printed.

If the -L flag is present, then print each alias in a manner
suitable for putting in a startup script. The exit status is
nonzero if a name (with no value) is given for which no alias
has been defined.

For more on aliases, include common problems, see the section
ALIASING in zshmisc(1).

autoload [ {*|-}RTUXdkmrtWz ] [ -w ] [ name ... ]
See the section `Autoloading Functions' in zshmisc(1) for full
details. The fpath parameter will be searched to find the
function definition when the function is first referenced.

If name consists of an absolute path, the function is defined to
load from the file given (searching as usual for dump files in
the given location). The name of the function is the basename
(non-directory part) of the file. It is normally an error if
the function is not found in the given location; however, if the
option -d is given, searching for the function defaults to
$fpath. If a function is loaded by absolute path, any functions
loaded from it that are marked for autoload without an absolute
path have the load path of the parent function temporarily
prepended to $fpath.

If the option -r or -R is given, the function is searched for
immediately and the location is recorded internally for use when
the function is executed; a relative path is expanded using the
value of $PWD. This protects against a change to $fpath after
the call to autoload. With -r, if the function is not found, it
is silently left unresolved until execution; with -R, an error
message is printed and command processing aborted immediately
the search fails, i.e. at the autoload command rather than at
function execution..

The flag -X may be used only inside a shell function. It causes
the calling function to be marked for autoloading and then
immediately loaded and executed, with the current array of
positional parameters as arguments. This replaces the previous
definition of the function. If no function definition is found,
an error is printed and the function remains undefined and
marked for autoloading. If an argument is given, it is used as
a directory (i.e. it does not include the name of the function)
in which the function is to be found; this may be combined with
the -d option to allow the function search to default to $fpath
if it is not in the given location.

The flag +X attempts to load each name as an autoloaded
function, but does not execute it. The exit status is zero
(success) if the function was not previously defined and a
definition for it was found. This does not replace any existing
definition of the function. The exit status is nonzero
(failure) if the function was already defined or when no
definition was found. In the latter case the function remains
undefined and marked for autoloading. If ksh-style autoloading
is enabled, the function created will contain the contents of
the file plus a call to the function itself appended to it, thus
giving normal ksh autoloading behaviour on the first call to the
function. If the -m flag is also given each name is treated as
a pattern and all functions already marked for autoload that
match the pattern are loaded.

With the -t flag, turn on execution tracing; with -T, turn on
execution tracing only for the current function, turning it off
on entry to any called functions that do not also have tracing
enabled.

With the -U flag, alias expansion is suppressed when the
function is loaded.

With the -w flag, the names are taken as names of files compiled
with the zcompile builtin, and all functions defined in them are
marked for autoloading.

The flags -z and -k mark the function to be autoloaded using the
zsh or ksh style, as if the option KSH_AUTOLOAD were unset or
were set, respectively. The flags override the setting of the
option at the time the function is loaded.

Note that the autoload command makes no attempt to ensure the
shell options set during the loading or execution of the file
have any particular value. For this, the emulate command can be
used:

emulate zsh -c 'autoload -Uz func'

arranges that when func is loaded the shell is in native zsh
emulation, and this emulation is also applied when func is run.

Some of the functions of autoload are also provided by functions
-u or functions -U, but autoload is a more comprehensive
interface.

bg [ job ... ]
job ... &
Put each specified job in the background, or the current job if
none is specified.

bindkey
See the section `Zle Builtins' in zshzle(1).

break [ n ]
Exit from an enclosing for, while, until, select or repeat loop.
If an arithmetic expression n is specified, then break n levels
instead of just one.

builtin name [ args ... ]
Executes the builtin name, with the given args.

bye Same as exit.

cap See the section `The zsh/cap Module' in zshmodules(1).

cd [ -qsLP ] [ arg ]
cd [ -qsLP ] old new
cd [ -qsLP ] {*|-}n
Change the current directory. In the first form, change the
current directory to arg, or to the value of $HOME if arg is not
specified. If arg is `-', change to the previous directory.

Otherwise, if arg begins with a slash, attempt to change to the
directory given by arg.

If arg does not begin with a slash, the behaviour depends on
whether the current directory `.' occurs in the list of
directories contained in the shell parameter cdpath. If it does
not, first attempt to change to the directory arg under the
current directory, and if that fails but cdpath is set and
contains at least one element attempt to change to the directory
arg under each component of cdpath in turn until successful. If
`.' occurs in cdpath, then cdpath is searched strictly in order
so that `.' is only tried at the appropriate point.

The order of testing cdpath is modified if the option POSIX_CD
is set, as described in the documentation for the option.

If no directory is found, the option CDABLE_VARS is set, and a
parameter named arg exists whose value begins with a slash,
treat its value as the directory. In that case, the parameter
is added to the named directory hash table.

The second form of cd substitutes the string new for the string
old in the name of the current directory, and tries to change to
this new directory.

The third form of cd extracts an entry from the directory stack,
and changes to that directory. An argument of the form `*n'
identifies a stack entry by counting from the left of the list
shown by the dirs command, starting with zero. An argument of
the form `-n' counts from the right. If the PUSHD_MINUS option
is set, the meanings of `*' and `-' in this context are swapped.
If the POSIX_CD option is set, this form of cd is not recognised
and will be interpreted as the first form.

If the -q (quiet) option is specified, the hook function chpwd
and the functions in the array chpwd_functions are not called.
This is useful for calls to cd that do not change the
environment seen by an interactive user.

If the -s option is specified, cd refuses to change the current
directory if the given pathname contains symlinks. If the -P
option is given or the CHASE_LINKS option is set, symbolic links
are resolved to their true values. If the -L option is given
symbolic links are retained in the directory (and not resolved)
regardless of the state of the CHASE_LINKS option.

chdir Same as cd.

clone See the section `The zsh/clone Module' in zshmodules(1).

command [ -pvV ] simple command
The simple command argument is taken as an external command
instead of a function or builtin and is executed. If the
POSIX_BUILTINS option is set, builtins will also be executed but
certain special properties of them are suppressed. The -p flag
causes a default path to be searched instead of that in $path.
With the -v flag, command is similar to whence and with -V, it
is equivalent to whence -v.

See also the section `Precommand Modifiers' in zshmisc(1).

comparguments
See the section `The zsh/computil Module' in zshmodules(1).

compcall
See the section `The zsh/compctl Module' in zshmodules(1).

compctl
See the section `The zsh/compctl Module' in zshmodules(1).

compdescribe
See the section `The zsh/computil Module' in zshmodules(1).

compfiles
See the section `The zsh/computil Module' in zshmodules(1).

compgroups
See the section `The zsh/computil Module' in zshmodules(1).

compquote
See the section `The zsh/computil Module' in zshmodules(1).

comptags
See the section `The zsh/computil Module' in zshmodules(1).

comptry
See the section `The zsh/computil Module' in zshmodules(1).

compvalues
See the section `The zsh/computil Module' in zshmodules(1).

continue [ n ]
Resume the next iteration of the enclosing for, while, until,
select or repeat loop. If an arithmetic expression n is
specified, break out of n-1 loops and resume at the nth
enclosing loop.

declare
Same as typeset.

dirs [ -c ] [ arg ... ]
dirs [ -lpv ]
With no arguments, print the contents of the directory stack.
Directories are added to this stack with the pushd command, and
removed with the cd or popd commands. If arguments are
specified, load them onto the directory stack, replacing
anything that was there, and push the current directory onto the
stack.

-c clear the directory stack.

-l print directory names in full instead of using of using ~
expressions (see Dynamic and Static named directories in
zshexpn(1)).

-p print directory entries one per line.

-v number the directories in the stack when printing.

disable [ -afmprs ] name ...
Temporarily disable the named hash table elements or patterns.
The default is to disable builtin commands. This allows you to
use an external command with the same name as a builtin command.
The -a option causes disable to act on regular or global
aliases. The -s option causes disable to act on suffix aliases.
The -f option causes disable to act on shell functions. The -r
options causes disable to act on reserved words. Without
arguments all disabled hash table elements from the
corresponding hash table are printed. With the -m flag the
arguments are taken as patterns (which should be quoted to
prevent them from undergoing filename expansion), and all hash
table elements from the corresponding hash table matching these
patterns are disabled. Disabled objects can be enabled with the
enable command.

With the option -p, name ... refer to elements of the shell's
pattern syntax as described in the section `Filename
Generation'. Certain elements can be disabled separately, as
given below.

Note that patterns not allowed by the current settings for the
options EXTENDED_GLOB, KSH_GLOB and SH_GLOB are never enabled,
regardless of the setting here. For example, if EXTENDED_GLOB
is not active, the pattern ^ is ineffective even if `disable -p
"^"' has not been issued. The list below indicates any option
settings that restrict the use of the pattern. It should be
noted that setting SH_GLOB has a wider effect than merely
disabling patterns as certain expressions, in particular those
involving parentheses, are parsed differently.

The following patterns may be disabled; all the strings need
quoting on the command line to prevent them from being
interpreted immediately as patterns and the patterns are shown
below in single quotes as a reminder.

'?' The pattern character ? wherever it occurs, including
when preceding a parenthesis with KSH_GLOB.

'*' The pattern character * wherever it occurs, including
recursive globbing and when preceding a parenthesis with
KSH_GLOB.

'[' Character classes.

'<' (NO_SH_GLOB)
Numeric ranges.

'|' (NO_SH_GLOB)
Alternation in grouped patterns, case statements, or
KSH_GLOB parenthesised expressions.

'(' (NO_SH_GLOB)
Grouping using single parentheses. Disabling this does
not disable the use of parentheses for KSH_GLOB where
they are introduced by a special character, nor for glob
qualifiers (use `setopt NO_BARE_GLOB_QUAL' to disable
glob qualifiers that use parentheses only).

'~' (EXTENDED_GLOB)
Exclusion in the form A~B.

'^' (EXTENDED_GLOB)
Exclusion in the form A^B.

'#' (EXTENDED_GLOB)
The pattern character # wherever it occurs, both for
repetition of a previous pattern and for indicating
globbing flags.

'?(' (KSH_GLOB)
The grouping form ?(...). Note this is also disabled if
'?' is disabled.

'*(' (KSH_GLOB)
The grouping form *(...). Note this is also disabled if
'*' is disabled.

'+(' (KSH_GLOB)
The grouping form +(...).

'!(' (KSH_GLOB)
The grouping form !(...).

'@(' (KSH_GLOB)
The grouping form @(...).

disown [ job ... ]
job ... &|
job ... &!
Remove the specified jobs from the job table; the shell will no
longer report their status, and will not complain if you try to
exit an interactive shell with them running or stopped. If no
job is specified, disown the current job.

If the jobs are currently stopped and the AUTO_CONTINUE option
is not set, a warning is printed containing information about
how to make them running after they have been disowned. If one
of the latter two forms is used, the jobs will automatically be
made running, independent of the setting of the AUTO_CONTINUE
option.

echo [ -neE ] [ arg ... ]
Write each arg on the standard output, with a space separating
each one. If the -n flag is not present, print a newline at the
end. echo recognizes the following escape sequences:

\a bell character
\b backspace
\c suppress subsequent characters and final newline
\e escape
\f form feed
\n linefeed (newline)
\r carriage return
\t horizontal tab
\v vertical tab
\\ backslash
\0NNN character code in octal
\xNN character code in hexadecimal
\uNNNN unicode character code in hexadecimal
\UNNNNNNNN
unicode character code in hexadecimal

The -E flag, or the BSD_ECHO option, can be used to disable
these escape sequences. In the latter case, -e flag can be used
to enable them.

Note that for standards compliance a double dash does not
terminate option processing; instead, it is printed directly.
However, a single dash does terminate option processing, so the
first dash, possibly following options, is not printed, but
everything following it is printed as an argument. The single
dash behaviour is different from other shells. For a more
portable way of printing text, see printf, and for a more
controllable way of printing text within zsh, see print.

echotc See the section `The zsh/termcap Module' in zshmodules(1).

echoti See the section `The zsh/terminfo Module' in zshmodules(1).

emulate [ -lLR ] [ {zsh|sh|ksh|csh} [ flags ... ] ]
Without any argument print current emulation mode.

With single argument set up zsh options to emulate the specified
shell as much as possible. csh will never be fully emulated.
If the argument is not one of the shells listed above, zsh will
be used as a default; more precisely, the tests performed on the
argument are the same as those used to determine the emulation
at startup based on the shell name, see the section
COMPATIBILITY in zsh(1) . In addition to setting shell options,
the command also restores the pristine state of pattern enables,
as if all patterns had been enabled using enable -p.

If the emulate command occurs inside a function that has been
marked for execution tracing with functions -t then the xtrace
option will be turned on regardless of emulation mode or other
options. Note that code executed inside the function by the .,
source, or eval commands is not considered to be running
directly from the function, hence does not provoke this
behaviour.

If the -R switch is given, all settable options are reset to
their default value corresponding to the specified emulation
mode, except for certain options describing the interactive
environment; otherwise, only those options likely to cause
portability problems in scripts and functions are altered. If
the -L switch is given, the options LOCAL_OPTIONS,
LOCAL_PATTERNS and LOCAL_TRAPS will be set as well, causing the
effects of the emulate command and any setopt, disable -p or
enable -p, and trap commands to be local to the immediately
surrounding shell function, if any; normally these options are
turned off in all emulation modes except ksh. The -L switch is
mutually exclusive with the use of -c in flags.

If there is a single argument and the -l switch is given, the
options that would be set or unset (the latter indicated with
the prefix `no') are listed. -l can be combined with -L or -R
and the list will be modified in the appropriate way. Note the
list does not depend on the current setting of options, i.e. it
includes all options that may in principle change, not just
those that would actually change.

The flags may be any of the invocation-time flags described in
the section INVOCATION in zsh(1), except that `-o EMACS' and `-o
VI' may not be used. Flags such as `+r'/`+o RESTRICTED' may be
prohibited in some circumstances.

If -c arg appears in flags, arg is evaluated while the requested
emulation is temporarily in effect. In this case the emulation
mode and all options are restored to their previous values
before emulate returns. The -R switch may precede the name of
the shell to emulate; note this has a meaning distinct from
including -R in flags.

Use of -c enables `sticky' emulation mode for functions defined
within the evaluated expression: the emulation mode is
associated thereafter with the function so that whenever the
function is executed the emulation (respecting the -R switch, if
present) and all options are set (and pattern disables cleared)
before entry to the function, and the state is restored after
exit. If the function is called when the sticky emulation is
already in effect, either within an `emulate shell -c'
expression or within another function with the same sticky
emulation, entry and exit from the function do not cause options
to be altered (except due to standard processing such as the
LOCAL_OPTIONS option). This also applies to functions marked
for autoload within the sticky emulation; the appropriate set of
options will be applied at the point the function is loaded as
well as when it is run.

For example:

emulate sh -c 'fni() { setopt cshnullglob; }
fno() { fni; }'
fno

The two functions fni and fno are defined with sticky sh
emulation. fno is then executed, causing options associated
with emulations to be set to their values in sh. fno then calls
fni; because fni is also marked for sticky sh emulation, no
option changes take place on entry to or exit from it. Hence
the option cshnullglob, turned off by sh emulation, will be
turned on within fni and remain on return to fno. On exit from
fno, the emulation mode and all options will be restored to the
state they were in before entry to the temporary emulation.

The documentation above is typically sufficient for the intended
purpose of executing code designed for other shells in a
suitable environment. More detailed rules follow.
1. The sticky emulation environment provided by `emulate
shell -c' is identical to that provided by entry to a
function marked for sticky emulation as a consequence of
being defined in such an environment. Hence, for
example, the sticky emulation is inherited by
subfunctions defined within functions with sticky
emulation.
2. No change of options takes place on entry to or exit from
functions that are not marked for sticky emulation, other
than those that would normally take place, even if those
functions are called within sticky emulation.
3. No special handling is provided for functions marked for
autoload nor for functions present in wordcode created by
the zcompile command.
4. The presence or absence of the -R switch to emulate
corresponds to different sticky emulation modes, so for
example `emulate sh -c', `emulate -R sh -c' and `emulate
csh -c' are treated as three distinct sticky emulations.
5. Difference in shell options supplied in addition to the
basic emulation also mean the sticky emulations are
different, so for example `emulate zsh -c' and `emulate
zsh -o cbases -c' are treated as distinct sticky
emulations.

enable [ -afmprs ] name ...
Enable the named hash table elements, presumably disabled
earlier with disable. The default is to enable builtin
commands. The -a option causes enable to act on regular or
global aliases. The -s option causes enable to act on suffix
aliases. The -f option causes enable to act on shell functions.
The -r option causes enable to act on reserved words. Without
arguments all enabled hash table elements from the corresponding
hash table are printed. With the -m flag the arguments are
taken as patterns (should be quoted) and all hash table elements
from the corresponding hash table matching these patterns are
enabled. Enabled objects can be disabled with the disable
builtin command.

enable -p reenables patterns disabled with disable -p. Note
that it does not override globbing options; for example, `enable
-p "~"' does not cause the pattern character ~ to be active
unless the EXTENDED_GLOB option is also set. To enable all
possible patterns (so that they may be individually disabled
with disable -p), use `setopt EXTENDED_GLOB KSH_GLOB
NO_SH_GLOB'.

eval [ arg ... ]
Read the arguments as input to the shell and execute the
resulting command(s) in the current shell process. The return
status is the same as if the commands had been executed directly
by the shell; if there are no args or they contain no commands
(i.e. are an empty string or whitespace) the return status is
zero.

exec [ -cl ] [ -a argv0 ] [ command [ arg ... ] ]
Replace the current shell with command rather than forking. If
command is a shell builtin command or a shell function, the
shell executes it, and exits when the command is complete.

With -c clear the environment; with -l prepend - to the argv[0]
string of the command executed (to simulate a login shell); with
-a argv0 set the argv[0] string of the command executed. See
the section `Precommand Modifiers' in zshmisc(1).

If the option POSIX_BUILTINS is set, command is never
interpreted as a shell builtin command or shell function. This
means further precommand modifiers such as builtin and noglob
are also not interpreted within the shell. Hence command is
always found by searching the command path.

If command is omitted but any redirections are specified, then
the redirections will take effect in the current shell.

exit [ n ]
Exit the shell with the exit status specified by an arithmetic
expression n; if none is specified, use the exit status from the
last command executed. An EOF condition will also cause the
shell to exit, unless the IGNORE_EOF option is set.

See notes at the end of the section JOBS in zshmisc(1) for some
possibly unexpected interactions of the exit command with jobs.

export [ name[=value] ... ]
The specified names are marked for automatic export to the
environment of subsequently executed commands. Equivalent to
typeset -gx. If a parameter specified does not already exist,
it is created in the global scope.

false [ arg ... ]
Do nothing and return an exit status of 1.

fc [ -e ename ] [ -s ] [ -LI ] [ -m match ] [ old=new ... ] [ first [
last ] ]
fc -l [ -LI ] [ -nrdfEiD ] [ -t timefmt ] [ -m match ]
[ old=new ... ] [ first [ last ] ]
fc -p [ -a ] [ filename [ histsize [ savehistsize ] ] ]
fc -P
fc -ARWI [ filename ]
The fc command controls the interactive history mechanism. Note
that reading and writing of history options is only performed if
the shell is interactive. Usually this is detected
automatically, but it can be forced by setting the interactive
option when starting the shell.

The first two forms of this command select a range of events
from first to last from the history list. The arguments first
and last may be specified as a number or as a string. A
negative number is used as an offset to the current history
event number. A string specifies the most recent event
beginning with the given string. All substitutions old=new, if
any, are then performed on the text of the events.

The range of events selected by numbers can be narrowed further
by the following flags.
-I restricts to only internal events (not from $HISTFILE)
-L restricts to only local events (not from other shells,
see SHARE_HISTORY in zshoptions(1) -- note that $HISTFILE
is considered local when read at startup)
-m takes the first argument as a pattern (which should be
quoted) and only the history events matching this pattern
are considered

If first is not specified, it will be set to -1 (the most recent
event), or to -16 if the -l flag is given. If last is not
specified, it will be set to first, or to -1 if the -l flag is
given. However, if the current event has added entries to the
history with `print -s' or `fc -R', then the default last for -l
includes all new history entries since the current event began.

When the -l flag is given, the resulting events are listed on
standard output. Otherwise the editor program specified by -e
ename is invoked on a file containing these history events. If
-e is not given, the value of the parameter FCEDIT is used; if
that is not set the value of the parameter EDITOR is used; if
that is not set a builtin default, usually `vi' is used. If
ename is `-', no editor is invoked. When editing is complete,
the edited command is executed.

The flag `-s' is equivalent to `-e -'. The flag -r reverses the
order of the events and the flag -n suppresses event numbers
when listing.

Also when listing,
-d prints timestamps for each event
-f prints full time-date stamps in the US `MM/DD/YY hh:mm'
format
-E prints full time-date stamps in the European `dd.mm.yyyy
hh:mm' format
-i prints full time-date stamps in ISO8601 `yyyy-mm-dd
hh:mm' format
-t fmt prints time and date stamps in the given format; fmt is
formatted with the strftime function with the zsh
extensions described for the %D{string} prompt format in
the section EXPANSION OF PROMPT SEQUENCES in zshmisc(1).
The resulting formatted string must be no more than 256
characters or will not be printed
-D prints elapsed times; may be combined with one of the
options above

`fc -p' pushes the current history list onto a stack and
switches to a new history list. If the -a option is also
specified, this history list will be automatically popped when
the current function scope is exited, which is a much better
solution than creating a trap function to call `fc -P' manually.
If no arguments are specified, the history list is left empty,
$HISTFILE is unset, and $HISTSIZE & $SAVEHIST are set to their
default values. If one argument is given, $HISTFILE is set to
that filename, $HISTSIZE & $SAVEHIST are left unchanged, and the
history file is read in (if it exists) to initialize the new
list. If a second argument is specified, $HISTSIZE & $SAVEHIST
are instead set to the single specified numeric value. Finally,
if a third argument is specified, $SAVEHIST is set to a separate
value from $HISTSIZE. You are free to change these environment
values for the new history list however you desire in order to
manipulate the new history list.

`fc -P' pops the history list back to an older list saved by `fc
-p'. The current list is saved to its $HISTFILE before it is
destroyed (assuming that $HISTFILE and $SAVEHIST are set
appropriately, of course). The values of $HISTFILE, $HISTSIZE,
and $SAVEHIST are restored to the values they had when `fc -p'
was called. Note that this restoration can conflict with making
these variables "local", so your best bet is to avoid local
declarations for these variables in functions that use `fc -p'.
The one other guaranteed-safe combination is declaring these
variables to be local at the top of your function and using the
automatic option (-a) with `fc -p'. Finally, note that it is
legal to manually pop a push marked for automatic popping if you
need to do so before the function exits.

`fc -R' reads the history from the given file, `fc -W' writes
the history out to the given file, and `fc -A' appends the
history out to the given file. If no filename is specified, the
$HISTFILE is assumed. If the -I option is added to -R, only
those events that are not already contained within the internal
history list are added. If the -I option is added to -A or -W,
only those events that are new since last incremental
append/write to the history file are appended/written. In any
case, the created file will have no more than $SAVEHIST entries.

fg [ job ... ]
job ...
Bring each specified job in turn to the foreground. If no job
is specified, resume the current job.

float [ {*|-}Hghlprtux ] [ {+|-}EFLRZ [ n ] ] [ name[=value] ... ]
Equivalent to typeset -E, except that options irrelevant to
floating point numbers are not permitted.

functions [ {*|-}UkmtTuWz ] [ -x num ] [ name ... ]
functions -c oldfn newfn
functions -M [-s] mathfn [ min [ max [ shellfn ] ] ]
functions -M [ -m pattern ... ]
functions +M [ -m ] mathfn ...
Equivalent to typeset -f, with the exception of the -c, -x, -M
and -W options. For functions -u and functions -U, see
autoload, which provides additional options. For functions -t
and functions -T, see typeset -f.

The -x option indicates that any functions output will have each
leading tab for indentation, added by the shell to show
syntactic structure, expanded to the given number num of spaces.
num can also be 0 to suppress all indentation.

The -W option turns on the option WARN_NESTED_VAR for the named
function or functions only. The option is turned off at the
start of nested functions (apart from anonoymous functions)
unless the called function also has the -W attribute.

The -c option causes oldfn to be copied to newfn. The copy is
efficiently handled internally by reference counting. If oldfn
was marked for autoload it is first loaded and if this fails the
copy fails. Either function may subsequently be redefined
without affecting the other. A typical idiom is that oldfn is
the name of a library shell function which is then redefined to
call newfn, thereby installing a modified version of the
function.

The -M and +M flags

Use of the -M option may not be combined with any of the options
handled by typeset -f.

functions -M mathfn defines mathfn as the name of a mathematical
function recognised in all forms of arithmetical expressions;
see the section `Arithmetic Evaluation' in zshmisc(1). By
default mathfn may take any number of comma-separated arguments.
If min is given, it must have exactly min args; if min and max
are both given, it must have at least min and at most max args.
max may be -1 to indicate that there is no upper limit.

By default the function is implemented by a shell function of
the same name; if shellfn is specified it gives the name of the
corresponding shell function while mathfn remains the name used
in arithmetical expressions. The name of the function in $0 is
mathfn (not shellfn as would usually be the case), provided the
option FUNCTION_ARGZERO is in effect. The positional parameters
in the shell function correspond to the arguments of the
mathematical function call.

The result of the last arithmetical expression evaluated inside
the shell function gives the result of the mathematical
function. This is not limited to arithmetic substitutions of
the form $((...)), but also includes arithmetical expressions
evaluated in any other way, including by the let builtin, by
((...)) statements, and even by the return builtin and by array
subscripts. Therefore, care must be taken not to use
syntactical constructs that perform arithmetic evaluation after
evaluating what is to be the result of the function. For
example:

# WRONG
zmath_cube() {
(( $1 * $1 * $1 ))
return 0
}
functions -M cube 1 1 zmath_cube
print $(( cube(3) ))

This will print `0' because of the return.

Commenting the return out would lead to a different problem: the
((...)) statement would become the last statement in the
function, so the return status ($?) of the function would be
non-zero (indicating failure) whenever the arithmetic result of
the function would happen to be zero (numerically):

# WRONG
zmath_cube() {
(( $1 * $1 * $1 ))
}
functions -M cube 1 1 zmath_cube
print $(( cube(0) ))

Instead, the true builtin can be used:

# RIGHT
zmath_cube() {
(( $1 * $1 * $1 ))
true
}
functions -M cube 1 1 zmath_cube
print $(( cube(3) ))

If the additional option -s is given to functions -M, the
argument to the function is a single string: anything between
the opening and matching closing parenthesis is passed to the
function as a single argument, even if it includes commas or
white space. The minimum and maximum argument specifiers must
therefore be 1 if given. An empty argument list is passed as a
zero-length string. Thus, the following string function takes a
single argument, including the commas, and prints 11:

stringfn() { (( $#1 )); true }
functions -Ms stringfn
print $(( stringfn(foo,bar,rod) ))

functions -M with no arguments lists all such user-defined
functions in the same form as a definition. With the additional
option -m and a list of arguments, all functions whose mathfn
matches one of the pattern arguments are listed.

function +M removes the list of mathematical functions; with the
additional option -m the arguments are treated as patterns and
all functions whose mathfn matches the pattern are removed.
Note that the shell function implementing the behaviour is not
removed (regardless of whether its name coincides with mathfn).

getcap See the section `The zsh/cap Module' in zshmodules(1).

getln [ -AclneE ] name ...
Read the top value from the buffer stack and put it in the shell
parameter name. Equivalent to read -zr.

getopts optstring name [ arg ... ]
Checks the args for legal options. If the args are omitted, use
the positional parameters. A valid option argument begins with
a `*' or a `-'. An argument not beginning with a `+' or a `-',
or the argument `--', ends the options. Note that a single `-'
is not considered a valid option argument. optstring contains
the letters that getopts recognizes. If a letter is followed by
a `:', that option requires an argument. The options can be
separated from the argument by blanks.

Each time it is invoked, getopts places the option letter it
finds in the shell parameter name, prepended with a `*' when arg
begins with a `*'. The index of the next arg is stored in
OPTIND. The option argument, if any, is stored in OPTARG.

The first option to be examined may be changed by explicitly
assigning to OPTIND. OPTIND has an initial value of 1, and is
normally set to 1 upon entry to a shell function and restored
upon exit. (The POSIX_BUILTINS option disables this, and also
changes the way the value is calculated to match other shells.)
OPTARG is not reset and retains its value from the most recent
call to getopts. If either of OPTIND or OPTARG is explicitly
unset, it remains unset, and the index or option argument is not
stored. The option itself is still stored in name in this case.

A leading `:' in optstring causes getopts to store the letter of
any invalid option in OPTARG, and to set name to `?' for an
unknown option and to `:' when a required argument is missing.
Otherwise, getopts sets name to `?' and prints an error message
when an option is invalid. The exit status is nonzero when
there are no more options.

hash [ -Ldfmrv ] [ name[=value] ] ...
hash can be used to directly modify the contents of the command
hash table, and the named directory hash table. Normally one
would modify these tables by modifying one's PATH (for the
command hash table) or by creating appropriate shell parameters
(for the named directory hash table). The choice of hash table
to work on is determined by the -d option; without the option
the command hash table is used, and with the option the named
directory hash table is used.

A command name starting with a / is never hashed, whether by
explicit use of the hash command or otherwise. Such a command
is always found by direct look up in the file system.

Given no arguments, and neither the -r or -f options, the
selected hash table will be listed in full.

The -r option causes the selected hash table to be emptied. It
will be subsequently rebuilt in the normal fashion. The -f
option causes the selected hash table to be fully rebuilt
immediately. For the command hash table this hashes all the
absolute directories in the PATH, and for the named directory
hash table this adds all users' home directories. These two
options cannot be used with any arguments.

The -m option causes the arguments to be taken as patterns
(which should be quoted) and the elements of the hash table
matching those patterns are printed. This is the only way to
display a limited selection of hash table elements.

For each name with a corresponding value, put `name' in the
selected hash table, associating it with the pathname `value'.
In the command hash table, this means that whenever `name' is
used as a command argument, the shell will try to execute the
file given by `value'. In the named directory hash table, this
means that `value' may be referred to as `~name'.

For each name with no corresponding value, attempt to add name
to the hash table, checking what the appropriate value is in the
normal manner for that hash table. If an appropriate value
can't be found, then the hash table will be unchanged.

The -v option causes hash table entries to be listed as they are
added by explicit specification. If has no effect if used with
-f.

If the -L flag is present, then each hash table entry is printed
in the form of a call to hash.

history
Same as fc -l.

integer [ {*|-}Hghlprtux ] [ {+|-}LRZi [ n ] ] [ name[=value] ... ]
Equivalent to typeset -i, except that options irrelevant to
integers are not permitted.

jobs [ -dlprs ] [ job ... ]
jobs -Z string
Lists information about each given job, or all jobs if job is
omitted. The -l flag lists process IDs, and the -p flag lists
process groups. If the -r flag is specified only running jobs
will be listed and if the -s flag is given only stopped jobs are
shown. If the -d flag is given, the directory from which the
job was started (which may not be the current directory of the
job) will also be shown.

The -Z option replaces the shell's argument and environment
space with the given string, truncated if necessary to fit.
This will normally be visible in ps (ps(1)) listings. This
feature is typically used by daemons, to indicate their state.

Full job control is only available in the top-level interactive
shell, not in commands run in the left hand side of pipelines or
within the (...) construct. However, a snapshot of the job
state at that point is taken, so it is still possible to use the
jobs builtin, or any parameter providing job information. This
gives information about the state of jobs at the point the
subshell was created. If background processes are created
within the subshell, then instead information about those
processes is provided.

For example,

sleep 10 & # Job in background
( # Shell forks
jobs # Shows information about "sleep 10 &"
sleep 5 & # Process in background (no job control)
jobs # Shows information about "sleep 5 &"
)

kill [ -s signal_name | -n signal_number | -sig ] job ...
kill -l [ sig ... ]
Sends either SIGTERM or the specified signal to the given jobs
or processes. Signals are given by number or by names, with or
without the `SIG' prefix. If the signal being sent is not
`KILL' or `CONT', then the job will be sent a `CONT' signal if
it is stopped. The argument job can be the process ID of a job
not in the job list. In the second form, kill -l, if sig is not
specified the signal names are listed. Otherwise, for each sig
that is a name, the corresponding signal number is listed. For
each sig that is a signal number or a number representing the
exit status of a process which was terminated or stopped by a
signal the name of the signal is printed.

On some systems, alternative signal names are allowed for a few
signals. Typical examples are SIGCHLD and SIGCLD or SIGPOLL and
SIGIO, assuming they correspond to the same signal number. kill
-l will only list the preferred form, however kill -l alt will
show if the alternative form corresponds to a signal number.
For example, under Linux kill -l IO and kill -l POLL both output
29, hence kill -IO and kill -POLL have the same effect.

Many systems will allow process IDs to be negative to kill a
process group or zero to kill the current process group.

let arg ...
Evaluate each arg as an arithmetic expression. See the section
`Arithmetic Evaluation' in zshmisc(1) for a description of
arithmetic expressions. The exit status is 0 if the value of
the last expression is nonzero, 1 if it is zero, and 2 if an
error occurred.

limit [ -hs ] [ resource [ limit ] ] ...
Set or display resource limits. Unless the -s flag is given,
the limit applies only the children of the shell. If -s is
given without other arguments, the resource limits of the
current shell is set to the previously set resource limits of
the children.

If limit is not specified, print the current limit placed on
resource, otherwise set the limit to the specified value. If
the -h flag is given, use hard limits instead of soft limits.
If no resource is given, print all limits.

When looping over multiple resources, the shell will abort
immediately if it detects a badly formed argument. However, if
it fails to set a limit for some other reason it will continue
trying to set the remaining limits.

resource can be one of:

addressspace
Maximum amount of address space used.
aiomemorylocked
Maximum amount of memory locked in RAM for AIO
operations.
aiooperations
Maximum number of AIO operations.
cachedthreads
Maximum number of cached threads.
coredumpsize
Maximum size of a core dump.
cputime
Maximum CPU seconds per process.
datasize
Maximum data size (including stack) for each process.
descriptors
Maximum value for a file descriptor.
filesize
Largest single file allowed.
kqueues
Maximum number of kqueues allocated.
maxproc
Maximum number of processes.
maxpthreads
Maximum number of threads per process.
memorylocked
Maximum amount of memory locked in RAM.
memoryuse
Maximum resident set size.
msgqueue
Maximum number of bytes in POSIX message queues.
posixlocks
Maximum number of POSIX locks per user.
pseudoterminals
Maximum number of pseudo-terminals.
resident
Maximum resident set size.
sigpending
Maximum number of pending signals.
sockbufsize
Maximum size of all socket buffers.
stacksize
Maximum stack size for each process.
swapsize
Maximum amount of swap used.
vmemorysize
Maximum amount of virtual memory.

Which of these resource limits are available depends on the
system. resource can be abbreviated to any unambiguous prefix.
It can also be an integer, which corresponds to the integer
defined for the resource by the operating system.

If argument corresponds to a number which is out of the range of
the resources configured into the shell, the shell will try to
read or write the limit anyway, and will report an error if this
fails. As the shell does not store such resources internally,
an attempt to set the limit will fail unless the -s option is
present.

limit is a number, with an optional scaling factor, as follows:

nh hours
nk kilobytes (default)
nm megabytes or minutes
ng gigabytes
[mm:]ss
minutes and seconds

The limit command is not made available by default when the
shell starts in a mode emulating another shell. It can be made
available with the command `zmodload -F zsh/rlimits b:limit'.

local [ {*|-}AHUahlprtux ] [ {+|-}EFLRZi [ n ] ] [ name[=value] ... ]
Same as typeset, except that the options -g, and -f are not
permitted. In this case the -x option does not force the use of
-g, i.e. exported variables will be local to functions.

logout [ n ]
Same as exit, except that it only works in a login shell.

noglob simple command
See the section `Precommand Modifiers' in zshmisc(1).

popd [ -q ] [ {*|-}n ]
Remove an entry from the directory stack, and perform a cd to
the new top directory. With no argument, the current top entry
is removed. An argument of the form `*n' identifies a stack
entry by counting from the left of the list shown by the dirs
command, starting with zero. An argument of the form -n counts
from the right. If the PUSHD_MINUS option is set, the meanings
of `*' and `-' in this context are swapped.

If the -q (quiet) option is specified, the hook function chpwd
and the functions in the array $chpwd_functions are not called,
and the new directory stack is not printed. This is useful for
calls to popd that do not change the environment seen by an
interactive user.

print [ -abcDilmnNoOpPrsSz ] [ -u n ] [ -f format ] [ -C cols ]
[ -v name ] [ -xX tabstop ] [ -R [ -en ]] [ arg ... ]
With the `-f' option the arguments are printed as described by
printf. With no flags or with the flag `-', the arguments are
printed on the standard output as described by echo, with the
following differences: the escape sequence `\M-x' (or `\Mx')
metafies the character x (sets the highest bit), `\C-x' (or
`\Cx') produces a control character (`\C-@' and `\C-?' give the
characters NULL and delete), a character code in octal is
represented by `\NNN' (instead of `\0NNN'), and `\E' is a
synonym for `\e'. Finally, if not in an escape sequence, `\'
escapes the following character and is not printed.

-a Print arguments with the column incrementing first. Only
useful with the -c and -C options.

-b Recognize all the escape sequences defined for the
bindkey command, see the section `Zle Builtins' in
zshzle(1).

-c Print the arguments in columns. Unless -a is also given,
arguments are printed with the row incrementing first.

-C cols
Print the arguments in cols columns. Unless -a is also
given, arguments are printed with the row incrementing
first.

-D Treat the arguments as paths, replacing directory
prefixes with ~ expressions corresponding to directory
names, as appropriate.

-i If given together with -o or -O, sorting is performed
case-independently.

-l Print the arguments separated by newlines instead of
spaces. Note: if the list of arguments is empty, print
-l will still output one empty line. To print a
possibly-empty list of arguments one per line, use print
-C1, as in `print -rC1 -- "$list[@]"'.

-m Take the first argument as a pattern (should be quoted),
and remove it from the argument list together with
subsequent arguments that do not match this pattern.

-n Do not add a newline to the output.

-N Print the arguments separated and terminated by nulls.
Again, print -rNC1 -- "$list[@]" is a canonical way to
print an arbitrary list as null-delimited records.

-o Print the arguments sorted in ascending order.

-O Print the arguments sorted in descending order.

-p Print the arguments to the input of the coprocess.

-P Perform prompt expansion (see EXPANSION OF PROMPT
SEQUENCES in zshmisc(1)). In combination with `-f',
prompt escape sequences are parsed only within
interpolated arguments, not within the format string.

-r Ignore the escape conventions of echo.

-R Emulate the BSD echo command, which does not process
escape sequences unless the -e flag is given. The -n
flag suppresses the trailing newline. Only the -e and -n
flags are recognized after -R; all other arguments and
options are printed.

-s Place the results in the history list instead of on the
standard output. Each argument to the print command is
treated as a single word in the history, regardless of
its content.

-S Place the results in the history list instead of on the
standard output. In this case only a single argument is
allowed; it will be split into words as if it were a full
shell command line. The effect is similar to reading the
line from a history file with the HIST_LEX_WORDS option
active.

-u n Print the arguments to file descriptor n.

-v name
Store the printed arguments as the value of the parameter
name.

-x tab-stop
Expand leading tabs on each line of output in the printed
string assuming a tab stop every tab-stop characters.
This is appropriate for formatting code that may be
indented with tabs. Note that leading tabs of any
argument to print, not just the first, are expanded, even
if print is using spaces to separate arguments (the
column count is maintained across arguments but may be
incorrect on output owing to previous unexpanded tabs).

The start of the output of each print command is assumed
to be aligned with a tab stop. Widths of multibyte
characters are handled if the option MULTIBYTE is in
effect. This option is ignored if other formatting
options are in effect, namely column alignment or printf
style, or if output is to a special location such as
shell history or the command line editor.

-X tab-stop
This is similar to -x, except that all tabs in the
printed string are expanded. This is appropriate if tabs
in the arguments are being used to produce a table
format.

-z Push the arguments onto the editing buffer stack,
separated by spaces.

If any of `-m', `-o' or `-O' are used in combination with `-f'
and there are no arguments (after the removal process in the
case of `-m') then nothing is printed.

printf [ -v name ] format [ arg ... ]
Print the arguments according to the format specification.
Formatting rules are the same as used in C. The same escape
sequences as for echo are recognised in the format. All C
conversion specifications ending in one of csdiouxXeEfgGn are
handled. In addition to this, `%b' can be used instead of `%s'
to cause escape sequences in the argument to be recognised and
`%q' can be used to quote the argument in such a way that allows
it to be reused as shell input. With the numeric format
specifiers, if the corresponding argument starts with a quote
character, the numeric value of the following character is used
as the number to print; otherwise the argument is evaluated as
an arithmetic expression. See the section `Arithmetic
Evaluation' in zshmisc(1) for a description of arithmetic
expressions. With `%n', the corresponding argument is taken as
an identifier which is created as an integer parameter.

Normally, conversion specifications are applied to each argument
in order but they can explicitly specify the nth argument is to
be used by replacing `%' by `%n$' and `*' by `*n$'. It is
recommended that you do not mix references of this explicit
style with the normal style and the handling of such mixed
styles may be subject to future change.

If arguments remain unused after formatting, the format string
is reused until all arguments have been consumed. With the print
builtin, this can be suppressed by using the -r option. If more
arguments are required by the format than have been specified,
the behaviour is as if zero or an empty string had been
specified as the argument.

The -v option causes the output to be stored as the value of the
parameter name, instead of printed. If name is an array and the
format string is reused when consuming arguments then one array
element will be used for each use of the format string.

pushd [ -qsLP ] [ arg ]
pushd [ -qsLP ] old new
pushd [ -qsLP ] {*|-}n
Change the current directory, and push the old current directory
onto the directory stack. In the first form, change the current
directory to arg. If arg is not specified, change to the second
directory on the stack (that is, exchange the top two entries),
or change to $HOME if the PUSHD_TO_HOME option is set or if
there is only one entry on the stack. Otherwise, arg is
interpreted as it would be by cd. The meaning of old and new in
the second form is also the same as for cd.

The third form of pushd changes directory by rotating the
directory list. An argument of the form `*n' identifies a stack
entry by counting from the left of the list shown by the dirs
command, starting with zero. An argument of the form `-n'
counts from the right. If the PUSHD_MINUS option is set, the
meanings of `*' and `-' in this context are swapped.

If the -q (quiet) option is specified, the hook function chpwd
and the functions in the array $chpwd_functions are not called,
and the new directory stack is not printed. This is useful for
calls to pushd that do not change the environment seen by an
interactive user.

If the option -q is not specified and the shell option
PUSHD_SILENT is not set, the directory stack will be printed
after a pushd is performed.

The options -s, -L and -P have the same meanings as for the cd
builtin.

pushln [ arg ... ]
Equivalent to print -nz.

pwd [ -rLP ]
Print the absolute pathname of the current working directory.
If the -r or the -P flag is specified, or the CHASE_LINKS option
is set and the -L flag is not given, the printed path will not
contain symbolic links.

r Same as fc -e -.

read [ -rszpqAclneE ] [ -t [ num ] ] [ -k [ num ] ] [ -d delim ]
[ -u n ] [ [name][?prompt] ] [ name ... ]
Read one line and break it into fields using the characters in
$IFS as separators, except as noted below. The first field is
assigned to the first name, the second field to the second name,
etc., with leftover fields assigned to the last name. If name
is omitted then REPLY is used for scalars and reply for arrays.

-r Raw mode: a `\' at the end of a line does not signify
line continuation and backslashes in the line don't quote
the following character and are not removed.

-s Don't echo back characters if reading from the terminal.

-q Read only one character from the terminal and set name to
`y' if this character was `y' or `Y' and to `n'
otherwise. With this flag set the return status is zero
only if the character was `y' or `Y'. This option may be
used with a timeout (see -t); if the read times out, or
encounters end of file, status 2 is returned. Input is
read from the terminal unless one of -u or -p is present.
This option may also be used within zle widgets.

-k [ num ]
Read only one (or num) characters. All are assigned to
the first name, without word splitting. This flag is
ignored when -q is present. Input is read from the
terminal unless one of -u or -p is present. This option
may also be used within zle widgets.

Note that despite the mnemonic `key' this option does
read full characters, which may consist of multiple bytes
if the option MULTIBYTE is set.

-z Read one entry from the editor buffer stack and assign it
to the first name, without word splitting. Text is
pushed onto the stack with `print -z' or with push-line
from the line editor (see zshzle(1)). This flag is
ignored when the -k or -q flags are present.

-e
-E The input read is printed (echoed) to the standard
output. If the -e flag is used, no input is assigned to
the parameters.

-A The first name is taken as the name of an array and all
words are assigned to it.

-c
-l These flags are allowed only if called inside a function
used for completion (specified with the -K flag to
compctl). If the -c flag is given, the words of the
current command are read. If the -l flag is given, the
whole line is assigned as a scalar. If both flags are
present, -l is used and -c is ignored.

-n Together with -c, the number of the word the cursor is on
is read. With -l, the index of the character the cursor
is on is read. Note that the command name is word number
1, not word 0, and that when the cursor is at the end of
the line, its character index is the length of the line
plus one.

-u n Input is read from file descriptor n.

-p Input is read from the coprocess.

-d delim
Input is terminated by the first character of delim
instead of by newline.

-t [ num ]
Test if input is available before attempting to read. If
num is present, it must begin with a digit and will be
evaluated to give a number of seconds, which may be a
floating point number; in this case the read times out if
input is not available within this time. If num is not
present, it is taken to be zero, so that read returns
immediately if no input is available. If no input is
available, return status 1 and do not set any variables.

This option is not available when reading from the editor
buffer with -z, when called from within completion with
-c or -l, with -q which clears the input queue before
reading, or within zle where other mechanisms should be
used to test for input.

Note that read does not attempt to alter the input
processing mode. The default mode is canonical input, in
which an entire line is read at a time, so usually `read
-t' will not read anything until an entire line has been
typed. However, when reading from the terminal with -k
input is processed one key at a time; in this case, only
availability of the first character is tested, so that
e.g. `read -t -k 2' can still block on the second
character. Use two instances of `read -t -k' if this is
not what is wanted.

If the first argument contains a `?', the remainder of this word
is used as a prompt on standard error when the shell is
interactive.

The value (exit status) of read is 1 when an end-of-file is
encountered, or when -c or -l is present and the command is not
called from a compctl function, or as described for -q.
Otherwise the value is 0.

The behavior of some combinations of the -k, -p, -q, -u and -z
flags is undefined. Presently -q cancels all the others, -p
cancels -u, -k cancels -z, and otherwise -z cancels both -p and
-u.

The -c or -l flags cancel any and all of -kpquz.

readonly
Same as typeset -r. With the POSIX_BUILTINS option set, same as
typeset -gr.

rehash Same as hash -r.

return [ n ]
Causes a shell function or `.' script to return to the invoking
script with the return status specified by an arithmetic
expression n. For example, the following prints `42':

() { integer foo=40; return "foo * 2" }
echo $?

If n is omitted, the return status is that of the last command
executed.

If return was executed from a trap in a TRAPNAL function, the
effect is different for zero and non-zero return status. With
zero status (or after an implicit return at the end of the
trap), the shell will return to whatever it was previously
processing; with a non-zero status, the shell will behave as
interrupted except that the return status of the trap is
retained. Note that the numeric value of the signal which
caused the trap is passed as the first argument, so the
statement `return "128+$1"' will return the same status as if
the signal had not been trapped.

sched See the section `The zsh/sched Module' in zshmodules(1).

set [ {*|-}options | {+|-}o [ option_name ] ] ... [ {+|-}A [ name ] ]
[ arg ... ]
Set the options for the shell and/or set the positional
parameters, or declare and set an array. If the -s option is
given, it causes the specified arguments to be sorted before
assigning them to the positional parameters (or to the array
name if -A is used). With +s sort arguments in descending
order. For the meaning of the other flags, see zshoptions(1).
Flags may be specified by name using the -o option. If no option
name is supplied with -o, the current option states are printed:
see the description of setopt below for more information on the
format. With +o they are printed in a form that can be used as
input to the shell.

If the -A flag is specified, name is set to an array containing
the given args; if no name is specified, all arrays are printed
together with their values.

If +A is used and name is an array, the given arguments will
replace the initial elements of that array; if no name is
specified, all arrays are printed without their values.

The behaviour of arguments after -A name or +A name depends on
whether the option KSH_ARRAYS is set. If it is not set, all
arguments following name are treated as values for the array,
regardless of their form. If the option is set, normal option
processing continues at that point; only regular arguments are
treated as values for the array. This means that

set -A array -x -- foo

sets array to `-x -- foo' if KSH_ARRAYS is not set, but sets the
array to foo and turns on the option `-x' if it is set.

If the -A flag is not present, but there are arguments beyond
the options, the positional parameters are set. If the option
list (if any) is terminated by `--', and there are no further
arguments, the positional parameters will be unset.

If no arguments and no `--' are given, then the names and values
of all parameters are printed on the standard output. If the
only argument is `*', the names of all parameters are printed.

For historical reasons, `set -' is treated as `set +xv' and `set
- args' as `set +xv -- args' when in any other emulation mode
than zsh's native mode.

setcap See the section `The zsh/cap Module' in zshmodules(1).

setopt [ {*|-}options | {+|-}o option_name ] [ -m ] [ name ... ]
Set the options for the shell. All options specified either
with flags or by name are set.

If no arguments are supplied, the names of all options currently
set are printed. The form is chosen so as to minimize the
differences from the default options for the current emulation
(the default emulation being native zsh, shown as <Z> in
zshoptions(1)). Options that are on by default for the
emulation are shown with the prefix no only if they are off,
while other options are shown without the prefix no and only if
they are on. In addition to options changed from the default
state by the user, any options activated automatically by the
shell (for example, SHIN_STDIN or INTERACTIVE) will be shown in
the list. The format is further modified by the option
KSH_OPTION_PRINT, however the rationale for choosing options
with or without the no prefix remains the same in this case.

If the -m flag is given the arguments are taken as patterns
(which should be quoted to protect them from filename
expansion), and all options with names matching these patterns
are set.

Note that a bad option name does not cause execution of
subsequent shell code to be aborted; this is behaviour is
different from that of `set -o'. This is because set is
regarded as a special builtin by the POSIX standard, but setopt
is not.

shift [ -p ] [ n ] [ name ... ]
The positional parameters ${n+1} ... are renamed to $1 ...,
where n is an arithmetic expression that defaults to 1. If any
names are given then the arrays with these names are shifted
instead of the positional parameters.

If the option -p is given arguments are instead removed (popped)
from the end rather than the start of the array.

source file [ arg ... ]
Same as `.', except that the current directory is always
searched and is always searched first, before directories in
$path.

stat See the section `The zsh/stat Module' in zshmodules(1).

suspend [ -f ]
Suspend the execution of the shell (send it a SIGTSTP) until it
receives a SIGCONT. Unless the -f option is given, this will
refuse to suspend a login shell.

test [ arg ... ]
[ [ arg ... ] ]
Like the system version of test. Added for compatibility; use
conditional expressions instead (see the section `Conditional
Expressions'). The main differences between the conditional
expression syntax and the test and [ builtins are: these
commands are not handled syntactically, so for example an empty
variable expansion may cause an argument to be omitted; syntax
errors cause status 2 to be returned instead of a shell error;
and arithmetic operators expect integer arguments rather than
arithmetic expressions.

The command attempts to implement POSIX and its extensions where
these are specified. Unfortunately there are intrinsic
ambiguities in the syntax; in particular there is no distinction
between test operators and strings that resemble them. The
standard attempts to resolve these for small numbers of
arguments (up to four); for five or more arguments compatibility
cannot be relied on. Users are urged wherever possible to use
the `[[' test syntax which does not have these ambiguities.

times Print the accumulated user and system times for the shell and
for processes run from the shell.

trap [ arg ] [ sig ... ]
arg is a series of commands (usually quoted to protect it from
immediate evaluation by the shell) to be read and executed when
the shell receives any of the signals specified by one or more
sig args. Each sig can be given as a number, or as the name of
a signal either with or without the string SIG in front (e.g. 1,
HUP, and SIGHUP are all the same signal).

If arg is `-', then the specified signals are reset to their
defaults, or, if no sig args are present, all traps are reset.

If arg is an empty string, then the specified signals are
ignored by the shell (and by the commands it invokes).

If arg is omitted but one or more sig args are provided (i.e.
the first argument is a valid signal number or name), the effect
is the same as if arg had been specified as `-'.

The trap command with no arguments prints a list of commands
associated with each signal.

If sig is ZERR then arg will be executed after each command with
a nonzero exit status. ERR is an alias for ZERR on systems that
have no SIGERR signal (this is the usual case).

If sig is DEBUG then arg will be executed before each command if
the option DEBUG_BEFORE_CMD is set (as it is by default), else
after each command. Here, a `command' is what is described as a
`sublist' in the shell grammar, see the section SIMPLE COMMANDS
& PIPELINES in zshmisc(1). If DEBUG_BEFORE_CMD is set various
additional features are available. First, it is possible to
skip the next command by setting the option ERR_EXIT; see the
description of the ERR_EXIT option in zshoptions(1). Also, the
shell parameter ZSH_DEBUG_CMD is set to the string corresponding
to the command to be executed following the trap. Note that
this string is reconstructed from the internal format and may
not be formatted the same way as the original text. The
parameter is unset after the trap is executed.

If sig is 0 or EXIT and the trap statement is executed inside
the body of a function, then the command arg is executed after
the function completes. The value of $? at the start of
execution is the exit status of the shell or the return status
of the function exiting. If sig is 0 or EXIT and the trap
statement is not executed inside the body of a function, then
the command arg is executed when the shell terminates; the trap
runs before any zshexit hook functions.

ZERR, DEBUG, and EXIT traps are not executed inside other traps.
ZERR and DEBUG traps are kept within subshells, while other
traps are reset.

Note that traps defined with the trap builtin are slightly
different from those defined as `TRAPNAL () { ... }', as the
latter have their own function environment (line numbers, local
variables, etc.) while the former use the environment of the
command in which they were called. For example,

trap 'print $LINENO' DEBUG

will print the line number of a command executed after it has
run, while

TRAPDEBUG() { print $LINENO; }

will always print the number zero.

Alternative signal names are allowed as described under kill
above. Defining a trap under either name causes any trap under
an alternative name to be removed. However, it is recommended
that for consistency users stick exclusively to one name or
another.

true [ arg ... ]
Do nothing and return an exit status of 0.

ttyctl [ -fu ]
The -f option freezes the tty (i.e. terminal or terminal
emulator), and -u unfreezes it. When the tty is frozen, no
changes made to the tty settings by external programs will be
honored by the shell, except for changes in the size of the
screen; the shell will simply reset the settings to their
previous values as soon as each command exits or is suspended.
Thus, stty and similar programs have no effect when the tty is
frozen. Freezing the tty does not cause the current state to be
remembered: instead, it causes future changes to the state to be
blocked.

Without options it reports whether the terminal is frozen or
not.

Note that, regardless of whether the tty is frozen or not, the
shell needs to change the settings when the line editor starts,
so unfreezing the tty does not guarantee settings made on the
command line are preserved. Strings of commands run between
editing the command line will see a consistent tty state. See
also the shell variable STTY for a means of initialising the tty
before running external commands and/or freezing the tty around
a single command.

type [ -wfpamsS ] name ...
Equivalent to whence -v.

typeset [ {*|-}AHUaghlmrtux ] [ {+|-}EFLRZip [ n ] ]
[ * ] [ name[=value] ... ]
typeset -T [ {*|-}Uglrux ] [ {+|-}LRZp [ n ] ]
[ * | SCALAR[=value] array[=(value ...)] [ sep ] ]
typeset -f [ {*|-}TUkmtuz ] [ + ] [ name ... ]
Set or display attributes and values for shell parameters.

Except as noted below for control flags that change the
behavior, a parameter is created for each name that does not
already refer to one. When inside a function, a new parameter
is created for every name (even those that already exist), and
is unset again when the function completes. See `Local
Parameters' in zshparam(1). The same rules apply to special
shell parameters, which retain their special attributes when
made local.

For each name=value assignment, the parameter name is set to
value. If the assignment is omitted and name does not refer to
an existing parameter, a new parameter is intialized to empty
string, zero, or empty array (as appropriate), unless the shell
option TYPESET_TO_UNSET is set. When that option is set, the
parameter attributes are recorded but the parameter remains
unset.

If the shell option TYPESET_SILENT is not set, for each
remaining name that refers to a parameter that is already set,
the name and value of the parameter are printed in the form of
an assignment. Nothing is printed for newly-created parameters,
or when any attribute flags listed below are given along with
the name. Using `*' instead of minus to introduce an attribute
turns it off.

If no name is present, the names and values of all parameters
are printed. In this case the attribute flags restrict the
display to only those parameters that have the specified
attributes, and using `*' rather than `-' to introduce the flag
suppresses printing of the values of parameters when there is no
parameter name.

All forms of the command handle scalar assignment. Array
assignment is possible if any of the reserved words declare,
export, float, integer, local, readonly or typeset is matched
when the line is parsed (N.B. not when it is executed). In this
case the arguments are parsed as assignments, except that the
`+=' syntax and the GLOB_ASSIGN option are not supported, and
scalar values after = are not split further into words, even if
expanded (regardless of the setting of the KSH_TYPESET option;
this option is obsolete).

Examples of the differences between command and reserved word
parsing:

# Reserved word parsing
typeset svar=$(echo one word) avar=(several words)

The above creates a scalar parameter svar and an array parameter
avar as if the assignments had been

svar="one word"
avar=(several words)

On the other hand:

# Normal builtin interface
builtin typeset svar=$(echo two words)

The builtin keyword causes the above to use the standard builtin
interface to typeset in which argument parsing is performed in
the same way as for other commands. This example creates a
scalar svar containing the value two and another scalar
parameter words with no value. An array value in this case
would either cause an error or be treated as an obscure set of
glob qualifiers.

Arbitrary arguments are allowed if they take the form of
assignments after command line expansion; however, these only
perform scalar assignment:

var='svar=val'
typeset $var

The above sets the scalar parameter svar to the value val.
Parentheses around the value within var would not cause array
assignment as they will be treated as ordinary characters when
$var is substituted. Any non-trivial expansion in the name part
of the assignment causes the argument to be treated in this
fashion:

typeset {var1,var2,var3}=name

The above syntax is valid, and has the expected effect of
setting the three parameters to the same value, but the command
line is parsed as a set of three normal command line arguments
to typeset after expansion. Hence it is not possible to assign
to multiple arrays by this means.

Note that each interface to any of the commands may be disabled
separately. For example, `disable -r typeset' disables the
reserved word interface to typeset, exposing the builtin
interface, while `disable typeset' disables the builtin. Note
that disabling the reserved word interface for typeset may cause
problems with the output of `typeset -p', which assumes the
reserved word interface is available in order to restore array
and associative array values.

Unlike parameter assignment statements, typeset's exit status on
an assignment that involves a command substitution does not
reflect the exit status of the command substitution. Therefore,
to test for an error in a command substitution, separate the
declaration of the parameter from its initialization:

# WRONG
typeset var1=$(exit 1) || echo "Trouble with var1"

# RIGHT
typeset var1 && var1=$(exit 1) || echo "Trouble with var1"

To initialize a parameter param to a command output and mark it
readonly, use typeset -r param or readonly param after the
parameter assignment statement.

If no attribute flags are given, and either no name arguments
are present or the flag +m is used, then each parameter name
printed is preceded by a list of the attributes of that
parameter (array, association, exported, float, integer,
readonly, or undefined for autoloaded parameters not yet
loaded). If +m is used with attribute flags, and all those
flags are introduced with *, the matching parameter names are
printed but their values are not.

The following control flags change the behavior of typeset:

* If `+' appears by itself in a separate word as the last
option, then the names of all parameters (functions with
-f) are printed, but the values (function bodies) are
not. No name arguments may appear, and it is an error
for any other options to follow `*'. The effect of `+'
is as if all attribute flags which precede it were given
with a `*' prefix. For example, `typeset -U +' is
equivalent to `typeset +U' and displays the names of all
arrays having the uniqueness attribute, whereas `typeset
-f -U *' displays the names of all autoloadable
functions. If * is the only option, then type
information (array, readonly, etc.) is also printed for
each parameter, in the same manner as `typeset +m "*"'.

-g The -g (global) means that any resulting parameter will
not be restricted to local scope. Note that this does
not necessarily mean that the parameter will be global,
as the flag will apply to any existing parameter (even if
unset) from an enclosing function. This flag does not
affect the parameter after creation, hence it has no
effect when listing existing parameters, nor does the
flag +g have any effect except in combination with -m
(see below).

-m If the -m flag is given the name arguments are taken as
patterns (use quoting to prevent these from being
interpreted as file patterns). With no attribute flags,
all parameters (or functions with the -f flag) with
matching names are printed (the shell option
TYPESET_SILENT is not used in this case).

If the +g flag is combined with -m, a new local parameter
is created for every matching parameter that is not
already local. Otherwise -m applies all other flags or
assignments to the existing parameters.

Except when assignments are made with name=value, using
+m forces the matching parameters and their attributes to
be printed, even inside a function. Note that -m is
ignored if no patterns are given, so `typeset -m'
displays attributes but `typeset -a +m' does not.

-p [ n ]
If the -p option is given, parameters and values are
printed in the form of a typeset command with an
assignment, regardless of other flags and options. Note
that the -H flag on parameters is respected; no value
will be shown for these parameters.

-p may be followed by an optional integer argument.
Currently only the value 1 is supported. In this case
arrays and associative arrays are printed with newlines
between indented elements for readability.

-T [ scalar[=value] array[=(value ...)] [ sep ] ]
This flag has a different meaning when used with -f; see
below. Otherwise the -T option requires zero, two, or
three arguments to be present. With no arguments, the
list of parameters created in this fashion is shown.
With two or three arguments, the first two are the name
of a scalar and of an array parameter (in that order)
that will be tied together in the manner of $PATH and
$path. The optional third argument is a single-character
separator which will be used to join the elements of the
array to form the scalar; if absent, a colon is used, as
with $PATH. Only the first character of the separator is
significant; any remaining characters are ignored.
Multibyte characters are not yet supported.

Only one of the scalar and array parameters may be
assigned an initial value (the restrictions on assignment
forms described above also apply).

Both the scalar and the array may be manipulated as
normal. If one is unset, the other will automatically be
unset too. There is no way of untying the variables
without unsetting them, nor of converting the type of one
of them with another typeset command; +T does not work,
assigning an array to scalar is an error, and assigning a
scalar to array sets it to be a single-element array.

Note that both `typeset -xT ...' and `export -T ...'
work, but only the scalar will be marked for export.
Setting the value using the scalar version causes a split
on all separators (which cannot be quoted). It is
possible to apply -T to two previously tied variables but
with a different separator character, in which case the
variables remain joined as before but the separator is
changed.

When an existing scalar is tied to a new array, the value
of the scalar is preserved but no attribute other than
export will be preserved.

Attribute flags that transform the final value (-L, -R, -Z, -l,
-u) are only applied to the expanded value at the point of a
parameter expansion expression using `$'. They are not applied
when a parameter is retrieved internally by the shell for any
purpose.

The following attribute flags may be specified:

-A The names refer to associative array parameters; see
`Array Parameters' in zshparam(1).

-L [ n ]
Left justify and remove leading blanks from the value
when the parameter is expanded. If n is nonzero, it
defines the width of the field. If n is zero, the width
is determined by the width of the value of the first
assignment. In the case of numeric parameters, the
length of the complete value assigned to the parameter is
used to determine the width, not the value that would be
output.

The width is the count of characters, which may be
multibyte characters if the MULTIBYTE option is in
effect. Note that the screen width of the character is
not taken into account; if this is required, use padding
with parameter expansion flags ${(ml...)...} as described
in `Parameter Expansion Flags' in zshexpn(1).

When the parameter is expanded, it is filled on the right
with blanks or truncated if necessary to fit the field.
Note truncation can lead to unexpected results with
numeric parameters. Leading zeros are removed if the -Z
flag is also set.

-R [ n ]
Similar to -L, except that right justification is used;
when the parameter is expanded, the field is left filled
with blanks or truncated from the end. May not be
combined with the -Z flag.

-U For arrays (but not for associative arrays), keep only
the first occurrence of each duplicated value. This may
also be set for tied parameters (see -T) or
colon-separated special parameters like PATH or FIGNORE,
etc. Note the flag takes effect on assignment, and the
type of the variable being assigned to is determinative;
for variables with shared values it is therefore
recommended to set the flag for all interfaces, e.g.
`typeset -U PATH path'.

This flag has a different meaning when used with -f; see
below.

-Z [ n ]
Specially handled if set along with the -L flag.
Otherwise, similar to -R, except that leading zeros are
used for padding instead of blanks if the first non-blank
character is a digit. Numeric parameters are specially
handled: they are always eligible for padding with
zeroes, and the zeroes are inserted at an appropriate
place in the output.

-a The names refer to array parameters. An array parameter
may be created this way, but it may be assigned to in the
typeset statement only if the reserved word form of
typeset is enabled (as it is by default). When
displaying, both normal and associative arrays are shown.

-f The names refer to functions rather than parameters. No
assignments can be made, and the only other valid flags
are -t, -T, -k, -u, -U and -z. The flag -t turns on
execution tracing for this function; the flag -T does the
same, but turns off tracing for any named (not anonymous)
function called from the present one, unless that
function also has the -t or -T flag. The -u and -U flags
cause the function to be marked for autoloading; -U also
causes alias expansion to be suppressed when the function
is loaded. See the description of the `autoload' builtin
for details.

Note that the builtin functions provides the same basic
capabilities as typeset -f but gives access to a few
extra options; autoload gives further additional options
for the case typeset -fu and typeset -fU.

-h Hide: only useful for special parameters (those marked
`<S>' in the table in zshparam(1)), and for local
parameters with the same name as a special parameter,
though harmless for others. A special parameter with
this attribute will not retain its special effect when
made local. Thus after `typeset -h PATH', a function
containing `typeset PATH' will create an ordinary local
parameter without the usual behaviour of PATH.
Alternatively, the local parameter may itself be given
this attribute; hence inside a function `typeset -h PATH'
creates an ordinary local parameter and the special PATH
parameter is not altered in any way. It is also possible
to create a local parameter using `typeset +h special',
where the local copy of special will retain its special
properties regardless of having the -h attribute. Global
special parameters loaded from shell modules (currently
those in zsh/mapfile and zsh/parameter) are automatically
given the -h attribute to avoid name clashes.

-H Hide value: specifies that typeset will not display the
value of the parameter when listing parameters; the
display for such parameters is always as if the `*' flag
had been given. Use of the parameter is in other
respects normal, and the option does not apply if the
parameter is specified by name, or by pattern with the -m
option. This is on by default for the parameters in the
zsh/parameter and zsh/mapfile modules. Note, however,
that unlike the -h flag this is also useful for
non-special parameters.

-i [ n ]
Use an internal integer representation. If n is nonzero
it defines the output arithmetic base, otherwise it is
determined by the first assignment. Bases from 2 to 36
inclusive are allowed.

-E [ n ]
Use an internal double-precision floating point
representation. On output the variable will be converted
to scientific notation. If n is nonzero it defines the
number of significant figures to display; the default is
ten.

-F [ n ]
Use an internal double-precision floating point
representation. On output the variable will be converted
to fixed-point decimal notation. If n is nonzero it
defines the number of digits to display after the decimal
point; the default is ten.

-l Convert the result to lower case whenever the parameter
is expanded. The value is not converted when assigned.

-r The given names are marked readonly. Note that if name
is a special parameter, the readonly attribute can be
turned on, but cannot then be turned off.

If the POSIX_BUILTINS option is set, the readonly
attribute is more restrictive: unset variables can be
marked readonly and cannot then be set; furthermore, the
readonly attribute cannot be removed from any variable.

It is still possible to change other attributes of the
variable though, some of which like -U or -Z would affect
the value. More generally, the readonly attribute should
not be relied on as a security mechanism.

Note that in zsh (like in pdksh but unlike most other
shells) it is still possible to create a local variable
of the same name as this is considered a different
variable (though this variable, too, can be marked
readonly). Special variables that have been made readonly
retain their value and readonly attribute when made
local.

-t Tags the named parameters. Tags have no special meaning
to the shell. This flag has a different meaning when
used with -f; see above.

-u Convert the result to upper case whenever the parameter
is expanded. The value is not converted when assigned.
This flag has a different meaning when used with -f; see
above.

-x Mark for automatic export to the environment of
subsequently executed commands. If the option
GLOBAL_EXPORT is set, this implies the option -g, unless
+g is also explicitly given; in other words the parameter
is not made local to the enclosing function. This is for
compatibility with previous versions of zsh.

ulimit [ -HSa ] [ { -bcdfiklmnpqrsTtvwx | -N resource } [ limit ] ... ]
Set or display resource limits of the shell and the processes
started by the shell. The value of limit can be a number in the
unit specified below or one of the values `unlimited', which
removes the limit on the resource, or `hard', which uses the
current value of the hard limit on the resource.

By default, only soft limits are manipulated. If the -H flag is
given use hard limits instead of soft limits. If the -S flag is
given together with the -H flag set both hard and soft limits.

If no options are used, the file size limit (-f) is assumed.

If limit is omitted the current value of the specified resources
are printed. When more than one resource value is printed, the
limit name and unit is printed before each value.

Not all the following resources are supported on all systems.
Running ulimit -a will show which are supported.

-a Lists all of the current resource limits.
-b Socket buffer size in bytes (N.B. not kilobytes)
-c 512-byte blocks on the size of core dumps.
-d Kilobytes on the size of the data segment.
-f 512-byte blocks on the size of files written.
-i The number of pending signals.
-k The number of kqueues allocated.
-l Kilobytes on the size of locked-in memory.
-m Kilobytes on the size of physical memory.
-n open file descriptors.
-p The number of pseudo-terminals.
-q Bytes in POSIX message queues.
-r Maximum real time priority. On some systems where this
is not available, such as NetBSD, this has the same
effect as -T for compatibility with sh.
-s Kilobytes on the size of the stack.
-T The number of simultaneous threads available to the user.
-t CPU seconds to be used.
-u The number of processes available to the user.
-v Kilobytes on the size of virtual memory. On some systems
this refers to the limit called `address space'.
-w Kilobytes on the size of swapped out memory.
-x The number of locks on files.

A resource may also be specified by integer in the form `-N
resource', where resource corresponds to the integer defined for
the resource by the operating system. This may be used to set
the limits for resources known to the shell which do not
correspond to option letters. Such limits will be shown by
number in the output of `ulimit -a'.

The number may alternatively be out of the range of limits
compiled into the shell. The shell will try to read or write
the limit anyway, and will report an error if this fails.

umask [ -S ] [ mask ]
The umask is set to mask. mask can be either an octal number or
a symbolic value as described in the chmod(1) man page. If mask
is omitted, the current value is printed. The -S option causes
the mask to be printed as a symbolic value. Otherwise, the mask
is printed as an octal number. Note that in the symbolic form
the permissions you specify are those which are to be allowed
(not denied) to the users specified.

unalias [ -ams ] name ...
Removes aliases. This command works the same as unhash -a,
except that the -a option removes all regular or global aliases,
or with -s all suffix aliases: in this case no name arguments
may appear. The options -m (remove by pattern) and -s without
-a (remove listed suffix aliases) behave as for unhash -a. Note
that the meaning of -a is different between unalias and unhash.

unfunction
Same as unhash -f.

unhash [ -adfms ] name ...
Remove the element named name from an internal hash table. The
default is remove elements from the command hash table. The -a
option causes unhash to remove regular or global aliases; note
when removing a global aliases that the argument must be quoted
to prevent it from being expanded before being passed to the
command. The -s option causes unhash to remove suffix aliases.
The -f option causes unhash to remove shell functions. The -d
options causes unhash to remove named directories. If the -m
flag is given the arguments are taken as patterns (should be
quoted) and all elements of the corresponding hash table with
matching names will be removed.

unlimit [ -hs ] resource ...
The resource limit for each resource is set to the hard limit.
If the -h flag is given and the shell has appropriate
privileges, the hard resource limit for each resource is
removed. The resources of the shell process are only changed if
the -s flag is given.

The unlimit command is not made available by default when the
shell starts in a mode emulating another shell. It can be made
available with the command `zmodload -F zsh/rlimits b:unlimit'.

unset [ -fmv ] name ...
Each named parameter is unset. Local parameters remain local
even if unset; they appear unset within scope, but the previous
value will still reappear when the scope ends.

Individual elements of associative array parameters may be unset
by using subscript syntax on name, which should be quoted (or
the entire command prefixed with noglob) to protect the
subscript from filename generation.

If the -m flag is specified the arguments are taken as patterns
(should be quoted) and all parameters with matching names are
unset. Note that this cannot be used when unsetting associative
array elements, as the subscript will be treated as part of the
pattern.

The -v flag specifies that name refers to parameters. This is
the default behaviour.

unset -f is equivalent to unfunction.

unsetopt [ {*|-}options | {+|-}o option_name ] [ name ... ]
Unset the options for the shell. All options specified either
with flags or by name are unset. If no arguments are supplied,
the names of all options currently unset are printed. If the -m
flag is given the arguments are taken as patterns (which should
be quoted to preserve them from being interpreted as glob
patterns), and all options with names matching these patterns
are unset.

vared See the section `Zle Builtins' in zshzle(1).

wait [ job ... ]
Wait for the specified jobs or processes. If job is not given
then all currently active child processes are waited for. Each
job can be either a job specification or the process ID of a job
in the job table. The exit status from this command is that of
the job waited for. If job represents an unknown job or process
ID, a warning is printed (unless the POSIX_BUILTINS option is
set) and the exit status is 127.

It is possible to wait for recent processes (specified by
process ID, not by job) that were running in the background even
if the process has exited. Typically the process ID will be
recorded by capturing the value of the variable $! immediately
after the process has been started. There is a limit on the
number of process IDs remembered by the shell; this is given by
the value of the system configuration parameter CHILD_MAX. When
this limit is reached, older process IDs are discarded, least
recently started processes first.

Note there is no protection against the process ID wrapping,
i.e. if the wait is not executed soon enough there is a chance
the process waited for is the wrong one. A conflict implies
both process IDs have been generated by the shell, as other
processes are not recorded, and that the user is potentially
interested in both, so this problem is intrinsic to process IDs.

whence [ -vcwfpamsS ] [ -x num ] name ...
For each name, indicate how it would be interpreted if used as a
command name.

If name is not an alias, built-in command, external command,
shell function, hashed command, or a reserved word, the exit
status shall be non-zero, and -- if -v, -c, or -w was passed --
a message will be written to standard output. (This is
different from other shells that write that message to standard
error.)

whence is most useful when name is only the last path component
of a command, i.e. does not include a `/'; in particular,
pattern matching only succeeds if just the non-directory
component of the command is passed.

-v Produce a more verbose report.

-c Print the results in a csh-like format. This takes
precedence over -v.

-w For each name, print `name: word' where word is one of
alias, builtin, command, function, hashed, reserved or
none, according as name corresponds to an alias, a
built-in command, an external command, a shell function,
a command defined with the hash builtin, a reserved word,
or is not recognised. This takes precedence over -v and
-c.

-f Causes the contents of a shell function to be displayed,
which would otherwise not happen unless the -c flag were
used.

-p Do a path search for name even if it is an alias,
reserved word, shell function or builtin.

-a Do a search for all occurrences of name throughout the
command path. Normally only the first occurrence is
printed.

-m The arguments are taken as patterns (pattern characters
should be quoted), and the information is displayed for
each command matching one of these patterns.

-s If a pathname contains symlinks, print the symlink-free
pathname as well.

-S As -s, but if the pathname had to be resolved by
following multiple symlinks, the intermediate steps are
printed, too. The symlink resolved at each step might be
anywhere in the path.

-x num Expand tabs when outputting shell functions using the -c
option. This has the same effect as the -x option to the
functions builtin.

where [ -wpmsS ] [ -x num ] name ...
Equivalent to whence -ca.

which [ -wpamsS ] [ -x num ] name ...
Equivalent to whence -c.

zcompile [ -U ] [ -z | -k ] [ -R | -M ] file [ name ... ]
zcompile -ca [ -m ] [ -R | -M ] file [ name ... ]
zcompile -t file [ name ... ]
This builtin command can be used to compile functions or
scripts, storing the compiled form in a file, and to examine
files containing the compiled form. This allows faster
autoloading of functions and sourcing of scripts by avoiding
parsing of the text when the files are read.

The first form (without the -c, -a or -t options) creates a
compiled file. If only the file argument is given, the output
file has the name `file.zwc' and will be placed in the same
directory as the file. The shell will load the compiled file
instead of the normal function file when the function is
autoloaded; see the section `Autoloading Functions' in
zshmisc(1) for a description of how autoloaded functions are
searched. The extension .zwc stands for `zsh word code'.

If there is at least one name argument, all the named files are
compiled into the output file given as the first argument. If
file does not end in .zwc, this extension is automatically
appended. Files containing multiple compiled functions are
called `digest' files, and are intended to be used as elements
of the FPATH/fpath special array.

The second form, with the -c or -a options, writes the compiled
definitions for all the named functions into file. For -c, the
names must be functions currently defined in the shell, not
those marked for autoloading. Undefined functions that are
marked for autoloading may be written by using the -a option, in
which case the fpath is searched and the contents of the
definition files for those functions, if found, are compiled
into file. If both -c and -a are given, names of both defined
functions and functions marked for autoloading may be given. In
either case, the functions in files written with the -c or -a
option will be autoloaded as if the KSH_AUTOLOAD option were
unset.

The reason for handling loaded and not-yet-loaded functions with
different options is that some definition files for autoloading
define multiple functions, including the function with the same
name as the file, and, at the end, call that function. In such
cases the output of `zcompile -c' does not include the
additional functions defined in the file, and any other
initialization code in the file is lost. Using `zcompile -a'
captures all this extra information.

If the -m option is combined with -c or -a, the names are used
as patterns and all functions whose names match one of these
patterns will be written. If no name is given, the definitions
of all functions currently defined or marked as autoloaded will
be written.

Note the second form cannot be used for compiling functions that
include redirections as part of the definition rather than
within the body of the function; for example

fn1() { { ... } >~/logfile }

can be compiled but

fn1() { ... } >~/logfile

cannot. It is possible to use the first form of zcompile to
compile autoloadable functions that include the full function
definition instead of just the body of the function.

The third form, with the -t option, examines an existing
compiled file. Without further arguments, the names of the
original files compiled into it are listed. The first line of
output shows the version of the shell which compiled the file
and how the file will be used (i.e. by reading it directly or by
mapping it into memory). With arguments, nothing is output and
the return status is set to zero if definitions for all names
were found in the compiled file, and non-zero if the definition
for at least one name was not found.

Other options:

-U Aliases are not expanded when compiling the named files.

-R When the compiled file is read, its contents are copied
into the shell's memory, rather than memory-mapped (see
-M). This happens automatically on systems that do not
support memory mapping.

When compiling scripts instead of autoloadable functions,
it is often desirable to use this option; otherwise the
whole file, including the code to define functions which
have already been defined, will remain mapped,
consequently wasting memory.

-M The compiled file is mapped into the shell's memory when
read. This is done in such a way that multiple instances
of the shell running on the same host will share this
mapped file. If neither -R nor -M is given, the zcompile
builtin decides what to do based on the size of the
compiled file.

-k
-z These options are used when the compiled file contains
functions which are to be autoloaded. If -z is given, the
function will be autoloaded as if the KSH_AUTOLOAD option
is not set, even if it is set at the time the compiled
file is read, while if the -k is given, the function will
be loaded as if KSH_AUTOLOAD is set. These options also
take precedence over any -k or -z options specified to
the autoload builtin. If neither of these options is
given, the function will be loaded as determined by the
setting of the KSH_AUTOLOAD option at the time the
compiled file is read.

These options may also appear as many times as necessary
between the listed names to specify the loading style of
all following functions, up to the next -k or -z.

The created file always contains two versions of the
compiled format, one for big-endian machines and one for
small-endian machines. The upshot of this is that the
compiled file is machine independent and if it is read or
mapped, only one half of the file is actually used (and
mapped).

zformat
See the section `The zsh/zutil Module' in zshmodules(1).

zftp See the section `The zsh/zftp Module' in zshmodules(1).

zle See the section `Zle Builtins' in zshzle(1).

zmodload [ -dL ] [ -s ] [ ... ]
zmodload -F [ -alLme -P param ] module [ [+-]feature ... ]
zmodload -e [ -A ] [ ... ]
zmodload [ -a [ -bcpf [ -I ] ] ] [ -iL ] ...
zmodload -u [ -abcdpf [ -I ] ] [ -iL ] ...
zmodload -A [ -L ] [ modalias[=module] ... ]
zmodload -R modalias ...
Performs operations relating to zsh's loadable modules. Loading
of modules while the shell is running (`dynamical loading') is
not available on all operating systems, or on all installations
on a particular operating system, although the zmodload command
itself is always available and can be used to manipulate modules
built into versions of the shell executable without dynamical
loading.

Without arguments the names of all currently loaded binary
modules are printed. The -L option causes this list to be in
the form of a series of zmodload commands. Forms with arguments
are:

zmodload [ -is ] name ...
zmodload -u [ -i ] name ...
In the simplest case, zmodload loads a binary module.
The module must be in a file with a name consisting of
the specified name followed by a standard suffix, usually
`.so' (`.sl' on HPUX). If the module to be loaded is
already loaded the duplicate module is ignored. If
zmodload detects an inconsistency, such as an invalid
module name or circular dependency list, the current code
block is aborted. If it is available, the module is
loaded if necessary, while if it is not available,
non-zero status is silently returned. The option -i is
accepted for compatibility but has no effect.

The named module is searched for in the same way a
command is, using $module_path instead of $path.
However, the path search is performed even when the
module name contains a `/', which it usually does. There
is no way to prevent the path search.

If the module supports features (see below), zmodload
tries to enable all features when loading a module. If
the module was successfully loaded but not all features
could be enabled, zmodload returns status 2.

If the option -s is given, no error is printed if the
module was not available (though other errors indicating
a problem with the module are printed). The return
status indicates if the module was loaded. This is
appropriate if the caller considers the module optional.

With -u, zmodload unloads modules. The same name must be
given that was given when the module was loaded, but it
is not necessary for the module to exist in the file
system. The -i option suppresses the error if the module
is already unloaded (or was never loaded).

Each module has a boot and a cleanup function. The
module will not be loaded if its boot function fails.
Similarly a module can only be unloaded if its cleanup
function runs successfully.

zmodload -F [ -almLe -P param ] module [ [+-]feature ... ]
zmodload -F allows more selective control over the
features provided by modules. With no options apart from
-F, the module named module is loaded, if it was not
already loaded, and the list of features is set to the
required state. If no features are specified, the module
is loaded, if it was not already loaded, but the state of
features is unchanged. Each feature may be preceded by a
* to turn the feature on, or - to turn it off; the + is
assumed if neither character is present. Any feature not
explicitly mentioned is left in its current state; if the
module was not previously loaded this means any such
features will remain disabled. The return status is zero
if all features were set, 1 if the module failed to load,
and 2 if some features could not be set (for example, a
parameter couldn't be added because there was a different
parameter of the same name) but the module was loaded.

The standard features are builtins, conditions,
parameters and math functions; these are indicated by the
prefix `b:', `c:' (`C:' for an infix condition), `p:' and
`f:', respectively, followed by the name that the
corresponding feature would have in the shell. For
example, `b:strftime' indicates a builtin named strftime
and p:EPOCHSECONDS indicates a parameter named
EPOCHSECONDS. The module may provide other (`abstract')
features of its own as indicated by its documentation;
these have no prefix.

With -l or -L, features provided by the module are
listed. With -l alone, a list of features together with
their states is shown, one feature per line. With -L
alone, a zmodload -F command that would cause enabled
features of the module to be turned on is shown. With
-lL, a zmodload -F command that would cause all the
features to be set to their current state is shown. If
one of these combinations is given with the option -P
param then the parameter param is set to an array of
features, either features together with their state or
(if -L alone is given) enabled features.

With the option -L the module name may be omitted; then a
list of all enabled features for all modules providing
features is printed in the form of zmodload -F commands.
If -l is also given, the state of both enabled and
disabled features is output in that form.

A set of features may be provided together with -l or -L
and a module name; in that case only the state of those
features is considered. Each feature may be preceded by
* or - but the character has no effect. If no set of
features is provided, all features are considered.

With -e, the command first tests that the module is
loaded; if it is not, status 1 is returned. If the
module is loaded, the list of features given as an
argument is examined. Any feature given with no prefix
is simply tested to see if the module provides it; any
feature given with a prefix * or - is tested to see if is
provided and in the given state. If the tests on all
features in the list succeed, status 0 is returned, else
status 1.

With -m, each entry in the given list of features is
taken as a pattern to be matched against the list of
features provided by the module. An initial * or - must
be given explicitly. This may not be combined with the
-a option as autoloads must be specified explicitly.

With -a, the given list of features is marked for
autoload from the specified module, which may not yet be
loaded. An optional * may appear before the feature
name. If the feature is prefixed with -, any existing
autoload is removed. The options -l and -L may be used
to list autoloads. Autoloading is specific to individual
features; when the module is loaded only the requested
feature is enabled. Autoload requests are preserved if
the module is subsequently unloaded until an explicit
`zmodload -Fa module -feature' is issued. It is not an
error to request an autoload for a feature of a module
that is already loaded.

When the module is loaded each autoload is checked
against the features actually provided by the module; if
the feature is not provided the autoload request is
deleted. A warning message is output; if the module is
being loaded to provide a different feature, and that
autoload is successful, there is no effect on the status
of the current command. If the module is already loaded
at the time when zmodload -Fa is run, an error message is
printed and status 1 returned.

zmodload -Fa can be used with the -l, -L, -e and -P
options for listing and testing the existence of
autoloadable features. In this case -l is ignored if -L
is specified. zmodload -FaL with no module name lists
autoloads for all modules.

Note that only standard features as described above can
be autoloaded; other features require the module to be
loaded before enabling.

zmodload -d [ -L ] [ name ]
zmodload -d name dep ...
zmodload -ud name [ dep ... ]
The -d option can be used to specify module dependencies.
The modules named in the second and subsequent arguments
will be loaded before the module named in the first
argument.

With -d and one argument, all dependencies for that
module are listed. With -d and no arguments, all module
dependencies are listed. This listing is by default in a
Makefile-like format. The -L option changes this format
to a list of zmodload -d commands.

If -d and -u are both used, dependencies are removed. If
only one argument is given, all dependencies for that
module are removed.

zmodload -ab [ -L ]
zmodload -ab [ -i ] name [ builtin ... ]
zmodload -ub [ -i ] builtin ...
The -ab option defines autoloaded builtins. It defines
the specified builtins. When any of those builtins is
called, the module specified in the first argument is
loaded and all its features are enabled (for selective
control of features use `zmodload -F -a' as described
above). If only the name is given, one builtin is
defined, with the same name as the module. -i suppresses
the error if the builtin is already defined or
autoloaded, but not if another builtin of the same name
is already defined.

With -ab and no arguments, all autoloaded builtins are
listed, with the module name (if different) shown in
parentheses after the builtin name. The -L option
changes this format to a list of zmodload -a commands.

If -b is used together with the -u option, it removes
builtins previously defined with -ab. This is only
possible if the builtin is not yet loaded. -i suppresses
the error if the builtin is already removed (or never
existed).

Autoload requests are retained if the module is
subsequently unloaded until an explicit `zmodload -ub
builtin' is issued.

zmodload -ac [ -IL ]
zmodload -ac [ -iI ] name [ cond ... ]
zmodload -uc [ -iI ] cond ...
The -ac option is used to define autoloaded condition
codes. The cond strings give the names of the conditions
defined by the module. The optional -I option is used to
define infix condition names. Without this option prefix
condition names are defined.

If given no condition names, all defined names are listed
(as a series of zmodload commands if the -L option is
given).

The -uc option removes definitions for autoloaded
conditions.

zmodload -ap [ -L ]
zmodload -ap [ -i ] name [ parameter ... ]
zmodload -up [ -i ] parameter ...
The -p option is like the -b and -c options, but makes
zmodload work on autoloaded parameters instead.

zmodload -af [ -L ]
zmodload -af [ -i ] name [ function ... ]
zmodload -uf [ -i ] function ...
The -f option is like the -b, -p, and -c options, but
makes zmodload work on autoloaded math functions instead.

zmodload -a [ -L ]
zmodload -a [ -i ] name [ builtin ... ]
zmodload -ua [ -i ] builtin ...
Equivalent to -ab and -ub.

zmodload -e [ -A ] [ string ... ]
The -e option without arguments lists all loaded modules;
if the -A option is also given, module aliases
corresponding to loaded modules are also shown. If
arguments are provided, nothing is printed; the return
status is set to zero if all strings given as arguments
are names of loaded modules and to one if at least on
string is not the name of a loaded module. This can be
used to test for the availability of things implemented
by modules. In this case, any aliases are automatically
resolved and the -A flag is not used.

zmodload -A [ -L ] [ modalias[=module] ... ]
For each argument, if both modalias and module are given,
define modalias to be an alias for the module module. If
the module modalias is ever subsequently requested,
either via a call to zmodload or implicitly, the shell
will attempt to load module instead. If module is not
given, show the definition of modalias. If no arguments
are given, list all defined module aliases. When
listing, if the -L flag was also given, list the
definition as a zmodload command to recreate the alias.

The existence of aliases for modules is completely
independent of whether the name resolved is actually
loaded as a module: while the alias exists, loading and
unloading the module under any alias has exactly the same
effect as using the resolved name, and does not affect
the connection between the alias and the resolved name
which can be removed either by zmodload -R or by
redefining the alias. Chains of aliases (i.e. where the
first resolved name is itself an alias) are valid so long
as these are not circular. As the aliases take the same
format as module names, they may include path separators:
in this case, there is no requirement for any part of the
path named to exist as the alias will be resolved first.
For example, `any/old/alias' is always a valid alias.

Dependencies added to aliased modules are actually added
to the resolved module; these remain if the alias is
removed. It is valid to create an alias whose name is
one of the standard shell modules and which resolves to a
different module. However, if a module has dependencies,
it will not be possible to use the module name as an
alias as the module will already be marked as a loadable
module in its own right.

Apart from the above, aliases can be used in the zmodload
command anywhere module names are required. However,
aliases will not be shown in lists of loaded modules with
a bare `zmodload'.

zmodload -R modalias ...
For each modalias argument that was previously defined as
a module alias via zmodload -A, delete the alias. If any
was not defined, an error is caused and the remainder of
the line is ignored.

Note that zsh makes no distinction between modules that were
linked into the shell and modules that are loaded dynamically.
In both cases this builtin command has to be used to make
available the builtins and other things defined by modules
(unless the module is autoloaded on these definitions). This is
true even for systems that don't support dynamic loading of
modules.

zparseopts
See the section `The zsh/zutil Module' in zshmodules(1).

zprof See the section `The zsh/zprof Module' in zshmodules(1).

zpty See the section `The zsh/zpty Module' in zshmodules(1).

zregexparse
See the section `The zsh/zutil Module' in zshmodules(1).

zsocket
See the section `The zsh/net/socket Module' in zshmodules(1).

zstyle See the section `The zsh/zutil Module' in zshmodules(1).

ztcp See the section `The zsh/net/tcp Module' in zshmodules(1).

NAME
zshzle - zsh command line editor

DESCRIPTION
If the ZLE option is set (which it is by default in interactive shells)
and the shell input is attached to the terminal, the user is able to
edit command lines.

There are two display modes. The first, multiline mode, is the
default. It only works if the TERM parameter is set to a valid
terminal type that can move the cursor up. The second, single line
mode, is used if TERM is invalid or incapable of moving the cursor up,
or if the SINGLE_LINE_ZLE option is set. This mode is similar to ksh,
and uses no termcap sequences. If TERM is "emacs", the ZLE option will
be unset by default.

The parameters BAUD, COLUMNS, and LINES are also used by the line
editor. See Parameters Used By The Shell in zshparam(1).

The parameter zle_highlight is also used by the line editor; see
Character Highlighting below. Highlighting of special characters and
the region between the cursor and the mark (as set with
set-mark-command in Emacs mode, or by visual-mode in Vi mode) is
enabled by default; consult this reference for more information.
Irascible conservatives will wish to know that all highlighting may be
disabled by the following setting:

zle_highlight=(none)

In many places, references are made to the numeric argument. This can
by default be entered in emacs mode by holding the alt key and typing a
number, or pressing escape before each digit, and in vi command mode by
typing the number before entering a command. Generally the numeric
argument causes the next command entered to be repeated the specified
number of times, unless otherwise noted below; this is implemented by
the digit-argument widget. See also the Arguments subsection of the
Widgets section for some other ways the numeric argument can be
modified.

KEYMAPS
A keymap in ZLE contains a set of bindings between key sequences and
ZLE commands. The empty key sequence cannot be bound.

There can be any number of keymaps at any time, and each keymap has one
or more names. If all of a keymap's names are deleted, it disappears.
bindkey can be used to manipulate keymap names.

Initially, there are eight keymaps:

emacs EMACS emulation
viins vi emulation - insert mode
vicmd vi emulation - command mode
viopp vi emulation - operator pending
visual vi emulation - selection active
isearch
incremental search mode
command
read a command name
.safe fallback keymap

The `.safe' keymap is special. It can never be altered, and the name
can never be removed. However, it can be linked to other names, which
can be removed. In the future other special keymaps may be added;
users should avoid using names beginning with `.' for their own
keymaps.

In addition to these names, either `emacs' or `viins' is also linked to
the name `main'. If one of the VISUAL or EDITOR environment variables
contain the string `vi' when the shell starts up then it will be
`viins', otherwise it will be `emacs'. bindkey's -e and -v options
provide a convenient way to override this default choice.

When the editor starts up, it will select the `main' keymap. If that
keymap doesn't exist, it will use `.safe' instead.

In the `.safe' keymap, each single key is bound to self-insert, except
for ^J (line feed) and ^M (return) which are bound to accept-line.
This is deliberately not pleasant to use; if you are using it, it means
you deleted the main keymap, and you should put it back.

Reading Commands
When ZLE is reading a command from the terminal, it may read a sequence
that is bound to some command and is also a prefix of a longer bound
string. In this case ZLE will wait a certain time to see if more
characters are typed, and if not (or they don't match any longer
string) it will execute the binding. This timeout is defined by the
KEYTIMEOUT parameter; its default is 0.4 sec. There is no timeout if
the prefix string is not itself bound to a command.

The key timeout is also applied when ZLE is reading the bytes from a
multibyte character string when it is in the appropriate mode. (This
requires that the shell was compiled with multibyte mode enabled;
typically also the locale has characters with the UTF-8 encoding,
although any multibyte encoding known to the operating system is
supported.) If the second or a subsequent byte is not read within the
timeout period, the shell acts as if ? were typed and resets the input
state.

As well as ZLE commands, key sequences can be bound to other strings,
by using `bindkey -s'. When such a sequence is read, the replacement
string is pushed back as input, and the command reading process starts
again using these fake keystrokes. This input can itself invoke
further replacement strings, but in order to detect loops the process
will be stopped if there are twenty such replacements without a real
command being read.

A key sequence typed by the user can be turned into a command name for
use in user-defined widgets with the read-command widget, described in
the subsection `Miscellaneous' of the section `Standard Widgets' below.

Local Keymaps
While for normal editing a single keymap is used exclusively, in many
modes a local keymap allows for some keys to be customised. For
example, in an incremental search mode, a binding in the isearch keymap
will override a binding in the main keymap but all keys that are not
overridden can still be used.

If a key sequence is defined in a local keymap, it will hide a key
sequence in the global keymap that is a prefix of that sequence. An
example of this occurs with the binding of iw in viopp as this hides
the binding of i in vicmd. However, a longer sequence in the global
keymap that shares the same prefix can still apply so for example the
binding of ^Xa in the global keymap will be unaffected by the binding
of ^Xb in the local keymap.

ZLE BUILTINS
The ZLE module contains three related builtin commands. The bindkey
command manipulates keymaps and key bindings; the vared command invokes
ZLE on the value of a shell parameter; and the zle command manipulates
editing widgets and allows command line access to ZLE commands from
within shell functions.

bindkey [ options ] -l [ -L ] [ keymap ... ]
bindkey [ options ] -d
bindkey [ options ] -D keymap ...
bindkey [ options ] -A old-keymap new-keymap
bindkey [ options ] -N new-keymap [ old-keymap ]
bindkey [ options ] -m
bindkey [ options ] -r in-string ...
bindkey [ options ] -s in-string out-string ...
bindkey [ options ] in-string command ...
bindkey [ options ] [ in-string ]
bindkey's options can be divided into three categories: keymap
selection for the current command, operation selection, and
others. The keymap selection options are:

-e Selects keymap `emacs' for any operations by the current
command, and also links `emacs' to `main' so that it is
selected by default the next time the editor starts.

-v Selects keymap `viins' for any operations by the current
command, and also links `viins' to `main' so that it is
selected by default the next time the editor starts.

-a Selects keymap `vicmd' for any operations by the current
command.

-M keymap
The keymap specifies a keymap name that is selected for
any operations by the current command.

If a keymap selection is required and none of the options above
are used, the `main' keymap is used. Some operations do not
permit a keymap to be selected, namely:

-l List all existing keymap names; if any arguments are
given, list just those keymaps.

If the -L option is also used, list in the form of
bindkey commands to create or link the keymaps. `bindkey
-lL main' shows which keymap is linked to `main', if any,
and hence if the standard emacs or vi emulation is in
effect. This option does not show the .safe keymap
because it cannot be created in that fashion; however,
neither is `bindkey -lL .safe' reported as an error, it
simply outputs nothing.

-d Delete all existing keymaps and reset to the default
state.

-D keymap ...
Delete the named keymaps.

-A old-keymap new-keymap
Make the new-keymap name an alias for old-keymap, so that
both names refer to the same keymap. The names have
equal standing; if either is deleted, the other remains.
If there is already a keymap with the new-keymap name, it
is deleted.

-N new-keymap [ old-keymap ]
Create a new keymap, named new-keymap. If a keymap
already has that name, it is deleted. If an old-keymap
name is given, the new keymap is initialized to be a
duplicate of it, otherwise the new keymap will be empty.

To use a newly created keymap, it should be linked to main.
Hence the sequence of commands to create and use a new keymap
`mymap' initialized from the emacs keymap (which remains
unchanged) is:

bindkey -N mymap emacs
bindkey -A mymap main

Note that while `bindkey -A newmap main' will work when newmap
is emacs or viins, it will not work for vicmd, as switching from
vi insert to command mode becomes impossible.

The following operations act on the `main' keymap if no keymap
selection option was given:

-m Add the built-in set of meta-key bindings to the selected
keymap. Only keys that are unbound or bound to
self-insert are affected.

-r in-string ...
Unbind the specified in-strings in the selected keymap.
This is exactly equivalent to binding the strings to
undefined-key.

When -R is also used, interpret the in-strings as ranges.

When -p is also used, the in-strings specify prefixes.
Any binding that has the given in-string as a prefix, not
including the binding for the in-string itself, if any,
will be removed. For example,

bindkey -rpM viins '^['

will remove all bindings in the vi-insert keymap
beginning with an escape character (probably cursor
keys), but leave the binding for the escape character
itself (probably vi-cmd-mode). This is incompatible with
the option -R.

-s in-string out-string ...
Bind each in-string to each out-string. When in-string
is typed, out-string will be pushed back and treated as
input to the line editor. When -R is also used,
interpret the in-strings as ranges.

Note that both in-string and out-string are subject to
the same form of interpretation, as described below.

in-string command ...
Bind each in-string to each command. When -R is used,
interpret the in-strings as ranges.

[ in-string ]
List key bindings. If an in-string is specified, the
binding of that string in the selected keymap is
displayed. Otherwise, all key bindings in the selected
keymap are displayed. (As a special case, if the -e or
-v option is used alone, the keymap is not displayed -
the implicit linking of keymaps is the only thing that
happens.)

When the option -p is used, the in-string must be
present. The listing shows all bindings which have the
given key sequence as a prefix, not including any
bindings for the key sequence itself.

When the -L option is used, the list is in the form of
bindkey commands to create the key bindings.

When the -R option is used as noted above, a valid range
consists of two characters, with an optional `-' between them.
All characters between the two specified, inclusive, are bound
as specified.

For either in-string or out-string, the following escape
sequences are recognised:

\a bell character
\b backspace
\e, \E escape
\f form feed
\n linefeed (newline)
\r carriage return
\t horizontal tab
\v vertical tab
\NNN character code in octal
\xNN character code in hexadecimal
\uNNNN unicode character code in hexadecimal
\UNNNNNNNN
unicode character code in hexadecimal
\M[-]X character with meta bit set
\C[-]X control character
^X control character

In all other cases, `\' escapes the following character. Delete
is written as `^?'. Note that `\M^?' and `^\M?' are not the
same, and that (unlike emacs), the bindings `\M-X' and `\eX' are
entirely distinct, although they are initialized to the same
bindings by `bindkey -m'.

vared [ -Aacghe ] [ -p prompt ] [ -r rprompt ]
[ -M main-keymap ] [ -m vicmd-keymap ]
[ -i init-widget ] [ -f finish-widget ]
[ -t tty ] name
The value of the parameter name is loaded into the edit buffer,
and the line editor is invoked. When the editor exits, name is
set to the string value returned by the editor. When the -c
flag is given, the parameter is created if it doesn't already
exist. The -a flag may be given with -c to create an array
parameter, or the -A flag to create an associative array. If
the type of an existing parameter does not match the type to be
created, the parameter is unset and recreated. The -g flag may
be given to suppress warnings from the WARN_CREATE_GLOBAL and
WARN_NESTED_VAR options.

If an array or array slice is being edited, separator characters
as defined in $IFS will be shown quoted with a backslash, as
will backslashes themselves. Conversely, when the edited text
is split into an array, a backslash quotes an immediately
following separator character or backslash; no other special
handling of backslashes, or any handling of quotes, is
performed.

Individual elements of existing array or associative array
parameters may be edited by using subscript syntax on name. New
elements are created automatically, even without -c.

If the -p flag is given, the following string will be taken as
the prompt to display at the left. If the -r flag is given, the
following string gives the prompt to display at the right. If
the -h flag is specified, the history can be accessed from ZLE.
If the -e flag is given, typing ^D (Control-D) on an empty line
causes vared to exit immediately with a non-zero return value.

The -M option gives a keymap to link to the main keymap during
editing, and the -m option gives a keymap to link to the vicmd
keymap during editing. For vi-style editing, this allows a pair
of keymaps to override viins and vicmd. For emacs-style
editing, only -M is normally needed but the -m option may still
be used. On exit, the previous keymaps will be restored.

Vared calls the usual `zle-line-init' and `zle-line-finish'
hooks before and after it takes control. Using the -i and -f
options, it is possible to replace these with other custom
widgets.

If `-t tty' is given, tty is the name of a terminal device to be
used instead of the default /dev/tty. If tty does not refer to
a terminal an error is reported.

zle
zle -l [ -L | -a ] [ string ... ]
zle -D widget ...
zle -A old-widget new-widget
zle -N widget [ function ]
zle -f flag [ flag... ]
zle -C widget completion-widget function
zle -R [ -c ] [ display-string ] [ string ... ]
zle -M string
zle -U string
zle -K keymap
zle -F [ -L | -w ] [ fd [ handler ] ]
zle -I
zle -T [ tc function | -r tc | -L ]
zle widget [ -n num ] [ -f flag ] [ -Nw ] [ -K keymap ] args ...
The zle builtin performs a number of different actions
concerning ZLE.

With no options and no arguments, only the return status will be
set. It is zero if ZLE is currently active and widgets could be
invoked using this builtin command and non-zero otherwise. Note
that even if non-zero status is returned, zle may still be
active as part of the completion system; this does not allow
direct calls to ZLE widgets.

Otherwise, which operation it performs depends on its options:

-l [ -L | -a ] [ string ]
List all existing user-defined widgets. If the -L option
is used, list in the form of zle commands to create the
widgets.

When combined with the -a option, all widget names are
listed, including the builtin ones. In this case the -L
option is ignored.

If at least one string is given, and -a is present or -L
is not used, nothing will be printed. The return status
will be zero if all strings are names of existing widgets
and non-zero if at least one string is not a name of a
defined widget. If -a is also present, all widget names
are used for the comparison including builtin widgets,
else only user-defined widgets are used.

If at least one string is present and the -L option is
used, user-defined widgets matching any string are listed
in the form of zle commands to create the widgets.

-D widget ...
Delete the named widgets.

-A old-widget new-widget
Make the new-widget name an alias for old-widget, so that
both names refer to the same widget. The names have
equal standing; if either is deleted, the other remains.
If there is already a widget with the new-widget name, it
is deleted.

-N widget [ function ]
Create a user-defined widget. If there is already a
widget with the specified name, it is overwritten. When
the new widget is invoked from within the editor, the
specified shell function is called. If no function name
is specified, it defaults to the same name as the widget.
For further information, see the section `Widgets' below.

-f flag [ flag... ]
Set various flags on the running widget. Possible values
for flag are:

yank for indicating that the widget has yanked text into
the buffer. If the widget is wrapping an existing
internal widget, no further action is necessary, but if
it has inserted the text manually, then it should also
take care to set YANK_START and YANK_END correctly.
yankbefore does the same but is used when the yanked text
appears after the cursor.

kill for indicating that text has been killed into the
cutbuffer. When repeatedly invoking a kill widget, text
is appended to the cutbuffer instead of replacing it, but
when wrapping such widgets, it is necessary to call `zle
-f kill' to retain this effect.

vichange for indicating that the widget represents a vi
change that can be repeated as a whole with
`vi-repeat-change'. The flag should be set early in the
function before inspecting the value of NUMERIC or
invoking other widgets. This has no effect for a widget
invoked from insert mode. If insert mode is active when
the widget finishes, the change extends until next
returning to command mode.

-C widget completion-widget function
Create a user-defined completion widget named widget. The
completion widget will behave like the built-in
completion-widget whose name is given as
completion-widget. To generate the completions, the shell
function function will be called. For further
information, see zshcompwid(1).

-R [ -c ] [ display-string ] [ string ... ]
Redisplay the command line. If a display-string is given
and not empty, this is shown in the status line
(immediately below the line being edited).

If the optional strings are given they are listed below
the prompt in the same way as completion lists are
printed. If no strings are given but the -c option is
used such a list is cleared.

Note that immediately after returning from running
widgets, the command line will be redisplayed and the
strings displayed will be erased. Therefore, this option
is only useful for widgets that do not exit immediately
after using it.

This command can safely be called outside user defined
widgets; if zle is active, the display will be refreshed,
while if zle is not active, the command has no effect.
In this case there will usually be no other arguments.

The status is zero if zle was active, else one.

-M string
As with the -R option, the string will be displayed below
the command line; unlike the -R option, the string will
not be put into the status line but will instead be
printed normally below the prompt. This means that the
string will still be displayed after the widget returns
(until it is overwritten by subsequent commands).

-U string
This pushes the characters in the string onto the input
stack of ZLE. After the widget currently executed
finishes ZLE will behave as if the characters in the
string were typed by the user.

As ZLE uses a stack, if this option is used repeatedly
the last string pushed onto the stack will be processed
first. However, the characters in each string will be
processed in the order in which they appear in the
string.

-K keymap
Selects the keymap named keymap. An error message will
be displayed if there is no such keymap.

This keymap selection affects the interpretation of
following keystrokes within this invocation of ZLE. Any
following invocation (e.g., the next command line) will
start as usual with the `main' keymap selected.

-F [ -L | -w ] [ fd [ handler ] ]
Only available if your system supports one of the `poll'
or `select' system calls; most modern systems do.

Installs handler (the name of a shell function) to handle
input from file descriptor fd. Installing a handler for
an fd which is already handled causes the existing
handler to be replaced. Any number of handlers for any
number of readable file descriptors may be installed.
Note that zle makes no attempt to check whether this fd
is actually readable when installing the handler. The
user must make their own arrangements for handling the
file descriptor when zle is not active.

When zle is attempting to read data, it will examine both
the terminal and the list of handled fd's. If data
becomes available on a handled fd, zle calls handler with
the fd which is ready for reading as the first argument.
Under normal circumstances this is the only argument, but
if an error was detected, a second argument provides
details: `hup' for a disconnect, `nval' for a closed or
otherwise invalid descriptor, or `err' for any other
condition. Systems that support only the `select' system
call always use `err'.

If the option -w is also given, the handler is instead a
line editor widget, typically a shell function made into
a widget using `zle -N'. In that case handler can use
all the facilities of zle to update the current editing
line. Note, however, that as handling fd takes place at
a low level changes to the display will not automatically
appear; the widget should call `zle -R' to force
redisplay. As of this writing, widget handlers only
support a single argument and thus are never passed a
string for error state, so widgets must be prepared to
test the descriptor themselves.

If either type of handler produces output to the
terminal, it should call `zle -I' before doing so (see
below). Handlers should not attempt to read from the
terminal.

If no handler is given, but an fd is present, any handler
for that fd is removed. If there is none, an error
message is printed and status 1 is returned.

If no arguments are given, or the -L option is supplied,
a list of handlers is printed in a form which can be
stored for later execution.

An fd (but not a handler) may optionally be given with
the -L option; in this case, the function will list the
handler if any, else silently return status 1.

Note that this feature should be used with care.
Activity on one of the fd's which is not properly handled
can cause the terminal to become unusable. Removing an
fd handler from within a signal trap may cause
unpredictable behavior.

Here is a simple example of using this feature. A
connection to a remote TCP port is created using the ztcp
command; see the description of the zsh/net/tcp module in
zshmodules(1). Then a handler is installed which simply
prints out any data which arrives on this connection.
Note that `select' will indicate that the file descriptor
needs handling if the remote side has closed the
connection; we handle that by testing for a failed read.

if ztcp pwspc 2811; then
tcpfd=$REPLY
handler() {
zle -I
local line
if ! read -r line <&$1; then
# select marks this fd if we reach EOF,
# so handle this specially.
print "[Read on fd $1 failed, removing.]" >&2
zle -F $1
return 1
fi
print -r - $line
}
zle -F $tcpfd handler
fi

-I Unusually, this option is most useful outside ordinary
widget functions, though it may be used within if normal
output to the terminal is required. It invalidates the
current zle display in preparation for output; typically
this will be from a trap function. It has no effect if
zle is not active. When a trap exits, the shell checks
to see if the display needs restoring, hence the
following will print output in such a way as not to
disturb the line being edited:

TRAPUSR1() {
# Invalidate zle display
[[ -o zle ]] && zle -I
# Show output
print Hello
}

In general, the trap function may need to test whether
zle is active before using this method (as shown in the
example), since the zsh/zle module may not even be
loaded; if it is not, the command can be skipped.

It is possible to call `zle -I' several times before
control is returned to the editor; the display will only
be invalidated the first time to minimise disruption.

Note that there are normally better ways of manipulating
the display from within zle widgets; see, for example,
`zle -R' above.

The returned status is zero if zle was invalidated, even
though this may have been by a previous call to `zle -I'
or by a system notification. To test if a zle widget may
be called at this point, execute zle with no arguments
and examine the return status.

-T This is used to add, list or remove internal
transformations on the processing performed by the line
editor. It is typically used only for debugging or
testing and is therefore of little interest to the
general user.

`zle -T transformation func' specifies that the given
transformation (see below) is effected by shell function
func.

`zle -Tr transformation' removes the given transformation
if it was present (it is not an error if none was).

`zle -TL' can be used to list all transformations
currently in operation.

Currently the only transformation is tc. This is used
instead of outputting termcap codes to the terminal.
When the transformation is in operation the shell
function is passed the termcap code that would be output
as its first argument; if the operation required a
numeric argument, that is passed as a second argument.
The function should set the shell variable REPLY to the
transformed termcap code. Typically this is used to
produce some simply formatted version of the code and
optional argument for debugging or testing. Note that
this transformation is not applied to other non-printing
characters such as carriage returns and newlines.

widget [ -n num ] [ -f flag ] [ -Nw ] [ -K keymap ] args ...
Invoke the specified widget. This can only be done when
ZLE is active; normally this will be within a
user-defined widget.

With the options -n and -N, the current numeric argument
will be saved and then restored after the call to widget;
`-n num' sets the numeric argument temporarily to num,
while `-N' sets it to the default, i.e. as if there were
none.

With the option -K, keymap will be used as the current
keymap during the execution of the widget. The previous
keymap will be restored when the widget exits.

Normally, calling a widget in this way does not set the
special parameter WIDGET and related parameters, so that
the environment appears as if the top-level widget called
by the user were still active. With the option -w,
WIDGET and related parameters are set to reflect the
widget being executed by the zle call.

Normally, when widget returns the special parameter
LASTWIDGET will point to it. This can be inhibited by
passing the option -f nolast.

Any further arguments will be passed to the widget; note
that as standard argument handling is performed, any
general argument list should be preceded by --. If it is
a shell function, these are passed down as positional
parameters; for builtin widgets it is up to the widget in
question what it does with them. Currently arguments are
only handled by the incremental-search commands, the
history-search-forward and -backward and the
corresponding functions prefixed by vi-, and by
universal-argument. No error is flagged if the command
does not use the arguments, or only uses some of them.

The return status reflects the success or failure of the
operation carried out by the widget, or if it is a
user-defined widget the return status of the shell
function.

A non-zero return status causes the shell to beep when
the widget exits, unless the BEEP options was unset or
the widget was called via the zle command. Thus if a
user defined widget requires an immediate beep, it should
call the beep widget directly.

ZLE WIDGETS
All actions in the editor are performed by `widgets'. A widget's job
is simply to perform some small action. The ZLE commands that key
sequences in keymaps are bound to are in fact widgets. Widgets can be
user-defined or built in.

The standard widgets built into ZLE are listed in the section `Standard
Widgets' below. Other built-in widgets can be defined by other modules
(see zshmodules(1)). Each built-in widget has two names: its normal
canonical name, and the same name preceded by a `.'. The `.' name is
special: it can't be rebound to a different widget. This makes the
widget available even when its usual name has been redefined.

User-defined widgets are defined using `zle -N', and implemented as
shell functions. When the widget is executed, the corresponding shell
function is executed, and can perform editing (or other) actions. It
is recommended that user-defined widgets should not have names starting
with `.'.

USER-DEFINED WIDGETS
User-defined widgets, being implemented as shell functions, can execute
any normal shell command. They can also run other widgets (whether
built-in or user-defined) using the zle builtin command. The standard
input of the function is redirected from /dev/null to prevent external
commands from unintentionally blocking ZLE by reading from the
terminal, but read -k or read -q can be used to read characters.
Finally, they can examine and edit the ZLE buffer being edited by
reading and setting the special parameters described below.

These special parameters are always available in widget functions, but
are not in any way special outside ZLE. If they have some normal value
outside ZLE, that value is temporarily inaccessible, but will return
when the widget function exits. These special parameters in fact have
local scope, like parameters created in a function using local.

Inside completion widgets and traps called while ZLE is active, these
parameters are available read-only.

Note that the parameters appear as local to any ZLE widget in which
they appear. Hence if it is desired to override them this needs to be
done within a nested function:

widget-function() {
# $WIDGET here refers to the special variable
# that is local inside widget-function
() {
# This anonymous nested function allows WIDGET
# to be used as a local variable. The -h
# removes the special status of the variable.
local -h WIDGET
}
}

BUFFER (scalar)
The entire contents of the edit buffer. If it is written to,
the cursor remains at the same offset, unless that would put it
outside the buffer.

BUFFERLINES (integer)
The number of screen lines needed for the edit buffer currently
displayed on screen (i.e. without any changes to the preceding
parameters done after the last redisplay); read-only.

CONTEXT (scalar)
The context in which zle was called to read a line; read-only.
One of the values:

start The start of a command line (at prompt PS1).

cont A continuation to a command line (at prompt PS2).

select In a select loop (at prompt PS3).

vared Editing a variable in vared.

CURSOR (integer)
The offset of the cursor, within the edit buffer. This is in
the range 0 to $#BUFFER, and is by definition equal to
$#LBUFFER. Attempts to move the cursor outside the buffer will
result in the cursor being moved to the appropriate end of the
buffer.

CUTBUFFER (scalar)
The last item cut using one of the `kill-' commands; the string
which the next yank would insert in the line. Later entries in
the kill ring are in the array killring. Note that the command
`zle copy-region-as-kill string' can be used to set the text of
the cut buffer from a shell function and cycle the kill ring in
the same way as interactively killing text.

HISTNO (integer)
The current history number. Setting this has the same effect as
moving up or down in the history to the corresponding history
line. An attempt to set it is ignored if the line is not stored
in the history. Note this is not the same as the parameter
HISTCMD, which always gives the number of the history line being
added to the main shell's history. HISTNO refers to the line
being retrieved within zle.

ISEARCHMATCH_ACTIVE (integer)
ISEARCHMATCH_START (integer)
ISEARCHMATCH_END (integer)
ISEARCHMATCH_ACTIVE indicates whether a part of the BUFFER is
currently matched by an incremental search pattern.
ISEARCHMATCH_START and ISEARCHMATCH_END give the location of the
matched part and are in the same units as CURSOR. They are only
valid for reading when ISEARCHMATCH_ACTIVE is non-zero.

All parameters are read-only.

KEYMAP (scalar)
The name of the currently selected keymap; read-only.

KEYS (scalar)
The keys typed to invoke this widget, as a literal string;
read-only.

KEYS_QUEUED_COUNT (integer)
The number of bytes pushed back to the input queue and therefore
available for reading immediately before any I/O is done;
read-only. See also PENDING; the two values are distinct.

killring (array)
The array of previously killed items, with the most recently
killed first. This gives the items that would be retrieved by a
yank-pop in the same order. Note, however, that the most
recently killed item is in $CUTBUFFER; $killring shows the array
of previous entries.

The default size for the kill ring is eight, however the length
may be changed by normal array operations. Any empty string in
the kill ring is ignored by the yank-pop command, hence the size
of the array effectively sets the maximum length of the kill
ring, while the number of non-zero strings gives the current
length, both as seen by the user at the command line.

LASTABORTEDSEARCH (scalar)
The last search string used by an interactive search that was
aborted by the user (status 3 returned by the search widget).

LASTSEARCH (scalar)
The last search string used by an interactive search; read-only.
This is set even if the search failed (status 0, 1 or 2 returned
by the search widget), but not if it was aborted by the user.

LASTWIDGET (scalar)
The name of the last widget that was executed; read-only.

LBUFFER (scalar)
The part of the buffer that lies to the left of the cursor
position. If it is assigned to, only that part of the buffer is
replaced, and the cursor remains between the new $LBUFFER and
the old $RBUFFER.

MARK (integer)
Like CURSOR, but for the mark. With vi-mode operators that wait
for a movement command to select a region of text, setting MARK
allows the selection to extend in both directions from the
initial cursor position.

NUMERIC (integer)
The numeric argument. If no numeric argument was given, this
parameter is unset. When this is set inside a widget function,
builtin widgets called with the zle builtin command will use the
value assigned. If it is unset inside a widget function, builtin
widgets called behave as if no numeric argument was given.

PENDING (integer)
The number of bytes pending for input, i.e. the number of bytes
which have already been typed and can immediately be read. On
systems where the shell is not able to get this information,
this parameter will always have a value of zero. Read-only.
See also KEYS_QUEUED_COUNT; the two values are distinct.

PREBUFFER (scalar)
In a multi-line input at the secondary prompt, this read-only
parameter contains the contents of the lines before the one the
cursor is currently in.

PREDISPLAY (scalar)
Text to be displayed before the start of the editable text
buffer. This does not have to be a complete line; to display a
complete line, a newline must be appended explicitly. The text
is reset on each new invocation (but not recursive invocation)
of zle.

POSTDISPLAY (scalar)
Text to be displayed after the end of the editable text buffer.
This does not have to be a complete line; to display a complete
line, a newline must be prepended explicitly. The text is reset
on each new invocation (but not recursive invocation) of zle.

RBUFFER (scalar)
The part of the buffer that lies to the right of the cursor
position. If it is assigned to, only that part of the buffer is
replaced, and the cursor remains between the old $LBUFFER and
the new $RBUFFER.

REGION_ACTIVE (integer)
Indicates if the region is currently active. It can be assigned
0 or 1 to deactivate and activate the region respectively. A
value of 2 activates the region in line-wise mode with the
highlighted text extending for whole lines only; see Character
Highlighting below.

region_highlight (array)
Each element of this array may be set to a string that describes
highlighting for an arbitrary region of the command line that
will take effect the next time the command line is redisplayed.
Highlighting of the non-editable parts of the command line in
PREDISPLAY and POSTDISPLAY are possible, but note that the P
flag is needed for character indexing to include PREDISPLAY.

Each string consists of the following whitespace-separated
parts:

o Optionally, a `P' to signify that the start and end
offset that follow include any string set by the
PREDISPLAY special parameter; this is needed if the
predisplay string itself is to be highlighted.
Whitespace between the `P' and the start offset is
optional.

o A start offset in the same units as CURSOR.

o An end offset in the same units as CURSOR.

o A highlight specification in the same format as used for
contexts in the parameter zle_highlight, see the section
`Character Highlighting' below; for example, standout or
fg=red,bold.

o Optionally, a string of the form `memo=token'. The token
consists of everything between the `=' and the next
whitespace, comma, NUL, or the end of the string. The
token is preserved verbatim but not parsed in any way.

Plugins may use this to identify array elements they have
added: for example, a plugin might set token to its (the
plugin's) name and then use `region_highlight=(
${region_highlight:#*memo=token} )' in order to remove
array elements it have added.

(This example uses the `${name:#pattern}' array-grepping
syntax described in the section `Parameter Expansion' in
zshexpn(1).)

For example,

region_highlight=("P0 20 bold memo=foobar")

specifies that the first twenty characters of the text including
any predisplay string should be highlighted in bold.

Note that the effect of region_highlight is not saved and
disappears as soon as the line is accepted.

Note that zsh 5.8 and older do not support the `memo=token'
field and may misparse the third (highlight specification) field
when a memo is given.

The final highlighting on the command line depends on both
region_highlight and zle_highlight; see the section CHARACTER
HIGHLIGHTING below for details.

registers (associative array)
The contents of each of the vi register buffers. These are
typically set using vi-set-buffer followed by a delete, change
or yank command.

SUFFIX_ACTIVE (integer)
SUFFIX_START (integer)
SUFFIX_END (integer)
SUFFIX_ACTIVE indicates whether an auto-removable completion
suffix is currently active. SUFFIX_START and SUFFIX_END give the
location of the suffix and are in the same units as CURSOR. They
are only valid for reading when SUFFIX_ACTIVE is non-zero.

All parameters are read-only.

UNDO_CHANGE_NO (integer)
A number representing the state of the undo history. The only
use of this is passing as an argument to the undo widget in
order to undo back to the recorded point. Read-only.

UNDO_LIMIT_NO (integer)
A number corresponding to an existing change in the undo
history; compare UNDO_CHANGE_NO. If this is set to a value
greater than zero, the undo command will not allow the line to
be undone beyond the given change number. It is still possible
to use `zle undo change' in a widget to undo beyond that point;
in that case, it will not be possible to undo at all until
UNDO_LIMIT_NO is reduced. Set to 0 to disable the limit.

A typical use of this variable in a widget function is as
follows (note the additional function scope is required):

() {
local UNDO_LIMIT_NO=$UNDO_CHANGE_NO
# Perform some form of recursive edit.
}

WIDGET (scalar)
The name of the widget currently being executed; read-only.

WIDGETFUNC (scalar)
The name of the shell function that implements a widget defined
with either zle -N or zle -C. In the former case, this is the
second argument to the zle -N command that defined the widget,
or the first argument if there was no second argument. In the
latter case this is the third argument to the zle -C command
that defined the widget. Read-only.

WIDGETSTYLE (scalar)
Describes the implementation behind the completion widget
currently being executed; the second argument that followed zle
-C when the widget was defined. This is the name of a builtin
completion widget. For widgets defined with zle -N this is set
to the empty string. Read-only.

YANK_ACTIVE (integer)
YANK_START (integer)
YANK_END (integer)
YANK_ACTIVE indicates whether text has just been yanked (pasted)
into the buffer. YANK_START and YANK_END give the location of
the pasted text and are in the same units as CURSOR. They are
only valid for reading when YANK_ACTIVE is non-zero. They can
also be assigned by widgets that insert text in a yank-like
fashion, for example wrappers of bracketed-paste. See also zle
-f.

YANK_ACTIVE is read-only.

ZLE_RECURSIVE (integer)
Usually zero, but incremented inside any instance of
recursive-edit. Hence indicates the current recursion level.

ZLE_RECURSIVE is read-only.

ZLE_STATE (scalar)
Contains a set of space-separated words that describe the
current zle state.

Currently, the states shown are the insert mode as set by the
overwrite-mode or vi-replace widgets and whether history
commands will visit imported entries as controlled by the
set-local-history widget. The string contains `insert' if
characters to be inserted on the command line move existing
characters to the right or `overwrite' if characters to be
inserted overwrite existing characters. It contains
`localhistory' if only local history commands will be visited or
`globalhistory' if imported history commands will also be
visited.

The substrings are sorted in alphabetical order so that if you
want to test for two specific substrings in a future-proof way,
you can do match by doing:

if [[ $ZLE_STATE == *globalhistory*insert* ]]; then ...; fi

Special Widgets
There are a few user-defined widgets which are special to the shell.
If they do not exist, no special action is taken. The environment
provided is identical to that for any other editing widget.

zle-isearch-exit
Executed at the end of incremental search at the point where the
isearch prompt is removed from the display. See
zle-isearch-update for an example.

zle-isearch-update
Executed within incremental search when the display is about to
be redrawn. Additional output below the incremental search
prompt can be generated by using `zle -M' within the widget.
For example,

zle-isearch-update() { zle -M "Line $HISTNO"; }
zle -N zle-isearch-update

Note the line output by `zle -M' is not deleted on exit from
incremental search. This can be done from a zle-isearch-exit
widget:

zle-isearch-exit() { zle -M ""; }
zle -N zle-isearch-exit

zle-line-pre-redraw
Executed whenever the input line is about to be redrawn,
providing an opportunity to update the region_highlight array.

zle-line-init
Executed every time the line editor is started to read a new
line of input. The following example puts the line editor into
vi command mode when it starts up.

zle-line-init() { zle -K vicmd; }
zle -N zle-line-init

(The command inside the function sets the keymap directly; it is
equivalent to zle vi-cmd-mode.)

zle-line-finish
This is similar to zle-line-init but is executed every time the
line editor has finished reading a line of input.

zle-history-line-set
Executed when the history line changes.

zle-keymap-select
Executed every time the keymap changes, i.e. the special
parameter KEYMAP is set to a different value, while the line
editor is active. Initialising the keymap when the line editor
starts does not cause the widget to be called.

The value $KEYMAP within the function reflects the new keymap.
The old keymap is passed as the sole argument.

This can be used for detecting switches between the vi command
(vicmd) and insert (usually main) keymaps.

STANDARD WIDGETS
The following is a list of all the standard widgets, and their default
bindings in emacs mode, vi command mode and vi insert mode (the
`emacs', `vicmd' and `viins' keymaps, respectively).

Note that cursor keys are bound to movement keys in all three keymaps;
the shell assumes that the cursor keys send the key sequences reported
by the terminal-handling library (termcap or terminfo). The key
sequences shown in the list are those based on the VT100, common on
many modern terminals, but in fact these are not necessarily bound. In
the case of the viins keymap, the initial escape character of the
sequences serves also to return to the vicmd keymap: whether this
happens is determined by the KEYTIMEOUT parameter, see zshparam(1).

Movement
vi-backward-blank-word (unbound) (B) (unbound)
Move backward one word, where a word is defined as a series of
non-blank characters.

vi-backward-blank-word-end (unbound) (gE) (unbound)
Move to the end of the previous word, where a word is defined as
a series of non-blank characters.

backward-char (^B ESC-[D) (unbound) (unbound)
Move backward one character.

vi-backward-char (unbound) (^H h ^?) (ESC-[D)
Move backward one character, without changing lines.

backward-word (ESC-B ESC-b) (unbound) (unbound)
Move to the beginning of the previous word.

emacs-backward-word
Move to the beginning of the previous word.

vi-backward-word (unbound) (b) (unbound)
Move to the beginning of the previous word, vi-style.

vi-backward-word-end (unbound) (ge) (unbound)
Move to the end of the previous word, vi-style.

beginning-of-line (^A) (unbound) (unbound)
Move to the beginning of the line. If already at the beginning
of the line, move to the beginning of the previous line, if any.

vi-beginning-of-line
Move to the beginning of the line, without changing lines.

down-line (unbound) (unbound) (unbound)
Move down a line in the buffer.

end-of-line (^E) (unbound) (unbound)
Move to the end of the line. If already at the end of the line,
move to the end of the next line, if any.

vi-end-of-line (unbound) ($) (unbound)
Move to the end of the line. If an argument is given to this
command, the cursor will be moved to the end of the line
(argument - 1) lines down.

vi-forward-blank-word (unbound) (W) (unbound)
Move forward one word, where a word is defined as a series of
non-blank characters.

vi-forward-blank-word-end (unbound) (E) (unbound)
Move to the end of the current word, or, if at the end of the
current word, to the end of the next word, where a word is
defined as a series of non-blank characters.

forward-char (^F ESC-[C) (unbound) (unbound)
Move forward one character.

vi-forward-char (unbound) (space l) (ESC-[C)
Move forward one character.

vi-find-next-char (^X^F) (f) (unbound)
Read a character from the keyboard, and move to the next
occurrence of it in the line.

vi-find-next-char-skip (unbound) (t) (unbound)
Read a character from the keyboard, and move to the position
just before the next occurrence of it in the line.

vi-find-prev-char (unbound) (F) (unbound)
Read a character from the keyboard, and move to the previous
occurrence of it in the line.

vi-find-prev-char-skip (unbound) (T) (unbound)
Read a character from the keyboard, and move to the position
just after the previous occurrence of it in the line.

vi-first-non-blank (unbound) (^) (unbound)
Move to the first non-blank character in the line.

vi-forward-word (unbound) (w) (unbound)
Move forward one word, vi-style.

forward-word (ESC-F ESC-f) (unbound) (unbound)
Move to the beginning of the next word. The editor's idea of a
word is specified with the WORDCHARS parameter.

emacs-forward-word
Move to the end of the next word.

vi-forward-word-end (unbound) (e) (unbound)
Move to the end of the next word.

vi-goto-column (ESC-|) (|) (unbound)
Move to the column specified by the numeric argument.

vi-goto-mark (unbound) (`) (unbound)
Move to the specified mark.

vi-goto-mark-line (unbound) (') (unbound)
Move to beginning of the line containing the specified mark.

vi-repeat-find (unbound) (;) (unbound)
Repeat the last vi-find command.

vi-rev-repeat-find (unbound) (,) (unbound)
Repeat the last vi-find command in the opposite direction.

up-line (unbound) (unbound) (unbound)
Move up a line in the buffer.

History Control
beginning-of-buffer-or-history (ESC-<) (gg) (unbound)
Move to the beginning of the buffer, or if already there, move
to the first event in the history list.

beginning-of-line-hist
Move to the beginning of the line. If already at the beginning
of the buffer, move to the previous history line.

beginning-of-history
Move to the first event in the history list.

down-line-or-history (^N ESC-[B) (j) (ESC-[B)
Move down a line in the buffer, or if already at the bottom
line, move to the next event in the history list.

vi-down-line-or-history (unbound) (*) (unbound)
Move down a line in the buffer, or if already at the bottom
line, move to the next event in the history list. Then move to
the first non-blank character on the line.

down-line-or-search
Move down a line in the buffer, or if already at the bottom
line, search forward in the history for a line beginning with
the first word in the buffer.

If called from a function by the zle command with arguments, the
first argument is taken as the string for which to search,
rather than the first word in the buffer.

down-history (unbound) (^N) (unbound)
Move to the next event in the history list.

history-beginning-search-backward
Search backward in the history for a line beginning with the
current line up to the cursor. This leaves the cursor in its
original position.

end-of-buffer-or-history (ESC->) (unbound) (unbound)
Move to the end of the buffer, or if already there, move to the
last event in the history list.

end-of-line-hist
Move to the end of the line. If already at the end of the
buffer, move to the next history line.

end-of-history
Move to the last event in the history list.

vi-fetch-history (unbound) (G) (unbound)
Fetch the history line specified by the numeric argument. This
defaults to the current history line (i.e. the one that isn't
history yet).

history-incremental-search-backward (^R ^Xr) (unbound) (unbound)
Search backward incrementally for a specified string. The
search is case-insensitive if the search string does not have
uppercase letters and no numeric argument was given. The string
may begin with `^' to anchor the search to the beginning of the
line. When called from a user-defined function returns the
following statuses: 0, if the search succeeded; 1, if the search
failed; 2, if the search term was a bad pattern; 3, if the
search was aborted by the send-break command.

A restricted set of editing functions is available in the
mini-buffer. Keys are looked up in the special isearch keymap,
and if not found there in the main keymap (note that by default
the isearch keymap is empty). An interrupt signal, as defined
by the stty setting, will stop the search and go back to the
original line. An undefined key will have the same effect.
Note that the following always perform the same task within
incremental searches and cannot be replaced by user defined
widgets, nor can the set of functions be extended. The
supported functions are:

accept-and-hold
accept-and-infer-next-history
accept-line
accept-line-and-down-history
Perform the usual function after exiting incremental
search. The command line displayed is executed.

backward-delete-char
vi-backward-delete-char
Back up one place in the search history. If the search
has been repeated this does not immediately erase a
character in the minibuffer.

accept-search
Exit incremental search, retaining the command line but
performing no further action. Note that this function is
not bound by default and has no effect outside
incremental search.

backward-delete-word
backward-kill-word
vi-backward-kill-word
Back up one character in the minibuffer; if multiple
searches have been performed since the character was
inserted the search history is rewound to the point just
before the character was entered. Hence this has the
effect of repeating backward-delete-char.

clear-screen
Clear the screen, remaining in incremental search mode.

history-incremental-search-backward
Find the next occurrence of the contents of the
mini-buffer. If the mini-buffer is empty, the most recent
previously used search string is reinstated.

history-incremental-search-forward
Invert the sense of the search.

magic-space
Inserts a non-magical space.

quoted-insert
vi-quoted-insert
Quote the character to insert into the minibuffer.

redisplay
Redisplay the command line, remaining in incremental
search mode.

vi-cmd-mode
Select the `vicmd' keymap; the `main' keymap (insert
mode) will be selected initially.

In addition, the modifications that were made while in vi
insert mode are merged to form a single undo event.

vi-repeat-search
vi-rev-repeat-search
Repeat the search. The direction of the search is
indicated in the mini-buffer.

Any character that is not bound to one of the above functions,
or self-insert or self-insert-unmeta, will cause the mode to be
exited. The character is then looked up and executed in the
keymap in effect at that point.

When called from a widget function by the zle command, the
incremental search commands can take a string argument. This
will be treated as a string of keys, as for arguments to the
bindkey command, and used as initial input for the command. Any
characters in the string which are unused by the incremental
search will be silently ignored. For example,

zle history-incremental-search-backward forceps

will search backwards for forceps, leaving the minibuffer
containing the string `forceps'.

history-incremental-search-forward (^S ^Xs) (unbound) (unbound)
Search forward incrementally for a specified string. The search
is case-insensitive if the search string does not have uppercase
letters and no numeric argument was given. The string may begin
with `^' to anchor the search to the beginning of the line. The
functions available in the mini-buffer are the same as for
history-incremental-search-backward.

history-incremental-pattern-search-backward
history-incremental-pattern-search-forward
These widgets behave similarly to the corresponding widgets with
no -pattern, but the search string typed by the user is treated
as a pattern, respecting the current settings of the various
options affecting pattern matching. See FILENAME GENERATION in
zshexpn(1) for a description of patterns. If no numeric
argument was given lowercase letters in the search string may
match uppercase letters in the history. The string may begin
with `^' to anchor the search to the beginning of the line.

The prompt changes to indicate an invalid pattern; this may
simply indicate the pattern is not yet complete.

Note that only non-overlapping matches are reported, so an
expression with wildcards may return fewer matches on a line
than are visible by inspection.

history-search-backward (ESC-P ESC-p) (unbound) (unbound)
Search backward in the history for a line beginning with the
first word in the buffer.

If called from a function by the zle command with arguments, the
first argument is taken as the string for which to search,
rather than the first word in the buffer.

vi-history-search-backward (unbound) (/) (unbound)
Search backward in the history for a specified string. The
string may begin with `^' to anchor the search to the beginning
of the line.

A restricted set of editing functions is available in the
mini-buffer. An interrupt signal, as defined by the stty
setting, will stop the search. The functions available in the
mini-buffer are: accept-line, backward-delete-char,
vi-backward-delete-char, backward-kill-word,
vi-backward-kill-word, clear-screen, redisplay, quoted-insert
and vi-quoted-insert.

vi-cmd-mode is treated the same as accept-line, and magic-space
is treated as a space. Any other character that is not bound to
self-insert or self-insert-unmeta will beep and be ignored. If
the function is called from vi command mode, the bindings of the
current insert mode will be used.

If called from a function by the zle command with arguments, the
first argument is taken as the string for which to search,
rather than the first word in the buffer.

history-search-forward (ESC-N ESC-n) (unbound) (unbound)
Search forward in the history for a line beginning with the
first word in the buffer.

If called from a function by the zle command with arguments, the
first argument is taken as the string for which to search,
rather than the first word in the buffer.

vi-history-search-forward (unbound) (?) (unbound)
Search forward in the history for a specified string. The
string may begin with `^' to anchor the search to the beginning
of the line. The functions available in the mini-buffer are the
same as for vi-history-search-backward. Argument handling is
also the same as for that command.

infer-next-history (^X^N) (unbound) (unbound)
Search in the history list for a line matching the current one
and fetch the event following it.

insert-last-word (ESC-_ ESC-.) (unbound) (unbound)
Insert the last word from the previous history event at the
cursor position. If a positive numeric argument is given,
insert that word from the end of the previous history event. If
the argument is zero or negative insert that word from the left
(zero inserts the previous command word). Repeating this
command replaces the word just inserted with the last word from
the history event prior to the one just used; numeric arguments
can be used in the same way to pick a word from that event.

When called from a shell function invoked from a user-defined
widget, the command can take one to three arguments. The first
argument specifies a history offset which applies to successive
calls to this widget: if it is -1, the default behaviour is
used, while if it is 1, successive calls will move forwards
through the history. The value 0 can be used to indicate that
the history line examined by the previous execution of the
command will be reexamined. Note that negative numbers should
be preceded by a `--' argument to avoid confusing them with
options.

If two arguments are given, the second specifies the word on the
command line in normal array index notation (as a more natural
alternative to the numeric argument). Hence 1 is the first
word, and -1 (the default) is the last word.

If a third argument is given, its value is ignored, but it is
used to signify that the history offset is relative to the
current history line, rather than the one remembered after the
previous invocations of insert-last-word.

For example, the default behaviour of the command corresponds to

zle insert-last-word -- -1 -1

while the command

zle insert-last-word -- -1 1 -

always copies the first word of the line in the history
immediately before the line being edited. This has the side
effect that later invocations of the widget will be relative to
that line.

vi-repeat-search (unbound) (n) (unbound)
Repeat the last vi history search.

vi-rev-repeat-search (unbound) (N) (unbound)
Repeat the last vi history search, but in reverse.

up-line-or-history (^P ESC-[A) (k) (ESC-[A)
Move up a line in the buffer, or if already at the top line,
move to the previous event in the history list.

vi-up-line-or-history (unbound) (-) (unbound)
Move up a line in the buffer, or if already at the top line,
move to the previous event in the history list. Then move to
the first non-blank character on the line.

up-line-or-search
Move up a line in the buffer, or if already at the top line,
search backward in the history for a line beginning with the
first word in the buffer.

If called from a function by the zle command with arguments, the
first argument is taken as the string for which to search,
rather than the first word in the buffer.

up-history (unbound) (^P) (unbound)
Move to the previous event in the history list.

history-beginning-search-forward
Search forward in the history for a line beginning with the
current line up to the cursor. This leaves the cursor in its
original position.

set-local-history
By default, history movement commands visit the imported lines
as well as the local lines. This widget lets you toggle this on
and off, or set it with the numeric argument. Zero for both
local and imported lines and nonzero for only local lines.

Modifying Text
vi-add-eol (unbound) (A) (unbound)
Move to the end of the line and enter insert mode.

vi-add-next (unbound) (a) (unbound)
Enter insert mode after the current cursor position, without
changing lines.

backward-delete-char (^H ^?) (unbound) (unbound)
Delete the character behind the cursor.

vi-backward-delete-char (unbound) (X) (^H)
Delete the character behind the cursor, without changing lines.
If in insert mode, this won't delete past the point where insert
mode was last entered.

backward-delete-word
Delete the word behind the cursor.

backward-kill-line
Kill from the beginning of the line to the cursor position.

backward-kill-word (^W ESC-^H ESC-^?) (unbound) (unbound)
Kill the word behind the cursor.

vi-backward-kill-word (unbound) (unbound) (^W)
Kill the word behind the cursor, without going past the point
where insert mode was last entered.

capitalize-word (ESC-C ESC-c) (unbound) (unbound)
Capitalize the current word and move past it.

vi-change (unbound) (c) (unbound)
Read a movement command from the keyboard, and kill from the
cursor position to the endpoint of the movement. Then enter
insert mode. If the command is vi-change, change the current
line.

For compatibility with vi, if the command is vi-forward-word or
vi-forward-blank-word, the whitespace after the word is not
included. If you prefer the more consistent behaviour with the
whitespace included use the following key binding:

bindkey -a -s cw dwi

vi-change-eol (unbound) (C) (unbound)
Kill to the end of the line and enter insert mode.

vi-change-whole-line (unbound) (S) (unbound)
Kill the current line and enter insert mode.

copy-region-as-kill (ESC-W ESC-w) (unbound) (unbound)
Copy the area from the cursor to the mark to the kill buffer.

If called from a ZLE widget function in the form `zle
copy-region-as-kill string' then string will be taken as the
text to copy to the kill buffer. The cursor, the mark and the
text on the command line are not used in this case.

copy-prev-word (ESC-^_) (unbound) (unbound)
Duplicate the word to the left of the cursor.

copy-prev-shell-word
Like copy-prev-word, but the word is found by using shell
parsing, whereas copy-prev-word looks for blanks. This makes a
difference when the word is quoted and contains spaces.

vi-delete (unbound) (d) (unbound)
Read a movement command from the keyboard, and kill from the
cursor position to the endpoint of the movement. If the command
is vi-delete, kill the current line.

delete-char
Delete the character under the cursor.

vi-delete-char (unbound) (x) (unbound)
Delete the character under the cursor, without going past the
end of the line.

delete-word
Delete the current word.

down-case-word (ESC-L ESC-l) (unbound) (unbound)
Convert the current word to all lowercase and move past it.

vi-down-case (unbound) (gu) (unbound)
Read a movement command from the keyboard, and convert all
characters from the cursor position to the endpoint of the
movement to lowercase. If the movement command is vi-down-case,
swap the case of all characters on the current line.

kill-word (ESC-D ESC-d) (unbound) (unbound)
Kill the current word.

gosmacs-transpose-chars
Exchange the two characters behind the cursor.

vi-indent (unbound) (>) (unbound)
Indent a number of lines.

vi-insert (unbound) (i) (unbound)
Enter insert mode.

vi-insert-bol (unbound) (I) (unbound)
Move to the first non-blank character on the line and enter
insert mode.

vi-join (^X^J) (J) (unbound)
Join the current line with the next one.

kill-line (^K) (unbound) (unbound)
Kill from the cursor to the end of the line. If already on the
end of the line, kill the newline character.

vi-kill-line (unbound) (unbound) (^U)
Kill from the cursor back to wherever insert mode was last
entered.

vi-kill-eol (unbound) (D) (unbound)
Kill from the cursor to the end of the line.

kill-region
Kill from the cursor to the mark.

kill-buffer (^X^K) (unbound) (unbound)
Kill the entire buffer.

kill-whole-line (^U) (unbound) (unbound)
Kill the current line.

vi-match-bracket (^X^B) (%) (unbound)
Move to the bracket character (one of {}, () or []) that matches
the one under the cursor. If the cursor is not on a bracket
character, move forward without going past the end of the line
to find one, and then go to the matching bracket.

vi-open-line-above (unbound) (O) (unbound)
Open a line above the cursor and enter insert mode.

vi-open-line-below (unbound) (o) (unbound)
Open a line below the cursor and enter insert mode.

vi-oper-swap-case (unbound) (g~) (unbound)
Read a movement command from the keyboard, and swap the case of
all characters from the cursor position to the endpoint of the
movement. If the movement command is vi-oper-swap-case, swap
the case of all characters on the current line.

overwrite-mode (^X^O) (unbound) (unbound)
Toggle between overwrite mode and insert mode.

vi-put-before (unbound) (P) (unbound)
Insert the contents of the kill buffer before the cursor. If
the kill buffer contains a sequence of lines (as opposed to
characters), paste it above the current line.

vi-put-after (unbound) (p) (unbound)
Insert the contents of the kill buffer after the cursor. If the
kill buffer contains a sequence of lines (as opposed to
characters), paste it below the current line.

put-replace-selection (unbound) (unbound) (unbound)
Replace the contents of the current region or selection with the
contents of the kill buffer. If the kill buffer contains a
sequence of lines (as opposed to characters), the current line
will be split by the pasted lines.

quoted-insert (^V) (unbound) (unbound)
Insert the next character typed into the buffer literally. An
interrupt character will not be inserted.

vi-quoted-insert (unbound) (unbound) (^Q ^V)
Display a `^' at the cursor position, and insert the next
character typed into the buffer literally. An interrupt
character will not be inserted.

quote-line (ESC-') (unbound) (unbound)
Quote the current line; that is, put a `'' character at the
beginning and the end, and convert all `'' characters to `'\'''.

quote-region (ESC-") (unbound) (unbound)
Quote the region from the cursor to the mark.

vi-replace (unbound) (R) (unbound)
Enter overwrite mode.

vi-repeat-change (unbound) (.) (unbound)
Repeat the last vi mode text modification. If a count was used
with the modification, it is remembered. If a count is given to
this command, it overrides the remembered count, and is
remembered for future uses of this command. The cut buffer
specification is similarly remembered.

vi-replace-chars (unbound) (r) (unbound)
Replace the character under the cursor with a character read
from the keyboard.

self-insert (printable characters) (unbound) (printable characters and
some control characters)
Insert a character into the buffer at the cursor position.

self-insert-unmeta (ESC-^I ESC-^J ESC-^M) (unbound) (unbound)
Insert a character into the buffer after stripping the meta bit
and converting ^M to ^J.

vi-substitute (unbound) (s) (unbound)
Substitute the next character(s).

vi-swap-case (unbound) (~) (unbound)
Swap the case of the character under the cursor and move past
it.

transpose-chars (^T) (unbound) (unbound)
Exchange the two characters to the left of the cursor if at end
of line, else exchange the character under the cursor with the
character to the left.

transpose-words (ESC-T ESC-t) (unbound) (unbound)
Exchange the current word with the one before it.

With a positive numeric argument N, the word around the cursor,
or following it if the cursor is between words, is transposed
with the preceding N words. The cursor is put at the end of the
resulting group of words.

With a negative numeric argument -N, the effect is the same as
using a positive argument N except that the original cursor
position is retained, regardless of how the words are
rearranged.

vi-unindent (unbound) (<) (unbound)
Unindent a number of lines.

vi-up-case (unbound) (gU) (unbound)
Read a movement command from the keyboard, and convert all
characters from the cursor position to the endpoint of the
movement to lowercase. If the movement command is vi-up-case,
swap the case of all characters on the current line.

up-case-word (ESC-U ESC-u) (unbound) (unbound)
Convert the current word to all caps and move past it.

yank (^Y) (unbound) (unbound)
Insert the contents of the kill buffer at the cursor position.

yank-pop (ESC-y) (unbound) (unbound)
Remove the text just yanked, rotate the kill-ring (the history
of previously killed text) and yank the new top. Only works
following yank, vi-put-before, vi-put-after or yank-pop.

vi-yank (unbound) (y) (unbound)
Read a movement command from the keyboard, and copy the region
from the cursor position to the endpoint of the movement into
the kill buffer. If the command is vi-yank, copy the current
line.

vi-yank-whole-line (unbound) (Y) (unbound)
Copy the current line into the kill buffer.

vi-yank-eol
Copy the region from the cursor position to the end of the line
into the kill buffer. Arguably, this is what Y should do in vi,
but it isn't what it actually does.

Arguments
digit-argument (ESC-0..ESC-9) (1-9) (unbound)
Start a new numeric argument, or add to the current one. See
also vi-digit-or-beginning-of-line. This only works if bound to
a key sequence ending in a decimal digit.

Inside a widget function, a call to this function treats the
last key of the key sequence which called the widget as the
digit.

neg-argument (ESC--) (unbound) (unbound)
Changes the sign of the following argument.

universal-argument
Multiply the argument of the next command by 4. Alternatively,
if this command is followed by an integer (positive or
negative), use that as the argument for the next command. Thus
digits cannot be repeated using this command. For example, if
this command occurs twice, followed immediately by forward-char,
move forward sixteen spaces; if instead it is followed by -2,
then forward-char, move backward two spaces.

Inside a widget function, if passed an argument, i.e. `zle
universal-argument num', the numeric argument will be set to
num; this is equivalent to `NUMERIC=num'.

argument-base
Use the existing numeric argument as a numeric base, which must
be in the range 2 to 36 inclusive. Subsequent use of
digit-argument and universal-argument will input a new numeric
argument in the given base. The usual hexadecimal convention is
used: the letter a or A corresponds to 10, and so on. Arguments
in bases requiring digits from 10 upwards are more conveniently
input with universal-argument, since ESC-a etc. are not usually
bound to digit-argument.

The function can be used with a command argument inside a
user-defined widget. The following code sets the base to 16 and
lets the user input a hexadecimal argument until a key out of
the digit range is typed:

zle argument-base 16
zle universal-argument

Completion
accept-and-menu-complete
In a menu completion, insert the current completion into the
buffer, and advance to the next possible completion.

complete-word
Attempt completion on the current word.

delete-char-or-list (^D) (unbound) (unbound)
Delete the character under the cursor. If the cursor is at the
end of the line, list possible completions for the current word.

expand-cmd-path
Expand the current command to its full pathname.

expand-or-complete (TAB) (unbound) (TAB)
Attempt shell expansion on the current word. If that fails,
attempt completion.

expand-or-complete-prefix
Attempt shell expansion on the current word up to cursor.

expand-history (ESC-space ESC-!) (unbound) (unbound)
Perform history expansion on the edit buffer.

expand-word (^X*) (unbound) (unbound)
Attempt shell expansion on the current word.

list-choices (ESC-^D) (^D =) (^D)
List possible completions for the current word.

list-expand (^Xg ^XG) (^G) (^G)
List the expansion of the current word.

magic-space
Perform history expansion and insert a space into the buffer.
This is intended to be bound to space.

menu-complete
Like complete-word, except that menu completion is used. See
the MENU_COMPLETE option.

menu-expand-or-complete
Like expand-or-complete, except that menu completion is used.

reverse-menu-complete
Perform menu completion, like menu-complete, except that if a
menu completion is already in progress, move to the previous
completion rather than the next.

end-of-list
When a previous completion displayed a list below the prompt,
this widget can be used to move the prompt below the list.

Miscellaneous
accept-and-hold (ESC-A ESC-a) (unbound) (unbound)
Push the contents of the buffer on the buffer stack and execute
it.

accept-and-infer-next-history
Execute the contents of the buffer. Then search the history
list for a line matching the current one and push the event
following onto the buffer stack.

accept-line (^J ^M) (^J ^M) (^J ^M)
Finish editing the buffer. Normally this causes the buffer to
be executed as a shell command.

accept-line-and-down-history (^O) (unbound) (unbound)
Execute the current line, and push the next history event on the
buffer stack.

auto-suffix-remove
If the previous action added a suffix (space, slash, etc.) to
the word on the command line, remove it. Otherwise do nothing.
Removing the suffix ends any active menu completion or menu
selection.

This widget is intended to be called from user-defined widgets
to enforce a desired suffix-removal behavior.

auto-suffix-retain
If the previous action added a suffix (space, slash, etc.) to
the word on the command line, force it to be preserved.
Otherwise do nothing. Retaining the suffix ends any active menu
completion or menu selection.

This widget is intended to be called from user-defined widgets
to enforce a desired suffix-preservation behavior.

beep Beep, unless the BEEP option is unset.

bracketed-paste (^[[200~) (^[[200~) (^[[200~)
This widget is invoked when text is pasted to the terminal
emulator. It is not intended to be bound to actual keys but
instead to the special sequence generated by the terminal
emulator when text is pasted.

When invoked interactively, the pasted text is inserted to the
buffer and placed in the cutbuffer. If a numeric argument is
given, shell quoting will be applied to the pasted text before
it is inserted.

When a named buffer is specified with vi-set-buffer ("x), the
pasted text is stored in that named buffer but not inserted.

When called from a widget function as `bracketed-paste name`,
the pasted text is assigned to the variable name and no other
processing is done.

See also the zle_bracketed_paste parameter.

vi-cmd-mode (^X^V) (unbound) (^[)
Enter command mode; that is, select the `vicmd' keymap. Yes,
this is bound by default in emacs mode.

vi-caps-lock-panic
Hang until any lowercase key is pressed. This is for vi users
without the mental capacity to keep track of their caps lock key
(like the author).

clear-screen (^L ESC-^L) (^L) (^L)
Clear the screen and redraw the prompt.

deactivate-region
Make the current region inactive. This disables vim-style visual
selection mode if it is active.

describe-key-briefly
Reads a key sequence, then prints the function bound to that
sequence.

exchange-point-and-mark (^X^X) (unbound) (unbound)
Exchange the cursor position (point) with the position of the
mark. Unless a negative numeric argument is given, the region
between point and mark is activated so that it can be
highlighted. If a zero numeric argument is given, the region is
activated but point and mark are not swapped.

execute-named-cmd (ESC-x) (:) (unbound)
Read the name of an editor command and execute it. Aliasing
this widget with `zle -A' or replacing it with `zle -N' has no
effect when interpreting key bindings, but `zle
execute-named-cmd' will invoke such an alias or replacement.

A restricted set of editing functions is available in the
mini-buffer. Keys are looked up in the special command keymap,
and if not found there in the main keymap. An interrupt signal,
as defined by the stty setting, will abort the function. Note
that the following always perform the same task within the
executed-named-cmd environment and cannot be replaced by user
defined widgets, nor can the set of functions be extended. The
allowed functions are: backward-delete-char,
vi-backward-delete-char, clear-screen, redisplay, quoted-insert,
vi-quoted-insert, backward-kill-word, vi-backward-kill-word,
kill-whole-line, vi-kill-line, backward-kill-line, list-choices,
delete-char-or-list, complete-word, accept-line,
expand-or-complete and expand-or-complete-prefix.

kill-region kills the last word, and vi-cmd-mode is treated the
same as accept-line. The space and tab characters, if not bound
to one of these functions, will complete the name and then list
the possibilities if the AUTO_LIST option is set. Any other
character that is not bound to self-insert or self-insert-unmeta
will beep and be ignored. The bindings of the current insert
mode will be used.

Currently this command may not be redefined or called by name.

execute-last-named-cmd (ESC-z) (unbound) (unbound)
Redo the last function executed with execute-named-cmd.

Like execute-named-cmd, this command may not be redefined, but
it may be called by name.

get-line (ESC-G ESC-g) (unbound) (unbound)
Pop the top line off the buffer stack and insert it at the
cursor position.

pound-insert (unbound) (#) (unbound)
If there is no # character at the beginning of the buffer, add
one to the beginning of each line. If there is one, remove a #
from each line that has one. In either case, accept the current
line. The INTERACTIVE_COMMENTS option must be set for this to
have any usefulness.

vi-pound-insert
If there is no # character at the beginning of the current line,
add one. If there is one, remove it. The INTERACTIVE_COMMENTS
option must be set for this to have any usefulness.

push-input
Push the entire current multiline construct onto the buffer
stack and return to the top-level (PS1) prompt. If the current
parser construct is only a single line, this is exactly like
push-line. Next time the editor starts up or is popped with
get-line, the construct will be popped off the top of the buffer
stack and loaded into the editing buffer.

push-line (^Q ESC-Q ESC-q) (unbound) (unbound)
Push the current buffer onto the buffer stack and clear the
buffer. Next time the editor starts up, the buffer will be
popped off the top of the buffer stack and loaded into the
editing buffer.

push-line-or-edit
At the top-level (PS1) prompt, equivalent to push-line. At a
secondary (PS2) prompt, move the entire current multiline
construct into the editor buffer. The latter is equivalent to
push-input followed by get-line.

read-command
Only useful from a user-defined widget. A keystroke is read
just as in normal operation, but instead of the command being
executed the name of the command that would be executed is
stored in the shell parameter REPLY. This can be used as the
argument of a future zle command. If the key sequence is not
bound, status 1 is returned; typically, however, REPLY is set to
undefined-key to indicate a useless key sequence.

recursive-edit
Only useful from a user-defined widget. At this point in the
function, the editor regains control until one of the standard
widgets which would normally cause zle to exit (typically an
accept-line caused by hitting the return key) is executed.
Instead, control returns to the user-defined widget. The status
returned is non-zero if the return was caused by an error, but
the function still continues executing and hence may tidy up.
This makes it safe for the user-defined widget to alter the
command line or key bindings temporarily.

The following widget, caps-lock, serves as an example.

self-insert-ucase() {
LBUFFER+=${(U)KEYS[-1]}
}

integer stat

zle -N self-insert self-insert-ucase
zle -A caps-lock save-caps-lock
zle -A accept-line caps-lock

zle recursive-edit
stat=$?

zle -A .self-insert self-insert
zle -A save-caps-lock caps-lock
zle -D save-caps-lock

(( stat )) && zle send-break

return $stat

This causes typed letters to be inserted capitalised until
either accept-line (i.e. typically the return key) is typed or
the caps-lock widget is invoked again; the later is handled by
saving the old definition of caps-lock as save-caps-lock and
then rebinding it to invoke accept-line. Note that an error
from the recursive edit is detected as a non-zero return status
and propagated by using the send-break widget.

redisplay (unbound) (^R) (^R)
Redisplays the edit buffer.

reset-prompt (unbound) (unbound) (unbound)
Force the prompts on both the left and right of the screen to be
re-expanded, then redisplay the edit buffer. This reflects
changes both to the prompt variables themselves and changes in
the expansion of the values (for example, changes in time or
directory, or changes to the value of variables referred to by
the prompt).

Otherwise, the prompt is only expanded each time zle starts, and
when the display has been interrupted by output from another
part of the shell (such as a job notification) which causes the
command line to be reprinted.

reset-prompt doesn't alter the special parameter LASTWIDGET.

send-break (^G ESC-^G) (unbound) (unbound)
Abort the current editor function, e.g. execute-named-command,
or the editor itself, e.g. if you are in vared. Otherwise abort
the parsing of the current line; in this case the aborted line
is available in the shell variable ZLE_LINE_ABORTED. If the
editor is aborted from within vared, the variable
ZLE_VARED_ABORTED is set.

run-help (ESC-H ESC-h) (unbound) (unbound)
Push the buffer onto the buffer stack, and execute the command
`run-help cmd', where cmd is the current command. run-help is
normally aliased to man.

vi-set-buffer (unbound) (") (unbound)
Specify a buffer to be used in the following command. There are
37 buffers that can be specified: the 26 `named' buffers "a to
"z, the `yank' buffer "0, the nine `queued' buffers "1 to "9 and
the `black hole' buffer "_. The named buffers can also be
specified as "A to "Z.

When a buffer is specified for a cut, change or yank command,
the text concerned replaces the previous contents of the
specified buffer. If a named buffer is specified using a
capital, the newly cut text is appended to the buffer instead of
overwriting it. When using the "_ buffer, nothing happens. This
can be useful for deleting text without affecting any buffers.

If no buffer is specified for a cut or change command, "1 is
used, and the contents of "1 to "8 are each shifted along one
buffer; the contents of "9 is lost. If no buffer is specified
for a yank command, "0 is used. Finally, a paste command without
a specified buffer will paste the text from the most recent
command regardless of any buffer that might have been used with
that command.

When called from a widget function by the zle command, the
buffer can optionally be specified with an argument. For
example,

zle vi-set-buffer A

vi-set-mark (unbound) (m) (unbound)
Set the specified mark at the cursor position.

set-mark-command (^@) (unbound) (unbound)
Set the mark at the cursor position. If called with a negative
numeric argument, do not set the mark but deactivate the region
so that it is no longer highlighted (it is still usable for
other purposes). Otherwise the region is marked as active.

spell-word (ESC-$ ESC-S ESC-s) (unbound) (unbound)
Attempt spelling correction on the current word.

split-undo
Breaks the undo sequence at the current change. This is useful
in vi mode as changes made in insert mode are coalesced on
entering command mode. Similarly, undo will normally revert as
one all the changes made by a user-defined widget.

undefined-key
This command is executed when a key sequence that is not bound
to any command is typed. By default it beeps.

undo (^_ ^Xu ^X^U) (u) (unbound)
Incrementally undo the last text modification. When called from
a user-defined widget, takes an optional argument indicating a
previous state of the undo history as returned by the
UNDO_CHANGE_NO variable; modifications are undone until that
state is reached, subject to any limit imposed by the
UNDO_LIMIT_NO variable.

Note that when invoked from vi command mode, the full prior
change made in insert mode is reverted, the changes having been
merged when command mode was selected.

redo (unbound) (^R) (unbound)
Incrementally redo undone text modifications.

vi-undo-change (unbound) (unbound) (unbound)
Undo the last text modification. If repeated, redo the
modification.

visual-mode (unbound) (v) (unbound)
Toggle vim-style visual selection mode. If line-wise visual mode
is currently enabled then it is changed to being character-wise.
If used following an operator, it forces the subsequent movement
command to be treated as a character-wise movement.

visual-line-mode (unbound) (V) (unbound)
Toggle vim-style line-wise visual selection mode. If
character-wise visual mode is currently enabled then it is
changed to being line-wise. If used following an operator, it
forces the subsequent movement command to be treated as a
line-wise movement.

what-cursor-position (^X=) (ga) (unbound)
Print the character under the cursor, its code as an octal,
decimal and hexadecimal number, the current cursor position
within the buffer and the column of the cursor in the current
line.

where-is
Read the name of an editor command and print the listing of key
sequences that invoke the specified command. A restricted set
of editing functions is available in the mini-buffer. Keys are
looked up in the special command keymap, and if not found there
in the main keymap.

which-command (ESC-?) (unbound) (unbound)
Push the buffer onto the buffer stack, and execute the command
`which-command cmd'. where cmd is the current command.
which-command is normally aliased to whence.

vi-digit-or-beginning-of-line (unbound) (0) (unbound)
If the last command executed was a digit as part of an argument,
continue the argument. Otherwise, execute vi-beginning-of-line.

Text Objects
Text objects are commands that can be used to select a block of text
according to some criteria. They are a feature of the vim text editor
and so are primarily intended for use with vi operators or from visual
selection mode. However, they can also be used from vi-insert or emacs
mode. Key bindings listed below apply to the viopp and visual keymaps.

select-a-blank-word (aW)
Select a word including adjacent blanks, where a word is defined
as a series of non-blank characters. With a numeric argument,
multiple words will be selected.

select-a-shell-word (aa)
Select the current command argument applying the normal rules
for quoting.

select-a-word (aw)
Select a word including adjacent blanks, using the normal
vi-style word definition. With a numeric argument, multiple
words will be selected.

select-in-blank-word (iW)
Select a word, where a word is defined as a series of non-blank
characters. With a numeric argument, multiple words will be
selected.

select-in-shell-word (ia)
Select the current command argument applying the normal rules
for quoting. If the argument begins and ends with matching quote
characters, these are not included in the selection.

select-in-word (iw)
Select a word, using the normal vi-style word definition. With a
numeric argument, multiple words will be selected.

CHARACTER HIGHLIGHTING
The line editor has the ability to highlight characters or regions of
the line that have a particular significance. This is controlled by
the array parameter zle_highlight, if it has been set by the user.

If the parameter contains the single entry none all highlighting is
turned off. Note the parameter is still expected to be an array.

Otherwise each entry of the array should consist of a word indicating a
context for highlighting, then a colon, then a comma-separated list of
the types of highlighting to apply in that context.

The contexts available for highlighting are the following:

default
Any text within the command line not affected by any other
highlighting. Text outside the editable area of the command
line is not affected.

isearch
When one of the incremental history search widgets is active,
the area of the command line matched by the search string or
pattern.

region The currently selected text. In emacs terminology, this is
referred to as the region and is bounded by the cursor (point)
and the mark. The region is only highlighted if it is active,
which is the case after the mark is modified with
set-mark-command or exchange-point-and-mark. Note that whether
or not the region is active has no effect on its use within
emacs style widgets, it simply determines whether it is
highlighted. In vi mode, the region corresponds to selected text
in visual mode.

special
Individual characters that have no direct printable
representation but are shown in a special manner by the line
editor. These characters are described below.

suffix This context is used in completion for characters that are
marked as suffixes that will be removed if the completion ends
at that point, the most obvious example being a slash (/) after
a directory name. Note that suffix removal is configurable; the
circumstances under which the suffix will be removed may differ
for different completions.

paste Following a command to paste text, the characters that were
inserted.

When region_highlight is set, the contexts that describe a region --
isearch, region, suffix, and paste -- are applied first, then
region_highlight is applied, then the remaining zle_highlight contexts
are applied. If a particular character is affected by multiple
specifications, the last specification wins.

zle_highlight may contain additional fields for controlling how
terminal sequences to change colours are output. Each of the following
is followed by a colon and a string in the same form as for key
bindings. This will not be necessary for the vast majority of
terminals as the defaults shown in parentheses are widely used.

fg_start_code (\e[3)
The start of the escape sequence for the foreground colour.
This is followed by one to three ASCII digits representing the
colour. Only used for palette colors, i.e. not 24-bit colors
specified via a color triplet.

fg_default_code (9)
The number to use instead of the colour to reset the default
foreground colour.

fg_end_code (m)
The end of the escape sequence for the foreground colour.

bg_start_code (\e[4)
The start of the escape sequence for the background colour. See
fg_start_code above.

bg_default_code (9)
The number to use instead of the colour to reset the default
background colour.

bg_end_code (m)
The end of the escape sequence for the background colour.

The available types of highlighting are the following. Note that not
all types of highlighting are available on all terminals:

none No highlighting is applied to the given context. It is not
useful for this to appear with other types of highlighting; it
is used to override a default.

fg=colour
The foreground colour should be set to colour, a decimal
integer, the name of one of the eight most widely-supported
colours or as a `#' followed by an RGB triplet in hexadecimal
format.

Not all terminals support this and, of those that do, not all
provide facilities to test the support, hence the user should
decide based on the terminal type. Most terminals support the
colours black, red, green, yellow, blue, magenta, cyan and
white, which can be set by name. In addition. default may be
used to set the terminal's default foreground colour.
Abbreviations are allowed; b or bl selects black. Some
terminals may generate additional colours if the bold attribute
is also present.

On recent terminals and on systems with an up-to-date terminal
database the number of colours supported may be tested by the
command `echotc Co'; if this succeeds, it indicates a limit on
the number of colours which will be enforced by the line editor.
The number of colours is in any case limited to 256 (i.e. the
range 0 to 255).

Some modern terminal emulators have support for 24-bit true
colour (16 million colours). In this case, the hex triplet
format can be used. This consists of a `#' followed by either a
three or six digit hexadecimal number describing the red, green
and blue components of the colour. Hex triplets can also be used
with 88 and 256 colour terminals via the zsh/nearcolor module
(see zshmodules(1)).

Colour is also known as color.

bg=colour
The background colour should be set to colour. This works
similarly to the foreground colour, except the background is not
usually affected by the bold attribute.

bold The characters in the given context are shown in a bold font.
Not all terminals distinguish bold fonts.

standout
The characters in the given context are shown in the terminal's
standout mode. The actual effect is specific to the terminal;
on many terminals it is inverse video. On some such terminals,
where the cursor does not blink it appears with standout mode
negated, making it less than clear where the cursor actually is.
On such terminals one of the other effects may be preferable for
highlighting the region and matched search string.

underline
The characters in the given context are shown underlined. Some
terminals show the foreground in a different colour instead; in
this case whitespace will not be highlighted.

The characters described above as `special' are as follows. The
formatting described here is used irrespective of whether the
characters are highlighted:

ASCII control characters
Control characters in the ASCII range are shown as `^' followed
by the base character.

Unprintable multibyte characters
This item applies to control characters not in the ASCII range,
plus other characters as follows. If the MULTIBYTE option is in
effect, multibyte characters not in the ASCII character set that
are reported as having zero width are treated as combining
characters when the option COMBINING_CHARS is on. If the option
is off, or if a character appears where a combining character is
not valid, the character is treated as unprintable.

Unprintable multibyte characters are shown as a hexadecimal
number between angle brackets. The number is the code point of
the character in the wide character set; this may or may not be
Unicode, depending on the operating system.

Invalid multibyte characters
If the MULTIBYTE option is in effect, any sequence of one or
more bytes that does not form a valid character in the current
character set is treated as a series of bytes each shown as a
special character. This case can be distinguished from other
unprintable characters as the bytes are represented as two
hexadecimal digits between angle brackets, as distinct from the
four or eight digits that are used for unprintable characters
that are nonetheless valid in the current character set.

Not all systems support this: for it to work, the system's
representation of wide characters must be code values from the
Universal Character Set, as defined by IS0 10646 (also known as
Unicode).

Wrapped double-width characters
When a double-width character appears in the final column of a
line, it is instead shown on the next line. The empty space left
in the original position is highlighted as a special character.

If zle_highlight is not set or no value applies to a particular
context, the defaults applied are equivalent to

zle_highlight=(region:standout special:standout
suffix:bold isearch:underline paste:standout)

i.e. both the region and special characters are shown in standout mode.

Within widgets, arbitrary regions may be highlighted by setting the
special array parameter region_highlight; see above.

NAME
zshcompwid - zsh completion widgets

DESCRIPTION
The shell's programmable completion mechanism can be manipulated in two
ways; here the low-level features supporting the newer, function-based
mechanism are defined. A complete set of shell functions based on
these features is described in zshcompsys(1), and users with no
interest in adding to that system (or, potentially, writing their own
-- see dictionary entry for `hubris') should skip the current section.
The older system based on the compctl builtin command is described in
zshcompctl(1).

Completion widgets are defined by the -C option to the zle builtin
command provided by the zsh/zle module (see zshzle(1)). For example,

zle -C complete expand-or-complete completer

defines a widget named `complete'. The second argument is the name of
any of the builtin widgets that handle completions: complete-word,
expand-or-complete, expand-or-complete-prefix, menu-complete,
menu-expand-or-complete, reverse-menu-complete, list-choices, or
delete-char-or-list. Note that this will still work even if the widget
in question has been re-bound.

When this newly defined widget is bound to a key using the bindkey
builtin command defined in the zsh/zle module (see zshzle(1)), typing
that key will call the shell function `completer'. This function is
responsible for generating completion matches using the builtins
described below. As with other ZLE widgets, the function is called
with its standard input closed.

Once the function returns, the completion code takes over control again
and treats the matches in the same manner as the specified builtin
widget, in this case expand-or-complete.

COMPLETION SPECIAL PARAMETERS
The parameters ZLE_REMOVE_SUFFIX_CHARS and ZLE_SPACE_SUFFIX_CHARS are
used by the completion mechanism, but are not special. See Parameters
Used By The Shell in zshparam(1).

Inside completion widgets, and any functions called from them, some
parameters have special meaning; outside these functions they are not
special to the shell in any way. These parameters are used to pass
information between the completion code and the completion widget. Some
of the builtin commands and the condition codes use or change the
current values of these parameters. Any existing values will be hidden
during execution of completion widgets; except for compstate, the
parameters are reset on each function exit (including nested function
calls from within the completion widget) to the values they had when
the function was entered.

CURRENT
This is the number of the current word, i.e. the word the cursor
is currently on in the words array. Note that this value is
only correct if the ksharrays option is not set.

IPREFIX
Initially this will be set to the empty string. This parameter
functions like PREFIX; it contains a string which precedes the
one in PREFIX and is not considered part of the list of matches.
Typically, a string is transferred from the beginning of PREFIX
to the end of IPREFIX, for example:

IPREFIX=${PREFIX%%\=*}=
PREFIX=${PREFIX#*=}

causes the part of the prefix up to and including the first
equal sign not to be treated as part of a matched string. This
can be done automatically by the compset builtin, see below.

ISUFFIX
As IPREFIX, but for a suffix that should not be considered part
of the matches; note that the ISUFFIX string follows the SUFFIX
string.

PREFIX Initially this will be set to the part of the current word from
the beginning of the word up to the position of the cursor; it
may be altered to give a common prefix for all matches.

QIPREFIX
This parameter is read-only and contains the quoted string up to
the word being completed. E.g. when completing `"foo', this
parameter contains the double quote. If the -q option of compset
is used (see below), and the original string was `"foo bar' with
the cursor on the `bar', this parameter contains `"foo '.

QISUFFIX
Like QIPREFIX, but containing the suffix.

SUFFIX Initially this will be set to the part of the current word from
the cursor position to the end; it may be altered to give a
common suffix for all matches. It is most useful when the
option COMPLETE_IN_WORD is set, as otherwise the whole word on
the command line is treated as a prefix.

compstate
This is an associative array with various keys and values that
the completion code uses to exchange information with the
completion widget. The keys are:

all_quotes
The -q option of the compset builtin command (see below)
allows a quoted string to be broken into separate words;
if the cursor is on one of those words, that word will be
completed, possibly invoking `compset -q' recursively.
With this key it is possible to test the types of quoted
strings which are currently broken into parts in this
fashion. Its value contains one character for each
quoting level. The characters are a single quote or a
double quote for strings quoted with these characters, a
dollars sign for strings quoted with $'...' and a
backslash for strings not starting with a quote
character. The first character in the value always
corresponds to the innermost quoting level.

context
This will be set by the completion code to the overall
context in which completion is attempted. Possible values
are:

array_value
when completing inside the value of an array
parameter assignment; in this case the words array
contains the words inside the parentheses.

brace_parameter
when completing the name of a parameter in a
parameter expansion beginning with ${. This
context will also be set when completing parameter
flags following ${(; the full command line
argument is presented and the handler must test
the value to be completed to ascertain that this
is the case.

assign_parameter
when completing the name of a parameter in a
parameter assignment.

command
when completing for a normal command (either in
command position or for an argument of the
command).

condition
when completing inside a `[[...]]' conditional
expression; in this case the words array contains
only the words inside the conditional expression.

math when completing in a mathematical environment such
as a `((...))' construct.

parameter
when completing the name of a parameter in a
parameter expansion beginning with $ but not ${.

redirect
when completing after a redirection operator.

subscript
when completing inside a parameter subscript.

value when completing the value of a parameter
assignment.

exact Controls the behaviour when the REC_EXACT option is set.
It will be set to accept if an exact match would be
accepted, and will be unset otherwise.

If it was set when at least one match equal to the string
on the line was generated, the match is accepted.

exact_string
The string of an exact match if one was found, otherwise
unset.

ignored
The number of completions that were ignored because they
matched one of the patterns given with the -F option to
the compadd builtin command.

insert This controls the manner in which a match is inserted
into the command line. On entry to the widget function,
if it is unset the command line is not to be changed; if
set to unambiguous, any prefix common to all matches is
to be inserted; if set to automenu-unambiguous, the
common prefix is to be inserted and the next invocation
of the completion code may start menu completion (due to
the AUTO_MENU option being set); if set to menu or
automenu menu completion will be started for the matches
currently generated (in the latter case this will happen
because the AUTO_MENU is set). The value may also contain
the string `tab' when the completion code would normally
not really do completion, but only insert the TAB
character.

On exit it may be set to any of the values above (where
setting it to the empty string is the same as unsetting
it), or to a number, in which case the match whose number
is given will be inserted into the command line.
Negative numbers count backward from the last match (with
`-1' selecting the last match) and out-of-range values
are wrapped around, so that a value of zero selects the
last match and a value one more than the maximum selects
the first. Unless the value of this key ends in a space,
the match is inserted as in a menu completion, i.e.
without automatically appending a space.

Both menu and automenu may also specify the number of the
match to insert, given after a colon. For example,
`menu:2' says to start menu completion, beginning with
the second match.

Note that a value containing the substring `tab' makes
the matches generated be ignored and only the TAB be
inserted.

Finally, it may also be set to all, which makes all
matches generated be inserted into the line.

insert_positions
When the completion system inserts an unambiguous string
into the line, there may be multiple places where
characters are missing or where the character inserted
differs from at least one match. The value of this key
contains a colon separated list of all these positions,
as indexes into the command line.

last_prompt
If this is set to a non-empty string for every match
added, the completion code will move the cursor back to
the previous prompt after the list of completions has
been displayed. Initially this is set or unset according
to the ALWAYS_LAST_PROMPT option.

list This controls whether or how the list of matches will be
displayed. If it is unset or empty they will never be
listed; if its value begins with list, they will always
be listed; if it begins with autolist or ambiguous, they
will be listed when the AUTO_LIST or LIST_AMBIGUOUS
options respectively would normally cause them to be.

If the substring force appears in the value, this makes
the list be shown even if there is only one match.
Normally, the list would be shown only if there are at
least two matches.

The value contains the substring packed if the
LIST_PACKED option is set. If this substring is given for
all matches added to a group, this group will show the
LIST_PACKED behavior. The same is done for the
LIST_ROWS_FIRST option with the substring rows.

Finally, if the value contains the string explanations,
only the explanation strings, if any, will be listed and
if it contains messages, only the messages (added with
the -x option of compadd) will be listed. If it contains
both explanations and messages both kinds of explanation
strings will be listed. It will be set appropriately on
entry to a completion widget and may be changed there.

list_lines
This gives the number of lines that are needed to display
the full list of completions. Note that to calculate the
total number of lines to display you need to add the
number of lines needed for the command line to this
value, this is available as the value of the BUFFERLINES
special parameter.

list_max
Initially this is set to the value of the LISTMAX
parameter. It may be set to any other value; when the
widget exits this value will be used in the same way as
the value of LISTMAX.

nmatches
The number of matches added by the completion code so
far.

old_insert
On entry to the widget this will be set to the number of
the match of an old list of completions that is currently
inserted into the command line. If no match has been
inserted, this is unset.

As with old_list, the value of this key will only be used
if it is the string keep. If it was set to this value by
the widget and there was an old match inserted into the
command line, this match will be kept and if the value of
the insert key specifies that another match should be
inserted, this will be inserted after the old one.

old_list
This is set to yes if there is still a valid list of
completions from a previous completion at the time the
widget is invoked. This will usually be the case if and
only if the previous editing operation was a completion
widget or one of the builtin completion functions. If
there is a valid list and it is also currently shown on
the screen, the value of this key is shown.

After the widget has exited the value of this key is only
used if it was set to keep. In this case the completion
code will continue to use this old list. If the widget
generated new matches, they will not be used.

parameter
The name of the parameter when completing in a subscript
or in the value of a parameter assignment.

pattern_insert
Normally this is set to menu, which specifies that menu
completion will be used whenever a set of matches was
generated using pattern_match (see below). If it is set
to any other non-empty string by the user and menu
completion is not selected by other option settings, the
code will instead insert any common prefix for the
generated matches as with normal completion.

pattern_match
Locally controls the behaviour given by the GLOB_COMPLETE
option. Initially it is set to `*' if and only if the
option is set. The completion widget may set it to this
value, to an empty string (which has the same effect as
unsetting it), or to any other non-empty string. If it
is non-empty, unquoted metacharacters on the command line
will be treated as patterns; if it is `*', then
additionally a wildcard `*' is assumed at the cursor
position; if it is empty or unset, metacharacters will be
treated literally.

Note that the match specifications given to the compadd
builtin command are not used if this is set to a
non-empty string.

quote When completing inside quotes, this contains the
quotation character (i.e. either a single quote, a double
quote, or a backtick). Otherwise it is unset.

quoting
When completing inside single quotes, this is set to the
string single; inside double quotes, the string double;
inside backticks, the string backtick. Otherwise it is
unset.

redirect
The redirection operator when completing in a redirection
position, i.e. one of <, >, etc.

restore
This is set to auto before a function is entered, which
forces the special parameters mentioned above (words,
CURRENT, PREFIX, IPREFIX, SUFFIX, and ISUFFIX) to be
restored to their previous values when the function
exits. If a function unsets it or sets it to any other
string, they will not be restored.

to_end Specifies the occasions on which the cursor is moved to
the end of a string when a match is inserted. On entry
to a widget function, it may be single if this will
happen when a single unambiguous match was inserted or
match if it will happen any time a match is inserted (for
example, by menu completion; this is likely to be the
effect of the ALWAYS_TO_END option).

On exit, it may be set to single as above. It may also
be set to always, or to the empty string or unset; in
those cases the cursor will be moved to the end of the
string always or never respectively. Any other string is
treated as match.

unambiguous
This key is read-only and will always be set to the
common (unambiguous) prefix the completion code has
generated for all matches added so far.

unambiguous_cursor
This gives the position the cursor would be placed at if
the common prefix in the unambiguous key were inserted,
relative to the value of that key. The cursor would be
placed before the character whose index is given by this
key.

unambiguous_positions
This contains all positions where characters in the
unambiguous string are missing or where the character
inserted differs from at least one of the matches. The
positions are given as indexes into the string given by
the value of the unambiguous key.

vared If completion is called while editing a line using the
vared builtin, the value of this key is set to the name
of the parameter given as an argument to vared. This key
is only set while a vared command is active.

words This array contains the words present on the command line
currently being edited.

COMPLETION BUILTIN COMMANDS

compadd [ -akqQfenUl12C ] [ -F array ]
[-P prefix ] [ -S suffix ]
[-p hidden-prefix ] [ -s hidden-suffix ]
[-i ignored-prefix ] [ -I ignored-suffix ]
[-W file-prefix ] [ -d array ]
[-J group-name ] [ -X explanation ] [ -x message ]
[-V group-name ] [ -o [ order ] ]
[-r remove-chars ] [ -R remove-func ]
[-D array ] [ -O array ] [ -A array ]
[-E number ]
[-M match-spec ] [ -- ] [ completions ... ]

This builtin command can be used to add matches directly and
control all the information the completion code stores with each
possible completion. The return status is zero if at least one
match was added and non-zero if no matches were added.

The completion code breaks each match into seven fields in the
order:

The first field is an ignored prefix taken from the command
line, the contents of the IPREFIX parameter plus the string
given with the -i option. With the -U option, only the string
from the -i option is used. The field <apre> is an optional
prefix string given with the -P option. The <hpre> field is a
string that is considered part of the match but that should not
be shown when listing completions, given with the -p option; for
example, functions that do filename generation might specify a
common path prefix this way. <body> is the part of the match
that should appear in the list of matches shown to the user.
The suffixes <hsuf>, <asuf> and <isuf> correspond to the
prefixes <hpre>, <apre> and <ipre> and are given by the options
-s, -S and -I, respectively.

The supported flags are:

-P prefix
This gives a string to be inserted before each match.
The string given is not considered as part of the match
and any shell metacharacters in it will not be quoted
when the string is inserted.

-S suffix
Like -P, but gives a string to be inserted after each
match.

-p hidden-prefix
This gives a string that should be inserted before each
match but that should not appear in the list of matches.
Unless the -U option is given, this string must be
matched as part of the string on the command line.

-s hidden-suffix
Like `-p', but gives a string to insert after each match.

-i ignored-prefix
This gives a string to insert just before any string
given with the `-P' option. Without `-P' the string is
inserted before the string given with `-p' or directly
before each match.

-I ignored-suffix
Like -i, but gives an ignored suffix.

-a With this flag the completions are taken as names of
arrays and the actual completions are their values. If
only some elements of the arrays are needed, the
completions may also contain subscripts, as in
`foo[2,-1]'.

-k With this flag the completions are taken as names of
associative arrays and the actual completions are their
keys. As for -a, the words may also contain subscripts,
as in `foo[(R)*bar*]'.

-d array
This adds per-completion display strings. The array
should contain one element per completion given. The
completion code will then display the first element
instead of the first completion, and so on. The array may
be given as the name of an array parameter or directly as
a space-separated list of words in parentheses.

If there are fewer display strings than completions, the
leftover completions will be displayed unchanged and if
there are more display strings than completions, the
leftover display strings will be silently ignored.

-l This option only has an effect if used together with the
-d option. If it is given, the display strings are listed
one per line, not arrayed in columns.

-o [ order ]
This controls the order in which matches are sorted.
order is a comma-separated list comprising the following
possible values. These values can be abbreviated to
their initial two or three characters. Note that the
order forms part of the group name space so matches with
different orderings will not be in the same group.

match If given, the order of the output is determined by
the match strings; otherwise it is determined by
the display strings (i.e. the strings given by the
-d option). This is the default if `-o' is
specified but the order argument is omitted.

nosort This specifies that the completions are pre-sorted
and their order should be preserved. This value
only makes sense alone and cannot be combined with
any others.

numeric
If the matches include numbers, sort them
numerically rather than lexicographically.

reverse
Arrange the matches backwards by reversing the
sort ordering.

-J group-name
Gives the name of the group that the matches should be
stored in.

-V group-name
Like -J but naming an unsorted group. This option is
identical to the combination of -J and -o nosort.

-1 If given together with the -V option, makes only
consecutive duplicates in the group be removed. If
combined with the -J option, this has no visible effect.
Note that groups with and without this flag are in
different name spaces.

-2 If given together with the -J or -V option, makes all
duplicates be kept. Again, groups with and without this
flag are in different name spaces.

-X explanation
The explanation string will be printed with the list of
matches, above the group currently selected.

Within the explanation, the following sequences may be
used to specify output attributes as described in the
section EXPANSION OF PROMPT SEQUENCES in zshmisc(1):
`%B', `%S', `%U', `%F', `%K' and their lower case
counterparts, as well as `%{...%}'. `%F', `%K' and
`%{...%}' take arguments in the same form as prompt
expansion. (Note that the sequence `%G' is not
available; an argument to `%{' should be used instead.)
The sequence `%%' produces a literal `%'.

These sequences are most often employed by users when
customising the format style (see zshcompsys(1)), but
they must also be taken into account when writing
completion functions, as passing descriptions with
unescaped `%' characters to utility functions such as
_arguments and _message may produce unexpected results.
If arbitrary text is to be passed in a description, it
can be escaped using e.g. ${my_str//\%/%%}.

-x message
Like -X, but the message will be printed even if there
are no matches in the group.

-q The suffix given with -S will be automatically removed if
the next character typed is a blank or does not insert
anything, or if the suffix consists of only one character
and the next character typed is the same character.

-r remove-chars
This is a more versatile form of the -q option. The
suffix given with -S or the slash automatically added
after completing directories will be automatically
removed if the next character typed inserts one of the
characters given in the remove-chars. This string is
parsed as a characters class and understands the
backslash sequences used by the print command. For
example, `-r "a-z\t"' removes the suffix if the next
character typed inserts a lower case character or a TAB,
and `-r "^0-9"' removes the suffix if the next character
typed inserts anything but a digit. One extra backslash
sequence is understood in this string: `\-' stands for
all characters that insert nothing. Thus `-S "=" -q' is
the same as `-S "=" -r "= \t\n\-"'.

This option may also be used without the -S option; then
any automatically added space will be removed when one of
the characters in the list is typed.

-R remove-func
This is another form of the -r option. When a match has
been accepted and a suffix has been inserted, the
function remove-func will be called after the next
character typed. It is passed the length of the suffix
as an argument and can use the special parameters
available in ordinary (non-completion) zle widgets (see
zshzle(1)) to analyse and modify the command line.

-f If this flag is given, all of the matches built from the
completions are marked as being the names of files. They
are not required to be actual filenames, but if they are,
and the option LIST_TYPES is set, the characters
describing the types of the files in the completion lists
will be shown. This also forces a slash to be added when
the name of a directory is completed.

-e This flag can be used to tell the completion code that
the matches added are parameter names for a parameter
expansion. This will make the AUTO_PARAM_SLASH and
AUTO_PARAM_KEYS options be used for the matches.

-W file-prefix
This string is a pathname that will be prepended to each
match together with any prefix specified by the -p option
to form a complete filename for testing. Hence it is
only useful if combined with the -f flag, as the tests
will not otherwise be performed.

-F array
Specifies an array containing patterns. completions that
match one of these patterns are ignored, that is, not
considered to be matches.

The array may be the name of an array parameter or a list
of literal patterns enclosed in parentheses and quoted,
as in `-F "(*?.o *?.h)"'. If the name of an array is
given, the elements of the array are taken as the
patterns.

-Q This flag instructs the completion code not to quote any
metacharacters in the matches when inserting them into
the command line.

-M match-spec
This gives local match specifications as described below
in the section `Completion Matching Control'. This option
may be given more than once. In this case all
match-specs given are concatenated with spaces between
them to form the specification string to use. Note that
they will only be used if the -U option is not given.

-n Specifies that matching completions are to be added to
the set of matches, but are not to be listed to the user.

-U If this flag is given, all completions are added to the
set of matches and no matching will be done by the
completion code. Normally this is used in functions that
do the matching themselves.

-O array
If this option is given, the completions are not added to
the set of matches. Instead, matching is done as usual
and all of the completions that match will be stored in
the array parameter whose name is given as array.

-A array
As the -O option, except that instead of those of the
completions which match being stored in array, the
strings generated internally by the completion code are
stored. For example, with a match specification of `-M
"L:|no="', a current word of `nof' and completions of
`foo', this option stores the string `nofoo' in the
array, whereas the -O option stores the `foo' originally
given.

-D array
As with -O, the completions are not added to the set of
matches. Instead, whenever the nth completion does not
match, the nth element of the array is removed. Elements
for which the corresponding completion matches are
retained. This option can be used more than once to
remove elements from multiple arrays.

-C This option adds a special match which expands to all
other matches when inserted into the line, even those
that are added after this option is used. Together with
the -d option it is possible to specify a string that
should be displayed in the list for this special match.
If no string is given, it will be shown as a string
containing the strings that would be inserted for the
other matches, truncated to the width of the screen.

-E number
This option adds number empty matches after matching
completions have been added. An empty match takes up
space in completion listings but will never be inserted
in the line and can't be selected with menu completion or
menu selection. This makes empty matches only useful to
format completion lists and to make explanatory string be
shown in completion lists (since empty matches can be
given display strings with the -d option). And because
all but one empty string would otherwise be removed, this
option implies the -V and -2 options (even if an explicit
-J option is given). This can be important to note as it
affects the name space into which matches are added.

-
-- This flag ends the list of flags and options. All
arguments after it will be taken as the completions even
if they begin with hyphens.

Except for the -M flag, if any of these flags is given more than
once, the first one (and its argument) will be used.

compset -p number
compset -P [ number ] pattern
compset -s number
compset -S [ number ] pattern
compset -n begin [ end ]
compset -N beg-pat [ end-pat ]
compset -q
This command simplifies modification of the special parameters,
while its return status allows tests on them to be carried out.

The options are:

-p number
If the value of the PREFIX parameter is at least number
characters long, the first number characters are removed
from it and appended to the contents of the IPREFIX
parameter.

-P [ number ] pattern
If the value of the PREFIX parameter begins with anything
that matches the pattern, the matched portion is removed
from PREFIX and appended to IPREFIX.

Without the optional number, the longest match is taken,
but if number is given, anything up to the numberth match
is moved. If the number is negative, the numberth
longest match is moved. For example, if PREFIX contains
the string `a=b=c', then compset -P '*\=' will move the
string `a=b=' into the IPREFIX parameter, but compset -P
1 '*\=' will move only the string `a='.

-s number
As -p, but transfer the last number characters from the
value of SUFFIX to the front of the value of ISUFFIX.

-S [ number ] pattern
As -P, but match the last portion of SUFFIX and transfer
the matched portion to the front of the value of ISUFFIX.

-n begin [ end ]
If the current word position as specified by the
parameter CURRENT is greater than or equal to begin,
anything up to the beginth word is removed from the words
array and the value of the parameter CURRENT is
decremented by begin.

If the optional end is given, the modification is done
only if the current word position is also less than or
equal to end. In this case, the words from position end
onwards are also removed from the words array.

Both begin and end may be negative to count backwards
from the last element of the words array.

-N beg-pat [ end-pat ]
If one of the elements of the words array before the one
at the index given by the value of the parameter CURRENT
matches the pattern beg-pat, all elements up to and
including the matching one are removed from the words
array and the value of CURRENT is changed to point to the
same word in the changed array.

If the optional pattern end-pat is also given, and there
is an element in the words array matching this pattern,
the parameters are modified only if the index of this
word is higher than the one given by the CURRENT
parameter (so that the matching word has to be after the
cursor). In this case, the words starting with the one
matching end-pat are also removed from the words array.
If words contains no word matching end-pat, the testing
and modification is performed as if it were not given.

-q The word currently being completed is split on spaces
into separate words, respecting the usual shell quoting
conventions. The resulting words are stored in the words
array, and CURRENT, PREFIX, SUFFIX, QIPREFIX, and
QISUFFIX are modified to reflect the word part that is
completed.

In all the above cases the return status is zero if the test
succeeded and the parameters were modified and non-zero
otherwise. This allows one to use this builtin in tests such as:

if compset -P '*\='; then ...

This forces anything up to and including the last equal sign to
be ignored by the completion code.

compcall [ -TD ]
This allows the use of completions defined with the compctl
builtin from within completion widgets. The list of matches
will be generated as if one of the non-widget completion
functions (complete-word, etc.) had been called, except that
only compctls given for specific commands are used. To force the
code to try completions defined with the -T option of compctl
and/or the default completion (whether defined by compctl -D or
the builtin default) in the appropriate places, the -T and/or -D
flags can be passed to compcall.

The return status can be used to test if a matching compctl
definition was found. It is non-zero if a compctl was found and
zero otherwise.

Note that this builtin is defined by the zsh/compctl module.

COMPLETION CONDITION CODES
The following additional condition codes for use within the [[ ... ]]
construct are available in completion widgets. These work on the
special parameters. All of these tests can also be performed by the
compset builtin, but in the case of the condition codes the contents of
the special parameters are not modified.

-prefix [ number ] pattern
true if the test for the -P option of compset would succeed.

-suffix [ number ] pattern
true if the test for the -S option of compset would succeed.

-after beg-pat
true if the test of the -N option with only the beg-pat given
would succeed.

-between beg-pat end-pat
true if the test for the -N option with both patterns would
succeed.

COMPLETION MATCHING CONTROL
When the user invokes completion, the current word on the command line
(that is, the word the cursor is currently on) is used to generate a
match pattern. Only those completions that match the pattern are
offered to the user as matches.

The default match pattern is generated from the current word by either

o appending a `*' (matching any number of characters in a
completion) or,

o if the shell option COMPLETE_IN_WORD is set, inserting a `*' at
the cursor position.

This narrow pattern can be broadened selectively by passing a match
specification to the compadd builtin command through its -M option (see
`Completion Builtin Commands' above). A match specification consists
of one or more matchers separated by whitespace. Matchers in a match
specification are applied one at a time, from left to right. Once all
matchers have been applied, completions are compared to the final match
pattern and non-matching ones are discarded.

o Note that the -M option is ignored if the current word contains
a glob pattern and the shell option GLOB_COMPLETE is set or if
the pattern_match key of the special associative array compstate
is set to a non-empty value (see `Completion Special Parameters'
above).

o Users of the completion system (see zshcompsys(1)) should
generally not use the -M option directly, but rather use the
matcher-list and matcher styles (see the subsection Standard
Styles in the documentation for COMPLETION SYSTEM CONFIGURATION
in zshcompsys(1)).

Each matcher consists of

o a case-sensitive letter

o a `:',

o one or more patterns separated by pipes (`|'),

o an equals sign (`='), and

o another pattern.

The patterns before the `=' are used to match substrings of the current
word. For each matched substring, the corresponding part of the match
pattern is broadened with the pattern after the `=', by means of a
logical OR.

Each pattern in a matcher cosists of either

o the empty string or

o a sequence of

o literal characters (which may be quoted with a `\'),

o question marks (`?'),

o bracket expressions (`[...]'; see the subsection Glob
Operators in the documentation for GLOB OPERATORS in
zshexpn(1)), and/or

o brace expressions (see below).

Other shell patterns are not allowed.

A brace expression, like a bracket expression, consists of a list of

o literal characters,

o ranges (`0-9'), and/or

o character classes (`[:name:]').

However, they differ from each other as follows:

o A brace expression is delimited by a pair of braces (`{...}').

o Brace expressions do not support negations. That is, an initial
`!' or `^' has no special meaning and will be interpreted as a
literal character.

o When a character in the current word matches the nth pattern in
a brace expression, the corresponding part of the match pattern
is broadened only with the nth pattern of the brace expression
on the other side of the `=', if there is one; if there is no
brace expression on the other side, then this pattern is the
empty string. However, if either brace expression has more
elements than the other, then the excess entries are simply
ignored. When comparing indexes, each literal character or
character class counts as one element, but each range is instead
expanded to the full list of literal characters it represents.
Additionally, if on both sides of the `=', the nth pattern is
`[:upper:]' or `[:lower:]', then these are expanded as ranges,
too.

Note that, although the matching system does not yet handle multibyte
characters, this is likely to be a future extension. Hence, using
`[:upper:]' and `[:lower:]' is recommended over `A-Z' and `a-z'.

Below are the different forms of matchers supported. Each uppercase
form behaves exactly like its lowercase counterpart, but adds an
additional step after the match pattern has filtered out non-matching
completions: Each of a match's substrings that was matched by a
subpattern from an uppercase matcher is replaced with the corresponding
substring of the current word. However, patterns from lowercase
matchers have higher weight: If a substring of the current word was
matched by patterns from both a lowercase and an uppercase matcher,
then the lowercase matcher's pattern wins and the corresponding part of
the match is not modified.

Unless indicated otherwise, each example listed assumes
COMPLETE_IN_WORD to be unset (as it is by default).

m:word-pat=match-pat
M:word-pat=match-pat

For each substring of the current word that matches word-pat,
broaden the corresponding part of the match pattern to
additionally match match-pat.

Examples:

m:{[:lower:]}={[:upper:]} lets any lower case character
in the current word be completed to itself or its
uppercase counterpart. So, the completions `foo', `FOO'
and `Foo' will are be considered matches for the word
`fo'.

M:_= inserts every underscore from the current word into
each match, in the same relative position, determined by
matching the substrings around it. So, given a
completion `foo', the word `f_o' will be completed to the
match `f_oo', even though the latter was not present as a
completion.

b:word-pat=match-pat
B:word-pat=match-pat
e:word-pat=match-pat
E:word-pat=match-pat

For each consecutive substring at the b:eginning or e:nd of the
current word that matches word-pat, broaden the corresponding
part of the match pattern to additionally match match-pat.

Examples:

`b:-=+' lets any number of minuses at the start of the
current word be completed to a minus or a plus.

`B:0=' adds all zeroes at the beginning of the current
word to the beginning of each match.

l:|word-pat=match-pat
L:|word-pat=match-pat
R:word-pat|=match-pat
r:word-pat|=match-pat

If there is a substring at the l:eft or r:ight edge of the
current word that matches word-pat, then broaden the
corresponding part of the match pattern to additionally match
match-pat.

For each l:, L:, r: and R: matcher (including the ones below),
the pattern match-pat may also be a `*'. This matches any
number of characters in a completion.

Examples:

`r:|=*' appends a `*' to the match pattern, even when
COMPLETE_IN_WORD is set and the cursor is not at the end
of the current word.

If the current word starts with a minus, then `L:|-='
will prepend it to each match.

l:anchor|word-pat=match-pat
L:anchor|word-pat=match-pat
r:word-pat|anchor=match-pat
R:word-pat|anchor=match-pat

For each substring of the current word that matches word-pat and
has on its l:eft or r:ight another substring matching anchor,
broaden the corresponding part of the match pattern to
additionally match match-pat.

Note that these matchers (and the ones below) modify only what
is matched by word-pat; they do not change the matching behavior
of what is matched by anchor (or coanchor; see the matchers
below). Thus, unless its corresponding part of the match
pattern has been modified, the anchor in the current word has to
match literally in each completion, just like any other
substring of the current word.

If a matcher includes at least one anchor (which includes the
matchers with two anchors, below), then match-pat may also be
`*' or `**'. `*' can match any part of a completion that does
not contain any substrings matching anchor, whereas a `**' can
match any part of a completion, period. (Note that this is
different from the behavior of `*' in the anchorless forms of
`l:' and `r:' and and also different from `*' and `**' in glob
expressions.)

Examples:

`r:|.=*' makes the completion `comp.sources.unix' a match
for the word `..u' -- but not for the word `.u'.

Given a completion `--foo', the matcher `L:--|no-=' will
complete the word `--no-' to the match `--no-foo'.

l:anchor||coanchor=match-pat
L:anchor||coanchor=match-pat
r:coanchor||anchor=match-pat
R:coanchor||anchor=match-pat

For any two consecutive substrings of the current word that
match anchor and coanchor, in the order given, insert the
pattern match-pat between their corresponding parts in the match
pattern.

Note that, unlike anchor, the pattern coanchor does not change
what `*' can match.

Examples:

`r:?||[[:upper:]]=*' will complete the current word `fB'
to `fooBar', but it will not complete it to `fooHooBar'
(because `*' here cannot match anything that includes a
match for `[[:upper:]]), nor will it complete `B' to
`fooBar' (because there is no character in the current
word to match coanchor).

Given the current word `pass.n' and a completion
`pass.byname', the matcher `L:.||[[:alpha:]]=by' will
produce the match `pass.name'.

Ignore this matcher and all matchers to its right.

This matcher is used to mark the end of a match specification.
In a single standalone list of matchers, this has no use, but
where match specifications are concatenated, as is often the
case when using the completion system (see zshcompsys(1)), it
can allow one match specification to override another.

COMPLETION WIDGET EXAMPLE
The first step is to define the widget:

zle -C complete complete-word complete-files

Then the widget can be bound to a key using the bindkey builtin
command:

bindkey '^X\t' complete

After that the shell function complete-files will be invoked after
typing control-X and TAB. The function should then generate the
matches, e.g.:

complete-files () { compadd - * }

This function will complete files in the current directory matching the
current word.

NAME
zshcompsys - zsh completion system

DESCRIPTION
This describes the shell code for the `new' completion system, referred
to as compsys. It is written in shell functions based on the features
described in zshcompwid(1).

The features are contextual, sensitive to the point at which completion
is started. Many completions are already provided. For this reason, a
user can perform a great many tasks without knowing any details beyond
how to initialize the system, which is described below in
INITIALIZATION.

The context that decides what completion is to be performed may be
o an argument or option position: these describe the position on
the command line at which completion is requested. For example
`first argument to rmdir, the word being completed names a
directory';

o a special context, denoting an element in the shell's syntax.
For example `a word in command position' or `an array
subscript'.

A full context specification contains other elements, as we shall
describe.

Besides commands names and contexts, the system employs two more
concepts, styles and tags. These provide ways for the user to
configure the system's behaviour.

Tags play a dual role. They serve as a classification system for the
matches, typically indicating a class of object that the user may need
to distinguish. For example, when completing arguments of the ls
command the user may prefer to try files before directories, so both of
these are tags. They also appear as the rightmost element in a context
specification.

Styles modify various operations of the completion system, such as
output formatting, but also what kinds of completers are used (and in
what order), or which tags are examined. Styles may accept arguments
and are manipulated using the zstyle command described in
zshmodules(1).

In summary, tags describe what the completion objects are, and style
how they are to be completed. At various points of execution, the
completion system checks what styles and/or tags are defined for the
current context, and uses that to modify its behavior. The full
description of context handling, which determines how tags and other
elements of the context influence the behaviour of styles, is described
below in COMPLETION SYSTEM CONFIGURATION.

When a completion is requested, a dispatcher function is called; see
the description of _main_complete in the list of control functions
below. This dispatcher decides which function should be called to
produce the completions, and calls it. The result is passed to one or
more completers, functions that implement individual completion
strategies: simple completion, error correction, completion with error
correction, menu selection, etc.

More generally, the shell functions contained in the completion system
are of two types:
o those beginning `comp' are to be called directly; there are only
a few of these;

o those beginning `_' are called by the completion code. The
shell functions of this set, which implement completion
behaviour and may be bound to keystrokes, are referred to as
`widgets'. These proliferate as new completions are required.

INITIALIZATION
If the system was installed completely, it should be enough to call the
shell function compinit from your initialization file; see the next
section. However, the function compinstall can be run by a user to
configure various aspects of the completion system.

Usually, compinstall will insert code into .zshrc, although if that is
not writable it will save it in another file and tell you that file's
location. Note that it is up to you to make sure that the lines added
to .zshrc are actually run; you may, for example, need to move them to
an earlier place in the file if .zshrc usually returns early. So long
as you keep them all together (including the comment lines at the start
and finish), you can rerun compinstall and it will correctly locate and
modify these lines. Note, however, that any code you add to this
section by hand is likely to be lost if you rerun compinstall, although
lines using the command `zstyle' should be gracefully handled.

The new code will take effect next time you start the shell, or run
.zshrc by hand; there is also an option to make them take effect
immediately. However, if compinstall has removed definitions, you will
need to restart the shell to see the changes.

To run compinstall you will need to make sure it is in a directory
mentioned in your fpath parameter, which should already be the case if
zsh was properly configured as long as your startup files do not remove
the appropriate directories from fpath. Then it must be autoloaded
(`autoload -U compinstall' is recommended). You can abort the
installation any time you are being prompted for information, and your
.zshrc will not be altered at all; changes only take place right at the
end, where you are specifically asked for confirmation.

Use of compinit
This section describes the use of compinit to initialize completion for
the current session when called directly; if you have run compinstall
it will be called automatically from your .zshrc.

To initialize the system, the function compinit should be in a
directory mentioned in the fpath parameter, and should be autoloaded
(`autoload -U compinit' is recommended), and then run simply as
`compinit'. This will define a few utility functions, arrange for all
the necessary shell functions to be autoloaded, and will then re-define
all widgets that do completion to use the new system. If you use the
menu-select widget, which is part of the zsh/complist module, you
should make sure that that module is loaded before the call to compinit
so that that widget is also re-defined. If completion styles (see
below) are set up to perform expansion as well as completion by
default, and the TAB key is bound to expand-or-complete, compinit will
rebind it to complete-word; this is necessary to use the correct form
of expansion.

Should you need to use the original completion commands, you can still
bind keys to the old widgets by putting a `.' in front of the widget
name, e.g. `.expand-or-complete'.

To speed up the running of compinit, it can be made to produce a dumped
configuration that will be read in on future invocations; this is the
default, but can be turned off by calling compinit with the option -D.
The dumped file is .zcompdump in the same directory as the startup
files (i.e. $ZDOTDIR or $HOME); alternatively, an explicit file name
can be given by `compinit -d dumpfile'. The next invocation of
compinit will read the dumped file instead of performing a full
initialization.

If the number of completion files changes, compinit will recognise this
and produce a new dump file. However, if the name of a function or the
arguments in the first line of a #compdef function (as described below)
change, it is easiest to delete the dump file by hand so that compinit
will re-create it the next time it is run. The check performed to see
if there are new functions can be omitted by giving the option -C. In
this case the dump file will only be created if there isn't one
already.

The dumping is actually done by another function, compdump, but you
will only need to run this yourself if you change the configuration
(e.g. using compdef) and then want to dump the new one. The name of
the old dumped file will be remembered for this purpose.

If the parameter _compdir is set, compinit uses it as a directory where
completion functions can be found; this is only necessary if they are
not already in the function search path.

For security reasons compinit also checks if the completion system
would use files not owned by root or by the current user, or files in
directories that are world- or group-writable or that are not owned by
root or by the current user. If such files or directories are found,
compinit will ask if the completion system should really be used. To
avoid these tests and make all files found be used without asking, use
the option -u, and to make compinit silently ignore all insecure files
and directories use the option -i. This security check is skipped
entirely when the -C option is given, provided the dumpfile exists.

The security check can be retried at any time by running the function
compaudit. This is the same check used by compinit, but when it is
executed directly any changes to fpath are made local to the function
so they do not persist. The directories to be checked may be passed as
arguments; if none are given, compaudit uses fpath and _compdir to find
completion system directories, adding missing ones to fpath as
necessary. To force a check of exactly the directories currently named
in fpath, set _compdir to an empty string before calling compaudit or
compinit.

The function bashcompinit provides compatibility with bash's
programmable completion system. When run it will define the functions,
compgen and complete which correspond to the bash builtins with the
same names. It will then be possible to use completion specifications
and functions written for bash.

Autoloaded files
The convention for autoloaded functions used in completion is that they
start with an underscore; as already mentioned, the fpath/FPATH
parameter must contain the directory in which they are stored. If zsh
was properly installed on your system, then fpath/FPATH automatically
contains the required directories for the standard functions.

For incomplete installations, if compinit does not find enough files
beginning with an underscore (fewer than twenty) in the search path, it
will try to find more by adding the directory _compdir to the search
path. If that directory has a subdirectory named Base, all
subdirectories will be added to the path. Furthermore, if the
subdirectory Base has a subdirectory named Core, compinit will add all
subdirectories of the subdirectories to the path: this allows the
functions to be in the same format as in the zsh source distribution.

When compinit is run, it searches all such files accessible via
fpath/FPATH and reads the first line of each of them. This line should
contain one of the tags described below. Files whose first line does
not start with one of these tags are not considered to be part of the
completion system and will not be treated specially.

The tags are:

#compdef name ... [ -{p|P} pattern ... [ -N name ... ] ]
The file will be made autoloadable and the function defined in
it will be called when completing names, each of which is either
the name of a command whose arguments are to be completed or one
of a number of special contexts in the form -context- described
below.

Each name may also be of the form `cmd=service'. When
completing the command cmd, the function typically behaves as if
the command (or special context) service was being completed
instead. This provides a way of altering the behaviour of
functions that can perform many different completions. It is
implemented by setting the parameter $service when calling the
function; the function may choose to interpret this how it
wishes, and simpler functions will probably ignore it.

If the #compdef line contains one of the options -p or -P, the
words following are taken to be patterns. The function will be
called when completion is attempted for a command or context
that matches one of the patterns. The options -p and -P are
used to specify patterns to be tried before or after other
completions respectively. Hence -P may be used to specify
default actions.

The option -N is used after a list following -p or -P; it
specifies that remaining words no longer define patterns. It is
possible to toggle between the three options as many times as
necessary.

#compdef -k style key-sequence ...
This option creates a widget behaving like the builtin widget
style and binds it to the given key-sequences, if any. The
style must be one of the builtin widgets that perform
completion, namely complete-word, delete-char-or-list,
expand-or-complete, expand-or-complete-prefix, list-choices,
menu-complete, menu-expand-or-complete, or
reverse-menu-complete. If the zsh/complist module is loaded
(see zshmodules(1)) the widget menu-select is also available.

When one of the key-sequences is typed, the function in the file
will be invoked to generate the matches. Note that a key will
not be re-bound if it already was (that is, was bound to
something other than undefined-key). The widget created has the
same name as the file and can be bound to any other keys using
bindkey as usual.

#compdef -K widget-name style key-sequence [ name style seq ... ]
This is similar to -k except that only one key-sequence argument
may be given for each widget-name style pair. However, the
entire set of three arguments may be repeated with a different
set of arguments. Note in particular that the widget-name must
be distinct in each set. If it does not begin with `_' this
will be added. The widget-name should not clash with the name
of any existing widget: names based on the name of the function
are most useful. For example,

#compdef -K _foo_complete complete-word "^X^C" \
_foo_list list-choices "^X^D"

(all on one line) defines a widget _foo_complete for completion,
bound to `^X^C', and a widget _foo_list for listing, bound to
`^X^D'.

#autoload [ options ]
Functions with the #autoload tag are marked for autoloading but
are not otherwise treated specially. Typically they are to be
called from within one of the completion functions. Any options
supplied will be passed to the autoload builtin; a typical use
is +X to force the function to be loaded immediately. Note that
the -U and -z flags are always added implicitly.

The # is part of the tag name and no white space is allowed after it.
The #compdef tags use the compdef function described below; the main
difference is that the name of the function is supplied implicitly.

The special contexts for which completion functions can be defined are:

-array-value-
The right hand side of an array-assignment (`name=(...)')

-assign-parameter-
The name of a parameter in an assignment, i.e. on the left hand
side of an `='

-brace-parameter-
The name of a parameter expansion within braces (`${...}')

-command-
A word in command position

-condition-
A word inside a condition (`[[...]]')

-default-
Any word for which no other completion is defined

-equal-
A word beginning with an equals sign

-first-
This is tried before any other completion function. The
function called may set the _compskip parameter to one of
various values: all: no further completion is attempted; a
string containing the substring patterns: no pattern completion
functions will be called; a string containing default: the
function for the `-default-' context will not be called, but
functions defined for commands will be.

-math- Inside mathematical contexts, such as `((...))'

-parameter-
The name of a parameter expansion (`$...')

-redirect-
The word after a redirection operator.

-subscript-
The contents of a parameter subscript.

-tilde-
After an initial tilde (`~'), but before the first slash in the
word.

-value-
On the right hand side of an assignment.

Default implementations are supplied for each of these contexts. In
most cases the context -context- is implemented by a corresponding
function _context, for example the context `-tilde-' and the function
`_tilde').

The contexts -redirect- and -value- allow extra context-specific
information. (Internally, this is handled by the functions for each
context calling the function _dispatch.) The extra information is
added separated by commas.

For the -redirect- context, the extra information is in the form
`-redirect-,op,command', where op is the redirection operator and
command is the name of the command on the line. If there is no command
on the line yet, the command field will be empty.

For the -value- context, the form is `-value-,name,command', where name
is the name of the parameter on the left hand side of the assignment.
In the case of elements of an associative array, for example
`assoc=(key <TAB>', name is expanded to `name-key'. In certain special
contexts, such as completing after `make CFLAGS=', the command part
gives the name of the command, here make; otherwise it is empty.

It is not necessary to define fully specific completions as the
functions provided will try to generate completions by progressively
replacing the elements with `-default-'. For example, when completing
after `foo=<TAB>', _value will try the names `-value-,foo,' (note the
empty command part), `-value-,foo,-default-'
and`-value-,-default-,-default-', in that order, until it finds a
function to handle the context.

As an example:

compdef '_files -g "*.log"' '-redirect-,2>,-default-'

completes files matching `*.log' after `2> <TAB>' for any command with
no more specific handler defined.

Also:

compdef _foo -value-,-default-,-default-

specifies that _foo provides completions for the values of parameters
for which no special function has been defined. This is usually
handled by the function _value itself.

The same lookup rules are used when looking up styles (as described
below); for example

zstyle ':completion:*:*:-redirect-,2>,*:*' file-patterns '*.log'

is another way to make completion after `2> <TAB>' complete files
matching `*.log'.

Functions
The following function is defined by compinit and may be called
directly.

compdef [ -ane ] function name ... [ -{p|P} pattern ... [ -N name ...]]
compdef -d name ...
compdef -k [ -an ] function style key-sequence [ key-sequence ... ]
compdef -K [ -an ] function name style key-seq [ name style seq ... ]
The first form defines the function to call for completion in
the given contexts as described for the #compdef tag above.

Alternatively, all the arguments may have the form
`cmd=service'. Here service should already have been defined by
`cmd1=service' lines in #compdef files, as described above. The
argument for cmd will be completed in the same way as service.

The function argument may alternatively be a string containing
almost any shell code. If the string contains an equal sign,
the above will take precedence. The option -e may be used to
specify the first argument is to be evaluated as shell code even
if it contains an equal sign. The string will be executed using
the eval builtin command to generate completions. This provides
a way of avoiding having to define a new completion function.
For example, to complete files ending in `.h' as arguments to
the command foo:

compdef '_files -g "*.h"' foo

The option -n prevents any completions already defined for the
command or context from being overwritten.

The option -d deletes any completion defined for the command or
contexts listed.

The names may also contain -p, -P and -N options as described
for the #compdef tag. The effect on the argument list is
identical, switching between definitions of patterns tried
initially, patterns tried finally, and normal commands and
contexts.

The parameter $_compskip may be set by any function defined for
a pattern context. If it is set to a value containing the
substring `patterns' none of the pattern-functions will be
called; if it is set to a value containing the substring `all',
no other function will be called. Setting $_compskip in this
manner is of particular utility when using the -p option, as
otherwise the dispatcher will move on to additional functions
(likely the default one) after calling the pattern-context one,
which can mangle the display of completion possibilities if not
handled properly.

The form with -k defines a widget with the same name as the
function that will be called for each of the key-sequences; this
is like the #compdef -k tag. The function should generate the
completions needed and will otherwise behave like the builtin
widget whose name is given as the style argument. The widgets
usable for this are: complete-word, delete-char-or-list,
expand-or-complete, expand-or-complete-prefix, list-choices,
menu-complete, menu-expand-or-complete, and
reverse-menu-complete, as well as menu-select if the
zsh/complist module is loaded. The option -n prevents the key
being bound if it is already to bound to something other than
undefined-key.

The form with -K is similar and defines multiple widgets based
on the same function, each of which requires the set of three
arguments name, style and key-sequence, where the latter two are
as for -k and the first must be a unique widget name beginning
with an underscore.

Wherever applicable, the -a option makes the function
autoloadable, equivalent to autoload -U function.

The function compdef can be used to associate existing completion
functions with new commands. For example,

compdef _pids foo

uses the function _pids to complete process IDs for the command foo.

Note also the _gnu_generic function described below, which can be used
to complete options for commands that understand the `--help' option.

COMPLETION SYSTEM CONFIGURATION
This section gives a short overview of how the completion system works,
and then more detail on how users can configure how and when matches
are generated.

Overview
When completion is attempted somewhere on the command line the
completion system begins building the context. The context represents
everything that the shell knows about the meaning of the command line
and the significance of the cursor position. This takes account of a
number of things including the command word (such as `grep' or `zsh')
and options to which the current word may be an argument (such as the
`-o' option to zsh which takes a shell option as an argument).

The context starts out very generic ("we are beginning a completion")
and becomes more specific as more is learned ("the current word is in a
position that is usually a command name" or "the current word might be
a variable name" and so on). Therefore the context will vary during
the same call to the completion system.

This context information is condensed into a string consisting of
multiple fields separated by colons, referred to simply as `the
context' in the remainder of the documentation. Note that a user of
the completion system rarely needs to compose a context string, unless
for example a new function is being written to perform completion for a
new command. What a user may need to do is compose a style pattern,
which is matched against a context when needed to look up
context-sensitive options that configure the completion system.

The next few paragraphs explain how a context is composed within the
completion function suite. Following that is discussion of how styles
are defined. Styles determine such things as how the matches are
generated, similarly to shell options but with much more control. They
are defined with the zstyle builtin command (see zshmodules(1)).

The context string always consists of a fixed set of fields, separated
by colons and with a leading colon before the first. Fields which are
not yet known are left empty, but the surrounding colons appear anyway.
The fields are always in the order
:completion:function:completer:command:argument:tag. These have the
following meaning:

o The literal string completion, saying that this style is used by
the completion system. This distinguishes the context from
those used by, for example, zle widgets and ZFTP functions.

o The function, if completion is called from a named widget rather
than through the normal completion system. Typically this is
blank, but it is set by special widgets such as predict-on and
the various functions in the Widget directory of the
distribution to the name of that function, often in an
abbreviated form.

o The completer currently active, the name of the function without
the leading underscore and with other underscores converted to
hyphens. A `completer' is in overall control of how completion
is to be performed; `complete' is the simplest, but other
completers exist to perform related tasks such as correction, or
to modify the behaviour of a later completer. See the section
`Control Functions' below for more information.

o The command or a special -context-, just at it appears following
the #compdef tag or the compdef function. Completion functions
for commands that have sub-commands usually modify this field to
contain the name of the command followed by a minus sign and the
sub-command. For example, the completion function for the cvs
command sets this field to cvs-add when completing arguments to
the add subcommand.

o The argument; this indicates which command line or option
argument we are completing. For command arguments this
generally takes the form argument-n, where n is the number of
the argument, and for arguments to options the form option-opt-n
where n is the number of the argument to option opt. However,
this is only the case if the command line is parsed with
standard UNIX-style options and arguments, so many completions
do not set this.

o The tag. As described previously, tags are used to discriminate
between the types of matches a completion function can generate
in a certain context. Any completion function may use any tag
name it likes, but a list of the more common ones is given
below.

The context is gradually put together as the functions are executed,
starting with the main entry point, which adds :completion: and the
function element if necessary. The completer then adds the completer
element. The contextual completion adds the command and argument
options. Finally, the tag is added when the types of completion are
known. For example, the context name

:completion::complete:dvips:option-o-1:files

says that normal completion was attempted as the first argument to the
option -o of the command dvips:

dvips -o ...

and the completion function will generate filenames.

Usually completion will be tried for all possible tags in an order
given by the completion function. However, this can be altered by
using the tag-order style. Completion is then restricted to the list
of given tags in the given order.

The _complete_help bindable command shows all the contexts and tags
available for completion at a particular point. This provides an easy
way of finding information for tag-order and other styles. It is
described in the section `Bindable Commands' below.

When looking up styles the completion system uses full context names,
including the tag. Looking up the value of a style therefore consists
of two things: the context, which is matched to the most specific (best
fitting) pattern, and the name of the style itself, which must be
matched exactly. The following examples demonstrate that patterns may
be loosely defined for styles that apply broadly, or as tightly defined
as desired for styles that apply in narrower circumstances.

For example, many completion functions can generate matches in a simple
and a verbose form and use the verbose style to decide which form
should be used. To make all such functions use the verbose form, put

zstyle ':completion:*' verbose yes

in a startup file (probably .zshrc). This gives the verbose style the
value yes in every context inside the completion system, unless that
context has a more specific definition. It is best to avoid giving the
pattern as `*' in case the style has some meaning outside the
completion system.

Many such general purpose styles can be configured simply by using the
compinstall function.

A more specific example of the use of the verbose style is by the
completion for the kill builtin. If the style is set, the builtin
lists full job texts and process command lines; otherwise it shows the
bare job numbers and PIDs. To turn the style off for this use only:

zstyle ':completion:*:*:kill:*:*' verbose no

For even more control, the style can use one of the tags `jobs' or
`processes'. To turn off verbose display only for jobs:

zstyle ':completion:*:*:kill:*:jobs' verbose no

The -e option to zstyle even allows completion function code to appear
as the argument to a style; this requires some understanding of the
internals of completion functions (see see zshcompwid(1))). For
example,

zstyle -e ':completion:*' hosts 'reply=($myhosts)'

This forces the value of the hosts style to be read from the variable
myhosts each time a host name is needed; this is useful if the value of
myhosts can change dynamically. For another useful example, see the
example in the description of the file-list style below. This form can
be slow and should be avoided for commonly examined styles such as menu
and list-rows-first.

Note that the order in which styles are defined does not matter; the
style mechanism uses the most specific possible match for a particular
style to determine the set of values. Strings are preferred over
patterns (for example, `:completion::complete:::foo' is more specific
than `:completion::complete:::*'), and longer patterns are preferred
over the pattern `*'. See zmodules(1) for details.

Context patterns that use something other than a wildcard (*) to match
the middle parts of the context -- the completer, command, and argument
in :completion:function:completer:command:argument:tag -- should
include all six colons (:) explicitly. Without this, a pattern such as
:completion:*:foo:* could match foo against a component other than the
intended one (for example, against completer when a match against
command was intended).

Style names like those of tags are arbitrary and depend on the
completion function. However, the following two sections list some of
the most common tags and styles.

Standard Tags
Some of the following are only used when looking up particular styles
and do not refer to a type of match.

accounts
used to look up the users-hosts style

all-expansions
used by the _expand completer when adding the single string
containing all possible expansions

all-files
for the names of all files (as distinct from a particular
subset, see the globbed-files tag).

arguments
for arguments to a command

arrays for names of array parameters

association-keys
for keys of associative arrays; used when completing inside a
subscript to a parameter of this type

bookmarks
when completing bookmarks (e.g. for URLs and the zftp function
suite)

builtins
for names of builtin commands

characters
for single characters in arguments of commands such as stty.
Also used when completing character classes after an opening
bracket

colormapids
for X colormap ids

colors for color names

commands
for names of external commands. Also used by complex commands
such as cvs when completing names subcommands.

contexts
for contexts in arguments to the zstyle builtin command

corrections
used by the _approximate and _correct completers for possible
corrections

cursors
for cursor names used by X programs

default
used in some contexts to provide a way of supplying a default
when more specific tags are also valid. Note that this tag is
used when only the function field of the context name is set

descriptions
used when looking up the value of the format style to generate
descriptions for types of matches

devices
for names of device special files

directories
for names of directories -- local-directories is used instead
when completing arguments of cd and related builtin commands
when the cdpath array is set

directory-stack
for entries in the directory stack

displays
for X display names

domains
for network domains

email-plugin
for email addresses from the `_email-plugin' backend of
_email_addresses

expansions
used by the _expand completer for individual words (as opposed
to the complete set of expansions) resulting from the expansion
of a word on the command line

extensions
for X server extensions

file-descriptors
for numbers of open file descriptors

files the generic file-matching tag used by functions completing
filenames

fonts for X font names

fstypes
for file system types (e.g. for the mount command)

functions
names of functions -- normally shell functions, although certain
commands may understand other kinds of function

globbed-files
for filenames when the name has been generated by pattern
matching

groups for names of user groups

history-words
for words from the history

hosts for hostnames

indexes
for array indexes

interfaces
for network interfaces

jobs for jobs (as listed by the `jobs' builtin)

keymaps
for names of zsh keymaps

keysyms
for names of X keysyms

libraries
for names of system libraries

limits for system limits

local-directories
for names of directories that are subdirectories of the current
working directory when completing arguments of cd and related
builtin commands (compare path-directories) -- when the cdpath
array is unset, directories is used instead

mailboxes
for e-mail folders

manuals
for names of manual pages

maps for map names (e.g. NIS maps)

messages
used to look up the format style for messages

modifiers
for names of X modifiers

modules
for modules (e.g. zsh modules)

my-accounts
used to look up the users-hosts style

named-directories
for named directories (you wouldn't have guessed that, would
you?)

names for all kinds of names

newsgroups
for USENET groups

nicknames
for nicknames of NIS maps

options
for command options

original
used by the _approximate, _correct and _expand completers when
offering the original string as a match

other-accounts
used to look up the users-hosts style

packages
for packages (e.g. rpm or installed Debian packages)

parameters
for names of parameters

path-directories
for names of directories found by searching the cdpath array
when completing arguments of cd and related builtin commands
(compare local-directories)

paths used to look up the values of the expand, ambiguous and
special-dirs styles

pods for perl pods (documentation files)

ports for communication ports

prefixes
for prefixes (like those of a URL)

printers
for print queue names

processes
for process identifiers

processes-names
used to look up the command style when generating the names of
processes for killall

sequences
for sequences (e.g. mh sequences)

sessions
for sessions in the zftp function suite

signals
for signal names

strings
for strings (e.g. the replacement strings for the cd builtin
command)

styles for styles used by the zstyle builtin command

suffixes
for filename extensions

tags for tags (e.g. rpm tags)

targets
for makefile targets

time-zones
for time zones (e.g. when setting the TZ parameter)

types for types of whatever (e.g. address types for the xhost command)

urls used to look up the urls and local styles when completing URLs

users for usernames

values for one of a set of values in certain lists

variant
used by _pick_variant to look up the command to run when
determining what program is installed for a particular command
name.

visuals
for X visuals

warnings
used to look up the format style for warnings

widgets
for zsh widget names

windows
for IDs of X windows

zsh-options
for shell options

Standard Styles
Note that the values of several of these styles represent boolean
values. Any of the strings `true', `on', `yes', and `1' can be used
for the value `true' and any of the strings `false', `off', `no', and
`0' for the value `false'. The behavior for any other value is
undefined except where explicitly mentioned. The default value may be
either `true' or `false' if the style is not set.

Some of these styles are tested first for every possible tag
corresponding to a type of match, and if no style was found, for the
default tag. The most notable styles of this type are menu,
list-colors and styles controlling completion listing such as
list-packed and last-prompt. When tested for the default tag, only the
function field of the context will be set so that a style using the
default tag will normally be defined along the lines of:

zstyle ':completion:*:default' menu ...

accept-exact
This is tested for the default tag in addition to the tags valid
for the current context. If it is set to `true' and any of the
trial matches is the same as the string on the command line,
this match will immediately be accepted (even if it would
otherwise be considered ambiguous).

When completing pathnames (where the tag used is `paths') this
style accepts any number of patterns as the value in addition to
the boolean values. Pathnames matching one of these patterns
will be accepted immediately even if the command line contains
some more partially typed pathname components and these match no
file under the directory accepted.

This style is also used by the _expand completer to decide if
words beginning with a tilde or parameter expansion should be
expanded. For example, if there are parameters foo and foobar,
the string `$foo' will only be expanded if accept-exact is set
to `true'; otherwise the completion system will be allowed to
complete $foo to $foobar. If the style is set to `continue',
_expand will add the expansion as a match and the completion
system will also be allowed to continue.

accept-exact-dirs
This is used by filename completion. Unlike accept-exact it is
a boolean. By default, filename completion examines all
components of a path to see if there are completions of that
component, even if the component matches an existing directory.
For example, when completion after /usr/bin/, the function
examines possible completions to /usr.

When this style is `true', any prefix of a path that matches an
existing directory is accepted without any attempt to complete
it further. Hence, in the given example, the path /usr/bin/ is
accepted immediately and completion tried in that directory.

This style is also useful when completing after directories that
magically appear when referenced, such as ZFS .zfs directories
or NetApp .snapshot directories. When the style is set the
shell does not check for the existence of the directory within
the parent directory.

If you wish to inhibit this behaviour entirely, set the
path-completion style (see below) to `false'.

add-space
This style is used by the _expand completer. If it is `true'
(the default), a space will be inserted after all words
resulting from the expansion, or a slash in the case of
directory names. If the value is `file', the completer will
only add a space to names of existing files. Either a boolean
`true' or the value `file' may be combined with `subst', in
which case the completer will not add a space to words generated
from the expansion of a substitution of the form `$(...)' or
`${...}'.

The _prefix completer uses this style as a simple boolean value
to decide if a space should be inserted before the suffix.

ambiguous
This applies when completing non-final components of filename
paths, in other words those with a trailing slash. If it is
set, the cursor is left after the first ambiguous component,
even if menu completion is in use. The style is always tested
with the paths tag.

assign-list
When completing after an equals sign that is being treated as an
assignment, the completion system normally completes only one
filename. In some cases the value may be a list of filenames
separated by colons, as with PATH and similar parameters. This
style can be set to a list of patterns matching the names of
such parameters.

The default is to complete lists when the word on the line
already contains a colon.

auto-description
If set, this style's value will be used as the description for
options that are not described by the completion functions, but
that have exactly one argument. The sequence `%d' in the value
will be replaced by the description for this argument.
Depending on personal preferences, it may be useful to set this
style to something like `specify: %d'. Note that this may not
work for some commands.

avoid-completer
This is used by the _all_matches completer to decide if the
string consisting of all matches should be added to the list
currently being generated. Its value is a list of names of
completers. If any of these is the name of the completer that
generated the matches in this completion, the string will not be
added.

The default value for this style is `_expand _old_list _correct
_approximate', i.e. it contains the completers for which a
string with all matches will almost never be wanted.

cache-path
This style defines the path where any cache files containing
dumped completion data are stored. It defaults to
`$ZDOTDIR/.zcompcache', or `$HOME/.zcompcache' if $ZDOTDIR is
not defined. The completion cache will not be used unless the
use-cache style is set.

cache-policy
This style defines the function that will be used to determine
whether a cache needs rebuilding. See the section on the
_cache_invalid function below.

call-command
This style is used in the function for commands such as make and
ant where calling the command directly to generate matches
suffers problems such as being slow or, as in the case of make
can potentially cause actions in the makefile to be executed. If
it is set to `true' the command is called to generate matches.
The default value of this style is `false'.

command
In many places, completion functions need to call external
commands to generate the list of completions. This style can be
used to override the command that is called in some such cases.
The elements of the value are joined with spaces to form a
command line to execute. The value can also start with a
hyphen, in which case the usual command will be added to the
end; this is most useful for putting `builtin' or `command' in
front to make sure the appropriate version of a command is
called, for example to avoid calling a shell function with the
same name as an external command.

As an example, the completion function for process IDs uses this
style with the processes tag to generate the IDs to complete and
the list of processes to display (if the verbose style is
`true'). The list produced by the command should look like the
output of the ps command. The first line is not displayed, but
is searched for the string `PID' (or `pid') to find the position
of the process IDs in the following lines. If the line does not
contain `PID', the first numbers in each of the other lines are
taken as the process IDs to complete.

Note that the completion function generally has to call the
specified command for each attempt to generate the completion
list. Hence care should be taken to specify only commands that
take a short time to run, and in particular to avoid any that
may never terminate.

command-path
This is a list of directories to search for commands to
complete. The default for this style is the value of the
special parameter path.

commands
This is used by the function completing sub-commands for the
system initialisation scripts (residing in /etc/init.d or
somewhere not too far away from that). Its values give the
default commands to complete for those commands for which the
completion function isn't able to find them out automatically.
The default for this style are the two strings `start' and
`stop'.

complete
This is used by the _expand_alias function when invoked as a
bindable command. If set to `true' and the word on the command
line is not the name of an alias, matching alias names will be
completed.

complete-options
This is used by the completer for cd, chdir and pushd. For
these commands a - is used to introduce a directory stack entry
and completion of these is far more common than completing
options. Hence unless the value of this style is `true' options
will not be completed, even after an initial -. If it is
`true', options will be completed after an initial - unless
there is a preceding -- on the command line.

completer
The strings given as the value of this style provide the names
of the completer functions to use. The available completer
functions are described in the section `Control Functions'
below.

Each string may be either the name of a completer function or a
string of the form `function:name'. In the first case the
completer field of the context will contain the name of the
completer without the leading underscore and with all other
underscores replaced by hyphens. In the second case the
function is the name of the completer to call, but the context
will contain the user-defined name in the completer field of the
context. If the name starts with a hyphen, the string for the
context will be build from the name of the completer function as
in the first case with the name appended to it. For example:

zstyle ':completion:*' completer _complete _complete:-foo

Here, completion will call the _complete completer twice, once
using `complete' and once using `complete-foo' in the completer
field of the context. Normally, using the same completer more
than once only makes sense when used with the `functions:name'
form, because otherwise the context name will be the same in all
calls to the completer; possible exceptions to this rule are the
_ignored and _prefix completers.

The default value for this style is `_complete _ignored': only
completion will be done, first using the ignored-patterns style
and the $fignore array and then without ignoring matches.

condition
This style is used by the _list completer function to decide if
insertion of matches should be delayed unconditionally. The
default is `true'.

delimiters
This style is used when adding a delimiter for use with history
modifiers or glob qualifiers that have delimited arguments. It
is an array of preferred delimiters to add. Non-special
characters are preferred as the completion system may otherwise
become confused. The default list is :, *, /, -, %. The list
may be empty to force a delimiter to be typed.

disabled
If this is set to `true', the _expand_alias completer and
bindable command will try to expand disabled aliases, too. The
default is `false'.

domains
A list of names of network domains for completion. If this is
not set, domain names will be taken from the file
/etc/resolv.conf.

environ
The environ style is used when completing for `sudo'. It is set
to an array of `VAR=value' assignments to be exported into the
local environment before the completion for the target command
is invoked.
zstyle ':completion:*:sudo::' environ \
PATH="/sbin:/usr/sbin:$PATH" HOME="/root"

expand This style is used when completing strings consisting of
multiple parts, such as path names.

If one of its values is the string `prefix', the partially typed
word from the line will be expanded as far as possible even if
trailing parts cannot be completed.

If one of its values is the string `suffix', matching names for
components after the first ambiguous one will also be added.
This means that the resulting string is the longest unambiguous
string possible. However, menu completion can be used to cycle
through all matches.

extra-verbose
If set, the completion listing is more verbose at the cost of a
probable decrease in completion speed. Completion performance
will suffer if this style is set to `true'.

fake This style may be set for any completion context. It specifies
additional strings that will always be completed in that
context. The form of each string is `value:description'; the
colon and description may be omitted, but any literal colons in
value must be quoted with a backslash. Any description provided
is shown alongside the value in completion listings.

It is important to use a sufficiently restrictive context when
specifying fake strings. Note that the styles fake-files and
fake-parameters provide additional features when completing
files or parameters.

fake-always
This works identically to the fake style except that the
ignored-patterns style is not applied to it. This makes it
possible to override a set of matches completely by setting the
ignored patterns to `*'.

The following shows a way of supplementing any tag with
arbitrary data, but having it behave for display purposes like a
separate tag. In this example we use the features of the
tag-order style to divide the named-directories tag into two
when performing completion with the standard completer complete
for arguments of cd. The tag named-directories-normal behaves
as normal, but the tag named-directories-mine contains a fixed
set of directories. This has the effect of adding the match
group `extra directories' with the given completions.

zstyle ':completion::complete:cd:*' tag-order \
'named-directories:-mine:extra\ directories
named-directories:-normal:named\ directories *'
zstyle ':completion::complete:cd:*:named-directories-mine' \
fake-always mydir1 mydir2
zstyle ':completion::complete:cd:*:named-directories-mine' \
ignored-patterns '*'

fake-files
This style is used when completing files and looked up without a
tag. Its values are of the form `dir:names...'. This will add
the names (strings separated by spaces) as possible matches when
completing in the directory dir, even if no such files really
exist. The dir may be a pattern; pattern characters or colons
in dir should be quoted with a backslash to be treated
literally.

This can be useful on systems that support special file systems
whose top-level pathnames can not be listed or generated with
glob patterns (but see accept-exact-dirs for a more general way
of dealing with this problem). It can also be used for
directories for which one does not have read permission.

The pattern form can be used to add a certain `magic' entry to
all directories on a particular file system.

fake-parameters
This is used by the completion function for parameter names.
Its values are names of parameters that might not yet be set but
should be completed nonetheless. Each name may also be followed
by a colon and a string specifying the type of the parameter
(like `scalar', `array' or `integer'). If the type is given,
the name will only be completed if parameters of that type are
required in the particular context. Names for which no type is
specified will always be completed.

file-list
This style controls whether files completed using the standard
builtin mechanism are to be listed with a long list similar to
ls -l. Note that this feature uses the shell module zsh/stat
for file information; this loads the builtin stat which will
replace any external stat executable. To avoid this the
following code can be included in an initialization file:

zmodload -i zsh/stat
disable stat

The style may either be set to a `true' value (or `all'), or one
of the values `insert' or `list', indicating that files are to
be listed in long format in all circumstances, or when
attempting to insert a file name, or when listing file names
without attempting to insert one.

More generally, the value may be an array of any of the above
values, optionally followed by =num. If num is present it gives
the maximum number of matches for which long listing style will
be used. For example,

zstyle ':completion:*' file-list list=20 insert=10

specifies that long format will be used when listing up to 20
files or inserting a file with up to 10 matches (assuming a
listing is to be shown at all, for example on an ambiguous
completion), else short format will be used.

zstyle -e ':completion:*' file-list \
'(( ${+NUMERIC} )) && reply=(true)'

specifies that long format will be used any time a numeric
argument is supplied, else short format.

file-patterns
This is used by the standard function for completing filenames,
_files. If the style is unset up to three tags are offered,
`globbed-files',`directories' and `all-files', depending on the
types of files expected by the caller of _files. The first two
(`globbed-files' and `directories') are normally offered
together to make it easier to complete files in sub-directories.

The file-patterns style provides alternatives to the default
tags, which are not used. Its value consists of elements of the
form `pattern:tag'; each string may contain any number of such
specifications separated by spaces.

The pattern is a pattern that is to be used to generate
filenames. Any occurrence of the sequence `%p' is replaced by
any pattern(s) passed by the function calling _files. Colons in
the pattern must be preceded by a backslash to make them
distinguishable from the colon before the tag. If more than one
pattern is needed, the patterns can be given inside braces,
separated by commas.

The tags of all strings in the value will be offered by _files
and used when looking up other styles. Any tags in the same
word will be offered at the same time and before later words.
If no `:tag' is given the `files' tag will be used.

The tag may also be followed by an optional second colon and a
description, which will be used for the `%d' in the value of the
format style (if that is set) instead of the default description
supplied by the completion function. The inclusion of a
description also gives precedence to associated options such as
for completion grouping so it can be used where files should be
separated.

For example, to make the rm command first complete only names of
object files and then the names of all files if there is no
matching object file:

zstyle ':completion:*:*:rm:*:*' file-patterns \
'*.o:object-files' '%p:all-files'

To alter the default behaviour of file completion -- offer files
matching a pattern and directories on the first attempt, then
all files -- to offer only matching files on the first attempt,
then directories, and finally all files:

zstyle ':completion:*' file-patterns \
'%p:globbed-files' '*(-/):directories' '*:all-files'

This works even where there is no special pattern: _files
matches all files using the pattern `*' at the first step and
stops when it sees this pattern. Note also it will never try a
pattern more than once for a single completion attempt.

To separate directories into a separate group from the files but
still complete them at the first attempt, a description needs to
be given. Note that directories need to be explicitly excluded
from the globbed-files because `*' will match directories. For
grouping, it is also necessary to set the group-name style.

zstyle ':completion:*' file-patterns \
'%p(^-/):globbed-files *(-/):directories:location'

During the execution of completion functions, the EXTENDED_GLOB
option is in effect, so the characters `#', `~' and `^' have
special meanings in the patterns.

file-sort
The standard filename completion function uses this style
without a tag to determine in which order the names should be
listed; menu completion will cycle through them in the same
order. The possible values are: `size' to sort by the size of
the file; `links' to sort by the number of links to the file;
`modification' (or `time' or `date') to sort by the last
modification time; `access' to sort by the last access time; and
`inode' (or `change') to sort by the last inode change time. If
the style is set to any other value, or is unset, files will be
sorted alphabetically by name. If the value contains the string
`reverse', sorting is done in the opposite order. If the value
contains the string `follow', timestamps are associated with the
targets of symbolic links; the default is to use the timestamps
of the links themselves.

file-split-chars
A set of characters that will cause all file completions for the
given context to be split at the point where any of the
characters occurs. A typical use is to set the style to :; then
everything up to and including the last : in the string so far
is ignored when completing files. As this is quite
heavy-handed, it is usually preferable to update completion
functions for contexts where this behaviour is useful.

filter The ldap plugin of email address completion (see
_email_addresses) uses this style to specify the attributes to
match against when filtering entries. So for example, if the
style is set to `sn', matching is done against surnames.
Standard LDAP filtering is used so normal completion matching is
bypassed. If this style is not set, the LDAP plugin is skipped.
You may also need to set the command style to specify how to
connect to your LDAP server.

force-list
This forces a list of completions to be shown at any point where
listing is done, even in cases where the list would usually be
suppressed. For example, normally the list is only shown if
there are at least two different matches. By setting this style
to `always', the list will always be shown, even if there is
only a single match that will immediately be accepted. The
style may also be set to a number. In this case the list will
be shown if there are at least that many matches, even if they
would all insert the same string.

This style is tested for the default tag as well as for each tag
valid for the current completion. Hence the listing can be
forced only for certain types of match.

format If this is set for the descriptions tag, its value is used as a
string to display above matches in completion lists. The
sequence `%d' in this string will be replaced with a short
description of what these matches are. This string may also
contain the output attribute sequences understood by compadd -X
(see zshcompwid(1)).

The style is tested with each tag valid for the current
completion before it is tested for the descriptions tag. Hence
different format strings can be defined for different types of
match.

Note also that some completer functions define additional
`%'-sequences. These are described for the completer functions
that make use of them.

Some completion functions display messages that may be
customised by setting this style for the messages tag. Here,
the `%d' is replaced with a message given by the completion
function.

Finally, the format string is looked up with the warnings tag,
for use when no matches could be generated at all. In this case
the `%d' is replaced with the descriptions for the matches that
were expected separated by spaces. The sequence `%D' is
replaced with the same descriptions separated by newlines.

It is possible to use printf-style field width specifiers with
`%d' and similar escape sequences. This is handled by the
zformat builtin command from the zsh/zutil module, see
zshmodules(1).

gain-privileges
If set to true, this style enables the use of commands like sudo
or doas to gain extra privileges when retrieving information for
completion. This is only done when a command such as sudo
appears on the command-line. To force the use of, e.g. sudo or
to override any prefix that might be added due to
gain-privileges, the command style can be used with a value that
begins with a hyphen.

glob This is used by the _expand completer. If it is set to `true'
(the default), globbing will be attempted on the words resulting
from a previous substitution (see the substitute style) or else
the original string from the line.

global If this is set to `true' (the default), the _expand_alias
completer and bindable command will try to expand global
aliases.

group-name
The completion system can group different types of matches,
which appear in separate lists. This style can be used to give
the names of groups for particular tags. For example, in
command position the completion system generates names of
builtin and external commands, names of aliases, shell functions
and parameters and reserved words as possible completions. To
have the external commands and shell functions listed
separately:

zstyle ':completion:*:*:-command-:*:commands' \
group-name commands
zstyle ':completion:*:*:-command-:*:functions' \
group-name functions

As a consequence, any match with the same tag will be displayed
in the same group.

If the name given is the empty string the name of the tag for
the matches will be used as the name of the group. So, to have
all different types of matches displayed separately, one can
just set:

zstyle ':completion:*' group-name ''

All matches for which no group name is defined will be put in a
group named -default-.

To display the group name in the output, see the format style
(q.v.) under the descriptions tag.

group-order
This style is additional to the group-name style to specify the
order for display of the groups defined by that style (compare
tag-order, which determines which completions appear at all).
The groups named are shown in the given order; any other groups
are shown in the order defined by the completion function.

For example, to have names of builtin commands, shell functions
and external commands appear in that order when completing in
command position:

zstyle ':completion:*:*:-command-:*:*' group-order \
builtins functions commands

groups A list of names of UNIX groups. If this is not set, group names
are taken from the YP database or the file `/etc/group'.

hidden If this is set to `true', matches for the given context will not
be listed, although any description for the matches set with the
format style will be shown. If it is set to `all', not even the
description will be displayed.

Note that the matches will still be completed; they are just not
shown in the list. To avoid having matches considered as
possible completions at all, the tag-order style can be modified
as described below.

hosts A list of names of hosts that should be completed. If this is
not set, hostnames are taken from the file `/etc/hosts'.

hosts-ports
This style is used by commands that need or accept hostnames and
network ports. The strings in the value should be of the form
`host:port'. Valid ports are determined by the presence of
hostnames; multiple ports for the same host may appear.

ignore-line
This is tested for each tag valid for the current completion.
If it is set to `true', none of the words that are already on
the line will be considered as possible completions. If it is
set to `current', the word the cursor is on will not be
considered as a possible completion. The value `current-shown'
is similar but only applies if the list of completions is
currently shown on the screen. Finally, if the style is set to
`other', all words on the line except for the current one will
be excluded from the possible completions.

The values `current' and `current-shown' are a bit like the
opposite of the accept-exact style: only strings with missing
characters will be completed.

Note that you almost certainly don't want to set this to `true'
or `other' for a general context such as `:completion:*'. This
is because it would disallow completion of, for example, options
multiple times even if the command in question accepts the
option more than once.

ignore-parents
The style is tested without a tag by the function completing
pathnames in order to determine whether to ignore the names of
directories already mentioned in the current word, or the name
of the current working directory. The value must include one or
both of the following strings:

parent The name of any directory whose path is already contained
in the word on the line is ignored. For example, when
completing after foo/../, the directory foo will not be
considered a valid completion.

pwd The name of the current working directory will not be
completed; hence, for example, completion after ../ will
not use the name of the current directory.

In addition, the value may include one or both of:

.. Ignore the specified directories only when the word on
the line contains the substring `../'.

directory
Ignore the specified directories only when names of
directories are completed, not when completing names of
files.

Excluded values act in a similar fashion to values of the
ignored-patterns style, so they can be restored to consideration
by the _ignored completer.

ignored-patterns
A list of patterns; any trial completion matching one of the
patterns will be excluded from consideration. The _ignored
completer can appear in the list of completers to restore the
ignored matches. This is a more configurable version of the
shell parameter $fignore.

Note that the EXTENDED_GLOB option is set during the execution
of completion functions, so the characters `#', `~' and `^' have
special meanings in the patterns.

insert This style is used by the _all_matches completer to decide
whether to insert the list of all matches unconditionally
instead of adding the list as another match.

insert-ids
When completing process IDs, for example as arguments to the
kill and wait builtins the name of a command may be converted to
the appropriate process ID. A problem arises when the process
name typed is not unique. By default (or if this style is set
explicitly to `menu') the name will be converted immediately to
a set of possible IDs, and menu completion will be started to
cycle through them.

If the value of the style is `single', the shell will wait until
the user has typed enough to make the command unique before
converting the name to an ID; attempts at completion will be
unsuccessful until that point. If the value is any other
string, menu completion will be started when the string typed by
the user is longer than the common prefix to the corresponding
IDs.

insert-sections
This style is used with tags of the form `manuals.X' when
completing names of manual pages. If set and the X in the tag
name matches the section number of the page being completed, the
section number is inserted along with the page name. For
example, given

zstyle ':completion:*:manuals.*' insert-sections true

man ssh_<TAB> may be completed to man 5 ssh_config.

The value may also be set to one of `prepend', or `suffix'.
`prepend' behaves the same as `true' as in the above example,
while `suffix' would complete man ssh_<TAB> as man ssh_config.5.

This is especially useful in conjunction with separate-sections,
as it ensures that the page requested of man corresponds to the
one displayed in the completion listing when there are multiple
pages with the same name (e.g., printf(1) and printf(3)).

The default for this style is `false'.

insert-tab
If this is set to `true', the completion system will insert a
TAB character (assuming that was used to start completion)
instead of performing completion when there is no non-blank
character to the left of the cursor. If it is set to `false',
completion will be done even there.

The value may also contain the substrings `pending' or
`pending=val'. In this case, the typed character will be
inserted instead of starting completion when there is
unprocessed input pending. If a val is given, completion will
not be done if there are at least that many characters of
unprocessed input. This is often useful when pasting characters
into a terminal. Note however, that it relies on the $PENDING
special parameter from the zsh/zle module being set properly
which is not guaranteed on all platforms.

The default value of this style is `true' except for completion
within vared builtin command where it is `false'.

insert-unambiguous
This is used by the _match and _approximate completers. These
completers are often used with menu completion since the word
typed may bear little resemblance to the final completion.
However, if this style is `true', the completer will start menu
completion only if it could find no unambiguous initial string
at least as long as the original string typed by the user.

In the case of the _approximate completer, the completer field
in the context will already have been set to one of correct-num
or approximate-num, where num is the number of errors that were
accepted.

In the case of the _match completer, the style may also be set
to the string `pattern'. Then the pattern on the line is left
unchanged if it does not match unambiguously.

keep-prefix
This style is used by the _expand completer. If it is `true',
the completer will try to keep a prefix containing a tilde or
parameter expansion. Hence, for example, the string `~/f*'
would be expanded to `~/foo' instead of `/home/user/foo'. If
the style is set to `changed' (the default), the prefix will
only be left unchanged if there were other changes between the
expanded words and the original word from the command line. Any
other value forces the prefix to be expanded unconditionally.

The behaviour of _expand when this style is `true' is to cause
_expand to give up when a single expansion with the restored
prefix is the same as the original; hence any remaining
completers may be called.

known-hosts-files
This style should contain a list of files to search for host
names and (if the use-ip style is set) IP addresses in a format
compatible with ssh known_hosts files. If it is not set, the
files /etc/ssh/ssh_known_hosts and ~/.ssh/known_hosts are used.

last-prompt
This is a more flexible form of the ALWAYS_LAST_PROMPT option.
If it is `true', the completion system will try to return the
cursor to the previous command line after displaying a
completion list. It is tested for all tags valid for the
current completion, then the default tag. The cursor will be
moved back to the previous line if this style is `true' for all
types of match. Note that unlike the ALWAYS_LAST_PROMPT option
this is independent of the numeric argument.

list This style is used by the _history_complete_word bindable
command. If it is set to `true' it has no effect. If it is set
to `false' matches will not be listed. This overrides the
setting of the options controlling listing behaviour, in
particular AUTO_LIST. The context always starts with
`:completion:history-words'.

list-colors
If the zsh/complist module is loaded, this style can be used to
set color specifications. This mechanism replaces the use of
the ZLS_COLORS and ZLS_COLOURS parameters described in the
section `The zsh/complist Module' in zshmodules(1), but the
syntax is the same.

If this style is set for the default tag, the strings in the
value are taken as specifications that are to be used
everywhere. If it is set for other tags, the specifications are
used only for matches of the type described by the tag. For
this to work best, the group-name style must be set to an empty
string.

In addition to setting styles for specific tags, it is also
possible to use group names specified explicitly by the
group-name tag together with the `(group)' syntax allowed by the
ZLS_COLORS and ZLS_COLOURS parameters and simply using the
default tag.

It is possible to use any color specifications already set up
for the GNU version of the ls command:

zstyle ':completion:*:default' list-colors \
${(s.:.)LS_COLORS}

The default colors are the same as for the GNU ls command and
can be obtained by setting the style to an empty string (i.e.
'').

list-dirs-first
This is used by file completion and corresponds to a particular
setting of the file-patterns style. If set, the default
directories to be completed are listed separately from and
before completion for other files.

list-grouped
If this style is `true' (the default), the completion system
will try to make certain completion listings more compact by
grouping matches. For example, options for commands that have
the same description (shown when the verbose style is set to
`true') will appear as a single entry. However, menu selection
can be used to cycle through all the matches.

list-packed
This is tested for each tag valid in the current context as well
as the default tag. If it is set to `true', the corresponding
matches appear in listings as if the LIST_PACKED option were
set. If it is set to `false', they are listed normally.

list-prompt
If this style is set for the default tag, completion lists that
don't fit on the screen can be scrolled (see the description of
the zsh/complist module in zshmodules(1)). The value, if not
the empty string, will be displayed after every screenful and
the shell will prompt for a key press; if the style is set to
the empty string, a default prompt will be used.

The value may contain the escape sequences: `%l' or `%L', which
will be replaced by the number of the last line displayed and
the total number of lines; `%m' or `%M', the number of the last
match shown and the total number of matches; and `%p' and `%P',
`Top' when at the beginning of the list, `Bottom' when at the
end and the position shown as a percentage of the total length
otherwise. In each case the form with the uppercase letter will
be replaced by a string of fixed width, padded to the right
with spaces, while the lowercase form will be replaced by a
variable width string. As in other prompt strings, the escape
sequences `%S', `%s', `%B', `%b', `%U', `%u' for entering and
leaving the display modes standout, bold and underline, and
`%F', `%f', `%K', `%k' for changing the foreground background
colour, are also available, as is the form `%{...%}' for
enclosing escape sequences which display with zero (or, with a
numeric argument, some other) width.

After deleting this prompt the variable LISTPROMPT should be
unset for the removal to take effect.

list-rows-first
This style is tested in the same way as the list-packed style
and determines whether matches are to be listed in a rows-first
fashion as if the LIST_ROWS_FIRST option were set.

list-separator
The value of this style is used in completion listing to
separate the string to complete from a description when possible
(e.g. when completing options). It defaults to `--' (two
hyphens).

list-suffixes
This style is used by the function that completes filenames. If
it is `true', and completion is attempted on a string containing
multiple partially typed pathname components, all ambiguous
components will be shown. Otherwise, completion stops at the
first ambiguous component.

local This is for use with functions that complete URLs for which the
corresponding files are available directly from the file system.
Its value should consist of three strings: a hostname, the path
to the default web pages for the server, and the directory name
used by a user placing web pages within their home area.

For example:

zstyle ':completion:*' local toast \
/var/http/public/toast public_html

Completion after `http://toast/stuff/' will look for files in
the directory /var/http/public/toast/stuff, while completion
after `http://toast/~yousir/' will look for files in the
directory ~yousir/public_html.

mail-directory
If set, zsh will assume that mailbox files can be found in the
directory specified. It defaults to `~/Mail'.

match-original
This is used by the _match completer. If it is set to only,
_match will try to generate matches without inserting a `*' at
the cursor position. If set to any other non-empty value, it
will first try to generate matches without inserting the `*' and
if that yields no matches, it will try again with the `*'
inserted. If it is unset or set to the empty string, matching
will only be performed with the `*' inserted.

matcher
This style is tested separately for each tag valid in the
current context. Its value is placed before any match
specifications given by the matcher-list style so can override
them via the use of an x: specification. The value should be in
the form described in the section `Completion Matching Control'
in zshcompwid(1). For examples of this, see the description of
the tag-order style.

For notes comparing the use of this and the matcher-list style,
see under the description of the tag-order style.

matcher-list
This style can be set to a list of match specifications that are
to be applied everywhere. Match specifications are described in
the section `Completion Matching Control' in zshcompwid(1). The
completion system will try them one after another for each
completer selected. For example, to try first simple completion
and, if that generates no matches, case-insensitive completion:

zstyle ':completion:*' matcher-list '' 'm:{a-zA-Z}={A-Za-z}'

By default each specification replaces the previous one;
however, if a specification is prefixed with *, it is added to
the existing list. Hence it is possible to create increasingly
general specifications without repetition:

zstyle ':completion:*' matcher-list \
'' '+m:{a-z}={A-Z}' '+m:{A-Z}={a-z}'

It is possible to create match specifications valid for
particular completers by using the third field of the context.
This applies only to completers that override the global
matcher-list, which as of this writing includes only _prefix and
_ignored. For example, to use the completers _complete and
_prefix but allow case-insensitive completion only with
_complete:

zstyle ':completion:*' completer _complete _prefix
zstyle ':completion:*:complete:*:*:*' matcher-list \
'' 'm:{a-zA-Z}={A-Za-z}'

User-defined names, as explained for the completer style, are
available. This makes it possible to try the same completer
more than once with different match specifications each time.
For example, to try normal completion without a match
specification, then normal completion with case-insensitive
matching, then correction, and finally partial-word completion:

zstyle ':completion:*' completer \
_complete _correct _complete:foo
zstyle ':completion:*:complete:*:*:*' matcher-list \
'' 'm:{a-zA-Z}={A-Za-z}'
zstyle ':completion:*:foo:*:*:*' matcher-list \
'm:{a-zA-Z}={A-Za-z} r:|[-_./]=* r:|=*'

If the style is unset in any context no match specification is
applied. Note also that some completers such as _correct and
_approximate do not use the match specifications at all, though
these completers will only ever be called once even if the
matcher-list contains more than one element.

Where multiple specifications are useful, note that the entire
completion is done for each element of matcher-list, which can
quickly reduce the shell's performance. As a rough rule of
thumb, one to three strings will give acceptable performance.
On the other hand, putting multiple space-separated values into
the same string does not have an appreciable impact on
performance.

If there is no current matcher or it is empty, and the option
NO_CASE_GLOB is in effect, the matching for files is performed
case-insensitively in any case. However, any matcher must
explicitly specify case-insensitive matching if that is
required.

For notes comparing the use of this and the matcher style, see
under the description of the tag-order style.

max-errors
This is used by the _approximate and _correct completer
functions to determine the maximum number of errors to allow.
The completer will try to generate completions by first allowing
one error, then two errors, and so on, until either a match or
matches were found or the maximum number of errors given by this
style has been reached.

If the value for this style contains the string `numeric', the
completer function will take any numeric argument as the maximum
number of errors allowed. For example, with

zstyle ':completion:*:approximate:::' max-errors 2 numeric

two errors are allowed if no numeric argument is given, but with
a numeric argument of six (as in `ESC-6 TAB'), up to six errors
are accepted. Hence with a value of `0 numeric', no correcting
completion will be attempted unless a numeric argument is given.

If the value contains the string `not-numeric', the completer
will not try to generate corrected completions when given a
numeric argument, so in this case the number given should be
greater than zero. For example, `2 not-numeric' specifies that
correcting completion with two errors will usually be performed,
but if a numeric argument is given, correcting completion will
not be performed.

The default value for this style is `2 numeric'.

max-matches-width
This style is used to determine the trade off between the width
of the display used for matches and the width used for their
descriptions when the verbose style is in effect. The value
gives the number of display columns to reserve for the matches.
The default is half the width of the screen.

This has the most impact when several matches have the same
description and so will be grouped together. Increasing the
style will allow more matches to be grouped together; decreasing
it will allow more of the description to be visible.

menu If this is `true' in the context of any of the tags defined for
the current completion menu completion will be used. The value
for a specific tag will take precedence over that for the
`default' tag.

If none of the values found in this way is `true' but at least
one is set to `auto', the shell behaves as if the AUTO_MENU
option is set.

If one of the values is explicitly set to `false', menu
completion will be explicitly turned off, overriding the
MENU_COMPLETE option and other settings.

In the form `yes=num', where `yes' may be any of the `true'
values (`yes', `true', `on' and `1'), menu completion will be
turned on if there are at least num matches. In the form
`yes=long', menu completion will be turned on if the list does
not fit on the screen. This does not activate menu completion
if the widget normally only lists completions, but menu
completion can be activated in that case with the value
`yes=long-list' (Typically, the value `select=long-list'
described later is more useful as it provides control over
scrolling.)

Similarly, with any of the `false' values (as in `no=10'), menu
completion will not be used if there are num or more matches.

The value of this widget also controls menu selection, as
implemented by the zsh/complist module. The following values
may appear either alongside or instead of the values above.

If the value contains the string `select', menu selection will
be started unconditionally.

In the form `select=num', menu selection will only be started if
there are at least num matches. If the values for more than one
tag provide a number, the smallest number is taken.

Menu selection can be turned off explicitly by defining a value
containing the string`no-select'.

It is also possible to start menu selection only if the list of
matches does not fit on the screen by using the value
`select=long'. To start menu selection even if the current
widget only performs listing, use the value `select=long-list'.

To turn on menu completion or menu selection when there are a
certain number of matches or the list of matches does not fit on
the screen, both of `yes=' and `select=' may be given twice,
once with a number and once with `long' or `long-list'.

Finally, it is possible to activate two special modes of menu
selection. The word `interactive' in the value causes
interactive mode to be entered immediately when menu selection
is started; see the description of the zsh/complist module in
zshmodules(1) for a description of interactive mode. Including
the string `search' does the same for incremental search mode.
To select backward incremental search, include the string
`search-backward'.

muttrc If set, gives the location of the mutt configuration file. It
defaults to `~/.muttrc'.

numbers
This is used with the jobs tag. If it is `true', the shell will
complete job numbers instead of the shortest unambiguous prefix
of the job command text. If the value is a number, job numbers
will only be used if that many words from the job descriptions
are required to resolve ambiguities. For example, if the value
is `1', strings will only be used if all jobs differ in the
first word on their command lines.

old-list
This is used by the _oldlist completer. If it is set to
`always', then standard widgets which perform listing will
retain the current list of matches, however they were generated;
this can be turned off explicitly with the value `never', giving
the behaviour without the _oldlist completer. If the style is
unset, or any other value, then the existing list of completions
is displayed if it is not already; otherwise, the standard
completion list is generated; this is the default behaviour of
_oldlist. However, if there is an old list and this style
contains the name of the completer function that generated the
list, then the old list will be used even if it was generated by
a widget which does not do listing.

For example, suppose you type ^Xc to use the _correct_word
widget, which generates a list of corrections for the word under
the cursor. Usually, typing ^D would generate a standard list
of completions for the word on the command line, and show that.
With _oldlist, it will instead show the list of corrections
already generated.

As another example consider the _match completer: with the
insert-unambiguous style set to `true' it inserts only a common
prefix string, if there is any. However, this may remove parts
of the original pattern, so that further completion could
produce more matches than on the first attempt. By using the
_oldlist completer and setting this style to _match, the list of
matches generated on the first attempt will be used again.

old-matches
This is used by the _all_matches completer to decide if an old
list of matches should be used if one exists. This is selected
by one of the `true' values or by the string `only'. If the
value is `only', _all_matches will only use an old list and
won't have any effect on the list of matches currently being
generated.

If this style is set it is generally unwise to call the
_all_matches completer unconditionally. One possible use is for
either this style or the completer style to be defined with the
-e option to zstyle to make the style conditional.

old-menu
This is used by the _oldlist completer. It controls how menu
completion behaves when a completion has already been inserted
and the user types a standard completion key such as TAB. The
default behaviour of _oldlist is that menu completion always
continues with the existing list of completions. If this style
is set to `false', however, a new completion is started if the
old list was generated by a different completion command; this
is the behaviour without the _oldlist completer.

For example, suppose you type ^Xc to generate a list of
corrections, and menu completion is started in one of the usual
ways. Usually, or with this style set to `false', typing TAB at
this point would start trying to complete the line as it now
appears. With _oldlist, it instead continues to cycle through
the list of corrections.

original
This is used by the _approximate and _correct completers to
decide if the original string should be added as a possible
completion. Normally, this is done only if there are at least
two possible corrections, but if this style is set to `true', it
is always added. Note that the style will be examined with the
completer field in the context name set to correct-num or
approximate-num, where num is the number of errors that were
accepted.

packageset
This style is used when completing arguments of the Debian
`dpkg' program. It contains an override for the default package
set for a given context. For example,

zstyle ':completion:*:complete:dpkg:option--status-1:*' \
packageset avail

causes available packages, rather than only installed packages,
to be completed for `dpkg --status'.

path The function that completes color names uses this style with the
colors tag. The value should be the pathname of a file
containing color names in the format of an X11 rgb.txt file. If
the style is not set but this file is found in one of various
standard locations it will be used as the default.

path-completion
This is used by filename completion. By default, filename
completion examines all components of a path to see if there are
completions of that component. For example, /u/b/z can be
completed to /usr/bin/zsh. Explicitly setting this style to
`false' inhibits this behaviour for path components up to the /
before the cursor; this overrides the setting of
accept-exact-dirs.

Even with the style set to `false', it is still possible to
complete multiple paths by setting the option COMPLETE_IN_WORD
and moving the cursor back to the first component in the path to
be completed. For example, /u/b/z can be completed to
/usr/bin/zsh if the cursor is after the /u.

pine-directory
If set, specifies the directory containing PINE mailbox files.
There is no default, since recursively searching this directory
is inconvenient for anyone who doesn't use PINE.

ports A list of Internet service names (network ports) to complete.
If this is not set, service names are taken from the file
`/etc/services'.

prefix-hidden
This is used for certain completions which share a common
prefix, for example command options beginning with dashes. If
it is `true', the prefix will not be shown in the list of
matches.

The default value for this style is `false'.

prefix-needed
This style is also relevant for matches with a common prefix.
If it is set to `true' this common prefix must be typed by the
user to generate the matches.

The style is applicable to the options, signals, jobs,
functions, and parameters completion tags.

For command options, this means that the initial `-', `*', or
`--' must be typed explicitly before option names will be
completed.

For signals, an initial `-' is required before signal names will
be completed.

For jobs, an initial `%' is required before job names will be
completed.

For function and parameter names, an initial `_' or `.' is
required before function or parameter names starting with those
characters will be completed.

The default value for this style is `false' for function and
parameter completions, and `true' otherwise.

preserve-prefix
This style is used when completing path names. Its value should
be a pattern matching an initial prefix of the word to complete
that should be left unchanged under all circumstances. For
example, on some Unices an initial `//' (double slash) has a
special meaning; setting this style to the string `//' will
preserve it. As another example, setting this style to `?:/'
under Cygwin would allow completion after `a:/...' and so on.

range This is used by the _history completer and the
_history_complete_word bindable command to decide which words
should be completed.

If it is a single number, only the last N words from the history
will be completed.

If it is a range of the form `max:slice', the last slice words
will be completed; then if that yields no matches, the slice
words before those will be tried and so on. This process stops
either when at least one match has been found, or max words have
been tried.

The default is to complete all words from the history at once.

recursive-files
If this style is set, its value is an array of patterns to be
tested against `$PWD/': note the trailing slash, which allows
directories in the pattern to be delimited unambiguously by
including slashes on both sides. If an ordinary file completion
fails and the word on the command line does not yet have a
directory part to its name, the style is retrieved using the
same tag as for the completion just attempted, then the elements
tested against $PWD/ in turn. If one matches, then the shell
reattempts completion by prepending the word on the command line
with each directory in the expansion of **/*(/) in turn.
Typically the elements of the style will be set to restrict the
number of directories beneath the current one to a manageable
number, for example `*/.git/*'.

For example,

zstyle ':completion:*' recursive-files '*/zsh/*'

If the current directory is /home/pws/zsh/Src, then zle_tr<TAB>
can be completed to Zle/zle_tricky.c.

regular
This style is used by the _expand_alias completer and bindable
command. If set to `true' (the default), regular aliases will
be expanded but only in command position. If it is set to
`false', regular aliases will never be expanded. If it is set
to `always', regular aliases will be expanded even if not in
command position.

rehash If this is set when completing external commands, the internal
list (hash) of commands will be updated for each search by
issuing the rehash command. There is a speed penalty for this
which is only likely to be noticeable when directories in the
path have slow file access.

remote-access
If set to `false', certain commands will be prevented from
making Internet connections to retrieve remote information.
This includes the completion for the CVS command.

It is not always possible to know if connections are in fact to
a remote site, so some may be prevented unnecessarily.

remove-all-dups
The _history_complete_word bindable command and the _history
completer use this to decide if all duplicate matches should be
removed, rather than just consecutive duplicates.

select-prompt
If this is set for the default tag, its value will be displayed
during menu selection (see the menu style above) when the
completion list does not fit on the screen as a whole. The same
escapes as for the list-prompt style are understood, except that
the numbers refer to the match or line the mark is on. A
default prompt is used when the value is the empty string.

select-scroll
This style is tested for the default tag and determines how a
completion list is scrolled during a menu selection (see the
menu style above) when the completion list does not fit on the
screen as a whole. If the value is `0' (zero), the list is
scrolled by half-screenfuls; if it is a positive integer, the
list is scrolled by the given number of lines; if it is a
negative number, the list is scrolled by a screenful minus the
absolute value of the given number of lines. The default is to
scroll by single lines.

separate-sections
This style is used with the manuals tag when completing names of
manual pages. If it is `true', entries for different sections
are added separately using tag names of the form `manuals.X',
where X is the section number. When the group-name style is
also in effect, pages from different sections will appear
separately. This style is also used similarly with the words
style when completing words for the dict command. It allows
words from different dictionary databases to be added
separately. See also insert-sections.

The default for this style is `false'.

show-ambiguity
If the zsh/complist module is loaded, this style can be used to
highlight the first ambiguous character in completion lists. The
value is either a color indication such as those supported by
the list-colors style or, with a value of `true', a default of
underlining is selected. The highlighting is only applied if the
completion display strings correspond to the actual matches.

show-completer
Tested whenever a new completer is tried. If it is `true', the
completion system outputs a progress message in the listing area
showing what completer is being tried. The message will be
overwritten by any output when completions are found and is
removed after completion is finished.

single-ignored
This is used by the _ignored completer when there is only one
match. If its value is `show', the single match will be
displayed but not inserted. If the value is `menu', then the
single match and the original string are both added as matches
and menu completion is started, making it easy to select either
of them.

sort This allows the standard ordering of matches to be overridden.

If its value is `true' or `false', sorting is enabled or
disabled. Additionally the values associated with the `-o'
option to compadd can also be listed: match, nosort, numeric,
reverse. If it is not set for the context, the standard
behaviour of the calling widget is used.

The style is tested first against the full context including the
tag, and if that fails to produce a value against the context
without the tag.

In many cases where a calling widget explicitly selects a
particular ordering in lieu of the default, a value of `true' is
not honoured. An example of where this is not the case is for
command history where the default of sorting matches
chronologically may be overridden by setting the style to
`true'.

In the _expand completer, if it is set to `true', the expansions
generated will always be sorted. If it is set to `menu', then
the expansions are only sorted when they are offered as single
strings but not in the string containing all possible
expansions.

special-dirs
Normally, the completion code will not produce the directory
names `.' and `..' as possible completions. If this style is
set to `true', it will add both `.' and `..' as possible
completions; if it is set to `..', only `..' will be added.

The following example sets special-dirs to `..' when the current
prefix is empty, is a single `.', or consists only of a path
beginning with `../'. Otherwise the value is `false'.

zstyle -e ':completion:*' special-dirs \
'[[ $PREFIX = (../)#(|.|..) ]] && reply=(..)'

squeeze-slashes
If set to `true', sequences of slashes in filename paths (for
example in `foo//bar') will be treated as a single slash. This
is the usual behaviour of UNIX paths. However, by default the
file completion function behaves as if there were a `*' between
the slashes.

stop If set to `true', the _history_complete_word bindable command
will stop once when reaching the beginning or end of the
history. Invoking _history_complete_word will then wrap around
to the opposite end of the history. If this style is set to
`false' (the default), _history_complete_word will loop
immediately as in a menu completion.

strip-comments
If set to `true', this style causes non-essential comment text
to be removed from completion matches. Currently it is only
used when completing e-mail addresses where it removes any
display name from the addresses, cutting them down to plain
user@host form.

subst-globs-only
This is used by the _expand completer. If it is set to `true',
the expansion will only be used if it resulted from globbing;
hence, if expansions resulted from the use of the substitute
style described below, but these were not further changed by
globbing, the expansions will be rejected.

The default for this style is `false'.

substitute
This boolean style controls whether the _expand completer will
first try to expand all substitutions in the string (such as
`$(...)' and `${...}').

The default is `true'.

suffix This is used by the _expand completer if the word starts with a
tilde or contains a parameter expansion. If it is set to
`true', the word will only be expanded if it doesn't have a
suffix, i.e. if it is something like `~foo' or `$foo' rather
than `~foo/' or `$foo/bar', unless that suffix itself contains
characters eligible for expansion. The default for this style
is `true'.

tag-order
This provides a mechanism for sorting how the tags available in
a particular context will be used.

The values for the style are sets of space-separated lists of
tags. The tags in each value will be tried at the same time; if
no match is found, the next value is used. (See the
file-patterns style for an exception to this behavior.)

For example:

zstyle ':completion:*:complete:-command-:*:*' tag-order \
'commands functions'

specifies that completion in command position first offers
external commands and shell functions. Remaining tags will be
tried if no completions are found.

In addition to tag names, each string in the value may take one
of the following forms:

- If any value consists of only a hyphen, then only the
tags specified in the other values are generated.
Normally all tags not explicitly selected are tried last
if the specified tags fail to generate any matches. This
means that a single value consisting only of a single
hyphen turns off completion.

! tags...
A string starting with an exclamation mark specifies
names of tags that are not to be used. The effect is the
same as if all other possible tags for the context had
been listed.

tag:label ...
Here, tag is one of the standard tags and label is an
arbitrary name. Matches are generated as normal but the
name label is used in contexts instead of tag. This is
not useful in words starting with !.

If the label starts with a hyphen, the tag is prepended
to the label to form the name used for lookup. This can
be used to make the completion system try a certain tag
more than once, supplying different style settings for
each attempt; see below for an example.

tag:label:description
As before, but description will replace the `%d' in the
value of the format style instead of the default
description supplied by the completion function. Spaces
in the description must be quoted with a backslash. A
`%d' appearing in description is replaced with the
description given by the completion function.

In any of the forms above the tag may be a pattern or several
patterns in the form `{pat1,pat2...}'. In this case all
matching tags will be used except for any given explicitly in
the same string.

One use of these features is to try one tag more than once,
setting other styles differently on each attempt, but still to
use all the other tags without having to repeat them all. For
example, to make completion of function names in command
position ignore all the completion functions starting with an
underscore the first time completion is tried:

zstyle ':completion:*:*:-command-:*:*' tag-order \
'functions:-non-comp *' functions
zstyle ':completion:*:functions-non-comp' \
ignored-patterns '_*'

On the first attempt, all tags will be offered but the functions
tag will be replaced by functions-non-comp. The
ignored-patterns style is set for this tag to exclude functions
starting with an underscore. If there are no matches, the
second value of the tag-order style is used which completes
functions using the default tag, this time presumably including
all function names.

The matches for one tag can be split into different groups. For
example:

zstyle ':completion:*' tag-order \
'options:-long:long\ options
options:-short:short\ options
options:-single-letter:single\ letter\ options'
zstyle ':completion:*:options-long' \
ignored-patterns '[-+](|-|[^-]*)'
zstyle ':completion:*:options-short' \
ignored-patterns '--*' '[-+]?'
zstyle ':completion:*:options-single-letter' \
ignored-patterns '???*'

With the group-names style set, options beginning with `--',
options beginning with a single `-' or `*' but containing
multiple characters, and single-letter options will be displayed
in separate groups with different descriptions.

Another use of patterns is to try multiple match specifications
one after another. The matcher-list style offers something
similar, but it is tested very early in the completion system
and hence can't be set for single commands nor for more specific
contexts. Here is how to try normal completion without any
match specification and, if that generates no matches, try again
with case-insensitive matching, restricting the effect to
arguments of the command foo:

zstyle ':completion:*:*:foo:*:*' tag-order '*' '*:-case'
zstyle ':completion:*-case' matcher 'm:{a-z}={A-Z}'

First, all the tags offered when completing after foo are tried
using the normal tag name. If that generates no matches, the
second value of tag-order is used, which tries all tags again
except that this time each has -case appended to its name for
lookup of styles. Hence this time the value for the matcher
style from the second call to zstyle in the example is used to
make completion case-insensitive.

It is possible to use the -e option of the zstyle builtin
command to specify conditions for the use of particular tags.
For example:

zstyle -e '*:-command-:*' tag-order '
if [[ -n $PREFIX$SUFFIX ]]; then
reply=( )
else
reply=( - )
fi'

Completion in command position will be attempted only if the
string typed so far is not empty. This is tested using the
PREFIX special parameter; see zshcompwid for a description of
parameters which are special inside completion widgets. Setting
reply to an empty array provides the default behaviour of trying
all tags at once; setting it to an array containing only a
hyphen disables the use of all tags and hence of all
completions.

If no tag-order style has been defined for a context, the
strings `(|*-)argument-* (|*-)option-* values' and `options'
plus all tags offered by the completion function will be used to
provide a sensible default behavior that causes arguments
(whether normal command arguments or arguments of options) to be
completed before option names for most commands.

urls This is used together with the urls tag by functions completing
URLs.

If the value consists of more than one string, or if the only
string does not name a file or directory, the strings are used
as the URLs to complete.

If the value contains only one string which is the name of a
normal file the URLs are taken from that file (where the URLs
may be separated by white space or newlines).

Finally, if the only string in the value names a directory, the
directory hierarchy rooted at this directory gives the
completions. The top level directory should be the file access
method, such as `http', `ftp', `bookmark' and so on. In many
cases the next level of directories will be a filename. The
directory hierarchy can descend as deep as necessary.

For example,

zstyle ':completion:*' urls ~/.urls
mkdir -p ~/.urls/ftp/ftp.zsh.org/pub

allows completion of all the components of the URL
ftp://ftp.zsh.org/pub after suitable commands such as `netscape'
or `lynx'. Note, however, that access methods and files are
completed separately, so if the hosts style is set hosts can be
completed without reference to the urls style.

See the description in the function _urls itself for more
information (e.g. `more $^fpath/_urls(N)').

use-cache
If this is set, the completion caching layer is activated for
any completions which use it (via the _store_cache,
_retrieve_cache, and _cache_invalid functions). The directory
containing the cache files can be changed with the cache-path
style.

use-compctl
If this style is set to a string not equal to false, 0, no, and
off, the completion system may use any completion specifications
defined with the compctl builtin command. If the style is
unset, this is done only if the zsh/compctl module is loaded.
The string may also contain the substring `first' to use
completions defined with `compctl -T', and the substring
`default' to use the completion defined with `compctl -D'.

Note that this is only intended to smooth the transition from
compctl to the new completion system and may disappear in the
future.

Note also that the definitions from compctl will only be used if
there is no specific completion function for the command in
question. For example, if there is a function _foo to complete
arguments to the command foo, compctl will never be invoked for
foo. However, the compctl version will be tried if foo only
uses default completion.

use-ip By default, the function _hosts that completes host names strips
IP addresses from entries read from host databases such as NIS
and ssh files. If this style is `true', the corresponding IP
addresses can be completed as well. This style is not use in
any context where the hosts style is set; note also it must be
set before the cache of host names is generated (typically the
first completion attempt).

users This may be set to a list of usernames to be completed. If it
is not set all usernames will be completed. Note that if it is
set only that list of users will be completed; this is because
on some systems querying all users can take a prohibitive amount
of time.

users-hosts
The values of this style should be of the form `user@host' or
`user:host'. It is used for commands that need pairs of user-
and hostnames. These commands will complete usernames from this
style (only), and will restrict subsequent hostname completion
to hosts paired with that user in one of the values of the
style.

It is possible to group values for sets of commands which allow
a remote login, such as rlogin and ssh, by using the my-accounts
tag. Similarly, values for sets of commands which usually refer
to the accounts of other people, such as talk and finger, can be
grouped by using the other-accounts tag. More ambivalent
commands may use the accounts tag.

users-hosts-ports
Like users-hosts but used for commands like telnet and
containing strings of the form `user@host:port'.

verbose
If set, as it is by default, the completion listing is more
verbose. In particular many commands show descriptions for
options if this style is `true'.

word This is used by the _list completer, which prevents the
insertion of completions until a second completion attempt when
the line has not changed. The normal way of finding out if the
line has changed is to compare its entire contents between the
two occasions. If this style is `true', the comparison is
instead performed only on the current word. Hence if completion
is performed on another word with the same contents, completion
will not be delayed.

CONTROL FUNCTIONS
The initialization script compinit redefines all the widgets which
perform completion to call the supplied widget function _main_complete.
This function acts as a wrapper calling the so-called `completer'
functions that generate matches. If _main_complete is called with
arguments, these are taken as the names of completer functions to be
called in the order given. If no arguments are given, the set of
functions to try is taken from the completer style. For example, to
use normal completion and correction if that doesn't generate any
matches:

zstyle ':completion:*' completer _complete _correct

after calling compinit. The default value for this style is `_complete
_ignored', i.e. normally only ordinary completion is tried, first with
the effect of the ignored-patterns style and then without it. The
_main_complete function uses the return status of the completer
functions to decide if other completers should be called. If the
return status is zero, no other completers are tried and the
_main_complete function returns.

If the first argument to _main_complete is a single hyphen, the
arguments will not be taken as names of completers. Instead, the
second argument gives a name to use in the completer field of the
context and the other arguments give a command name and arguments to
call to generate the matches.

The following completer functions are contained in the distribution,
although users may write their own. Note that in contexts the leading
underscore is stripped, for example basic completion is performed in
the context `:completion::complete:...'.

_all_matches
This completer can be used to add a string consisting of all
other matches. As it influences later completers it must appear
as the first completer in the list. The list of all matches is
affected by the avoid-completer and old-matches styles described
above.

It may be useful to use the _generic function described below to
bind _all_matches to its own keystroke, for example:

zle -C all-matches complete-word _generic
bindkey '^Xa' all-matches
zstyle ':completion:all-matches:*' old-matches only
zstyle ':completion:all-matches::::' completer _all_matches

Note that this does not generate completions by itself: first
use any of the standard ways of generating a list of
completions, then use ^Xa to show all matches. It is possible
instead to add a standard completer to the list and request that
the list of all matches should be directly inserted:

zstyle ':completion:all-matches::::' completer \
_all_matches _complete
zstyle ':completion:all-matches:*' insert true

In this case the old-matches style should not be set.

_approximate
This is similar to the basic _complete completer but allows the
completions to undergo corrections. The maximum number of
errors can be specified by the max-errors style; see the
description of approximate matching in zshexpn(1) for how errors
are counted. Normally this completer will only be tried after
the normal _complete completer:

zstyle ':completion:*' completer _complete _approximate

This will give correcting completion if and only if normal
completion yields no possible completions. When corrected
completions are found, the completer will normally start menu
completion allowing you to cycle through these strings.

This completer uses the tags corrections and original when
generating the possible corrections and the original string.
The format style for the former may contain the additional
sequences `%e' and `%o' which will be replaced by the number of
errors accepted to generate the corrections and the original
string, respectively.

The completer progressively increases the number of errors
allowed up to the limit by the max-errors style, hence if a
completion is found with one error, no completions with two
errors will be shown, and so on. It modifies the completer name
in the context to indicate the number of errors being tried: on
the first try the completer field contains `approximate-1', on
the second try `approximate-2', and so on.

When _approximate is called from another function, the number of
errors to accept may be passed with the -a option. The argument
is in the same format as the max-errors style, all in one
string.

Note that this completer (and the _correct completer mentioned
below) can be quite expensive to call, especially when a large
number of errors are allowed. One way to avoid this is to set
up the completer style using the -e option to zstyle so that
some completers are only used when completion is attempted a
second time on the same string, e.g.:

zstyle -e ':completion:*' completer '
if [[ $_last_try != "$HISTNO$BUFFER$CURSOR" ]]; then
_last_try="$HISTNO$BUFFER$CURSOR"
reply=(_complete _match _prefix)
else
reply=(_ignored _correct _approximate)
fi'

This uses the HISTNO parameter and the BUFFER and CURSOR special
parameters that are available inside zle and completion widgets
to find out if the command line hasn't changed since the last
time completion was tried. Only then are the _ignored, _correct
and _approximate completers called.

_canonical_paths [ -A var ] [ -N ] [ -MJV12nfX ] tag descr [ paths ...
] This completion function completes all paths given to it, and
also tries to offer completions which point to the same file as
one of the paths given (relative path when an absolute path is
given, and vice versa; when ..'s are present in the word to be
completed; and some paths got from symlinks).

-A, if specified, takes the paths from the array variable
specified. Paths can also be specified on the command line as
shown above. -N, if specified, prevents canonicalizing the
paths given before using them for completion, in case they are
already so. The options -M, -J, -V, -1, -2, -n, -F, -X are
passed to compadd.

See _description for a description of tag and descr.

_cmdambivalent
Completes the remaining positional arguments as an external
command. The external command and its arguments are completed
as separate arguments (in a manner appropriate for completing
/usr/bin/env) if there are two or more remaining positional
arguments on the command line, and as a quoted command string
(in the manner of system(...)) otherwise. See also _cmdstring
and _precommand.

This function takes no arguments.

_cmdstring
Completes an external command as a single argument, as for
system(...).

_complete
This completer generates all possible completions in a
context-sensitive manner, i.e. using the settings defined with
the compdef function explained above and the current settings of
all special parameters. This gives the normal completion
behaviour.

To complete arguments of commands, _complete uses the utility
function _normal, which is in turn responsible for finding the
particular function; it is described below. Various contexts of
the form -context- are handled specifically. These are all
mentioned above as possible arguments to the #compdef tag.

Before trying to find a function for a specific context,
_complete checks if the parameter `compcontext' is set. Setting
`compcontext' allows the usual completion dispatching to be
overridden which is useful in places such as a function that
uses vared for input. If it is set to an array, the elements are
taken to be the possible matches which will be completed using
the tag `values' and the description `value'. If it is set to an
associative array, the keys are used as the possible completions
and the values (if non-empty) are used as descriptions for the
matches. If `compcontext' is set to a string containing colons,
it should be of the form `tag:descr:action'. In this case the
tag and descr give the tag and description to use and the action
indicates what should be completed in one of the forms accepted
by the _arguments utility function described below.

Finally, if `compcontext' is set to a string without colons, the
value is taken as the name of the context to use and the
function defined for that context will be called. For this
purpose, there is a special context named -command-line- that
completes whole command lines (commands and their arguments).
This is not used by the completion system itself but is
nonetheless handled when explicitly called.

_correct
Generate corrections, but not completions, for the current word;
this is similar to _approximate but will not allow any number of
extra characters at the cursor as that completer does. The
effect is similar to spell-checking. It is based on
_approximate, but the completer field in the context name is
correct.

For example, with:

zstyle ':completion:::::' completer \
_complete _correct _approximate
zstyle ':completion:*:correct:::' max-errors 2 not-numeric
zstyle ':completion:*:approximate:::' max-errors 3 numeric

correction will accept up to two errors. If a numeric argument
is given, correction will not be performed, but correcting
completion will be, and will accept as many errors as given by
the numeric argument. Without a numeric argument, first
correction and then correcting completion will be tried, with
the first one accepting two errors and the second one accepting
three errors.

When _correct is called as a function, the number of errors to
accept may be given following the -a option. The argument is in
the same form a values to the accept style, all in one string.

This completer function is intended to be used without the
_approximate completer or, as in the example, just before it.
Using it after the _approximate completer is useless since
_approximate will at least generate the corrected strings
generated by the _correct completer -- and probably more.

_expand
This completer function does not really perform completion, but
instead checks if the word on the command line is eligible for
expansion and, if it is, gives detailed control over how this
expansion is done. For this to happen, the completion system
needs to be invoked with complete-word, not expand-or-complete
(the default binding for TAB), as otherwise the string will be
expanded by the shell's internal mechanism before the completion
system is started. Note also this completer should be called
before the _complete completer function.

The tags used when generating expansions are all-expansions for
the string containing all possible expansions, expansions when
adding the possible expansions as single matches and original
when adding the original string from the line. The order in
which these strings are generated, if at all, can be controlled
by the group-order and tag-order styles, as usual.

The format string for all-expansions and for expansions may
contain the sequence `%o' which will be replaced by the original
string from the line.

The kind of expansion to be tried is controlled by the
substitute, glob and subst-globs-only styles.

It is also possible to call _expand as a function, in which case
the different modes may be selected with options: -s for
substitute, -g for glob and -o for subst-globs-only.

_expand_alias
If the word the cursor is on is an alias, it is expanded and no
other completers are called. The types of aliases which are to
be expanded can be controlled with the styles regular, global
and disabled.

This function is also a bindable command, see the section
`Bindable Commands' below.

_extensions
If the cursor follows the string `*.', filename extensions are
completed. The extensions are taken from files in current
directory or a directory specified at the beginning of the
current word. For exact matches, completion continues to allow
other completers such as _expand to expand the pattern. The
standard add-space and prefix-hidden styles are observed.

_external_pwds
Completes current directories of other zsh processes belonging
to the current user.

This is intended to be used via _generic, bound to a custom key
combination. Note that pattern matching is enabled so matching
is performed similar to how it works with the _match completer.

_history
Complete words from the shell's command history. This
completer can be controlled by the remove-all-dups, and sort
styles as for the _history_complete_word bindable command, see
the section `Bindable Commands' below and the section
`Completion System Configuration' above.

_ignored
The ignored-patterns style can be set to a list of patterns
which are compared against possible completions; matching ones
are removed. With this completer those matches can be
reinstated, as if no ignored-patterns style were set. The
completer actually generates its own list of matches; which
completers are invoked is determined in the same way as for the
_prefix completer. The single-ignored style is also available
as described above.

_list This completer allows the insertion of matches to be delayed
until completion is attempted a second time without the word on
the line being changed. On the first attempt, only the list of
matches will be shown. It is affected by the styles condition
and word, see the section `Completion System Configuration'
above.

_match This completer is intended to be used after the _complete
completer. It behaves similarly but the string on the command
line may be a pattern to match against trial completions. This
gives the effect of the GLOB_COMPLETE option.

Normally completion will be performed by taking the pattern from
the line, inserting a `*' at the cursor position and comparing
the resulting pattern with the possible completions generated.
This can be modified with the match-original style described
above.

The generated matches will be offered in a menu completion
unless the insert-unambiguous style is set to `true'; see the
description above for other options for this style.

Note that matcher specifications defined globally or used by the
completion functions (the styles matcher-list and matcher) will
not be used.

_menu This completer was written as simple example function to show
how menu completion can be enabled in shell code. However, it
has the notable effect of disabling menu selection which can be
useful with _generic based widgets. It should be used as the
first completer in the list. Note that this is independent of
the setting of the MENU_COMPLETE option and does not work with
the other menu completion widgets such as reverse-menu-complete,
or accept-and-menu-complete.

_oldlist
This completer controls how the standard completion widgets
behave when there is an existing list of completions which may
have been generated by a special completion (i.e. a
separately-bound completion command). It allows the ordinary
completion keys to continue to use the list of completions thus
generated, instead of producing a new list of ordinary
contextual completions. It should appear in the list of
completers before any of the widgets which generate matches. It
uses two styles: old-list and old-menu, see the section
`Completion System Configuration' above.

_precommand
Complete an external command in word-separated arguments, as for
exec and /usr/bin/env.

_prefix
This completer can be used to try completion with the suffix
(everything after the cursor) ignored. In other words, the
suffix will not be considered to be part of the word to
complete. The effect is similar to the
expand-or-complete-prefix command.

The completer style is used to decide which other completers are
to be called to generate matches. If this style is unset, the
list of completers set for the current context is used --
except, of course, the _prefix completer itself. Furthermore,
if this completer appears more than once in the list of
completers only those completers not already tried by the last
invocation of _prefix will be called.

For example, consider this global completer style:

zstyle ':completion:*' completer \
_complete _prefix _correct _prefix:foo

Here, the _prefix completer tries normal completion but ignoring
the suffix. If that doesn't generate any matches, and neither
does the call to the _correct completer after it, _prefix will
be called a second time and, now only trying correction with the
suffix ignored. On the second invocation the completer part of
the context appears as `foo'.

To use _prefix as the last resort and try only normal completion
when it is invoked:

zstyle ':completion:*' completer _complete ... _prefix
zstyle ':completion::prefix:*' completer _complete

The add-space style is also respected. If it is set to `true'
then _prefix will insert a space between the matches generated
(if any) and the suffix.

Note that this completer is only useful if the COMPLETE_IN_WORD
option is set; otherwise, the cursor will be moved to the end of
the current word before the completion code is called and hence
there will be no suffix.

_user_expand
This completer behaves similarly to the _expand completer but
instead performs expansions defined by users. The styles
add-space and sort styles specific to the _expand completer are
usable with _user_expand in addition to other styles handled
more generally by the completion system. The tag all-expansions
is also available.

The expansion depends on the array style user-expand being
defined for the current context; remember that the context for
completers is less specific than that for contextual completion
as the full context has not yet been determined. Elements of
the array may have one of the following forms:

$hash

hash is the name of an associative array. Note this is
not a full parameter expression, merely a $, suitably
quoted to prevent immediate expansion, followed by the
name of an associative array. If the trial expansion
word matches a key in hash, the resulting expansion is
the corresponding value.
_func

_func is the name of a shell function whose name must
begin with _ but is not otherwise special to the
completion system. The function is called with the trial
word as an argument. If the word is to be expanded, the
function should set the array reply to a list of
expansions. Optionally, it can set REPLY to a word that
will be used as a description for the set of expansions.
The return status of the function is irrelevant.

BINDABLE COMMANDS
In addition to the context-dependent completions provided, which are
expected to work in an intuitively obvious way, there are a few widgets
implementing special behaviour which can be bound separately to keys.
The following is a list of these and their default bindings.

_bash_completions
This function is used by two widgets, _bash_complete-word and
_bash_list-choices. It exists to provide compatibility with
completion bindings in bash. The last character of the binding
determines what is completed: `!', command names; `$',
environment variables; `@', host names; `/', file names; `~'
user names. In bash, the binding preceded by `\e' gives
completion, and preceded by `^X' lists options. As some of
these bindings clash with standard zsh bindings, only `\e~' and
`^X~' are bound by default. To add the rest, the following
should be added to .zshrc after compinit has been run:

for key in '!' '$' '@' '/' '~'; do
bindkey "\e$key" _bash_complete-word
bindkey "^X$key" _bash_list-choices
done

This includes the bindings for `~' in case they were already
bound to something else; the completion code does not override
user bindings.

_correct_filename (^XC)
Correct the filename path at the cursor position. Allows up to
six errors in the name. Can also be called with an argument to
correct a filename path, independently of zle; the correction is
printed on standard output.

_correct_word (^Xc)
Performs correction of the current argument using the usual
contextual completions as possible choices. This stores the
string `correct-word' in the function field of the context name
and then calls the _correct completer.

_expand_alias (^Xa)
This function can be used as a completer and as a bindable
command. It expands the word the cursor is on if it is an
alias. The types of alias expanded can be controlled with the
styles regular, global and disabled.

When used as a bindable command there is one additional feature
that can be selected by setting the complete style to `true'.
In this case, if the word is not the name of an alias,
_expand_alias tries to complete the word to a full alias name
without expanding it. It leaves the cursor directly after the
completed word so that invoking _expand_alias once more will
expand the now-complete alias name.

_expand_word (^Xe)
Performs expansion on the current word: equivalent to the
standard expand-word command, but using the _expand completer.
Before calling it, the function field of the context is set to
`expand-word'.

_generic
This function is not defined as a widget and not bound by
default. However, it can be used to define a widget and will
then store the name of the widget in the function field of the
context and call the completion system. This allows custom
completion widgets with their own set of style settings to be
defined easily. For example, to define a widget that performs
normal completion and starts menu selection:

zle -C foo complete-word _generic
bindkey '...' foo
zstyle ':completion:foo:*' menu yes select=1

Note in particular that the completer style may be set for the
context in order to change the set of functions used to generate
possible matches. If _generic is called with arguments, those
are passed through to _main_complete as the list of completers
in place of those defined by the completer style.

_history_complete_word (\e/)
Complete words from the shell's command history. This uses the
list, remove-all-dups, sort, and stop styles.

_most_recent_file (^Xm)
Complete the name of the most recently modified file matching
the pattern on the command line (which may be blank). If given
a numeric argument N, complete the Nth most recently modified
file. Note the completion, if any, is always unique.

_next_tags (^Xn)
This command alters the set of matches used to that for the next
tag, or set of tags, either as given by the tag-order style or
as set by default; these matches would otherwise not be
available. Successive invocations of the command cycle through
all possible sets of tags.

_read_comp (^X^R)
Prompt the user for a string, and use that to perform completion
on the current word. There are two possibilities for the
string. First, it can be a set of words beginning `_', for
example `_files -/', in which case the function with any
arguments will be called to generate the completions.
Unambiguous parts of the function name will be completed
automatically (normal completion is not available at this point)
until a space is typed.

Second, any other string will be passed as a set of arguments to
compadd and should hence be an expression specifying what should
be completed.

A very restricted set of editing commands is available when
reading the string: `DEL' and `^H' delete the last character;
`^U' deletes the line, and `^C' and `^G' abort the function,
while `RET' accepts the completion. Note the string is used
verbatim as a command line, so arguments must be quoted in
accordance with standard shell rules.

Once a string has been read, the next call to _read_comp will
use the existing string instead of reading a new one. To force
a new string to be read, call _read_comp with a numeric
argument.

_complete_debug (^X?)
This widget performs ordinary completion, but captures in a
temporary file a trace of the shell commands executed by the
completion system. Each completion attempt gets its own file.
A command to view each of these files is pushed onto the editor
buffer stack.

_complete_help (^Xh)
This widget displays information about the context names, the
tags, and the completion functions used when completing at the
current cursor position. If given a numeric argument other than
1 (as in `ESC-2 ^Xh'), then the styles used and the contexts for
which they are used will be shown, too.

Note that the information about styles may be incomplete; it
depends on the information available from the completion
functions called, which in turn is determined by the user's own
styles and other settings.

_complete_help_generic
Unlike other commands listed here, this must be created as a
normal ZLE widget rather than a completion widget (i.e. with zle
-N). It is used for generating help with a widget bound to the
_generic widget that is described above.

If this widget is created using the name of the function, as it
is by default, then when executed it will read a key sequence.
This is expected to be bound to a call to a completion function
that uses the _generic widget. That widget will be executed,
and information provided in the same format that the
_complete_help widget displays for contextual completion.

If the widget's name contains debug, for example if it is
created as `zle -N _complete_debug_generic
_complete_help_generic', it will read and execute the keystring
for a generic widget as before, but then generate debugging
information as done by _complete_debug for contextual
completion.

If the widget's name contains noread, it will not read a
keystring but instead arrange that the next use of a generic
widget run in the same shell will have the effect as described
above.

The widget works by setting the shell parameter
ZSH_TRACE_GENERIC_WIDGET which is read by _generic. Unsetting
the parameter cancels any pending effect of the noread form.

For example, after executing the following:

zle -N _complete_debug_generic _complete_help_generic
bindkey '^x:' _complete_debug_generic

typing `C-x :' followed by the key sequence for a generic widget
will cause trace output for that widget to be saved to a file.

_complete_tag (^Xt)
This widget completes symbol tags created by the etags or ctags
programmes (note there is no connection with the completion
system's tags) stored in a file TAGS, in the format used by
etags, or tags, in the format created by ctags. It will look
back up the path hierarchy for the first occurrence of either
file; if both exist, the file TAGS is preferred. You can
specify the full path to a TAGS or tags file by setting the
parameter $TAGSFILE or $tagsfile respectively. The
corresponding completion tags used are etags and vtags, after
emacs and vi respectively.

UTILITY FUNCTIONS
Descriptions follow for utility functions that may be useful when
writing completion functions. If functions are installed in
subdirectories, most of these reside in the Base subdirectory. Like
the example functions for commands in the distribution, the utility
functions generating matches all follow the convention of returning
status zero if they generated completions and non-zero if no matching
completions could be added.

_absolute_command_paths
This function completes external commands as absolute paths
(unlike _command_names -e which completes their basenames). It
takes no arguments.

_all_labels [ -x ] [ -12VJ ] tag name descr [ command arg ... ]
This is a convenient interface to the _next_label function
below, implementing the loop shown in the _next_label example.
The command and its arguments are called to generate the
matches. The options stored in the parameter name will
automatically be inserted into the args passed to the command.
Normally, they are put directly after the command, but if one of
the args is a single hyphen, they are inserted directly before
that. If the hyphen is the last argument, it will be removed
from the argument list before the command is called. This
allows _all_labels to be used in almost all cases where the
matches can be generated by a single call to the compadd builtin
command or by a call to one of the utility functions.

For example:

local expl
...
if _requested foo; then
...
_all_labels foo expl '...' compadd ... - $matches
fi

Will complete the strings from the matches parameter, using
compadd with additional options which will take precedence over
those generated by _all_labels.

_alternative [ -O name ] [ -C name ] spec ...
This function is useful in simple cases where multiple tags are
available. Essentially it implements a loop like the one
described for the _tags function below.

The tags to use and the action to perform if a tag is requested
are described using the specs which are of the form:
`tag:descr:action'. The tags are offered using _tags and if the
tag is requested, the action is executed with the given
description descr. The actions are those accepted by the
_arguments function (described below), with the following
exceptions:
o The `->state' and `=...' forms are not supported.

o The `((a\:bar b\:baz))' form does not need the colon to
be escaped, since the specs have no colon-separated
fields after the action.

For example, the action may be a simple function call:

_alternative \
'users:user:_users' \
'hosts:host:_hosts'

offers usernames and hostnames as possible matches, generated by
the _users and _hosts functions respectively.

Like _arguments, this function uses _all_labels to execute the
actions, which will loop over all sets of tags. Special
handling is only required if there is an additional valid tag,
for example inside a function called from _alternative.

The option `-O name' is used in the same way as by the
_arguments function. In other words, the elements of the name
array will be passed to compadd when executing an action.

Like _tags this function supports the -C option to give a
different name for the argument context field.

_arguments [ -nswWCRS ] [ -A pat ] [ -O name ] [ -M matchspec ]
[ : ] spec ...
_arguments [ opt ... ] -- [ -l ] [ -i pats ] [ -s pair ]
[ helpspec ...]
This function can be used to give a complete specification for
completion for a command whose arguments follow standard UNIX
option and argument conventions.

Options Overview

Options to _arguments itself must be in separate words, i.e. -s
-w, not -sw. The options are followed by specs that describe
options and arguments of the analyzed command. To avoid
ambiguity, all options to _arguments itself may be separated
from the spec forms by a single colon.

The `--' form is used to intuit spec forms from the help output
of the command being analyzed, and is described in detail below.
The opts for the `--' form are otherwise the same options as the
first form. Note that `-s' following `--' has a distinct
meaning from `-s' preceding `--', and both may appear.

The option switches -s, -S, -A, -w, and -W affect how _arguments
parses the analyzed command line's options. These switches are
useful for commands with standard argument parsing.

The options of _arguments have the following meanings:

-n With this option, _arguments sets the parameter NORMARG
to the position of the first normal argument in the
$words array, i.e. the position after the end of the
options. If that argument has not been reached, NORMARG
is set to -1. The caller should declare `integer
NORMARG' if the -n option is passed; otherwise the
parameter is not used.

-s Enable option stacking for single-letter options, whereby
multiple single-letter options may be combined into a
single word. For example, the two options `-x' and `-y'
may be combined into a single word `-xy'. By default,
every word corresponds to a single option name (`-xy' is
a single option named `xy').

Options beginning with a single hyphen or plus sign are
eligible for stacking; words beginning with two hyphens
are not.

Note that -s after -- has a different meaning, which is
documented in the segment entitled `Deriving spec forms
from the help output'.

-w In combination with -s, allow option stacking even if one
or more of the options take arguments. For example, if
-x takes an argument, with no -s, `-xy' is considered as
a single (unhandled) option; with -s, -xy is an option
with the argument `y'; with both -s and -w, -xy is the
option -x and the option -y with arguments to -x (and to
-y, if it takes arguments) still to come in subsequent
words.

-W This option takes -w a stage further: it is possible to
complete single-letter options even after an argument
that occurs in the same word. However, it depends on the
action performed whether options will really be completed
at this point. For more control, use a utility function
like _guard as part of the action.

-C Modify the curcontext parameter for an action of the form
`->state'. This is discussed in detail below.

-R Return status 300 instead of zero when a $state is to be
handled, in the `->string' syntax.

-S Do not complete options after a `--' appearing on the
line, and ignore the `--'. For example, with -S, in the
line

foobar -x -- -y

the `-x' is considered an option, the `-y' is considered
an argument, and the `--' is considered to be neither.

-A pat Do not complete options after the first non-option
argument on the line. pat is a pattern matching all
strings which are not to be taken as arguments. For
example, to make _arguments stop completing options after
the first normal argument, but ignoring all strings
starting with a hyphen even if they are not described by
one of the optspecs, the form is `-A "-*"'.

-O name
Pass the elements of the array name as arguments to
functions called to execute actions. This is discussed
in detail below.

-M matchspec
Use the match specification matchspec for completing
option names and values. The default matchspec allows
partial word completion after `_' and `-', such as
completing `-f-b' to `-foo-bar'. The default matchspec
is:
r:|[_-]=* r:|=*

-0 When populating values of the `opt_args' associative
array, don't backslash-escape colons and backslashes and
use NUL rather than colon for joining multiple values.
This option is described in more detail below, under the
heading specs: actions.

specs: overview

Each of the following forms is a spec describing individual sets
of options or arguments on the command line being analyzed.

n:message:action
n::message:action
This describes the n'th normal argument. The message
will be printed above the matches generated and the
action indicates what can be completed in this position
(see below). If there are two colons before the message
the argument is optional. If the message contains only
white space, nothing will be printed above the matches
unless the action adds an explanation string itself.

:message:action
::message:action
Similar, but describes the next argument, whatever number
that happens to be. If all arguments are specified in
this form in the correct order the numbers are
unnecessary.

*:message:action
*::message:action
*:::message:action
This describes how arguments (usually non-option
arguments, those not beginning with - or *) are to be
completed when neither of the first two forms was
provided. Any number of arguments can be completed in
this fashion.

With two colons before the message, the words special
array and the CURRENT special parameter are modified to
refer only to the normal arguments when the action is
executed or evaluated. With three colons before the
message they are modified to refer only to the normal
arguments covered by this description.

optspec
optspec:...
This describes an option. The colon indicates handling
for one or more arguments to the option; if it is not
present, the option is assumed to take no arguments.

The following forms are available for the initial
optspec, whether or not the option has arguments.

*optspec
Here optspec is one of the remaining forms below.
This indicates the following optspec may be
repeated. Otherwise if the corresponding option
is already present on the command line to the left
of the cursor it will not be offered again.

-optname
*optname
In the simplest form the optspec is just the
option name beginning with a minus or a plus sign,
such as `-foo'. The first argument for the option
(if any) must follow as a separate word directly
after the option.

Either of `-+optname' and `+-optname' can be used
to specify that -optname and *optname are both
valid.

In all the remaining forms, the leading `-' may be
replaced by or paired with `*' in this way.

-optname-
The first argument of the option must come
directly after the option name in the same word.
For example, `-foo-:...' specifies that the
completed option and argument will look like
`-fooarg'.

-optname*
The first argument may appear immediately after
optname in the same word, or may appear as a
separate word after the option. For example,
`-foo+:...' specifies that the completed option
and argument will look like either `-fooarg' or
`-foo arg'.

-optname=
The argument may appear as the next word, or in
same word as the option name provided that it is
separated from it by an equals sign, for example
`-foo=arg' or `-foo arg'.

-optname=-
The argument to the option must appear after an
equals sign in the same word, and may not be given
in the next argument.

optspec[explanation]
An explanation string may be appended to any of
the preceding forms of optspec by enclosing it in
brackets, as in `-q[query operation]'.

The verbose style is used to decide whether the
explanation strings are displayed with the option
in a completion listing.

If no bracketed explanation string is given but
the auto-description style is set and only one
argument is described for this optspec, the value
of the style is displayed, with any appearance of
the sequence `%d' in it replaced by the message of
the first optarg that follows the optspec; see
below.

It is possible for options with a literal `*' or `=' to
appear, but that character must be quoted, for example
`-\+'.

Each optarg following an optspec must take one of the
following forms:

:message:action
::message:action
An argument to the option; message and action are
treated as for ordinary arguments. In the first
form, the argument is mandatory, and in the second
form it is optional.

This group may be repeated for options which take
multiple arguments. In other words,
:message1:action1:message2:action2 specifies that
the option takes two arguments.

:*pattern:message:action
:*pattern::message:action
:*pattern:::message:action
This describes multiple arguments. Only the last
optarg for an option taking multiple arguments may
be given in this form. If the pattern is empty
(i.e. :*:), all the remaining words on the line
are to be completed as described by the action;
otherwise, all the words up to and including a
word matching the pattern are to be completed
using the action.

Multiple colons are treated as for the `*:...'
forms for ordinary arguments: when the message is
preceded by two colons, the words special array
and the CURRENT special parameter are modified
during the execution or evaluation of the action
to refer only to the words after the option. When
preceded by three colons, they are modified to
refer only to the words covered by this
description.

Any literal colon in an optname, message, or action must be
preceded by a backslash, `\:'.

Each of the forms above may be preceded by a list in parentheses
of option names and argument numbers. If the given option is on
the command line, the options and arguments indicated in
parentheses will not be offered. For example, `(-two -three
1)-one:...' completes the option `-one'; if this appears on the
command line, the options -two and -three and the first ordinary
argument will not be completed after it. `(-foo):...' specifies
an ordinary argument completion; -foo will not be completed if
that argument is already present.

Other items may appear in the list of excluded options to
indicate various other items that should not be applied when the
current specification is matched: a single star (*) for the rest
arguments (i.e. a specification of the form `*:...'); a colon
(:) for all normal (non-option-) arguments; and a hyphen (-) for
all options. For example, if `(*)' appears before an option and
the option appears on the command line, the list of remaining
arguments (those shown in the above table beginning with `*:')
will not be completed.

To aid in reuse of specifications, it is possible to precede any
of the forms above with `!'; then the form will no longer be
completed, although if the option or argument appears on the
command line they will be skipped as normal. The main use for
this is when the arguments are given by an array, and _arguments
is called repeatedly for more specific contexts: on the first
call `_arguments $global_options' is used, and on subsequent
calls `_arguments !$^global_options'.

specs: actions

In each of the forms above the action determines how completions
should be generated. Except for the `->string' form below, the
action will be executed by calling the _all_labels function to
process all tag labels. No special handling of tags is needed
unless a function call introduces a new one.

The functions called to execute actions will be called with the
elements of the array named by the `-O name' option as
arguments. This can be used, for example, to pass the same set
of options for the compadd builtin to all actions.

The forms for action are as follows.

(single unquoted space)
This is useful where an argument is required but it is
not possible or desirable to generate matches for it.
The message will be displayed but no completions listed.
Note that even in this case the colon at the end of the
message is needed; it may only be omitted when neither a
message nor an action is given.

(item1 item2 ...)
One of a list of possible matches, for example:

:foo:(foo bar baz)

((item1\:desc1 ...))
Similar to the above, but with descriptions for each
possible match. Note the backslash before the colon.
For example,

:foo:((a\:bar b\:baz))

The matches will be listed together with their
descriptions if the description style is set with the
values tag in the context.

->string
In this form, _arguments processes the arguments and
options and then returns control to the calling function
with parameters set to indicate the state of processing;
the calling function then makes its own arrangements for
generating completions. For example, functions that
implement a state machine can use this type of action.

Where _arguments encounters action in the `->string'
format, it will strip all leading and trailing whitespace
from string and set the array state to the set of all
strings for which an action is to be performed. The
elements of the array state_descr are assigned the
corresponding message field from each optarg containing
such an action.

By default and in common with all other well behaved
completion functions, _arguments returns status zero if
it was able to add matches and non-zero otherwise.
However, if the -R option is given, _arguments will
instead return a status of 300 to indicate that $state is
to be handled.

In addition to $state and $state_descr, _arguments also
sets the global parameters `context', `line' and
`opt_args' as described below, and does not reset any
changes made to the special parameters such as PREFIX and
words. This gives the calling function the choice of
resetting these parameters or propagating changes in
them.

A function calling _arguments with at least one action
containing a `->string' must therefore declare
appropriate local parameters:

local context state state_descr line
typeset -A opt_args

to prevent _arguments from altering the global
environment.

{eval-string}
A string in braces is evaluated as shell code to generate
matches. If the eval-string itself does not begin with
an opening parenthesis or brace it is split into separate
words before execution.

= action
If the action starts with `= ' (an equals sign followed
by a space), _arguments will insert the contents of the
argument field of the current context as the new first
element in the words special array and increment the
value of the CURRENT special parameter. This has the
effect of inserting a dummy word onto the completion
command line while not changing the point at which
completion is taking place.

This is most useful with one of the specifiers that
restrict the words on the command line on which the
action is to operate (the two- and three-colon forms
above). One particular use is when an action itself
causes _arguments on a restricted range; it is necessary
to use this trick to insert an appropriate command name
into the range for the second call to _arguments to be
able to parse the line.

word...
word...
This covers all forms other than those above. If the
action starts with a space, the remaining list of words
will be invoked unchanged.

Otherwise it will be invoked with some extra strings
placed after the first word; these are to be passed down
as options to the compadd builtin. They ensure that the
state specified by _arguments, in particular the
descriptions of options and arguments, is correctly
passed to the completion command. These additional
arguments are taken from the array parameter `expl'; this
will be set up before executing the action and hence may
be referred to inside it, typically in an expansion of
the form `$expl[@]' which preserves empty elements of the
array.

During the performance of the action the array `line' will be
set to the normal arguments from the command line, i.e. the
words from the command line after the command name excluding all
options and their arguments. Options are stored in the
associative array `opt_args' with option names as keys and their
arguments as the values. By default, all colons and backslashes
in the value are escaped with backslashes, and if an option has
multiple arguments (for example, when using an optspec of the
form `*optspec'), they are joined with (unescaped) colons.
However, if the -0 option was passed, no backslash escaping is
performed, and multiple values are joined with NUL bytes. For
example, after `zsh -o foo:foo -o bar:bar -o <TAB>', the
contents of `opt_args' would be

typeset -A opt_args=( [-o]='foo\:foo:bar\:bar:' )

by default, and

typeset -A opt_args=( [-o]=$'foo:foo\x00bar:bar\x00' )

if _arguments had been called with the -0 option.

The parameter `context' is set when returning to the calling
function to perform an action of the form `->string'. It is set
to an array of elements corresponding to the elements of $state.
Each element is a suitable name for the argument field of the
context: either a string of the form `option-opt-n' for the n'th
argument of the option -opt, or a string of the form
`argument-n' for the n'th argument. For `rest' arguments, that
is those in the list at the end not handled by position, n is
the string `rest'. For example, when completing the argument of
the -o option, the name is `option-o-1', while for the second
normal (non-option-) argument it is `argument-2'.

Furthermore, during the evaluation of the action the context
name in the curcontext parameter is altered to append the same
string that is stored in the context parameter.

The option -C tells _arguments to modify the curcontext
parameter for an action of the form `->state'. This is the
standard parameter used to keep track of the current context.
Here it (and not the context array) should be made local to the
calling function to avoid passing back the modified value and
should be initialised to the current value at the start of the
function:

local curcontext="$curcontext"

This is useful where it is not possible for multiple states to
be valid together.

Grouping Options

Options can be grouped to simplify exclusion lists. A group is
introduced with `*' followed by a name for the group in the
subsequent word. Whole groups can then be referenced in an
exclusion list or a group name can be used to disambiguate
between two forms of the same option. For example:

_arguments \
'(group2--x)-a' \
* group1 \
-m \
'(group2)-n' \
* group2 \
-x -y

If the name of a group is specified in the form `(name)' then
only one value from that group will ever be completed; more
formally, all specifications are mutually exclusive to all other
specifications in that group. This is useful for defining
options that are aliases for each other. For example:

_arguments \
-a -b \
* '(operation)' \
{-c,--compress}'[compress]' \
{-d,--decompress}'[decompress]' \
{-l,--list}'[list]'

If an option in a group appears on the command line, it is
stored in the associative array `opt_args' with 'group-option'
as a key. In the example above, a key `operation--c' is used if
the option `-c' is present on the command line.

Specifying Multiple Sets of Arguments

It is possible to specify multiple sets of options and arguments
with the sets separated by single hyphens. This differs from
groups in that sets are considered to be mutually exclusive of
each other.

Specifications before the first set and from any group are
common to all sets. For example:

_arguments \
-a \
- set1 \
-c \
- set2 \
-d \
':arg:(x2 y2)'

This defines two sets. When the command line contains the
option `-c', the `-d' option and the argument will not be
considered possible completions. When it contains `-d' or an
argument, the option `-c' will not be considered. However,
after `-a' both sets will still be considered valid.

As for groups, the name of a set may appear in exclusion lists,
either alone or preceding a normal option or argument
specification.

The completion code has to parse the command line separately for
each set. This can be slow so sets should only be used when
necessary. A useful alternative is often an option
specification with rest-arguments (as in `-foo:*:...'); here the
option -foo swallows up all remaining arguments as described by
the optarg definitions.

Deriving spec forms from the help output

The option `--' allows _arguments to work out the names of long
options that support the `--help' option which is standard in
many GNU commands. The command word is called with the argument
`--help' and the output examined for option names. Clearly, it
can be dangerous to pass this to commands which may not support
this option as the behaviour of the command is unspecified.

In addition to options, `_arguments --' will try to deduce the
types of arguments available for options when the form
`--opt=val' is valid. It is also possible to provide hints by
examining the help text of the command and adding helpspec of
the form `pattern:message:action'; note that other _arguments
spec forms are not used. The pattern is matched against the
help text for an option, and if it matches the message and
action are used as for other argument specifiers. The special
case of `*:' means both message and action are empty, which has
the effect of causing options having no description in the help
output to be ordered in listings ahead of options that have a
description.

For example:

_arguments -- '*\*:toggle:(yes no)' \
'*=FILE*:file:_files' \
'*=DIR*:directory:_files -/' \
'*=PATH*:directory:_files -/'

Here, `yes' and `no' will be completed as the argument of
options whose description ends in a star; file names will be
completed for options that contain the substring `=FILE' in the
description; and directories will be completed for options whose
description contains `=DIR' or `=PATH'. The last three are in
fact the default and so need not be given explicitly, although
it is possible to override the use of these patterns. A typical
help text which uses this feature is:

-C, --directory=DIR change to directory DIR

so that the above specifications will cause directories to be
completed after `--directory', though not after `-C'.

Note also that _arguments tries to find out automatically if the
argument for an option is optional. This can be specified
explicitly by doubling the colon before the message.

If the pattern ends in `(-)', this will be removed from the
pattern and the action will be used only directly after the `=',
not in the next word. This is the behaviour of a normal
specification defined with the form `=-'.

By default, the command (with the option `--help') is run after
resetting all the locale categories (except for LC_CTYPE) to
`C'. If the localized help output is known to work, the option
`-l' can be specified after the `_arguments --' so that the
command is run in the current locale.

The `_arguments --' can be followed by the option `-i patterns'
to give patterns for options which are not to be completed. The
patterns can be given as the name of an array parameter or as a
literal list in parentheses. For example,

_arguments -- -i \
"(--(en|dis)able-FEATURE*)"

will cause completion to ignore the options `--enable-FEATURE'
and `--disable-FEATURE' (this example is useful with GNU
configure).

The `_arguments --' form can also be followed by the option `-s
pair' to describe option aliases. The pair consists of a list
of alternating patterns and corresponding replacements, enclosed
in parens and quoted so that it forms a single argument word in
the _arguments call.

For example, some configure-script help output describes options
only as `--enable-foo', but the script also accepts the negated
form `--disable-foo'. To allow completion of the second form:

_arguments -- -s "((#s)--enable- --disable-)"

Miscellaneous notes

Finally, note that _arguments generally expects to be the
primary function handling any completion for which it is used.
It may have side effects which change the treatment of any
matches added by other functions called after it. To combine
_arguments with other functions, those functions should be
called either before _arguments, as an action within a spec, or
in handlers for `->state' actions.

Here is a more general example of the use of _arguments:

_arguments '-l+:left border:' \
'-format:paper size:(letter A4)' \
'*-copy:output file:_files::resolution:(300 600)' \
':postscript file:_files -g \*.$ps\|eps$' \
'*:page number:'

This describes three options: `-l', `-format', and `-copy'. The
first takes one argument described as `left border' for which no
completion will be offered because of the empty action. Its
argument may come directly after the `-l' or it may be given as
the next word on the line.

The `-format' option takes one argument in the next word,
described as `paper size' for which only the strings `letter'
and `A4' will be completed.

The `-copy' option may appear more than once on the command line
and takes two arguments. The first is mandatory and will be
completed as a filename. The second is optional (because of the
second colon before the description `resolution') and will be
completed from the strings `300' and `600'.

The last two descriptions say what should be completed as
arguments. The first describes the first argument as a
`postscript file' and makes files ending in `ps' or `eps' be
completed. The last description gives all other arguments the
description `page number' but does not offer completions.

_cache_invalid cache_identifier
This function returns status zero if the completions cache
corresponding to the given cache identifier needs rebuilding.
It determines this by looking up the cache-policy style for the
current context. This should provide a function name which is
run with the full path to the relevant cache file as the only
argument.

Example:

_example_caching_policy () {
# rebuild if cache is more than a week old
local -a oldp
oldp=( "$1"(Nm+7) )
(( $#oldp ))
}

_call_function return name [ arg ... ]
If a function name exists, it is called with the arguments args.
The return argument gives the name of a parameter in which the
return status from the function name should be stored; if return
is empty or a single hyphen it is ignored.

The return status of _call_function itself is zero if the
function name exists and was called and non-zero otherwise.

_call_program [ -l ] [ -p ] tag string ...
This function provides a mechanism for the user to override the
use of an external command. It looks up the command style with
the supplied tag. If the style is set, its value is used as the
command to execute. The strings from the call to _call_program,
or from the style if set, are concatenated with spaces between
them and the resulting string is evaluated. The return status
is the return status of the command called.

By default, the command is run in an environment where all the
locale categories (except for LC_CTYPE) are reset to `C' by
calling the utility function _comp_locale (see below). If the
option `-l' is given, the command is run with the current
locale.

If the option `-p' is supplied it indicates that the command
output is influenced by the permissions it is run with. If the
gain-privileges style is set to true, _call_program will make
use of commands such as sudo, if present on the command-line, to
match the permissions to whatever the final command is likely to
run under. When looking up the gain-privileges and command
styles, the command component of the zstyle context will end
with a slash (`/') followed by the command that would be used to
gain privileges.

_combination [ -s pattern ] tag style spec ... field opts ...
This function is used to complete combinations of values, for
example pairs of hostnames and usernames. The style argument
gives the style which defines the pairs; it is looked up in a
context with the tag specified.

The style name consists of field names separated by hyphens, for
example `users-hosts-ports'. For each field for a value is
already known, a spec of the form `field=pattern' is given. For
example, if the command line so far specifies a user `pws', the
argument `users=pws' should appear.

The next argument with no equals sign is taken as the name of
the field for which completions should be generated (presumably
not one of the fields for which the value is known).

The matches generated will be taken from the value of the style.
These should contain the possible values for the combinations in
the appropriate order (users, hosts, ports in the example
above). The values for the different fields are separated by
colons. This can be altered with the option -s to _combination
which specifies a pattern. Typically this is a character class,
as for example `-s "[:@]"' in the case of the users-hosts style.
Each `field=pattern' specification restricts the completions
which apply to elements of the style with appropriately matching
fields.

If no style with the given name is defined for the given tag, or
if none of the strings in style's value match, but a function
name of the required field preceded by an underscore is defined,
that function will be called to generate the matches. For
example, if there is no `users-hosts-ports' or no matching
hostname when a host is required, the function `_hosts' will
automatically be called.

If the same name is used for more than one field, in both the
`field=pattern' and the argument that gives the name of the
field to be completed, the number of the field (starting with
one) may be given after the fieldname, separated from it by a
colon.

All arguments after the required field name are passed to
compadd when generating matches from the style value, or to the
functions for the fields if they are called.

_command_names [ -e | - ]
This function completes words that are valid at command
position: names of aliases, builtins, hashed commands,
functions, and so on. With the -e flag, only hashed commands
are completed. The - flag is ignored.

_comp_locale
This function resets all the locale categories other than
LC_CTYPE to `C' so that the output from external commands can be
easily analyzed by the completion system. LC_CTYPE retains the
current value (taking LC_ALL and LANG into account), ensuring
that non-ASCII characters in file names are still handled
properly.

This function should normally be run only in a subshell, because
the new locale is exported to the environment. Typical usage
would be `$(_comp_locale; command ...)'.

_completers [ -p ]
This function completes names of completers.

-p Include the leading underscore (`_') in the matches.

_default
This function corresponds to the -default- special context which
is applied where no completion is defined. It is useful to call
it under certain error conditions such as completion after an
unrecognised subcommand. This applies the concept of graceful
degradation to the completion system, allowing it to fallback on
basic completion of commonly useful things like filenames.

_describe [-12JVx] [ -oO | -t tag ] descr name1 [ name2 ] [ opt ... ]
[ -- name1 [ name2 ] [ opt ... ] ... ]
This function associates completions with descriptions.
Multiple groups separated by -- can be supplied, potentially
with different completion options opts.

The descr is taken as a string to display above the matches if
the format style for the descriptions tag is set. This is
followed by one or two names of arrays followed by options to
pass to compadd. The array name1 contains the possible
completions with their descriptions in the form
`completion:description'. Any literal colons in completion must
be quoted with a backslash. If a name2 is given, it should have
the same number of elements as name1; in this case the
corresponding elements are added as possible completions instead
of the completion strings from name1. The completion list will
retain the descriptions from name1. Finally, a set of
completion options can appear.

If the option `-o' appears before the first argument, the
matches added will be treated as names of command options (N.B.
not shell options), typically following a `-', `--' or `*' on
the command line. In this case _describe uses the
prefix-hidden, prefix-needed and verbose styles to find out if
the strings should be added as completions and if the
descriptions should be shown. Without the `-o' option, only the
verbose style is used to decide how descriptions are shown. If
`-O' is used instead of `-o', command options are completed as
above but _describe will not handle the prefix-needed style.

With the -t option a tag can be specified. The default is
`values' or, if the -o option is given, `options'.

The options -1, -2, -J, -V, -x are passed to _next_label.

If selected by the list-grouped style, strings with the same
description will appear together in the list.

_describe uses the _all_labels function to generate the matches,
so it does not need to appear inside a loop over tag labels.

_description [ -x ] [ -12VJ ] tag name descr [ spec ... ]
This function is not to be confused with the previous one; it is
used as a helper function for creating options to compadd. It
is buried inside many of the higher level completion functions
and so often does not need to be called directly.

The styles listed below are tested in the current context using
the given tag. The resulting options for compadd are put into
the array named name (this is traditionally `expl', but this
convention is not enforced). The description for the
corresponding set of matches is passed to the function in descr.

The styles tested are: format, hidden, matcher, ignore-line,
ignored-patterns, group-name and sort. The format style is
first tested for the given tag and then for the descriptions tag
if no value was found, while the remainder are only tested for
the tag given as the first argument. The function also calls
_setup which tests some more styles.

The string returned by the format style (if any) will be
modified so that the sequence `%d' is replaced by the descr
given as the third argument without any leading or trailing
white space. If, after removing the white space, the descr is
the empty string, the format style will not be used and the
options put into the name array will not contain an explanation
string to be displayed above the matches.

If _description is called with more than three arguments, the
additional specs should be of the form `char:str'. These supply
escape sequence replacements for the format style: every
appearance of `%char' will be replaced by string. If no
additional specs are given but the description in descr conforms
to a common form then further escape sequences are set for
elements of that description. These elements correspond to a
default value (`%o'), the units (`%m') range of acceptable
values (`%r') and the remaining initial part of the description
(`%h'). The form the description takes consists of specifying
the units and range in parentheses and the default value in
square brackets, for example:

_description times expl 'timeout (seconds) (0-60) [20]'

It is possible to use zformat conditional expressions when
styling these elements. So, for example, to add `default:' as a
tag but only when there is a default value to show, the format
style might include `%(o.default: %o.)'.

If the -x option is given, the description will be passed to
compadd using the -x option instead of the default -X. This
means that the description will be displayed even if there are
no corresponding matches.

The options placed in the array name take account of the
group-name style, so matches are placed in a separate group
where necessary. The group normally has its elements sorted (by
passing the option -J to compadd), but if an option starting
with `-V', `-J', `-1', or `-2' is passed to _description, that
option will be included in the array. Hence it is possible for
the completion group to be unsorted by giving the option `-V',
`-1V', or `-2V'.

In most cases, the function will be used like this:

local expl
_description files expl file
compadd "$expl[@]" - "$files[@]"

Note the use of the parameter expl, the hyphen, and the list of
matches. Almost all calls to compadd within the completion
system use a similar format; this ensures that user-specified
styles are correctly passed down to the builtins which implement
the internals of completion.

_dir_list [ -s sep ] [ -S ]
Complete a list of directory names separated by colons (the same
format as $PATH).

-s sep Use sep as separator between items. sep defaults to a
colon (`:').

-S Add sep instead of slash (`/') as an autoremoveable
suffix.

_dispatch context string ...
This sets the current context to context and looks for
completion functions to handle this context by hunting through
the list of command names or special contexts (as described
above for compdef) given as strings. The first completion
function to be defined for one of the contexts in the list is
used to generate matches. Typically, the last string is
-default- to cause the function for default completion to be
used as a fallback.

The function sets the parameter $service to the string being
tried, and sets the context/command field (the fourth) of the
$curcontext parameter to the context given as the first
argument.

_email_addresses [ -c ] [ -n plugin ]
Complete email addresses. Addresses are provided by plugins.

-c Complete bare localhost@domain.tld addresses, without a
name part or a comment. Without this option, RFC822
`Firstname Lastname <address>' strings are completed.

-n plugin
Complete aliases from plugin.

The following plugins are available by default: _email-ldap (see
the filter style), _email-local (completes user@hostname Unix
addresses), _email-mail (completes aliases from ~/.mailrc),
_email-mush, _email-mutt, and _email-pine.

Addresses from the _email-foo plugin are added under the tag
`email-foo'.

Writing plugins

Plugins are written as separate functions with names starting
with `_email-'. They are invoked with the -c option and compadd
options. They should either do their own completion or set the
$reply array to a list of `alias:address' elements and return
300. New plugins will be picked up and run automatically.

_files The function _files is a wrapper around _path_files. It supports
all of the same functionality, with some enhancements --
notably, it respects the list-dirs-first style, and it allows
users to override the behaviour of the -g and -/ options with
the file-patterns style. _files should therefore be preferred
over _path_files in most cases.

This function accepts the full set of options allowed by
_path_files, described below.

_gnu_generic
This function is a simple wrapper around the _arguments function
described above. It can be used to determine automatically the
long options understood by commands that produce a list when
passed the option `--help'. It is intended to be used as a
top-level completion function in its own right. For example, to
enable option completion for the commands foo and bar, use

compdef _gnu_generic foo bar

after the call to compinit.

The completion system as supplied is conservative in its use of
this function, since it is important to be sure the command
understands the option `--help'.

_guard [ options ] pattern descr
This function displays descr if pattern matches the string to be
completed. It is intended to be used in the action for the
specifications passed to _arguments and similar functions.

The return status is zero if the message was displayed and the
word to complete is not empty, and non-zero otherwise.

The pattern may be preceded by any of the options understood by
compadd that are passed down from _description, namely -M, -J,
-V, -1, -2, -n, -F and -X. All of these options will be
ignored. This fits in conveniently with the argument-passing
conventions of actions for _arguments.

As an example, consider a command taking the options -n and
-none, where -n must be followed by a numeric value in the same
word. By using:

_arguments '-n-: :_guard "[0-9]#" "numeric value"' '-none'

_arguments can be made to both display the message `numeric
value' and complete options after `-n<TAB>'. If the `-n' is
already followed by one or more digits (the pattern passed to
_guard) only the message will be displayed; if the `-n' is
followed by another character, only options are completed.

_message [ -r12 ] [ -VJ group ] descr
_message -e [ tag ] descr
The descr is used in the same way as the third argument to the
_description function, except that the resulting string will
always be shown whether or not matches were generated. This is
useful for displaying a help message in places where no
completions can be generated.

The format style is examined with the messages tag to find a
message; the usual tag, descriptions, is used only if the style
is not set with the former.

If the -r option is given, no style is used; the descr is taken
literally as the string to display. This is most useful when
the descr comes from a pre-processed argument list which already
contains an expanded description. Note that this option does
not disable the `%'-sequence parsing done by compadd.

The -12VJ options and the group are passed to compadd and hence
determine the group the message string is added to.

The second -e form gives a description for completions with the
tag tag to be shown even if there are no matches for that tag.
This form is called by _arguments in the event that there is no
action for an option specification. The tag can be omitted and
if so the tag is taken from the parameter $curtag; this is
maintained by the completion system and so is usually correct.
Note that if there are no matches at the time this function is
called, compstate[insert] is cleared, so additional matches
generated later are not inserted on the command line.

_multi_parts [ -i ] sep array
The argument sep is a separator character. The array may be
either the name of an array parameter or a literal array in the
form `(foo bar)', a parenthesised list of words separated by
whitespace. The possible completions are the strings from the
array. However, each chunk delimited by sep will be completed
separately. For example, the _tar function uses `_multi_parts /
patharray' to complete partial file paths from the given array
of complete file paths.

The -i option causes _multi_parts to insert a unique match even
if that requires multiple separators to be inserted. This is
not usually the expected behaviour with filenames, but certain
other types of completion, for example those with a fixed set of
possibilities, may be more suited to this form.

Like other utility functions, this function accepts the `-V',
`-J', `-1', `-2', `-n', `-f', `-X', `-M', `-P', `-S', `-r',
`-R', and `-q' options and passes them to the compadd builtin.

_next_label [ -x ] [ -12VJ ] tag name descr [ option ... ]
This function is used to implement the loop over different tag
labels for a particular tag as described above for the tag-order
style. On each call it checks to see if there are any more tag
labels; if there is it returns status zero, otherwise non-zero.
As this function requires a current tag to be set, it must
always follow a call to _tags or _requested.

The -x12VJ options and the first three arguments are passed to
the _description function. Where appropriate the tag will be
replaced by a tag label in this call. Any description given in
the tag-order style is preferred to the descr passed to
_next_label.

The options given after the descr are set in the parameter given
by name, and hence are to be passed to compadd or whatever
function is called to add the matches.

Here is a typical use of this function for the tag foo. The
call to _requested determines if tag foo is required at all; the
loop over _next_label handles any labels defined for the tag in
the tag-order style.

local expl ret=1
...
if _requested foo; then
...
while _next_label foo expl '...'; do
compadd "$expl[@]" ... && ret=0
done
...
fi
return ret

_normal [ -P | -p precommand ]
This is the standard function called to handle completion
outside any special -context-. It is called both to complete
the command word and also the arguments for a command. In the
second case, _normal looks for a special completion for that
command, and if there is none it uses the completion for the
-default- context.

A second use is to reexamine the command line specified by the
$words array and the $CURRENT parameter after those have been
modified. For example, the function _precommand, which
completes after precommand specifiers such as nohup, removes the
first word from the words array, decrements the CURRENT
parameter, then calls `_normal -p $service'. The effect is that
`nohup cmd ...' is treated in the same way as `cmd ...'.

-P Reset the list of precommands. This option should be used
if completing a command line which allows internal
commands (e.g. builtins and functions) regardless of
prior precommands (e.g. `zsh -c').

-p precommand
Append precommand to the list of precommands. This option
should be used in nearly all cases in which -P is not
applicable.

If the command name matches one of the patterns given by one of
the options -p or -P to compdef, the corresponding completion
function is called and then the parameter _compskip is checked.
If it is set completion is terminated at that point even if no
matches have been found. This is the same effect as in the
-first- context.

_numbers [ option ... ] [ description ] [ suffix ... ]
This can be used where a number is followed by a suffix to
indicate the units. The unit suffixes are completed and can
also be included in the description used when completion is
invoked for the preceding number.

In addition to common compadd options, _numbers accepts the
following options:

-t tag Specify a tag to use instead of the default of numbers.

-u units
Indicate the default units for the number, e.g. bytes.

-l min Specify the lowest possible value for the number.

-m max Specify the highest possible value for the number.

-d default
Specify the default value.

-N Allow negative numbers. This is implied if the range
includes a negative.

-f Allow decimal numbers.

Where a particular suffix represents the default units for a
number, it should be prefixed with a colon. Additionally,
suffixes can be followed by a colon and a description. So for
example, the following allows the age of something to be
specified, either in seconds or with an optional suffix with a
longer unit of time:

_numbers -u seconds age :s:seconds m:minutes h:hours d:days

It is typically helpful for units to be presented in order of
magnitude when completed. To facilitate this, the order in
which they are given is preserved.

When the format style is looked up with the descriptions tag or
the tag specified with -t, the list of suffixes is available as
a `%x' escape sequence. This is in addition to the usual
sequences documented under the format style. The form this list
takes can also be configured. To this end, the format style is
first looked up with the tag unit-suffixes. The retrieved format
is applied to each suffix in turn and the results are then
concatenated to form the completed list. For the unit-suffixes
format, `%x' expands to the individual suffix and `%X' to its
description. %d' indicates a default suffix and can be used in a
condition. The index and reverse index are set in `%i' and `%r'
respectively and are useful for text included only with the
first and last suffixes in the list. So for example, the
following joins the suffixes together as a comma-separated list:

zstyle ':completion:*:unit-suffixes' format '%x%(r::,)'

_options
This can be used to complete the names of shell options. It
provides a matcher specification that ignores a leading `no',
ignores underscores and allows upper-case letters to match their
lower-case counterparts (for example, `glob', `noglob',
`NO_GLOB' are all completed). Any arguments are propagated to
the compadd builtin.

_options_set and _options_unset
These functions complete only set or unset options, with the
same matching specification used in the _options function.

Note that you need to uncomment a few lines in the
_main_complete function for these functions to work properly.
The lines in question are used to store the option settings in
effect before the completion widget locally sets the options it
needs. Hence these functions are not generally used by the
completion system.

_parameters
This is used to complete the names of shell parameters.

The option `-g pattern' limits the completion to parameters
whose type matches the pattern. The type of a parameter is that
shown by `print ${(t)param}', hence judicious use of `*' in
pattern is probably necessary.

All other arguments are passed to the compadd builtin.

_path_files
This function is used throughout the completion system to
complete filenames. It allows completion of partial paths. For
example, the string `/u/i/s/sig' may be completed to
`/usr/include/sys/signal.h'.

The options accepted by both _path_files and _files are:

-f Complete all filenames. This is the default.

-/ Specifies that only directories should be completed.

-g pattern
Specifies that only files matching the pattern should be
completed.

-W paths
Specifies path prefixes that are to be prepended to the
string from the command line to generate the filenames
but that should not be inserted as completions nor shown
in completion listings. Here, paths may be the name of
an array parameter, a literal list of paths enclosed in
parentheses or an absolute pathname.

-F ignored-files
This behaves as for the corresponding option to the
compadd builtin. It gives direct control over which
filenames should be ignored. If the option is not
present, the ignored-patterns style is used.

Both _path_files and _files also accept the following options
which are passed to compadd: `-J', `-V', `-1', `-2', `-n', `-X',
`-M', `-P', `-S', `-q', `-r', and `-R'.

Finally, the _path_files function uses the styles expand,
ambiguous, special-dirs, list-suffixes and file-sort described
above.

_pick_variant [ -b builtin-label ] [ -c command ] [ -r name ]
label=pattern ... label [ arg ... ]
This function is used to resolve situations where a single
command name requires more than one type of handling, either
because it has more than one variant or because there is a name
clash between two different commands.

The command to run is taken from the first element of the array
words unless this is overridden by the option -c. This command
is run and its output is compared with a series of patterns.
Arguments to be passed to the command can be specified at the
end after all the other arguments. The patterns to try in order
are given by the arguments label=pattern; if the output of
`command arg ...' contains pattern, then label is selected as
the label for the command variant. If none of the patterns
match, the final command label is selected and status 1 is
returned.

If the `-b builtin-label' is given, the command is tested to see
if it is provided as a shell builtin, possibly autoloaded; if
so, the label builtin-label is selected as the label for the
variant.

If the `-r name' is given, the label picked is stored in the
parameter named name.

The results are also cached in the _cmd_variant associative
array indexed by the name of the command run.

_regex_arguments name spec ...
This function generates a completion function name which matches
the specifications specs, a set of regular expressions as
described below. After running _regex_arguments, the function
name should be called as a normal completion function. The
pattern to be matched is given by the contents of the words
array up to the current cursor position joined together with
null characters; no quotation is applied.

The arguments are grouped as sets of alternatives separated by
`|', which are tried one after the other until one matches.
Each alternative consists of a one or more specifications which
are tried left to right, with each pattern matched being
stripped in turn from the command line being tested, until all
of the group succeeds or until one fails; in the latter case,
the next alternative is tried. This structure can be repeated
to arbitrary depth by using parentheses; matching proceeds from
inside to outside.

A special procedure is applied if no test succeeds but the
remaining command line string contains no null character
(implying the remaining word is the one for which completions
are to be generated). The completion target is restricted to
the remaining word and any actions for the corresponding
patterns are executed. In this case, nothing is stripped from
the command line string. The order of evaluation of the actions
can be determined by the tag-order style; the various formats
supported by _alternative can be used in action. The descr is
used for setting up the array parameter expl.

Specification arguments take one of following forms, in which
metacharacters such as `(', `)', `#' and `|' should be quoted.

/pattern/ [%lookahead%] [-guard] [:tag:descr:action]
This is a single primitive component. The function tests
whether the combined pattern
`(#b)((#B)pattern)lookahead*' matches the command line
string. If so, `guard' is evaluated and its return
status is examined to determine if the test has
succeeded. The pattern string `[]' is guaranteed never
to match. The lookahead is not stripped from the command
line before the next pattern is examined.

The argument starting with : is used in the same manner
as an argument to _alternative.

A component is used as follows: pattern is tested to see
if the component already exists on the command line. If
it does, any following specifications are examined to
find something to complete. If a component is reached
but no such pattern exists yet on the command line, the
string containing the action is used to generate matches
to insert at that point.

/pattern/+ [%lookahead%] [-guard] [:tag:descr:action]
This is similar to `/pattern/ ...' but the left part of
the command line string (i.e. the part already matched by
previous patterns) is also considered part of the
completion target.

/pattern/- [%lookahead%] [-guard] [:tag:descr:action]
This is similar to `/pattern/ ...' but the actions of the
current and previously matched patterns are ignored even
if the following `pattern' matches the empty string.

( spec )
Parentheses may be used to groups specs; note each
parenthesis is a single argument to _regex_arguments.

spec # This allows any number of repetitions of spec.

spec spec
The two specs are to be matched one after the other as
described above.

spec | spec
Either of the two specs can be matched.

The function _regex_words can be used as a helper function to
generate matches for a set of alternative words possibly with
their own arguments as a command line argument.

Examples:

_regex_arguments _tst /$'[^\0]#\0'/ \
/$'[^\0]#\0'/ :'compadd aaa'

This generates a function _tst that completes aaa as its only
argument. The tag and description for the action have been
omitted for brevity (this works but is not recommended in normal
use). The first component matches the command word, which is
arbitrary; the second matches any argument. As the argument is
also arbitrary, any following component would not depend on aaa
being present.

_regex_arguments _tst /$'[^\0]#\0'/ \
/$'aaa\0'/ :'compadd aaa'

This is a more typical use; it is similar, but any following
patterns would only match if aaa was present as the first
argument.

_regex_arguments _tst /$'[^\0]#\0'/ $ \
/$'aaa\0'/ :'compadd aaa' \
/$'bbb\0'/ :'compadd bbb' $ \#

In this example, an indefinite number of command arguments may
be completed. Odd arguments are completed as aaa and even
arguments as bbb. Completion fails unless the set of aaa and
bbb arguments before the current one is matched correctly.

_regex_arguments _tst /$'[^\0]#\0'/ \
$ /$'aaa\0'/ :'compadd aaa' \| \
/$'bbb\0'/ :'compadd bbb' $ \#

This is similar, but either aaa or bbb may be completed for any
argument. In this case _regex_words could be used to generate a
suitable expression for the arguments.

_regex_words tag description spec ...
This function can be used to generate arguments for the
_regex_arguments command which may be inserted at any point
where a set of rules is expected. The tag and description give
a standard tag and description pertaining to the current
context. Each spec contains two or three arguments separated by
a colon: note that there is no leading colon in this case.

Each spec gives one of a set of words that may be completed at
this point, together with arguments. It is thus roughly
equivalent to the _arguments function when used in normal
(non-regex) completion.

The part of the spec before the first colon is the word to be
completed. This may contain a *; the entire word, before and
after the * is completed, but only the text before the * is
required for the context to be matched, so that further
arguments may be completed after the abbreviated form.

The second part of spec is a description for the word being
completed.

The optional third part of the spec describes how words
following the one being completed are themselves to be
completed. It will be evaluated in order to avoid problems with
quoting. This means that typically it contains a reference to
an array containing previously generated regex arguments.

The option -t term specifies a terminator for the word instead
of the usual space. This is handled as an auto-removable suffix
in the manner of the option -s sep to _values.

The result of the processing by _regex_words is placed in the
array reply, which should be made local to the calling function.
If the set of words and arguments may be matched repeatedly, a #
should be appended to the generated array at that point.

For example:

local -a reply
_regex_words mydb-commands 'mydb commands' \
'add:add an entry to mydb:$mydb_add_cmds' \
'show:show entries in mydb'
_regex_arguments _mydb "$reply[@]"
_mydb "$@"

This shows a completion function for a command mydb which takes
two command arguments, add and show. show takes no arguments,
while the arguments for add have already been prepared in an
array mydb_add_cmds, quite possibly by a previous call to
_regex_words.

_requested [ -x ] [ -12VJ ] tag [ name descr [ command [ arg ... ] ]
This function is called to decide whether a tag already
registered by a call to _tags (see below) has been requested by
the user and hence completion should be performed for it. It
returns status zero if the tag is requested and non-zero
otherwise. The function is typically used as part of a loop
over different tags as follows:

_tags foo bar baz
while _tags; do
if _requested foo; then
... # perform completion for foo
fi
... # test the tags bar and baz in the same way
... # exit loop if matches were generated
done

Note that the test for whether matches were generated is not
performed until the end of the _tags loop. This is so that the
user can set the tag-order style to specify a set of tags to be
completed at the same time.

If name and descr are given, _requested calls the _description
function with these arguments together with the options passed
to _requested.

If command is given, the _all_labels function will be called
immediately with the same arguments. In simple cases this makes
it possible to perform the test for the tag and the matching in
one go. For example:

local expl ret=1
_tags foo bar baz
while _tags; do
_requested foo expl 'description' \
compadd foobar foobaz && ret=0
...
(( ret )) || break
done

If the command is not compadd, it must nevertheless be prepared
to handle the same options.

_retrieve_cache cache_identifier
This function retrieves completion information from the file
given by cache_identifier, stored in a directory specified by
the cache-path style which defaults to ~/.zcompcache. The
return status is zero if retrieval was successful. It will only
attempt retrieval if the use-cache style is set, so you can call
this function without worrying about whether the user wanted to
use the caching layer.

See _store_cache below for more details.

_sep_parts
This function is passed alternating arrays and separators as
arguments. The arrays specify completions for parts of strings
to be separated by the separators. The arrays may be the names
of array parameters or a quoted list of words in parentheses.
For example, with the array `hosts=(ftp news)' the call
`_sep_parts '(foo bar)' @ hosts' will complete the string `f'
to `foo' and the string `b@n' to `bar@news'.

This function accepts the compadd options `-V', `-J', `-1',
`-2', `-n', `-X', `-M', `-P', `-S', `-r', `-R', and `-q' and
passes them on to the compadd builtin used to add the matches.

_sequence [ -s sep ] [ -n max ] [ -d ] function [ - ] ...
This function is a wrapper to other functions for completing
items in a separated list. The same function is used to complete
each item in the list. The separator is specified with the -s
option. If -s is omitted it will use `,'. Duplicate values are
not matched unless -d is specified. If there is a fixed or
maximum number of items in the list, this can be specified with
the -n option.

Common compadd options are passed on to the function. It is
possible to use compadd directly with _sequence, though _values
may be more appropriate in this situation.

_setup tag [ group ]
This function sets up the special parameters used by the
completion system appropriately for the tag given as the first
argument. It uses the styles list-colors, list-packed,
list-rows-first, last-prompt, accept-exact, menu and force-list.

The optional group supplies the name of the group in which the
matches will be placed. If it is not given, the tag is used as
the group name.

This function is called automatically from _description and
hence is not normally called explicitly.

_store_cache cache_identifier param ...
This function, together with _retrieve_cache and _cache_invalid,
implements a caching layer which can be used in any completion
function. Data obtained by costly operations are stored in
parameters; this function then dumps the values of those
parameters to a file. The data can then be retrieved quickly
from that file via _retrieve_cache, even in different instances
of the shell.

The cache_identifier specifies the file which the data should be
dumped to. The file is stored in a directory specified by the
cache-path style which defaults to ~/.zcompcache. The remaining
params arguments are the parameters to dump to the file.

The return status is zero if storage was successful. The
function will only attempt storage if the use-cache style is
set, so you can call this function without worrying about
whether the user wanted to use the caching layer.

The completion function may avoid calling _retrieve_cache when
it already has the completion data available as parameters.
However, in that case it should call _cache_invalid to check
whether the data in the parameters and in the cache are still
valid.

See the _perl_modules completion function for a simple example
of the usage of the caching layer.

_tags [ [ -C name ] tag ... ]
If called with arguments, these are taken to be the names of
tags valid for completions in the current context. These tags
are stored internally and sorted by using the tag-order style.

Next, _tags is called repeatedly without arguments from the same
completion function. This successively selects the first,
second, etc. set of tags requested by the user. The return
status is zero if at least one of the tags is requested and
non-zero otherwise. To test if a particular tag is to be tried,
the _requested function should be called (see above).

If `-C name' is given, name is temporarily stored in the
argument field (the fifth) of the context in the curcontext
parameter during the call to _tags; the field is restored on
exit. This allows _tags to use a more specific context without
having to change and reset the curcontext parameter (which has
the same effect).

_tilde_files
Like _files, but resolve leading tildes according to the rules
of filename expansion, so the suggested completions don't start
with a `~' even if the filename on the command-line does.

_values [ -O name ] [ -s sep ] [ -S sep ] [ -wC ] desc spec ...
This is used to complete arbitrary keywords (values) and their
arguments, or lists of such combinations.

If the first argument is the option `-O name', it will be used
in the same way as by the _arguments function. In other words,
the elements of the name array will be passed to compadd when
executing an action.

If the first argument (or the first argument after `-O name') is
`-s', the next argument is used as the character that separates
multiple values. This character is automatically added after
each value in an auto-removable fashion (see below); all values
completed by `_values -s' appear in the same word on the command
line, unlike completion using _arguments. If this option is not
present, only a single value will be completed per word.

Normally, _values will only use the current word to determine
which values are already present on the command line and hence
are not to be completed again. If the -w option is given, other
arguments are examined as well.

The first non-option argument, desc, is used as a string to
print as a description before listing the values.

All other arguments describe the possible values and their
arguments in the same format used for the description of options
by the _arguments function (see above). The only differences
are that no minus or plus sign is required at the beginning,
values can have only one argument, and the forms of action
beginning with an equal sign are not supported.

The character separating a value from its argument can be set
using the option -S (like -s, followed by the character to use
as the separator in the next argument). By default the equals
sign will be used as the separator between values and arguments.

Example:

_values -s , 'description' \
'*foo[bar]' \
'(two)*one[number]:first count:' \
'two[another number]::second count:(1 2 3)'

This describes three possible values: `foo', `one', and `two'.
The first is described as `bar', takes no argument and may
appear more than once. The second is described as `number', may
appear more than once, and takes one mandatory argument
described as `first count'; no action is specified, so it will
not be completed. The `(two)' at the beginning says that if the
value `one' is on the line, the value `two' will no longer be
considered a possible completion. Finally, the last value
(`two') is described as `another number' and takes an optional
argument described as `second count' for which the completions
(to appear after an `=') are `1', `2', and `3'. The _values
function will complete lists of these values separated by
commas.

Like _arguments, this function temporarily adds another context
name component to the arguments element (the fifth) of the
current context while executing the action. Here this name is
just the name of the value for which the argument is completed.

The style verbose is used to decide if the descriptions for the
values (but not those for the arguments) should be printed.

The associative array val_args is used to report values and
their arguments; this works similarly to the opt_args
associative array used by _arguments. Hence the function
calling _values should declare the local parameters state,
state_descr, line, context and val_args:

local context state state_descr line
typeset -A val_args

when using an action of the form `->string'. With this function
the context parameter will be set to the name of the value whose
argument is to be completed. Note that for _values, the state
and state_descr are scalars rather than arrays. Only a single
matching state is returned.

Note also that _values normally adds the character used as the
separator between values as an auto-removable suffix (similar to
a `/' after a directory). However, this is not possible for a
`->string' action as the matches for the argument are generated
by the calling function. To get the usual behaviour, the
calling function can add the separator x as a suffix by passing
the options `-qS x' either directly or indirectly to compadd.

The option -C is treated in the same way as it is by _arguments.
In that case the parameter curcontext should be made local
instead of context (as described above).

_wanted [ -x ] [ -C name ] [ -12VJ ] tag name descr command [ arg ...]
In many contexts, completion can only generate one particular
set of matches, usually corresponding to a single tag. However,
it is still necessary to decide whether the user requires
matches of this type. This function is useful in such a case.

The arguments to _wanted are the same as those to _requested,
i.e. arguments to be passed to _description. However, in this
case the command is not optional; all the processing of tags,
including the loop over both tags and tag labels and the
generation of matches, is carried out automatically by _wanted.

Hence to offer only one tag and immediately add the
corresponding matches with the given description:

local expl
_wanted tag expl 'description' \
compadd -- match1 match2...

See also the use of _wanted in the example function in the
subsection `Dynamic named directories' in zshexpn(1).

Note that, as for _requested, the command must be able to accept
options to be passed down to compadd.

Like _tags this function supports the -C option to give a
different name for the argument context field. The -x option
has the same meaning as for _description.

_widgets [ -g pattern ]
This function completes names of zle widgets (see the section
`Widgets' in zshzle(1)). The pattern, if present, is matched
against values of the $widgets special parameter, documented in
the section `The zsh/zleparameter Module' in zshmodules(1).

COMPLETION SYSTEM VARIABLES
There are some standard variables, initialised by the _main_complete
function and then used from other functions.

The standard variables are:

_comp_caller_options
The completion system uses setopt to set a number of options.
This allows functions to be written without concern for
compatibility with every possible combination of user options.
However, sometimes completion needs to know what the user's
option preferences are. These are saved in the
_comp_caller_options associative array. Option names, spelled in
lowercase without underscores, are mapped to one or other of the
strings `on' and `off'.

_comp_priv_prefix
Completion functions such as _sudo can set the _comp_priv_prefix
array to a command prefix that may then be used by _call_program
to match the privileges when calling programs to generate
matches.

Two more features are offered by the _main_complete function. The
arrays compprefuncs and comppostfuncs may contain names of functions
that are to be called immediately before or after completion has been
tried. A function will only be called once unless it explicitly
reinserts itself into the array.

COMPLETION DIRECTORIES
In the source distribution, the files are contained in various
subdirectories of the Completion directory. They may have been
installed in the same structure, or into one single function directory.
The following is a description of the files found in the original
directory structure. If you wish to alter an installed file, you will
need to copy it to some directory which appears earlier in your fpath
than the standard directory where it appears.

Base The core functions and special completion widgets automatically
bound to keys. You will certainly need most of these, though
will probably not need to alter them. Many of these are
documented above.

Zsh Functions for completing arguments of shell builtin commands and
utility functions for this. Some of these are also used by
functions from the Unix directory.

Unix Functions for completing arguments of external commands and
suites of commands. They may need modifying for your system,
although in many cases some attempt is made to decide which
version of a command is present. For example, completion for
the mount command tries to determine the system it is running
on, while completion for many other utilities try to decide
whether the GNU version of the command is in use, and hence
whether the --help option is supported.

X, AIX, BSD, ...
Completion and utility function for commands available only on
some systems. These are not arranged hierarchically, so, for
example, both the Linux and Debian directories, as well as the X
directory, may be useful on your system.

NAME
zshcompctl - zsh programmable completion

DESCRIPTION
This version of zsh has two ways of performing completion of words on
the command line. New users of the shell may prefer to use the newer
and more powerful system based on shell functions; this is described in
zshcompsys(1), and the basic shell mechanisms which support it are
described in zshcompwid(1). This manual entry describes the older
compctl command.

compctl [ -CDT ] options [ command ... ]
compctl [ -CDT ] options [ -x pattern options - ... -- ]
[ * options [ -x ... -- ] ... [+] ] [ command ... ]
compctl -M match-specs ...
compctl -L [ -CDTM ] [ command ... ]
compctl * command ...

Control the editor's completion behavior according to the supplied set
of options. Various editing commands, notably expand-or-complete-word,
usually bound to tab, will attempt to complete a word typed by the
user, while others, notably delete-char-or-list, usually bound to ^D in
EMACS editing mode, list the possibilities; compctl controls what those
possibilities are. They may for example be filenames (the most common
case, and hence the default), shell variables, or words from a
user-specified list.

COMMAND FLAGS
Completion of the arguments of a command may be different for each
command or may use the default. The behavior when completing the
command word itself may also be separately specified. These correspond
to the following flags and arguments, all of which (except for -L) may
be combined with any combination of the options described subsequently
in the section `Option Flags':

command ...
controls completion for the named commands, which must be listed
last on the command line. If completion is attempted for a
command with a pathname containing slashes and no completion
definition is found, the search is retried with the last
pathname component. If the command starts with a =, completion
is tried with the pathname of the command.

Any of the command strings may be patterns of the form normally
used for filename generation. These should be quoted to protect
them from immediate expansion; for example the command string
'foo*' arranges for completion of the words of any command
beginning with foo. When completion is attempted, all pattern
completions are tried in the reverse order of their definition
until one matches. By default, completion then proceeds as
normal, i.e. the shell will try to generate more matches for the
specific command on the command line; this can be overridden by
including -tn in the flags for the pattern completion.

Note that aliases are expanded before the command name is
determined unless the COMPLETE_ALIASES option is set. Commands
may not be combined with the -C, -D or -T flags.

-C controls completion when the command word itself is being
completed. If no compctl -C command has been issued, the names
of any executable command (whether in the path or specific to
the shell, such as aliases or functions) are completed.

-D controls default completion behavior for the arguments of
commands not assigned any special behavior. If no compctl -D
command has been issued, filenames are completed.

-T supplies completion flags to be used before any other processing
is done, even before processing for compctls defined for
specific commands. This is especially useful when combined with
extended completion (the -x flag, see the section `Extended
Completion' below). Using this flag you can define default
behavior which will apply to all commands without exception, or
you can alter the standard behavior for all commands. For
example, if your access to the user database is too slow and/or
it contains too many users (so that completion after `~' is too
slow to be usable), you can use

compctl -T -x 's[~] C[0,[^/]#]' -k friends -S/ -tn

to complete the strings in the array friends after a `~'. The
C[...] argument is necessary so that this form of ~-completion
is not tried after the directory name is finished.

-L lists the existing completion behavior in a manner suitable for
putting into a start-up script; the existing behavior is not
changed. Any combination of the above forms, or the -M flag
(which must follow the -L flag), may be specified, otherwise all
defined completions are listed. Any other flags supplied are
ignored.

no argument
If no argument is given, compctl lists all defined completions
in an abbreviated form; with a list of options, all completions
with those flags set (not counting extended completion) are
listed.

If the * flag is alone and followed immediately by the command list,
the completion behavior for all the commands in the list is reset to
the default. In other words, completion will subsequently use the
options specified by the -D flag.

The form with -M as the first and only option defines global matching
specifications (see zshcompwid). The match specifications given will be
used for every completion attempt (only when using compctl, not with
the new completion system) and are tried in the order in which they are
defined until one generates at least one match. E.g.:

compctl -M '' 'm:{a-zA-Z}={A-Za-z}'

This will first try completion without any global match specifications
(the empty string) and, if that generates no matches, will try case
insensitive completion.

OPTION FLAGS
[ -fcFBdeaRGovNAIOPZEnbjrzu/12 ]
[ -k array ] [ -g globstring ] [ -s subststring ]
[ -K function ]
[ -Q ] [ -P prefix ] [ -S suffix ]
[ -W file-prefix ] [ -H num pattern ]
[ -q ] [ -X explanation ] [ -Y explanation ]
[ -y func-or-var ] [ -l cmd ] [ -h cmd ] [ -U ]
[ -t continue ] [ -J name ] [ -V name ]
[ -M match-spec ]

The remaining options specify the type of command arguments to look for
during completion. Any combination of these flags may be specified;
the result is a sorted list of all the possibilities. The options are
as follows.

Simple Flags
These produce completion lists made up by the shell itself:

-f Filenames and file system paths.

-/ Just file system paths.

-c Command names, including aliases, shell functions, builtins and
reserved words.

-F Function names.

-B Names of builtin commands.

-m Names of external commands.

-w Reserved words.

-a Alias names.

-R Names of regular (non-global) aliases.

-G Names of global aliases.

-d This can be combined with -F, -B, -w, -a, -R and -G to get names
of disabled functions, builtins, reserved words or aliases.

-e This option (to show enabled commands) is in effect by default,
but may be combined with -d; -de in combination with -F, -B, -w,
-a, -R and -G will complete names of functions, builtins,
reserved words or aliases whether or not they are disabled.

-o Names of shell options (see zshoptions(1)).

-v Names of any variable defined in the shell.

-N Names of scalar (non-array) parameters.

-A Array names.

-I Names of integer variables.

-O Names of read-only variables.

-p Names of parameters used by the shell (including special
parameters).

-Z Names of shell special parameters.

-E Names of environment variables.

-n Named directories.

-b Key binding names.

-j Job names: the first word of the job leader's command line.
This is useful with the kill builtin.

-r Names of running jobs.

-z Names of suspended jobs.

-u User names.

Flags with Arguments
These have user supplied arguments to determine how the list of
completions is to be made up:

-k array
Names taken from the elements of $array (note that the `$' does
not appear on the command line). Alternatively, the argument
array itself may be a set of space- or comma-separated values in
parentheses, in which any delimiter may be escaped with a
backslash; in this case the argument should be quoted. For
example,

compctl -k "(cputime filesize datasize stacksize
coredumpsize resident descriptors)" limit

-g globstring
The globstring is expanded using filename globbing; it should be
quoted to protect it from immediate expansion. The resulting
filenames are taken as the possible completions. Use `*(/)'
instead of `*/' for directories. The fignore special parameter
is not applied to the resulting files. More than one pattern
may be given separated by blanks. (Note that brace expansion is
not part of globbing. Use the syntax `(either|or)' to match
alternatives.)

-s subststring
The subststring is split into words and these words are than
expanded using all shell expansion mechanisms (see zshexpn(1)).
The resulting words are taken as possible completions. The
fignore special parameter is not applied to the resulting files.
Note that -g is faster for filenames.

-K function
Call the given function to get the completions. Unless the name
starts with an underscore, the function is passed two arguments:
the prefix and the suffix of the word on which completion is to
be attempted, in other words those characters before the cursor
position, and those from the cursor position onwards. The whole
command line can be accessed with the -c and -l flags of the
read builtin. The function should set the variable reply to an
array containing the completions (one completion per element);
note that reply should not be made local to the function. From
such a function the command line can be accessed with the -c and
-l flags to the read builtin. For example,

function whoson { reply=(`users`); }
compctl -K whoson talk

completes only logged-on users after `talk'. Note that `whoson'
must return an array, so `reply=`users`' would be incorrect.

-H num pattern
The possible completions are taken from the last num history
lines. Only words matching pattern are taken. If num is zero
or negative the whole history is searched and if pattern is the
empty string all words are taken (as with `*'). A typical use
is

compctl -D -f * -H 0 ''

which forces completion to look back in the history list for a
word if no filename matches.

Control Flags
These do not directly specify types of name to be completed, but
manipulate the options that do:

-Q This instructs the shell not to quote any metacharacters in the
possible completions. Normally the results of a completion are
inserted into the command line with any metacharacters quoted so
that they are interpreted as normal characters. This is
appropriate for filenames and ordinary strings. However, for
special effects, such as inserting a backquoted expression from
a completion array (-k) so that the expression will not be
evaluated until the complete line is executed, this option must
be used.

-P prefix
The prefix is inserted just before the completed string; any
initial part already typed will be completed and the whole
prefix ignored for completion purposes. For example,

compctl -j -P "%" kill

inserts a `%' after the kill command and then completes job
names.

-S suffix
When a completion is found the suffix is inserted after the
completed string. In the case of menu completion the suffix is
inserted immediately, but it is still possible to cycle through
the list of completions by repeatedly hitting the same key.

-W file-prefix
With directory file-prefix: for command, file, directory and
globbing completion (options -c, -f, -/, -g), the file prefix is
implicitly added in front of the completion. For example,

compctl -/ -W ~/Mail maildirs

completes any subdirectories to any depth beneath the directory
~/Mail, although that prefix does not appear on the command
line. The file-prefix may also be of the form accepted by the
-k flag, i.e. the name of an array or a literal list in
parenthesis. In this case all the directories in the list will
be searched for possible completions.

-q If used with a suffix as specified by the -S option, this causes
the suffix to be removed if the next character typed is a blank
or does not insert anything or if the suffix consists of only
one character and the next character typed is the same
character; this the same rule used for the AUTO_REMOVE_SLASH
option. The option is most useful for list separators (comma,
colon, etc.).

-l cmd This option restricts the range of command line words that are
considered to be arguments. If combined with one of the
extended completion patterns `p[...]', `r[...]', or `R[...]'
(see the section `Extended Completion' below) the range is
restricted to the range of arguments specified in the brackets.
Completion is then performed as if these had been given as
arguments to the cmd supplied with the option. If the cmd string
is empty the first word in the range is instead taken as the
command name, and command name completion performed on the first
word in the range. For example,

compctl -x 'r[-exec,;]' -l '' -- find

completes arguments between `-exec' and the following `;' (or
the end of the command line if there is no such string) as if
they were a separate command line.

-h cmd Normally zsh completes quoted strings as a whole. With this
option, completion can be done separately on different parts of
such strings. It works like the -l option but makes the
completion code work on the parts of the current word that are
separated by spaces. These parts are completed as if they were
arguments to the given cmd. If cmd is the empty string, the
first part is completed as a command name, as with -l.

-U Use the whole list of possible completions, whether or not they
actually match the word on the command line. The word typed so
far will be deleted. This is most useful with a function (given
by the -K option) which can examine the word components passed
to it (or via the read builtin's -c and -l flags) and use its
own criteria to decide what matches. If there is no completion,
the original word is retained. Since the produced possible
completions seldom have interesting common prefixes and
suffixes, menu completion is started immediately if AUTO_MENU is
set and this flag is used.

-y func-or-var
The list provided by func-or-var is displayed instead of the
list of completions whenever a listing is required; the actual
completions to be inserted are not affected. It can be provided
in two ways. Firstly, if func-or-var begins with a $ it defines
a variable, or if it begins with a left parenthesis a literal
array, which contains the list. A variable may have been set by
a call to a function using the -K option. Otherwise it contains
the name of a function which will be executed to create the
list. The function will be passed as an argument list all
matching completions, including prefixes and suffixes expanded
in full, and should set the array reply to the result. In both
cases, the display list will only be retrieved after a complete
list of matches has been created.

Note that the returned list does not have to correspond, even in
length, to the original set of matches, and may be passed as a
scalar instead of an array. No special formatting of characters
is performed on the output in this case; in particular, newlines
are printed literally and if they appear output in columns is
suppressed.

-X explanation
Print explanation when trying completion on the current set of
options. A `%n' in this string is replaced by the number of
matches that were added for this explanation string. The
explanation only appears if completion was tried and there was
no unique match, or when listing completions. Explanation
strings will be listed together with the matches of the group
specified together with the -X option (using the -J or -V
option). If the same explanation string is given to multiple -X
options, the string appears only once (for each group) and the
number of matches shown for the `%n' is the total number of all
matches for each of these uses. In any case, the explanation
string will only be shown if there was at least one match added
for the explanation string.

The sequences %B, %b, %S, %s, %U, and %u specify output
attributes (bold, standout, and underline), %F, %f, %K, %k
specify foreground and background colours, and %{...%} can be
used to include literal escape sequences as in prompts.

-Y explanation
Identical to -X, except that the explanation first undergoes
expansion following the usual rules for strings in double
quotes. The expansion will be carried out after any functions
are called for the -K or -y options, allowing them to set
variables.

-t continue
The continue-string contains a character that specifies which
set of completion flags should be used next. It is useful:

(i) With -T, or when trying a list of pattern completions, when
compctl would usually continue with ordinary processing after
finding matches; this can be suppressed with `-tn'.

(ii) With a list of alternatives separated by *, when compctl
would normally stop when one of the alternatives generates
matches. It can be forced to consider the next set of
completions by adding `-t+' to the flags of the alternative
before the `*'.

(iii) In an extended completion list (see below), when compctl
would normally continue until a set of conditions succeeded,
then use only the immediately following flags. With `-t-',
compctl will continue trying extended completions after the next
`-'; with `-tx' it will attempt completion with the default
flags, in other words those before the `-x'.

-J name
This gives the name of the group the matches should be placed
in. Groups are listed and sorted separately; likewise, menu
completion will offer the matches in the groups in the order in
which the groups were defined. If no group name is explicitly
given, the matches are stored in a group named default. The
first time a group name is encountered, a group with that name
is created. After that all matches with the same group name are
stored in that group.

This can be useful with non-exclusive alternative completions.
For example, in

compctl -f -J files -t+ * -v -J variables foo

both files and variables are possible completions, as the -t+
forces both sets of alternatives before and after the * to be
considered at once. Because of the -J options, however, all
files are listed before all variables.

-V name
Like -J, but matches within the group will not be sorted in
listings nor in menu completion. These unsorted groups are in a
different name space from the sorted ones, so groups defined as
-J files and -V files are distinct.

-1 If given together with the -V option, makes only consecutive
duplicates in the group be removed. Note that groups with and
without this flag are in different name spaces.

-2 If given together with the -J or -V option, makes all duplicates
be kept. Again, groups with and without this flag are in
different name spaces.

-M match-spec
This defines additional matching control specifications that
should be used only when testing words for the list of flags
this flag appears in. The format of the match-spec string is
described in zshcompwid.

ALTERNATIVE COMPLETION
compctl [ -CDT ] options * options [ + ... ] [ + ] command ...

The form with `*' specifies alternative options. Completion is tried
with the options before the first `*'. If this produces no matches
completion is tried with the flags after the `*' and so on. If there
are no flags after the last `*' and a match has not been found up to
that point, default completion is tried. If the list of flags contains
a -t with a * character, the next list of flags is used even if the
current list produced matches.

Additional options are available that restrict completion to some part
of the command line; this is referred to as `extended completion'.

EXTENDED COMPLETION
compctl [ -CDT ] options -x pattern options - ... --
[ command ... ]
compctl [ -CDT ] options [ -x pattern options - ... -- ]
[ * options [ -x ... -- ] ... [+] ] [ command ... ]

The form with `-x' specifies extended completion for the commands
given; as shown, it may be combined with alternative completion using
`*'. Each pattern is examined in turn; when a match is found, the
corresponding options, as described in the section `Option Flags'
above, are used to generate possible completions. If no pattern
matches, the options given before the -x are used.

Note that each pattern should be supplied as a single argument and
should be quoted to prevent expansion of metacharacters by the shell.

A pattern is built of sub-patterns separated by commas; it matches if
at least one of these sub-patterns matches (they are `or'ed). These
sub-patterns are in turn composed of other sub-patterns separated by
white spaces which match if all of the sub-patterns match (they are
`and'ed). An element of the sub-patterns is of the form `c[...][...]',
where the pairs of brackets may be repeated as often as necessary, and
matches if any of the sets of brackets match (an `or'). The example
below makes this clearer.

The elements may be any of the following:

s[string]...
Matches if the current word on the command line starts with one
of the strings given in brackets. The string is not removed and
is not part of the completion.

S[string]...
Like s[string] except that the string is part of the completion.

p[from,to]...
Matches if the number of the current word is between one of the
from and to pairs inclusive. The comma and to are optional; to
defaults to the same value as from. The numbers may be
negative: -n refers to the n'th last word on the line.

c[offset,string]...
Matches if the string matches the word offset by offset from the
current word position. Usually offset will be negative.

C[offset,pattern]...
Like c but using pattern matching instead.

w[index,string]...
Matches if the word in position index is equal to the
corresponding string. Note that the word count is made after
any alias expansion.

W[index,pattern]...
Like w but using pattern matching instead.

n[index,string]...
Matches if the current word contains string. Anything up to and
including the indexth occurrence of this string will not be
considered part of the completion, but the rest will. index may
be negative to count from the end: in most cases, index will be
1 or -1. For example,

compctl -s '`users`' -x 'n[1,@]' -k hosts -- talk

will usually complete usernames, but if you insert an @ after
the name, names from the array hosts (assumed to contain
hostnames, though you must make the array yourself) will be
completed. Other commands such as rcp can be handled similarly.

N[index,string]...
Like n except that the string will be taken as a character
class. Anything up to and including the indexth occurrence of
any of the characters in string will not be considered part of
the completion.

m[min,max]...
Matches if the total number of words lies between min and max
inclusive.

r[str1,str2]...
Matches if the cursor is after a word with prefix str1. If
there is also a word with prefix str2 on the command line after
the one matched by str1 it matches only if the cursor is before
this word. If the comma and str2 are omitted, it matches if the
cursor is after a word with prefix str1.

R[str1,str2]...
Like r but using pattern matching instead.

q[str]...
Matches the word currently being completed is in single quotes
and the str begins with the letter `s', or if completion is done
in double quotes and str starts with the letter `d', or if
completion is done in backticks and str starts with a `b'.

EXAMPLE
compctl -u -x 's[+] c[-1,-f],s[-f+]' \
-g '~/Mail/*(:t)' - 's[-f],c[-1,-f]' -f -- mail

This is to be interpreted as follows:

If the current command is mail, then

if ((the current word begins with * and the previous word is -f)
or (the current word begins with -f+)), then complete the
non-directory part (the `:t' glob modifier) of files in the directory
~/Mail; else

if the current word begins with -f or the previous word was -f, then
complete any file; else

complete user names.

NAME
zshmodules - zsh loadable modules

DESCRIPTION
Some optional parts of zsh are in modules, separate from the core of
the shell. Each of these modules may be linked in to the shell at
build time, or can be dynamically linked while the shell is running if
the installation supports this feature. Modules are linked at runtime
with the zmodload command, see zshbuiltins(1).

The modules that are bundled with the zsh distribution are:

zsh/attr
Builtins for manipulating extended attributes (xattr).

zsh/cap
Builtins for manipulating POSIX.1e (POSIX.6) capability
(privilege) sets.

zsh/clone
A builtin that can clone a running shell onto another terminal.

zsh/compctl
The compctl builtin for controlling completion.

zsh/complete
The basic completion code.

zsh/complist
Completion listing extensions.

zsh/computil
A module with utility builtins needed for the shell function
based completion system.

zsh/curses
curses windowing commands

zsh/datetime
Some date/time commands and parameters.

zsh/db/gdbm
Builtins for managing associative array parameters tied to GDBM
databases.

zsh/deltochar
A ZLE function duplicating EMACS' zap-to-char.

zsh/example
An example of how to write a module.

zsh/files
Some basic file manipulation commands as builtins.

zsh/langinfo
Interface to locale information.

zsh/mapfile
Access to external files via a special associative array.

zsh/mathfunc
Standard scientific functions for use in mathematical
evaluations.

zsh/nearcolor
Map colours to the nearest colour in the available palette.

zsh/newuser
Arrange for files for new users to be installed.

zsh/parameter
Access to internal hash tables via special associative arrays.

zsh/pcre
Interface to the PCRE library.

zsh/param/private
Builtins for managing private-scoped parameters in function
context.

zsh/regex
Interface to the POSIX regex library.

zsh/sched
A builtin that provides a timed execution facility within the
shell.

zsh/net/socket
Manipulation of Unix domain sockets

zsh/stat
A builtin command interface to the stat system call.

zsh/system
A builtin interface to various low-level system features.

zsh/net/tcp
Manipulation of TCP sockets

zsh/termcap
Interface to the termcap database.

zsh/terminfo
Interface to the terminfo database.

zsh/watch
Reporting of login and logout events.

zsh/zftp
A builtin FTP client.

zsh/zle
The Zsh Line Editor, including the bindkey and vared builtins.

zsh/zleparameter
Access to internals of the Zsh Line Editor via parameters.

zsh/zprof
A module allowing profiling for shell functions.

zsh/zpty
A builtin for starting a command in a pseudo-terminal.

zsh/zselect
Block and return when file descriptors are ready.

zsh/zutil
Some utility builtins, e.g. the one for supporting configuration
via styles.

THE ZSH/ATTR MODULE
The zsh/attr module is used for manipulating extended attributes. The
-h option causes all commands to operate on symbolic links instead of
their targets. The builtins in this module are:

zgetattr [ -h ] filename attribute [ parameter ]
Get the extended attribute attribute from the specified
filename. If the optional argument parameter is given, the
attribute is set on that parameter instead of being printed to
stdout.

zsetattr [ -h ] filename attribute value
Set the extended attribute attribute on the specified filename
to value.

zdelattr [ -h ] filename attribute
Remove the extended attribute attribute from the specified
filename.

zlistattr [ -h ] filename [ parameter ]
List the extended attributes currently set on the specified
filename. If the optional argument parameter is given, the list
of attributes is set on that parameter instead of being printed
to stdout.

zgetattr and zlistattr allocate memory dynamically. If the attribute
or list of attributes grows between the allocation and the call to get
them, they return 2. On all other errors, 1 is returned. This allows
the calling function to check for this case and retry.

THE ZSH/CAP MODULE
The zsh/cap module is used for manipulating POSIX.1e (POSIX.6)
capability sets. If the operating system does not support this
interface, the builtins defined by this module will do nothing. The
builtins in this module are:

cap [ capabilities ]
Change the shell's process capability sets to the specified
capabilities, otherwise display the shell's current
capabilities.

getcap filename ...
This is a built-in implementation of the POSIX standard utility.
It displays the capability sets on each specified filename.

setcap capabilities filename ...
This is a built-in implementation of the POSIX standard utility.
It sets the capability sets on each specified filename to the
specified capabilities.

THE ZSH/CLONE MODULE
The zsh/clone module makes available one builtin command:

clone tty
Creates a forked instance of the current shell, attached to the
specified tty. In the new shell, the PID, PPID and TTY special
parameters are changed appropriately. $! is set to zero in the
new shell, and to the new shell's PID in the original shell.

The return status of the builtin is zero in both shells if
successful, and non-zero on error.

The target of clone should be an unused terminal, such as an
unused virtual console or a virtual terminal created by

xterm -e sh -c 'trap : INT QUIT TSTP; tty;
while :; do sleep 100000000; done'

Some words of explanation are warranted about this long xterm
command line: when doing clone on a pseudo-terminal, some other
session ("session" meant as a unix session group, or SID) is
already owning the terminal. Hence the cloned zsh cannot acquire
the pseudo-terminal as a controlling tty. That means two things:

o the job control signals will go to the
sh-started-by-xterm process group (that's why we disable
INT QUIT and TSTP with trap; otherwise the while loop
could get suspended or killed)

o the cloned shell will have job control disabled, and the
job control keys (control-C, control-\ and control-Z)
will not work.

This does not apply when cloning to an unused vc.

Cloning to a used (and unprepared) terminal will result in two
processes reading simultaneously from the same terminal, with
input bytes going randomly to either process.

clone is mostly useful as a shell built-in replacement for
openvt.

THE ZSH/COMPCTL MODULE
The zsh/compctl module makes available two builtin commands. compctl,
is the old, deprecated way to control completions for ZLE. See
zshcompctl(1). The other builtin command, compcall can be used in
user-defined completion widgets, see zshcompwid(1).

THE ZSH/COMPLETE MODULE
The zsh/complete module makes available several builtin commands which
can be used in user-defined completion widgets, see zshcompwid(1).

THE ZSH/COMPLIST MODULE
The zsh/complist module offers three extensions to completion listings:
the ability to highlight matches in such a list, the ability to scroll
through long lists and a different style of menu completion.

Colored completion listings
Whenever one of the parameters ZLS_COLORS or ZLS_COLOURS is set and the
zsh/complist module is loaded or linked into the shell, completion
lists will be colored. Note, however, that complist will not
automatically be loaded if it is not linked in: on systems with
dynamic loading, `zmodload zsh/complist' is required.

The parameters ZLS_COLORS and ZLS_COLOURS describe how matches are
highlighted. To turn on highlighting an empty value suffices, in which
case all the default values given below will be used. The format of
the value of these parameters is the same as used by the GNU version of
the ls command: a colon-separated list of specifications of the form
`name=value'. The name may be one of the following strings, most of
which specify file types for which the value will be used. The strings
and their default values are:

no 0 for normal text (i.e. when displaying something other than a
matched file)

fi 0 for regular files

di 32 for directories

ln 36 for symbolic links. If this has the special value target,
symbolic links are dereferenced and the target file used to
determine the display format.

pi 31 for named pipes (FIFOs)

so 33 for sockets

bd 44;37
for block devices

cd 44;37
for character devices

or none
for a symlink to nonexistent file (default is the value defined
for ln)

mi none
for a non-existent file (default is the value defined for fi);
this code is currently not used

su 37;41
for files with setuid bit set

sg 30;43
for files with setgid bit set

tw 30;42
for world writable directories with sticky bit set

ow 34;43
for world writable directories without sticky bit set

sa none
for files with an associated suffix alias; this is only tested
after specific suffixes, as described below

st 37;44
for directories with sticky bit set but not world writable

ex 35 for executable files

lc \e[ for the left code (see below)

rc m for the right code

tc 0 for the character indicating the file type printed after
filenames if the LIST_TYPES option is set

sp 0 for the spaces printed after matches to align the next column

ec none
for the end code

Apart from these strings, the name may also be an asterisk (`*')
followed by any string. The value given for such a string will be used
for all files whose name ends with the string. The name may also be an
equals sign (`=') followed by a pattern; the EXTENDED_GLOB option will
be turned on for evaluation of the pattern. The value given for this
pattern will be used for all matches (not just filenames) whose display
string are matched by the pattern. Definitions for the form with the
leading equal sign take precedence over the values defined for file
types, which in turn take precedence over the form with the leading
asterisk (file extensions).

The leading-equals form also allows different parts of the displayed
strings to be colored differently. For this, the pattern has to use
the `(#b)' globbing flag and pairs of parentheses surrounding the parts
of the strings that are to be colored differently. In this case the
value may consist of more than one color code separated by equal signs.
The first code will be used for all parts for which no explicit code is
specified and the following codes will be used for the parts matched by
the sub-patterns in parentheses. For example, the specification
`=(#b)(?)*(?)=0=3=7' will be used for all matches which are at least
two characters long and will use the code `3' for the first character,
`7' for the last character and `0' for the rest.

All three forms of name may be preceded by a pattern in parentheses.
If this is given, the value will be used only for matches in groups
whose names are matched by the pattern given in the parentheses. For
example, `(g*)m*=43' highlights all matches beginning with `m' in
groups whose names begin with `g' using the color code `43'. In case
of the `lc', `rc', and `ec' codes, the group pattern is ignored.

Note also that all patterns are tried in the order in which they appear
in the parameter value until the first one matches which is then used.
Patterns may be matched against completions, descriptions (possibly
with spaces appended for padding), or lines consisting of a completion
followed by a description. For consistent coloring it may be necessary
to use more than one pattern or a pattern with backreferences.

When printing a match, the code prints the value of lc, the value for
the file-type or the last matching specification with a `*', the value
of rc, the string to display for the match itself, and then the value
of ec if that is defined or the values of lc, no, and rc if ec is not
defined.

The default values are ISO 6429 (ANSI) compliant and can be used on
vt100 compatible terminals such as xterms. On monochrome terminals the
default values will have no visible effect. The colors function from
the contribution can be used to get associative arrays containing the
codes for ANSI terminals (see the section `Other Functions' in
zshcontrib(1)). For example, after loading colors, one could use
`$color[red]' to get the code for foreground color red and
`$color[bg-green]' for the code for background color green.

If the completion system invoked by compinit is used, these parameters
should not be set directly because the system controls them itself.
Instead, the list-colors style should be used (see the section
`Completion System Configuration' in zshcompsys(1)).

Scrolling in completion listings
To enable scrolling through a completion list, the LISTPROMPT parameter
must be set. Its value will be used as the prompt; if it is the empty
string, a default prompt will be used. The value may contain escapes
of the form `%x'. It supports the escapes `%B', `%b', `%S', `%s',
`%U', `%u', `%F', `%f', `%K', `%k' and `%{...%}' used also in shell
prompts as well as three pairs of additional sequences: a `%l' or `%L'
is replaced by the number of the last line shown and the total number
of lines in the form `number/total'; a `%m' or `%M' is replaced with
the number of the last match shown and the total number of matches; and
`%p' or `%P' is replaced with `Top', `Bottom' or the position of the
first line shown in percent of the total number of lines, respectively.
In each of these cases the form with the uppercase letter will be
replaced with a string of fixed width, padded to the right with spaces,
while the lowercase form will not be padded.

If the parameter LISTPROMPT is set, the completion code will not ask if
the list should be shown. Instead it immediately starts displaying the
list, stopping after the first screenful, showing the prompt at the
bottom, waiting for a keypress after temporarily switching to the
listscroll keymap. Some of the zle functions have a special meaning
while scrolling lists:

send-break
stops listing discarding the key pressed

accept-line, down-history, down-line-or-history
down-line-or-search, vi-down-line-or-history
scrolls forward one line

complete-word, menu-complete, expand-or-complete
expand-or-complete-prefix, menu-complete-or-expand
scrolls forward one screenful

accept-search
stop listing but take no other action

Every other character stops listing and immediately processes the key
as usual. Any key that is not bound in the listscroll keymap or that
is bound to undefined-key is looked up in the keymap currently
selected.

As for the ZLS_COLORS and ZLS_COLOURS parameters, LISTPROMPT should not
be set directly when using the shell function based completion system.
Instead, the list-prompt style should be used.

Menu selection
The zsh/complist module also offers an alternative style of selecting
matches from a list, called menu selection, which can be used if the
shell is set up to return to the last prompt after showing a completion
list (see the ALWAYS_LAST_PROMPT option in zshoptions(1)).

Menu selection can be invoked directly by the widget menu-select
defined by this module. This is a standard ZLE widget that can be
bound to a key in the usual way as described in zshzle(1).

Alternatively, the parameter MENUSELECT can be set to an integer, which
gives the minimum number of matches that must be present before menu
selection is automatically turned on. This second method requires that
menu completion be started, either directly from a widget such as
menu-complete, or due to one of the options MENU_COMPLETE or AUTO_MENU
being set. If MENUSELECT is set, but is 0, 1 or empty, menu selection
will always be started during an ambiguous menu completion.

When using the completion system based on shell functions, the
MENUSELECT parameter should not be used (like the ZLS_COLORS and
ZLS_COLOURS parameters described above). Instead, the menu style
should be used with the select=... keyword.

After menu selection is started, the matches will be listed. If there
are more matches than fit on the screen, only the first screenful is
shown. The matches to insert into the command line can be selected
from this list. In the list one match is highlighted using the value
for ma from the ZLS_COLORS or ZLS_COLOURS parameter. The default value
for this is `7' which forces the selected match to be highlighted using
standout mode on a vt100-compatible terminal. If neither ZLS_COLORS
nor ZLS_COLOURS is set, the same terminal control sequence as for the
`%S' escape in prompts is used.

If there are more matches than fit on the screen and the parameter
MENUPROMPT is set, its value will be shown below the matches. It
supports the same escape sequences as LISTPROMPT, but the number of the
match or line shown will be that of the one where the mark is placed.
If its value is the empty string, a default prompt will be used.

The MENUSCROLL parameter can be used to specify how the list is
scrolled. If the parameter is unset, this is done line by line, if it
is set to `0' (zero), the list will scroll half the number of lines of
the screen. If the value is positive, it gives the number of lines to
scroll and if it is negative, the list will be scrolled the number of
lines of the screen minus the (absolute) value.

As for the ZLS_COLORS, ZLS_COLOURS and LISTPROMPT parameters, neither
MENUPROMPT nor MENUSCROLL should be set directly when using the shell
function based completion system. Instead, the select-prompt and
select-scroll styles should be used.

The completion code sometimes decides not to show all of the matches in
the list. These hidden matches are either matches for which the
completion function which added them explicitly requested that they not
appear in the list (using the -n option of the compadd builtin command)
or they are matches which duplicate a string already in the list
(because they differ only in things like prefixes or suffixes that are
not displayed). In the list used for menu selection, however, even
these matches are shown so that it is possible to select them. To
highlight such matches the hi and du capabilities in the ZLS_COLORS and
ZLS_COLOURS parameters are supported for hidden matches of the first
and second kind, respectively.

Selecting matches is done by moving the mark around using the zle
movement functions. When not all matches can be shown on the screen at
the same time, the list will scroll up and down when crossing the top
or bottom line. The following zle functions have special meaning
during menu selection. Note that the following always perform the same
task within the menu selection map and cannot be replaced by user
defined widgets, nor can the set of functions be extended:

accept-line, accept-search
accept the current match and leave menu selection (but do not
cause the command line to be accepted)

send-break
leaves menu selection and restores the previous contents of the
command line

redisplay, clear-screen
execute their normal function without leaving menu selection

accept-and-hold, accept-and-menu-complete
accept the currently inserted match and continue selection
allowing to select the next match to insert into the line

accept-and-infer-next-history
accepts the current match and then tries completion with menu
selection again; in the case of files this allows one to select
a directory and immediately attempt to complete files in it; if
there are no matches, a message is shown and one can use undo to
go back to completion on the previous level, every other key
leaves menu selection (including the other zle functions which
are otherwise special during menu selection)

undo removes matches inserted during the menu selection by one of the
three functions before

down-history, down-line-or-history
vi-down-line-or-history, down-line-or-search
moves the mark one line down

up-history, up-line-or-history
vi-up-line-or-history, up-line-or-search
moves the mark one line up

forward-char, vi-forward-char
moves the mark one column right

backward-char, vi-backward-char
moves the mark one column left

forward-word, vi-forward-word
vi-forward-word-end, emacs-forward-word
moves the mark one screenful down

backward-word, vi-backward-word, emacs-backward-word
moves the mark one screenful up

vi-forward-blank-word, vi-forward-blank-word-end
moves the mark to the first line of the next group of matches

vi-backward-blank-word
moves the mark to the last line of the previous group of matches

beginning-of-history
moves the mark to the first line

end-of-history
moves the mark to the last line

beginning-of-buffer-or-history, beginning-of-line
beginning-of-line-hist, vi-beginning-of-line
moves the mark to the leftmost column

end-of-buffer-or-history, end-of-line
end-of-line-hist, vi-end-of-line
moves the mark to the rightmost column

complete-word, menu-complete, expand-or-complete
expand-or-complete-prefix, menu-expand-or-complete
moves the mark to the next match

reverse-menu-complete
moves the mark to the previous match

vi-insert
this toggles between normal and interactive mode; in interactive
mode the keys bound to self-insert and self-insert-unmeta insert
into the command line as in normal editing mode but without
leaving menu selection; after each character completion is tried
again and the list changes to contain only the new matches; the
completion widgets make the longest unambiguous string be
inserted in the command line and undo and backward-delete-char
go back to the previous set of matches

history-incremental-search-forward
history-incremental-search-backward
this starts incremental searches in the list of completions
displayed; in this mode, accept-line only leaves incremental
search, going back to the normal menu selection mode

All movement functions wrap around at the edges; any other zle function
not listed leaves menu selection and executes that function. It is
possible to make widgets in the above list do the same by using the
form of the widget with a `.' in front. For example, the widget
`.accept-line' has the effect of leaving menu selection and accepting
the entire command line.

During this selection the widget uses the keymap menuselect. Any key
that is not defined in this keymap or that is bound to undefined-key is
looked up in the keymap currently selected. This is used to ensure
that the most important keys used during selection (namely the cursor
keys, return, and TAB) have sensible defaults. However, keys in the
menuselect keymap can be modified directly using the bindkey builtin
command (see zshmodules(1)). For example, to make the return key leave
menu selection without accepting the match currently selected one could
call

bindkey -M menuselect '^M' send-break

after loading the zsh/complist module.

THE ZSH/COMPUTIL MODULE
The zsh/computil module adds several builtin commands that are used by
some of the completion functions in the completion system based on
shell functions (see zshcompsys(1) ). Except for compquote these
builtin commands are very specialised and thus not very interesting
when writing your own completion functions. In summary, these builtin
commands are:

comparguments
This is used by the _arguments function to do the argument and
command line parsing. Like compdescribe it has an option -i to
do the parsing and initialize some internal state and various
options to access the state information to decide what should be
completed.

compdescribe
This is used by the _describe function to build the displays for
the matches and to get the strings to add as matches with their
options. On the first call one of the options -i or -I should
be supplied as the first argument. In the first case, display
strings without the descriptions will be generated, in the
second case, the string used to separate the matches from their
descriptions must be given as the second argument and the
descriptions (if any) will be shown. All other arguments are
like the definition arguments to _describe itself.

Once compdescribe has been called with either the -i or the -I
option, it can be repeatedly called with the -g option and the
names of four parameters as its arguments. This will step
through the different sets of matches and store the value of
compstate[list] in the first scalar, the options for compadd in
the second array, the matches in the third array, and the
strings to be displayed in the completion listing in the fourth
array. The arrays may then be directly given to compadd to
register the matches with the completion code.

compfiles
Used by the _path_files function to optimize complex recursive
filename generation (globbing). It does three things. With the
-p and -P options it builds the glob patterns to use, including
the paths already handled and trying to optimize the patterns
with respect to the prefix and suffix from the line and the
match specification currently used. The -i option does the
directory tests for the ignore-parents style and the -r option
tests if a component for some of the matches are equal to the
string on the line and removes all other matches if that is
true.

compgroups
Used by the _tags function to implement the internals of the
group-order style. This only takes its arguments as names of
completion groups and creates the groups for it (all six types:
sorted and unsorted, both without removing duplicates, with
removing all duplicates and with removing consecutive
duplicates).

compquote [ -p ] names ...
There may be reasons to write completion functions that have to
add the matches using the -Q option to compadd and perform
quoting themselves. Instead of interpreting the first character
of the all_quotes key of the compstate special association and
using the q flag for parameter expansions, one can use this
builtin command. The arguments are the names of scalar or array
parameters and the values of these parameters are quoted as
needed for the innermost quoting level. If the -p option is
given, quoting is done as if there is some prefix before the
values of the parameters, so that a leading equal sign will not
be quoted.

The return status is non-zero in case of an error and zero
otherwise.

comptags
comptry
These implement the internals of the tags mechanism.

compvalues
Like comparguments, but for the _values function.

THE ZSH/CURSES MODULE
The zsh/curses module makes available one builtin command and various
parameters.

Builtin
zcurses init
zcurses end
zcurses addwin targetwin nlines ncols begin_y begin_x [ parentwin ]
zcurses delwin targetwin
zcurses refresh [ targetwin ... ]
zcurses touch targetwin ...
zcurses move targetwin new_y new_x
zcurses clear targetwin [ redraw | eol | bot ]
zcurses position targetwin array
zcurses char targetwin character
zcurses string targetwin string
zcurses border targetwin border
zcurses attr targetwin [ [*|-]attribute | fg_col/bg_col ] [...]
zcurses bg targetwin [ [*|-]attribute | fg_col/bg_col | @char ] [...]
zcurses scroll targetwin [ on | off | [*|-]lines ]
zcurses input targetwin [ param [ kparam [ mparam ] ] ]
zcurses mouse [ delay num | [*|-]motion ]
zcurses timeout targetwin intval
zcurses querychar targetwin [ param ]
zcurses resize height width [ endwin | nosave | endwin_nosave ]
Manipulate curses windows. All uses of this command should be
bracketed by `zcurses init' to initialise use of curses, and
`zcurses end' to end it; omitting `zcurses end' can cause the
terminal to be in an unwanted state.

The subcommand addwin creates a window with nlines lines and
ncols columns. Its upper left corner will be placed at row
begin_y and column begin_x of the screen. targetwin is a string
and refers to the name of a window that is not currently
assigned. Note in particular the curses convention that
vertical values appear before horizontal values.

If addwin is given an existing window as the final argument, the
new window is created as a subwindow of parentwin. This differs
from an ordinary new window in that the memory of the window
contents is shared with the parent's memory. Subwindows must be
deleted before their parent. Note that the coordinates of
subwindows are relative to the screen, not the parent, as with
other windows.

Use the subcommand delwin to delete a window created with
addwin. Note that end does not implicitly delete windows, and
that delwin does not erase the screen image of the window.

The window corresponding to the full visible screen is called
stdscr; it always exists after `zcurses init' and cannot be
delete with delwin.

The subcommand refresh will refresh window targetwin; this is
necessary to make any pending changes (such as characters you
have prepared for output with char) visible on the screen.
refresh without an argument causes the screen to be cleared and
redrawn. If multiple windows are given, the screen is updated
once at the end.

The subcommand touch marks the targetwins listed as changed.
This is necessary before refreshing windows if a window that was
in front of another window (which may be stdscr) is deleted.

The subcommand move moves the cursor position in targetwin to
new coordinates new_y and new_x. Note that the subcommand
string (but not the subcommand char) advances the cursor
position over the characters added.

The subcommand clear erases the contents of targetwin. One (and
no more than one) of three options may be specified. With the
option redraw, in addition the next refresh of targetwin will
cause the screen to be cleared and repainted. With the option
eol, targetwin is only cleared to the end of the current cursor
line. With the option bot, targetwin is cleared to the end of
the window, i.e everything to the right and below the cursor is
cleared.

The subcommand position writes various positions associated with
targetwin into the array named array. These are, in order:
- The y and x coordinates of the cursor relative to the top
left of targetwin
- The y and x coordinates of the top left of targetwin on
the screen
- The size of targetwin in y and x dimensions.

Outputting characters and strings are achieved by char and
string respectively.

To draw a border around window targetwin, use border. Note that
the border is not subsequently handled specially: in other
words, the border is simply a set of characters output at the
edge of the window. Hence it can be overwritten, can scroll off
the window, etc.

The subcommand attr will set targetwin's attributes or
foreground/background color pair for any successive character
output. Each attribute given on the line may be prepended by a
* to set or a - to unset that attribute; + is assumed if absent.
The attributes supported are blink, bold, dim, reverse,
standout, and underline.

Each fg_col/bg_col attribute (to be read as `fg_col on bg_col')
sets the foreground and background color for character output.
The color default is sometimes available (in particular if the
library is ncurses), specifying the foreground or background
color with which the terminal started. The color pair
default/default is always available. To use more than the 8
named colors (red, green, etc.) construct the fg_col/bg_col
pairs where fg_col and bg_col are decimal integers, e.g 128/200.
The maximum color value is 254 if the terminal supports 256
colors.

bg overrides the color and other attributes of all characters in
the window. Its usual use is to set the background initially,
but it will overwrite the attributes of any characters at the
time when it is called. In addition to the arguments allowed
with attr, an argument @char specifies a character to be shown
in otherwise blank areas of the window. Owing to limitations of
curses this cannot be a multibyte character (use of ASCII
characters only is recommended). As the specified set of
attributes override the existing background, turning attributes
off in the arguments is not useful, though this does not cause
an error.

The subcommand scroll can be used with on or off to enabled or
disable scrolling of a window when the cursor would otherwise
move below the window due to typing or output. It can also be
used with a positive or negative integer to scroll the window up
or down the given number of lines without changing the current
cursor position (which therefore appears to move in the opposite
direction relative to the window). In the second case, if
scrolling is off it is temporarily turned on to allow the window
to be scrolled.

The subcommand input reads a single character from the window
without echoing it back. If param is supplied the character is
assigned to the parameter param, else it is assigned to the
parameter REPLY.

If both param and kparam are supplied, the key is read in
`keypad' mode. In this mode special keys such as function keys
and arrow keys return the name of the key in the parameter
kparam. The key names are the macros defined in the curses.h or
ncurses.h with the prefix `KEY_' removed; see also the
description of the parameter zcurses_keycodes below. Other keys
cause a value to be set in param as before. On a successful
return only one of param or kparam contains a non-empty string;
the other is set to an empty string.

If mparam is also supplied, input attempts to handle mouse
input. This is only available with the ncurses library; mouse
handling can be detected by checking for the exit status of
`zcurses mouse' with no arguments. If a mouse button is clicked
(or double- or triple-clicked, or pressed or released with a
configurable delay from being clicked) then kparam is set to the
string MOUSE, and mparam is set to an array consisting of the
following elements:
- An identifier to discriminate different input devices;
this is only rarely useful.
- The x, y and z coordinates of the mouse click relative to
the full screen, as three elements in that order (i.e.
the y coordinate is, unusually, after the x coordinate).
The z coordinate is only available for a few unusual
input devices and is otherwise set to zero.
- Any events that occurred as separate items; usually there
will be just one. An event consists of PRESSED,
RELEASED, CLICKED, DOUBLE_CLICKED or TRIPLE_CLICKED
followed immediately (in the same element) by the number
of the button.
- If the shift key was pressed, the string SHIFT.
- If the control key was pressed, the string CTRL.
- If the alt key was pressed, the string ALT.

Not all mouse events may be passed through to the terminal
window; most terminal emulators handle some mouse events
themselves. Note that the ncurses manual implies that using
input both with and without mouse handling may cause the mouse
cursor to appear and disappear.

The subcommand mouse can be used to configure the use of the
mouse. There is no window argument; mouse options are global.
`zcurses mouse' with no arguments returns status 0 if mouse
handling is possible, else status 1. Otherwise, the possible
arguments (which may be combined on the same command line) are
as follows. delay num sets the maximum delay in milliseconds
between press and release events to be considered as a click;
the value 0 disables click resolution, and the default is one
sixth of a second. motion proceeded by an optional `*' (the
default) or - turns on or off reporting of mouse motion in
addition to clicks, presses and releases, which are always
reported. However, it appears reports for mouse motion are not
currently implemented.

The subcommand timeout specifies a timeout value for input from
targetwin. If intval is negative, `zcurses input' waits
indefinitely for a character to be typed; this is the default.
If intval is zero, `zcurses input' returns immediately; if there
is typeahead it is returned, else no input is done and status 1
is returned. If intval is positive, `zcurses input' waits
intval milliseconds for input and if there is none at the end of
that period returns status 1.

The subcommand querychar queries the character at the current
cursor position. The return values are stored in the array
named param if supplied, else in the array reply. The first
value is the character (which may be a multibyte character if
the system supports them); the second is the color pair in the
usual fg_col/bg_col notation, or 0 if color is not supported.
Any attributes other than color that apply to the character, as
set with the subcommand attr, appear as additional elements.

The subcommand resize resizes stdscr and all windows to given
dimensions (windows that stick out from the new dimensions are
resized down). The underlying curses extension (resize_term
call) can be unavailable. To verify, zeroes can be used for
height and width. If the result of the subcommand is 0,
resize_term is available (2 otherwise). Tests show that resizing
can be normally accomplished by calling zcurses end and zcurses
refresh. The resize subcommand is provided for versatility.
Multiple system configurations have been checked and zcurses end
and zcurses refresh are still needed for correct terminal state
after resize. To invoke them with resize, use endwin argument.
Using nosave argument will cause new terminal state to not be
saved internally by zcurses. This is also provided for
versatility and should normally be not needed.

Parameters
ZCURSES_COLORS
Readonly integer. The maximum number of colors the terminal
supports. This value is initialised by the curses library and
is not available until the first time zcurses init is run.

ZCURSES_COLOR_PAIRS
Readonly integer. The maximum number of color pairs
fg_col/bg_col that may be defined in `zcurses attr' commands;
note this limit applies to all color pairs that have been used
whether or not they are currently active. This value is
initialised by the curses library and is not available until the
first time zcurses init is run.

zcurses_attrs
Readonly array. The attributes supported by zsh/curses;
available as soon as the module is loaded.

zcurses_colors
Readonly array. The colors supported by zsh/curses; available
as soon as the module is loaded.

zcurses_keycodes
Readonly array. The values that may be returned in the second
parameter supplied to `zcurses input' in the order in which they
are defined internally by curses. Not all function keys are
listed, only F0; curses reserves space for F0 up to F63.

zcurses_windows
Readonly array. The current list of windows, i.e. all windows
that have been created with `zcurses addwin' and not removed
with `zcurses delwin'.

THE ZSH/DATETIME MODULE
The zsh/datetime module makes available one builtin command:

strftime [ -s scalar | -n ] format [ epochtime [ nanoseconds ] ]
strftime -r [ -q ] [ -s scalar | -n ] format timestring
Output the date in the format specified. With no epochtime, the
current system date/time is used; optionally, epochtime may be
used to specify the number of seconds since the epoch, and
nanoseconds may additionally be used to specify the number of
nanoseconds past the second (otherwise that number is assumed to
be 0). See strftime(3) for details. The zsh extensions
described in the section EXPANSION OF PROMPT SEQUENCES in
zshmisc(1) are also available.

-n Suppress printing a newline after the formatted string.

-q Run quietly; suppress printing of all error messages
described below. Errors for invalid epochtime values are
always printed.

-r With the option -r (reverse), use format to parse the
input string timestring and output the number of seconds
since the epoch at which the time occurred. The parsing
is implemented by the system function strptime; see
strptime(3). This means that zsh format extensions are
not available, but for reverse lookup they are not
required.

In most implementations of strftime any timezone in the
timestring is ignored and the local timezone declared by
the TZ environment variable is used; other parameters are
set to zero if not present.

If timestring does not match format the command returns
status 1 and prints an error message. If timestring
matches format but not all characters in timestring were
used, the conversion succeeds but also prints an error
message.

If either of the system functions strptime or mktime is
not available, status 2 is returned and an error message
is printed.

-s scalar
Assign the date string (or epoch time in seconds if -r is
given) to scalar instead of printing it.

Note that depending on the system's declared integral time type,
strftime may produce incorrect results for epoch times greater
than 2147483647 which corresponds to 2038-01-19 03:14:07 +0000.

The zsh/datetime module makes available several parameters; all are
readonly:

EPOCHREALTIME
A floating point value representing the number of seconds since
the epoch. The notional accuracy is to nanoseconds if the
clock_gettime call is available and to microseconds otherwise,
but in practice the range of double precision floating point and
shell scheduling latencies may be significant effects.

EPOCHSECONDS
An integer value representing the number of seconds since the
epoch.

epochtime
An array value containing the number of seconds since the epoch
in the first element and the remainder of the time since the
epoch in nanoseconds in the second element. To ensure the two
elements are consistent the array should be copied or otherwise
referenced as a single substitution before the values are used.
The following idiom may be used:

for secs nsecs in $epochtime; do
...
done

THE ZSH/DB/GDBM MODULE
The zsh/db/gdbm module is used to create "tied" associative arrays that
interface to database files. If the GDBM interface is not available,
the builtins defined by this module will report an error. This module
is also intended as a prototype for creating additional database
interfaces, so the ztie builtin may move to a more generic module in
the future.

The builtins in this module are:

ztie -d db/gdbm -f filename [ -r ] arrayname
Open the GDBM database identified by filename and, if
successful, create the associative array arrayname linked to the
file. To create a local tied array, the parameter must first be
declared, so commands similar to the following would be executed
inside a function scope:

local -A sampledb
ztie -d db/gdbm -f sample.gdbm sampledb

The -r option opens the database file for reading only, creating
a parameter with the readonly attribute. Without this option,
using `ztie' on a file for which the user does not have write
permission is an error. If writable, the database is opened
synchronously so fields changed in arrayname are immediately
written to filename.

Changes to the file modes filename after it has been opened do
not alter the state of arrayname, but `typeset -r arrayname'
works as expected.

zuntie [ -u ] arrayname ...
Close the GDBM database associated with each arrayname and then
unset the parameter. The -u option forces an unset of
parameters made readonly with `ztie -r'.

This happens automatically if the parameter is explicitly unset
or its local scope (function) ends. Note that a readonly
parameter may not be explicitly unset, so the only way to unset
a global parameter created with `ztie -r' is to use `zuntie -u'.

zgdbmpath parametername
Put path to database file assigned to parametername into REPLY
scalar.

zgdbm_tied
Array holding names of all tied parameters.

The fields of an associative array tied to GDBM are neither cached nor
otherwise stored in memory, they are read from or written to the
database on each reference. Thus, for example, the values in a
readonly array may be changed by a second writer of the same database
file.

THE ZSH/DELTOCHAR MODULE
The zsh/deltochar module makes available two ZLE functions:

delete-to-char
Read a character from the keyboard, and delete from the cursor
position up to and including the next (or, with repeat count n,
the nth) instance of that character. Negative repeat counts
mean delete backwards.

zap-to-char
This behaves like delete-to-char, except that the final
occurrence of the character itself is not deleted.

THE ZSH/EXAMPLE MODULE
The zsh/example module makes available one builtin command:

example [ -flags ] [ args ... ]
Displays the flags and arguments it is invoked with.

The purpose of the module is to serve as an example of how to write a
module.

THE ZSH/FILES MODULE
The zsh/files module makes available some common commands for file
manipulation as builtins; these commands are probably not needed for
many normal situations but can be useful in emergency recovery
situations with constrained resources. The commands do not implement
all features now required by relevant standards committees.

For all commands, a variant beginning zf_ is also available and loaded
automatically. Using the features capability of zmodload will let you
load only those names you want. Note that it's possible to load only
the builtins with zsh-specific names using the following command:

zmodload -m -F zsh/files b:zf_\*

The commands loaded by default are:

chgrp [ -hRs ] group filename ...
Changes group of files specified. This is equivalent to chown
with a user-spec argument of `:group'.

chmod [ -Rs ] mode filename ...
Changes mode of files specified.

The specified mode must be in octal.

The -R option causes chmod to recursively descend into
directories, changing the mode of all files in the directory
after changing the mode of the directory itself.

The -s option is a zsh extension to chmod functionality. It
enables paranoid behaviour, intended to avoid security problems
involving a chmod being tricked into affecting files other than
the ones intended. It will refuse to follow symbolic links, so
that (for example) ``chmod 600 /tmp/foo/passwd'' can't
accidentally chmod /etc/passwd if /tmp/foo happens to be a link
to /etc. It will also check where it is after leaving
directories, so that a recursive chmod of a deep directory tree
can't end up recursively chmoding /usr as a result of
directories being moved up the tree.

chown [ -hRs ] user-spec filename ...
Changes ownership and group of files specified.

The user-spec can be in four forms:

user change owner to user; do not change group
user:: change owner to user; do not change group
user: change owner to user; change group to user's primary
group
user:group
change owner to user; change group to group
:group do not change owner; change group to group

In each case, the `:' may instead be a `.'. The rule is that if
there is a `:' then the separator is `:', otherwise if there is
a `.' then the separator is `.', otherwise there is no
separator.

Each of user and group may be either a username (or group name,
as appropriate) or a decimal user ID (group ID). Interpretation
as a name takes precedence, if there is an all-numeric username
(or group name).

If the target is a symbolic link, the -h option causes chown to
set the ownership of the link instead of its target.

The -R option causes chown to recursively descend into
directories, changing the ownership of all files in the
directory after changing the ownership of the directory itself.

The -s option is a zsh extension to chown functionality. It
enables paranoid behaviour, intended to avoid security problems
involving a chown being tricked into affecting files other than
the ones intended. It will refuse to follow symbolic links, so
that (for example) ``chown luser /tmp/foo/passwd'' can't
accidentally chown /etc/passwd if /tmp/foo happens to be a link
to /etc. It will also check where it is after leaving
directories, so that a recursive chown of a deep directory tree
can't end up recursively chowning /usr as a result of
directories being moved up the tree.

ln [ -dfhins ] filename dest
ln [ -dfhins ] filename ... dir
Creates hard (or, with -s, symbolic) links. In the first form,
the specified destination is created, as a link to the specified
filename. In the second form, each of the filenames is taken in
turn, and linked to a pathname in the specified directory that
has the same last pathname component.

Normally, ln will not attempt to create hard links to
directories. This check can be overridden using the -d option.
Typically only the super-user can actually succeed in creating
hard links to directories. This does not apply to symbolic
links in any case.

By default, existing files cannot be replaced by links. The -i
option causes the user to be queried about replacing existing
files. The -f option causes existing files to be silently
deleted, without querying. -f takes precedence.

The -h and -n options are identical and both exist for
compatibility; either one indicates that if the target is a
symlink then it should not be dereferenced. Typically this is
used in combination with -sf so that if an existing link points
to a directory then it will be removed, instead of followed. If
this option is used with multiple filenames and the target is a
symbolic link pointing to a directory then the result is an
error.

mkdir [ -p ] [ -m mode ] dir ...
Creates directories. With the -p option, non-existing parent
directories are first created if necessary, and there will be no
complaint if the directory already exists. The -m option can be
used to specify (in octal) a set of file permissions for the
created directories, otherwise mode 777 modified by the current
umask (see umask(2)) is used.

mv [ -fi ] filename dest
mv [ -fi ] filename ... dir
Moves files. In the first form, the specified filename is moved
to the specified destination. In the second form, each of the
filenames is taken in turn, and moved to a pathname in the
specified directory that has the same last pathname component.

By default, the user will be queried before replacing any file
that the user cannot write to, but writable files will be
silently removed. The -i option causes the user to be queried
about replacing any existing files. The -f option causes any
existing files to be silently deleted, without querying. -f
takes precedence.

Note that this mv will not move files across devices.
Historical versions of mv, when actual renaming is impossible,
fall back on copying and removing files; if this behaviour is
desired, use cp and rm manually. This may change in a future
version.

rm [ -dfiRrs ] filename ...
Removes files and directories specified.

Normally, rm will not remove directories (except with the -R or
-r options). The -d option causes rm to try removing
directories with unlink (see unlink(2)), the same method used
for files. Typically only the super-user can actually succeed
in unlinking directories in this way. -d takes precedence over
-R and -r.

By default, the user will be queried before removing any file
that the user cannot write to, but writable files will be
silently removed. The -i option causes the user to be queried
about removing any files. The -f option causes files to be
silently deleted, without querying, and suppresses all error
indications. -f takes precedence.

The -R and -r options cause rm to recursively descend into
directories, deleting all files in the directory before removing
the directory with the rmdir system call (see rmdir(2)).

The -s option is a zsh extension to rm functionality. It
enables paranoid behaviour, intended to avoid common security
problems involving a root-run rm being tricked into removing
files other than the ones intended. It will refuse to follow
symbolic links, so that (for example) ``rm /tmp/foo/passwd''
can't accidentally remove /etc/passwd if /tmp/foo happens to be
a link to /etc. It will also check where it is after leaving
directories, so that a recursive removal of a deep directory
tree can't end up recursively removing /usr as a result of
directories being moved up the tree.

rmdir dir ...
Removes empty directories specified.

sync Calls the system call of the same name (see sync(2)), which
flushes dirty buffers to disk. It might return before the I/O
has actually been completed.

THE ZSH/LANGINFO MODULE
The zsh/langinfo module makes available one parameter:

langinfo
An associative array that maps langinfo elements to their
values.

Your implementation may support a number of the following keys:

CODESET, D_T_FMT, D_FMT, T_FMT, RADIXCHAR, THOUSEP, YESEXPR,
NOEXPR, CRNCYSTR, ABDAY_{1..7}, DAY_{1..7}, ABMON_{1..12},
MON_{1..12}, T_FMT_AMPM, AM_STR, PM_STR, ERA, ERA_D_FMT,
ERA_D_T_FMT, ERA_T_FMT, ALT_DIGITS

THE ZSH/MAPFILE MODULE
The zsh/mapfile module provides one special associative array parameter
of the same name.

mapfile
This associative array takes as keys the names of files; the
resulting value is the content of the file. The value is
treated identically to any other text coming from a parameter.
The value may also be assigned to, in which case the file in
question is written (whether or not it originally existed); or
an element may be unset, which will delete the file in question.
For example, `vared 'mapfile[myfile]'' works as expected,
editing the file `myfile'.

When the array is accessed as a whole, the keys are the names of
files in the current directory, and the values are empty (to
save a huge overhead in memory). Thus ${(k)mapfile} has the
same effect as the glob operator *(D), since files beginning
with a dot are not special. Care must be taken with expressions
such as rm ${(k)mapfile}, which will delete every file in the
current directory without the usual `rm *' test.

The parameter mapfile may be made read-only; in that case, files
referenced may not be written or deleted.

A file may conveniently be read into an array as one line per
element with the form `array=("${(f@)mapfile[filename]}")'. The
double quotes and the `@' are necessary to prevent empty lines
from being removed. Note that if the file ends with a newline,
the shell will split on the final newline, generating an
additional empty field; this can be suppressed by using
`array=("${(f@)${mapfile[filename]%$'\n'}}")'.

Limitations
Although reading and writing of the file in question is efficiently
handled, zsh's internal memory management may be arbitrarily baroque;
however, mapfile is usually very much more efficient than anything
involving a loop. Note in particular that the whole contents of the
file will always reside physically in memory when accessed (possibly
multiple times, due to standard parameter substitution operations). In
particular, this means handling of sufficiently long files (greater
than the machine's swap space, or than the range of the pointer type)
will be incorrect.

No errors are printed or flagged for non-existent, unreadable, or
unwritable files, as the parameter mechanism is too low in the shell
execution hierarchy to make this convenient.

It is unfortunate that the mechanism for loading modules does not yet
allow the user to specify the name of the shell parameter to be given
the special behaviour.

THE ZSH/MATHFUNC MODULE
The zsh/mathfunc module provides standard mathematical functions for
use when evaluating mathematical formulae. The syntax agrees with
normal C and FORTRAN conventions, for example,

(( f = sin(0.3) ))

assigns the sine of 0.3 to the parameter f.

Most functions take floating point arguments and return a floating
point value. However, any necessary conversions from or to integer
type will be performed automatically by the shell. Apart from atan
with a second argument and the abs, int and float functions, all
functions behave as noted in the manual page for the corresponding C
function, except that any arguments out of range for the function in
question will be detected by the shell and an error reported.

The following functions take a single floating point argument: acos,
acosh, asin, asinh, atan, atanh, cbrt, ceil, cos, cosh, erf, erfc, exp,
expm1, fabs, floor, gamma, j0, j1, lgamma, log, log10, log1p, log2,
logb, sin, sinh, sqrt, tan, tanh, y0, y1. The atan function can
optionally take a second argument, in which case it behaves like the C
function atan2. The ilogb function takes a single floating point
argument, but returns an integer.

The function signgam takes no arguments, and returns an integer, which
is the C variable of the same name, as described in gamma(3). Note
that it is therefore only useful immediately after a call to gamma or
lgamma. Note also that `signgam()' and `signgam' are distinct
expressions.

The functions min, max, and sum are defined not in this module but in
the zmathfunc autoloadable function, described in the section
`Mathematical Functions' in zshcontrib(1).

The following functions take two floating point arguments: copysign,
fmod, hypot, nextafter.

The following take an integer first argument and a floating point
second argument: jn, yn.

The following take a floating point first argument and an integer
second argument: ldexp, scalb.

The function abs does not convert the type of its single argument; it
returns the absolute value of either a floating point number or an
integer. The functions float and int convert their arguments into a
floating point or integer value (by truncation) respectively.

Note that the C pow function is available in ordinary math evaluation
as the `**' operator and is not provided here.

The function rand48 is available if your system's mathematical library
has the function erand48(3). It returns a pseudo-random floating point
number between 0 and 1. It takes a single string optional argument.

If the argument is not present, the random number seed is initialised
by three calls to the rand(3) function --- this produces the same
random numbers as the next three values of $RANDOM.

If the argument is present, it gives the name of a scalar parameter
where the current random number seed will be stored. On the first
call, the value must contain at least twelve hexadecimal digits (the
remainder of the string is ignored), or the seed will be initialised in
the same manner as for a call to rand48 with no argument. Subsequent
calls to rand48(param) will then maintain the seed in the parameter
param as a string of twelve hexadecimal digits, with no base signifier.
The random number sequences for different parameters are completely
independent, and are also independent from that used by calls to rand48
with no argument.

For example, consider

print $(( rand48(seed) ))
print $(( rand48() ))
print $(( rand48(seed) ))

Assuming $seed does not exist, it will be initialised by the first
call. In the second call, the default seed is initialised; note,
however, that because of the properties of rand() there is a
correlation between the seeds used for the two initialisations, so for
more secure uses, you should generate your own 12-byte seed. The third
call returns to the same sequence of random numbers used in the first
call, unaffected by the intervening rand48().

THE ZSH/NEARCOLOR MODULE
The zsh/nearcolor module replaces colours specified as hex triplets
with the nearest colour in the 88 or 256 colour palettes that are
widely used by terminal emulators. By default, 24-bit true colour
escape codes are generated when colours are specified using hex
triplets. These are not supported by all terminals. The purpose of
this module is to make it easier to define colour preferences in a form
that can work across a range of terminal emulators.

Aside from the default colour, the ANSI standard for terminal escape
codes provides for eight colours. The bright attribute brings this to
sixteen. These basic colours are commonly used in terminal applications
due to being widely supported. Expanded 88 and 256 colour palettes are
also common and, while the first sixteen colours vary somewhat between
terminals and configurations, these add a generally consistent and
predictable set of colours.

In order to use the zsh/nearcolor module, it only needs to be loaded.
Thereafter, whenever a colour is specified using a hex triplet, it will
be compared against each of the available colours and the closest will
be selected. The first sixteen colours are never matched in this
process due to being unpredictable.

It isn't possible to reliably detect support for true colour in the
terminal emulator. It is therefore recommended to be selective in
loading the zsh/nearcolor module. For example, the following checks the
COLORTERM environment variable:

[[ $COLORTERM = *(24bit|truecolor)* ]] || zmodload zsh/nearcolor

Note that some terminals accept the true color escape codes but map
them internally to a more limited palette in a similar manner to the
zsh/nearcolor module.

THE ZSH/NEWUSER MODULE
The zsh/newuser module is loaded at boot if it is available, the RCS
option is set, and the PRIVILEGED option is not set (all three are true
by default). This takes place immediately after commands in the global
zshenv file (typically /etc/zshenv), if any, have been executed. If
the module is not available it is silently ignored by the shell; the
module may safely be removed from $MODULE_PATH by the administrator if
it is not required.

On loading, the module tests if any of the start-up files .zshenv,
.zprofile, .zshrc or .zlogin exist in the directory given by the
environment variable ZDOTDIR, or the user's home directory if that is
not set. The test is not performed and the module halts processing if
the shell was in an emulation mode (i.e. had been invoked as some other
shell than zsh).

If none of the start-up files were found, the module then looks for the
file newuser first in a sitewide directory, usually the parent
directory of the site-functions directory, and if that is not found the
module searches in a version-specific directory, usually the parent of
the functions directory containing version-specific functions. (These
directories can be configured when zsh is built using the
--enable-site-scriptdir=dir and --enable-scriptdir=dir flags to
configure, respectively; the defaults are prefix/share/zsh and
prefix/share/zsh/$ZSH_VERSION where the default prefix is /usr/local.)

If the file newuser is found, it is then sourced in the same manner as
a start-up file. The file is expected to contain code to install
start-up files for the user, however any valid shell code will be
executed.

The zsh/newuser module is then unconditionally unloaded.

Note that it is possible to achieve exactly the same effect as the
zsh/newuser module by adding code to /etc/zshenv. The module exists
simply to allow the shell to make arrangements for new users without
the need for intervention by package maintainers and system
administrators.

The script supplied with the module invokes the shell function
zsh-newuser-install. This may be invoked directly by the user even if
the zsh/newuser module is disabled. Note, however, that if the module
is not installed the function will not be installed either. The
function is documented in the section `User Configuration Functions' in
zshcontrib(1).

THE ZSH/PARAMETER MODULE
The zsh/parameter module gives access to some of the internal hash
tables used by the shell by defining some special parameters.

options
The keys for this associative array are the names of the options
that can be set and unset using the setopt and unsetopt
builtins. The value of each key is either the string on if the
option is currently set, or the string off if the option is
unset. Setting a key to one of these strings is like setting or
unsetting the option, respectively. Unsetting a key in this
array is like setting it to the value off.

commands
This array gives access to the command hash table. The keys are
the names of external commands, the values are the pathnames of
the files that would be executed when the command would be
invoked. Setting a key in this array defines a new entry in this
table in the same way as with the hash builtin. Unsetting a key
as in `unset "commands[foo]"' removes the entry for the given
key from the command hash table.

functions
This associative array maps names of enabled functions to their
definitions. Setting a key in it is like defining a function
with the name given by the key and the body given by the value.
Unsetting a key removes the definition for the function named by
the key.

dis_functions
Like functions but for disabled functions.

functions_source
This readonly associative array maps names of enabled functions
to the name of the file containing the source of the function.

For an autoloaded function that has already been loaded, or
marked for autoload with an absolute path, or that has had its
path resolved with `functions -r', this is the file found for
autoloading, resolved to an absolute path.

For a function defined within the body of a script or sourced
file, this is the name of that file. In this case, this is the
exact path originally used to that file, which may be a relative
path.

For any other function, including any defined at an interactive
prompt or an autoload function whose path has not yet been
resolved, this is the empty string. However, the hash element
is reported as defined just so long as the function is present:
the keys to this hash are the same as those to $functions.

dis_functions_source
Like functions_source but for disabled functions.

builtins
This associative array gives information about the builtin
commands currently enabled. The keys are the names of the
builtin commands and the values are either `undefined' for
builtin commands that will automatically be loaded from a module
if invoked or `defined' for builtin commands that are already
loaded.

dis_builtins
Like builtins but for disabled builtin commands.

reswords
This array contains the enabled reserved words.

dis_reswords
Like reswords but for disabled reserved words.

patchars
This array contains the enabled pattern characters.

dis_patchars
Like patchars but for disabled pattern characters.

aliases
This maps the names of the regular aliases currently enabled to
their expansions.

dis_aliases
Like aliases but for disabled regular aliases.

galiases
Like aliases, but for global aliases.

dis_galiases
Like galiases but for disabled global aliases.

saliases
Like raliases, but for suffix aliases.

dis_saliases
Like saliases but for disabled suffix aliases.

parameters
The keys in this associative array are the names of the
parameters currently defined. The values are strings describing
the type of the parameter, in the same format used by the t
parameter flag, see zshexpn(1) . Setting or unsetting keys in
this array is not possible.

modules
An associative array giving information about modules. The keys
are the names of the modules loaded, registered to be
autoloaded, or aliased. The value says which state the named
module is in and is one of the strings `loaded', `autoloaded',
or `alias:name', where name is the name the module is aliased
to.

Setting or unsetting keys in this array is not possible.

dirstack
A normal array holding the elements of the directory stack. Note
that the output of the dirs builtin command includes one more
directory, the current working directory.

history
This associative array maps history event numbers to the full
history lines. Although it is presented as an associative
array, the array of all values (${history[@]}) is guaranteed to
be returned in order from most recent to oldest history event,
that is, by decreasing history event number.

historywords
A special array containing the words stored in the history.
These also appear in most to least recent order.

jobdirs
This associative array maps job numbers to the directories from
which the job was started (which may not be the current
directory of the job).

The keys of the associative arrays are usually valid job
numbers, and these are the values output with, for example,
${(k)jobdirs}. Non-numeric job references may be used when
looking up a value; for example, ${jobdirs[%+]} refers to the
current job.

See the jobs builtin for how job information is provided in a
subshell.

jobtexts
This associative array maps job numbers to the texts of the
command lines that were used to start the jobs.

Handling of the keys of the associative array is as described
for jobdirs above.

See the jobs builtin for how job information is provided in a
subshell.

jobstates
This associative array gives information about the states of the
jobs currently known. The keys are the job numbers and the
values are strings of the form `job-state:mark:pid=state...'.
The job-state gives the state the whole job is currently in, one
of `running', `suspended', or `done'. The mark is `*' for the
current job, `-' for the previous job and empty otherwise. This
is followed by one `:pid=state' for every process in the job.
The pids are, of course, the process IDs and the state describes
the state of that process.

Handling of the keys of the associative array is as described
for jobdirs above.

See the jobs builtin for how job information is provided in a
subshell.

nameddirs
This associative array maps the names of named directories to
the pathnames they stand for.

userdirs
This associative array maps user names to the pathnames of their
home directories.

usergroups
This associative array maps names of system groups of which the
current user is a member to the corresponding group identifiers.
The contents are the same as the groups output by the id
command.

funcfiletrace
This array contains the absolute line numbers and corresponding
file names for the point where the current function, sourced
file, or (if EVAL_LINENO is set) eval command was called. The
array is of the same length as funcsourcetrace and functrace,
but differs from funcsourcetrace in that the line and file are
the point of call, not the point of definition, and differs from
functrace in that all values are absolute line numbers in files,
rather than relative to the start of a function, if any.

funcsourcetrace
This array contains the file names and line numbers of the
points where the functions, sourced files, and (if EVAL_LINENO
is set) eval commands currently being executed were defined.
The line number is the line where the `function name' or `name
()' started. In the case of an autoloaded function the line
number is reported as zero. The format of each element is
filename:lineno.

For functions autoloaded from a file in native zsh format, where
only the body of the function occurs in the file, or for files
that have been executed by the source or `.' builtins, the trace
information is shown as filename:0, since the entire file is the
definition. The source file name is resolved to an absolute
path when the function is loaded or the path to it otherwise
resolved.

Most users will be interested in the information in the
funcfiletrace array instead.

funcstack
This array contains the names of the functions, sourced files,
and (if EVAL_LINENO is set) eval commands. currently being
executed. The first element is the name of the function using
the parameter.

The standard shell array zsh_eval_context can be used to
determine the type of shell construct being executed at each
depth: note, however, that is in the opposite order, with the
most recent item last, and it is more detailed, for example
including an entry for toplevel, the main shell code being
executed either interactively or from a script, which is not
present in $funcstack.

functrace
This array contains the names and line numbers of the callers
corresponding to the functions currently being executed. The
format of each element is name:lineno. Callers are also shown
for sourced files; the caller is the point where the source or
`.' command was executed.

THE ZSH/PCRE MODULE
The zsh/pcre module makes some commands available as builtins:

pcre_compile [ -aimxs ] PCRE
Compiles a perl-compatible regular expression.

Option -a will force the pattern to be anchored. Option -i will
compile a case-insensitive pattern. Option -m will compile a
multi-line pattern; that is, ^ and $ will match newlines within
the pattern. Option -x will compile an extended pattern,
wherein whitespace and # comments are ignored. Option -s makes
the dot metacharacter match all characters, including those that
indicate newline.

pcre_study
Studies the previously-compiled PCRE which may result in faster
matching.

pcre_match [ -v var ] [ -a arr ] [ -n offset ] [ -b ] string
Returns successfully if string matches the previously-compiled
PCRE.

Upon successful match, if the expression captures substrings
within parentheses, pcre_match will set the array match to those
substrings, unless the -a option is given, in which case it will
set the array arr. Similarly, the variable MATCH will be set to
the entire matched portion of the string, unless the -v option
is given, in which case the variable var will be set. No
variables are altered if there is no successful match. A -n
option starts searching for a match from the byte offset
position in string. If the -b option is given, the variable
ZPCRE_OP will be set to an offset pair string, representing the
byte offset positions of the entire matched portion within the
string. For example, a ZPCRE_OP set to "32 45" indicates that
the matched portion began on byte offset 32 and ended on byte
offset 44. Here, byte offset position 45 is the position
directly after the matched portion. Keep in mind that the byte
position isn't necessarily the same as the character position
when UTF-8 characters are involved. Consequently, the byte
offset positions are only to be relied on in the context of
using them for subsequent searches on string, using an offset
position as an argument to the -n option. This is mostly used
to implement the "find all non-overlapping matches"
functionality.

A simple example of "find all non-overlapping matches":

string="The following zip codes: 78884 90210 99513"
pcre_compile -m "\d{5}"
accum=()
pcre_match -b -- $string
while [[ $? -eq 0 ]] do
b=($=ZPCRE_OP)
accum+=$MATCH
pcre_match -b -n $b[2] -- $string
done
print -l $accum

The zsh/pcre module makes available the following test condition:

expr -pcre-match pcre
Matches a string against a perl-compatible regular expression.

For example,

[[ "$text" -pcre-match ^d+$ ]] &&
print text variable contains only "d's".

If the REMATCH_PCRE option is set, the =~ operator is equivalent
to -pcre-match, and the NO_CASE_MATCH option may be used. Note
that NO_CASE_MATCH never applies to the pcre_match builtin,
instead use the -i switch of pcre_compile.

THE ZSH/PARAM/PRIVATE MODULE
The zsh/param/private module is used to create parameters whose scope
is limited to the current function body, and not to other functions
called by the current function.

This module provides a single autoloaded builtin:

private [ {*|-}AHUahlmrtux ] [ {+|-}EFLRZi [ n ] ] [ name[=value] ... ]
The private builtin accepts all the same options and arguments
as local (zshbuiltins(1)) except for the `-T' option. Tied
parameters may not be made private.

The `-p' option is presently a no-op because the state of
private parameters cannot reliably be reloaded. This also
applies to printing private parameters with `typeset -p'.

If used at the top level (outside a function scope), private
creates a normal parameter in the same manner as declare or
typeset. A warning about this is printed if WARN_CREATE_GLOBAL
is set (zshoptions(1)). Used inside a function scope, private
creates a local parameter similar to one declared with local,
except having special properties noted below.

Special parameters which expose or manipulate internal shell
state, such as ARGC, argv, COLUMNS, LINES, UID, EUID, IFS,
PROMPT, RANDOM, SECONDS, etc., cannot be made private unless the
`-h' option is used to hide the special meaning of the
parameter. This may change in the future.

As with other typeset equivalents, private is both a builtin and a
reserved word, so arrays may be assigned with parenthesized word list
name=(value...) syntax. However, the reserved word `private' is not
available until zsh/param/private is loaded, so care must be taken with
order of execution and parsing for function definitions which use
private. To compensate for this, the module also adds the option `-P'
to the `local' builtin to declare private parameters.

For example, this construction fails if zsh/param/private has not yet
been loaded when `bad_declaration' is defined:
bad_declaration() {
zmodload zsh/param/private
private array=( one two three )
}

This construction works because local is already a keyword, and the
module is loaded before the statement is executed:
good_declaration() {
zmodload zsh/param/private
local -P array=( one two three )
}

The following is usable in scripts but may have trouble with autoload:
zmodload zsh/param/private
iffy_declaration() {
private array=( one two three )
}

The private builtin may always be used with scalar assignments and for
declarations without assignments.

Parameters declared with private have the following properties:

o Within the function body where it is declared, the parameter
behaves as a local, except as noted above for tied or special
parameters.

o The type of a parameter declared private cannot be changed in
the scope where it was declared, even if the parameter is unset.
Thus an array cannot be assigned to a private scalar, etc.

o Within any other function called by the declaring function, the
private parameter does NOT hide other parameters of the same
name, so for example a global parameter of the same name is
visible and may be assigned or unset. This includes calls to
anonymous functions, although that may also change in the
future. However, the private name may not be created outside
the local scope when it was not previously declared.

o An exported private remains in the environment of inner scopes
but appears unset for the current shell in those scopes.
Generally, exporting private parameters should be avoided.

Note that this differs from the static scope defined by compiled
languages derived from C, in that the a new call to the same function
creates a new scope, i.e., the parameter is still associated with the
call stack rather than with the function definition. It differs from
ksh `typeset -S' because the syntax used to define the function has no
bearing on whether the parameter scope is respected.

THE ZSH/REGEX MODULE
The zsh/regex module makes available the following test condition:

expr -regex-match regex
Matches a string against a POSIX extended regular expression.
On successful match, matched portion of the string will normally
be placed in the MATCH variable. If there are any capturing
parentheses within the regex, then the match array variable will
contain those. If the match is not successful, then the
variables will not be altered.

For example,

[[ alphabetical -regex-match ^a([^a]+)a([^a]+)a ]] &&
print -l $MATCH X $match

If the option REMATCH_PCRE is not set, then the =~ operator will
automatically load this module as needed and will invoke the
-regex-match operator.

If BASH_REMATCH is set, then the array BASH_REMATCH will be set
instead of MATCH and match.

Note that the zsh/regex module logic relies on the host system.
The same expr and regex pair could produce different results on
different platforms if a regex with non-standard syntax is
given.

For example, no syntax for matching a word boundary is defined
in the POSIX extended regular expression standard. GNU libc and
BSD libc both provide such syntaxes as extensions (\b and
[[:<:]]/[[:>:]] respectively), but neither of these syntaxes is
supported by both of these implementations.

Refer to the regcomp(3) and re_format(7) manual pages on your
system for locally-supported syntax.

THE ZSH/SCHED MODULE
The zsh/sched module makes available one builtin command and one
parameter.

sched [-o] [*]hh:mm[:ss] command ...
sched [-o] [*]seconds command ...
sched [ -item ]
Make an entry in the scheduled list of commands to execute. The
time may be specified in either absolute or relative time, and
either as hours, minutes and (optionally) seconds separated by a
colon, or seconds alone. An absolute number of seconds
indicates the time since the epoch (1970/01/01 00:00); this is
useful in combination with the features in the zsh/datetime
module, see the zsh/datetime module entry in zshmodules(1).

With no arguments, prints the list of scheduled commands. If
the scheduled command has the -o flag set, this is shown at the
start of the command.

With the argument `-item', removes the given item from the list.
The numbering of the list is continuous and entries are in time
order, so the numbering can change when entries are added or
deleted.

Commands are executed either immediately before a prompt, or
while the shell's line editor is waiting for input. In the
latter case it is useful to be able to produce output that does
not interfere with the line being edited. Providing the option
-o causes the shell to clear the command line before the event
and redraw it afterwards. This should be used with any
scheduled event that produces visible output to the terminal; it
is not needed, for example, with output that updates a terminal
emulator's title bar.

To effect changes to the editor buffer when an event executes,
use the `zle' command with no arguments to test whether the
editor is active, and if it is, then use `zle widget' to access
the editor via the named widget.

The sched builtin is not made available by default when the
shell starts in a mode emulating another shell. It can be made
available with the command `zmodload -F zsh/sched b:sched'.

zsh_scheduled_events
A readonly array corresponding to the events scheduled by the
sched builtin. The indices of the array correspond to the
numbers shown when sched is run with no arguments (provided that
the KSH_ARRAYS option is not set). The value of the array
consists of the scheduled time in seconds since the epoch (see
the section `The zsh/datetime Module' for facilities for using
this number), followed by a colon, followed by any options
(which may be empty but will be preceded by a `-' otherwise),
followed by a colon, followed by the command to be executed.

The sched builtin should be used for manipulating the events.
Note that this will have an immediate effect on the contents of
the array, so that indices may become invalid.

THE ZSH/NET/SOCKET MODULE
The zsh/net/socket module makes available one builtin command:

zsocket [ -altv ] [ -d fd ] [ args ]
zsocket is implemented as a builtin to allow full use of shell
command line editing, file I/O, and job control mechanisms.

Outbound Connections
zsocket [ -v ] [ -d fd ] filename
Open a new Unix domain connection to filename. The shell
parameter REPLY will be set to the file descriptor associated
with that connection. Currently, only stream connections are
supported.

If -d is specified, its argument will be taken as the target
file descriptor for the connection.

In order to elicit more verbose output, use -v.

File descriptors can be closed with normal shell syntax when no
longer needed, for example:

exec {REPLY}>&-

Inbound Connections
zsocket -l [ -v ] [ -d fd ] filename
zsocket -l will open a socket listening on filename. The shell
parameter REPLY will be set to the file descriptor associated
with that listener. The file descriptor remains open in
subshells and forked external executables.

If -d is specified, its argument will be taken as the target
file descriptor for the connection.

In order to elicit more verbose output, use -v.

zsocket -a [ -tv ] [ -d targetfd ] listenfd
zsocket -a will accept an incoming connection to the socket
associated with listenfd. The shell parameter REPLY will be set
to the file descriptor associated with the inbound connection.
The file descriptor remains open in subshells and forked
external executables.

If -d is specified, its argument will be taken as the target
file descriptor for the connection.

If -t is specified, zsocket will return if no incoming
connection is pending. Otherwise it will wait for one.

In order to elicit more verbose output, use -v.

THE ZSH/STAT MODULE
The zsh/stat module makes available one builtin command under two
possible names:

zstat [ -gnNolLtTrs ] [ -f fd ] [ -H hash ] [ -A array ] [ -F fmt ]
[ *element ] [ file ... ]
stat ...
The command acts as a front end to the stat system call (see
stat(2)). The same command is provided with two names; as the
name stat is often used by an external command it is recommended
that only the zstat form of the command is used. This can be
arranged by loading the module with the command `zmodload -F
zsh/stat b:zstat'.

If the stat call fails, the appropriate system error message
printed and status 1 is returned. The fields of struct stat
give information about the files provided as arguments to the
command. In addition to those available from the stat call, an
extra element `link' is provided. These elements are:

device The number of the device on which the file resides.

inode The unique number of the file on this device (`inode'
number).

mode The mode of the file; that is, the file's type and access
permissions. With the -s option, this will be returned
as a string corresponding to the first column in the
display of the ls -l command.

nlink The number of hard links to the file.

uid The user ID of the owner of the file. With the -s
option, this is displayed as a user name.

gid The group ID of the file. With the -s option, this is
displayed as a group name.

rdev The raw device number. This is only useful for special
devices.

size The size of the file in bytes.

atime
mtime
ctime The last access, modification and inode change times of
the file, respectively, as the number of seconds since
midnight GMT on 1st January, 1970. With the -s option,
these are printed as strings for the local time zone; the
format can be altered with the -F option, and with the -g
option the times are in GMT.

blksize
The number of bytes in one allocation block on the device
on which the file resides.

block The number of disk blocks used by the file.

link If the file is a link and the -L option is in effect,
this contains the name of the file linked to, otherwise
it is empty. Note that if this element is selected
(``zstat +link'') then the -L option is automatically
used.

A particular element may be selected by including its name
preceded by a `*' in the option list; only one element is
allowed. The element may be shortened to any unique set of
leading characters. Otherwise, all elements will be shown for
all files.

Options:

-A array
Instead of displaying the results on standard output,
assign them to an array, one struct stat element per
array element for each file in order. In this case
neither the name of the element nor the name of the files
appears in array unless the -t or -n options were given,
respectively. If -t is given, the element name appears
as a prefix to the appropriate array element; if -n is
given, the file name appears as a separate array element
preceding all the others. Other formatting options are
respected.

-H hash
Similar to -A, but instead assign the values to hash.
The keys are the elements listed above. If the -n option
is provided then the name of the file is included in the
hash with key name.

-f fd Use the file on file descriptor fd instead of named
files; no list of file names is allowed in this case.

-F fmt Supplies a strftime (see strftime(3)) string for the
formatting of the time elements. The format string
supports all of the zsh extensions described in the
section EXPANSION OF PROMPT SEQUENCES in zshmisc(1). In
particular, -F %s.%N can be used to show timestamps with
nanosecond precision if supported by the system. The -s
option is implied.

-g Show the time elements in the GMT time zone. The -s
option is implied.

-l List the names of the type elements (to standard output
or an array as appropriate) and return immediately;
arguments, and options other than -A, are ignored.

-L Perform an lstat (see lstat(2)) rather than a stat system
call. In this case, if the file is a link, information
about the link itself rather than the target file is
returned. This option is required to make the link
element useful. It's important to note that this is the
exact opposite from ls(1), etc.

-n Always show the names of files. Usually these are only
shown when output is to standard output and there is more
than one file in the list.

-N Never show the names of files.

-o If a raw file mode is printed, show it in octal, which is
more useful for human consumption than the default of
decimal. A leading zero will be printed in this case.
Note that this does not affect whether a raw or formatted
file mode is shown, which is controlled by the -r and -s
options, nor whether a mode is shown at all.

-r Print raw data (the default format) alongside string data
(the -s format); the string data appears in parentheses
after the raw data.

-s Print mode, uid, gid and the three time elements as
strings instead of numbers. In each case the format is
like that of ls -l.

-t Always show the type names for the elements of struct
stat. Usually these are only shown when output is to
standard output and no individual element has been
selected.

-T Never show the type names of the struct stat elements.

THE ZSH/SYSTEM MODULE
The zsh/system module makes available various builtin commands and
parameters.

Builtins
syserror [ -e errvar ] [ -p prefix ] [ errno | errname ]
This command prints out the error message associated with errno,
a system error number, followed by a newline to standard error.

Instead of the error number, a name errname, for example ENOENT,
may be used. The set of names is the same as the contents of
the array errnos, see below.

If the string prefix is given, it is printed in front of the
error message, with no intervening space.

If errvar is supplied, the entire message, without a newline, is
assigned to the parameter names errvar and nothing is output.

A return status of 0 indicates the message was successfully
printed (although it may not be useful if the error number was
out of the system's range), a return status of 1 indicates an
error in the parameters, and a return status of 2 indicates the
error name was not recognised (no message is printed for this).

sysopen [ -arw ] [ -m permissions ] [ -o options ]
-u fd file
This command opens a file. The -r, -w and -a flags indicate
whether the file should be opened for reading, writing and
appending, respectively. The -m option allows the initial
permissions to use when creating a file to be specified in octal
form. The file descriptor is specified with -u. Either an
explicit file descriptor in the range 0 to 9 can be specified or
a variable name can be given to which the file descriptor number
will be assigned.

The -o option allows various system specific options to be
specified as a comma-separated list. The following is a list of
possible options. Note that, depending on the system, some may
not be available.
cloexec
mark file to be closed when other programs are executed
(else the file descriptor remains open in subshells and
forked external executables)

create
creat create file if it does not exist

excl create file, error if it already exists

noatime
suppress updating of the file atime

nofollow
fail if file is a symbolic link

nonblock
the file is opened in nonblocking mode

sync request that writes wait until data has been physically
written

truncate
trunc truncate file to size 0

To close the file, use one of the following:

exec {fd}<&-
exec {fd}>&-

sysread [ -c countvar ] [ -i infd ] [ -o outfd ]
[ -s bufsize ] [ -t timeout ] [ param ]
Perform a single system read from file descriptor infd, or zero
if that is not given. The result of the read is stored in param
or REPLY if that is not given. If countvar is given, the number
of bytes read is assigned to the parameter named by countvar.

The maximum number of bytes read is bufsize or 8192 if that is
not given, however the command returns as soon as any number of
bytes was successfully read.

If timeout is given, it specifies a timeout in seconds, which
may be zero to poll the file descriptor. This is handled by the
poll system call if available, otherwise the select system call
if available.

If outfd is given, an attempt is made to write all the bytes
just read to the file descriptor outfd. If this fails, because
of a system error other than EINTR or because of an internal zsh
error during an interrupt, the bytes read but not written are
stored in the parameter named by param if supplied (no default
is used in this case), and the number of bytes read but not
written is stored in the parameter named by countvar if that is
supplied. If it was successful, countvar contains the full
number of bytes transferred, as usual, and param is not set.

The error EINTR (interrupted system call) is handled internally
so that shell interrupts are transparent to the caller. Any
other error causes a return.

The possible return statuses are
0 At least one byte of data was successfully read and, if
appropriate, written.

1 There was an error in the parameters to the command.
This is the only error for which a message is printed to
standard error.

2 There was an error on the read, or on polling the input
file descriptor for a timeout. The parameter ERRNO gives
the error.

3 Data were successfully read, but there was an error
writing them to outfd. The parameter ERRNO gives the
error.

4 The attempt to read timed out. Note this does not set
ERRNO as this is not a system error.

5 No system error occurred, but zero bytes were read. This
usually indicates end of file. The parameters are set
according to the usual rules; no write to outfd is
attempted.

sysseek [ -u fd ] [ -w start|end|current ] offset
The current file position at which future reads and writes will
take place is adjusted to the specified byte offset. The offset
is evaluated as a math expression. The -u option allows the file
descriptor to be specified. By default the offset is specified
relative to the start or the file but, with the -w option, it is
possible to specify that the offset should be relative to the
current position or the end of the file.

syswrite [ -c countvar ] [ -o outfd ] data
The data (a single string of bytes) are written to the file
descriptor outfd, or 1 if that is not given, using the write
system call. Multiple write operations may be used if the first
does not write all the data.

If countvar is given, the number of byte written is stored in
the parameter named by countvar; this may not be the full length
of data if an error occurred.

The error EINTR (interrupted system call) is handled internally
by retrying; otherwise an error causes the command to return.
For example, if the file descriptor is set to non-blocking
output, an error EAGAIN (on some systems, EWOULDBLOCK) may
result in the command returning early.

The return status may be 0 for success, 1 for an error in the
parameters to the command, or 2 for an error on the write; no
error message is printed in the last case, but the parameter
ERRNO will reflect the error that occurred.

zsystem flock [ -t timeout ] [ -i interval ] [ -f var ] [-er] file
zsystem flock -u fd_expr
The builtin zsystem's subcommand flock performs advisory file
locking (via the fcntl(2) system call) over the entire contents
of the given file. This form of locking requires the processes
accessing the file to cooperate; its most obvious use is between
two instances of the shell itself.

In the first form the named file, which must already exist, is
locked by opening a file descriptor to the file and applying a
lock to the file descriptor. The lock terminates when the shell
process that created the lock exits; it is therefore often
convenient to create file locks within subshells, since the lock
is automatically released when the subshell exits. Note that
use of the print builtin with the -u option will, as a side
effect, release the lock, as will redirection to the file in the
shell holding the lock. To work around this use a subshell,
e.g. `(print message) >> file'. Status 0 is returned if the
lock succeeds, else status 1.

In the second form the file descriptor given by the arithmetic
expression fd_expr is closed, releasing a lock. The file
descriptor can be queried by using the `-f var' form during the
lock; on a successful lock, the shell variable var is set to the
file descriptor used for locking. The lock will be released if
the file descriptor is closed by any other means, for example
using `exec {var}>&-'; however, the form described here performs
a safety check that the file descriptor is in use for file
locking.

By default the shell waits indefinitely for the lock to succeed.
The option -t timeout specifies a timeout for the lock in
seconds; fractional seconds are allowed. During this period,
the shell will attempt to lock the file every interval seconds
if the -i interval option is given, otherwise once a second.
(This interval is shortened before the last attempt if needed,
so that the shell waits only until the timeout and not longer.)
If the attempt times out, status 2 is returned.

(Note: timeout is limited to 2^30-1 seconds (about 34 years),
and interval to 0.999 * LONG_MAX microseconds (only about 35
minutes on 32-bit systems).)

If the option -e is given, the file descriptor for the lock is
preserved when the shell uses exec to start a new process;
otherwise it is closed at that point and the lock released.

If the option -r is given, the lock is only for reading,
otherwise it is for reading and writing. The file descriptor is
opened accordingly.

zsystem supports subcommand
The builtin zsystem's subcommand supports tests whether a given
subcommand is supported. It returns status 0 if so, else status
1. It operates silently unless there was a syntax error (i.e.
the wrong number of arguments), in which case status 255 is
returned. Status 1 can indicate one of two things: subcommand
is known but not supported by the current operating system, or
subcommand is not known (possibly because this is an older
version of the shell before it was implemented).

Math Functions
systell(fd)
The systell math function returns the current file position for
the file descriptor passed as an argument.

Parameters
errnos A readonly array of the names of errors defined on the system.
These are typically macros defined in C by including the system
header file errno.h. The index of each name (assuming the
option KSH_ARRAYS is unset) corresponds to the error number.
Error numbers num before the last known error which have no name
are given the name Enum in the array.

Note that aliases for errors are not handled; only the canonical
name is used.

sysparams
A readonly associative array. The keys are:

pid Returns the process ID of the current process, even in
subshells. Compare $$, which returns the process ID of
the main shell process.

ppid Returns the current process ID of the parent of the
current process, even in subshells. Compare $PPID, which
returns the process ID of the initial parent of the main
shell process.

procsubstpid
Returns the process ID of the last process started for
process substitution, i.e. the <(...) and >(...)
expansions.

THE ZSH/NET/TCP MODULE
The zsh/net/tcp module makes available one builtin command:

ztcp [ -acflLtv ] [ -d fd ] [ args ]
ztcp is implemented as a builtin to allow full use of shell
command line editing, file I/O, and job control mechanisms.

If ztcp is run with no options, it will output the contents of
its session table.

If it is run with only the option -L, it will output the
contents of the session table in a format suitable for automatic
parsing. The option is ignored if given with a command to open
or close a session. The output consists of a set of lines, one
per session, each containing the following elements separated by
spaces:

File descriptor
The file descriptor in use for the connection. For
normal inbound (I) and outbound (O) connections this may
be read and written by the usual shell mechanisms.
However, it should only be close with `ztcp -c'.

Connection type
A letter indicating how the session was created:

Z A session created with the zftp command.

L A connection opened for listening with `ztcp -l'.

I An inbound connection accepted with `ztcp -a'.

O An outbound connection created with `ztcp host
...'.

The local host
This is usually set to an all-zero IP address as the
address of the localhost is irrelevant.

The local port
This is likely to be zero unless the connection is for
listening.

The remote host
This is the fully qualified domain name of the peer, if
available, else an IP address. It is an all-zero IP
address for a session opened for listening.

The remote port
This is zero for a connection opened for listening.

Outbound Connections
ztcp [ -v ] [ -d fd ] host [ port ]
Open a new TCP connection to host. If the port is omitted, it
will default to port 23. The connection will be added to the
session table and the shell parameter REPLY will be set to the
file descriptor associated with that connection.

If -d is specified, its argument will be taken as the target
file descriptor for the connection.

In order to elicit more verbose output, use -v.

Inbound Connections
ztcp -l [ -v ] [ -d fd ] port
ztcp -l will open a socket listening on TCP port. The socket
will be added to the session table and the shell parameter REPLY
will be set to the file descriptor associated with that
listener.

If -d is specified, its argument will be taken as the target
file descriptor for the connection.

In order to elicit more verbose output, use -v.

ztcp -a [ -tv ] [ -d targetfd ] listenfd
ztcp -a will accept an incoming connection to the port
associated with listenfd. The connection will be added to the
session table and the shell parameter REPLY will be set to the
file descriptor associated with the inbound connection.

If -d is specified, its argument will be taken as the target
file descriptor for the connection.

If -t is specified, ztcp will return if no incoming connection
is pending. Otherwise it will wait for one.

In order to elicit more verbose output, use -v.

Closing Connections
ztcp -cf [ -v ] [ fd ]
ztcp -c [ -v ] [ fd ]
ztcp -c will close the socket associated with fd. The socket
will be removed from the session table. If fd is not specified,
ztcp will close everything in the session table.

Normally, sockets registered by zftp (see zshmodules(1) ) cannot
be closed this way. In order to force such a socket closed, use
-f.

In order to elicit more verbose output, use -v.

Example
Here is how to create a TCP connection between two instances of zsh.
We need to pick an unassigned port; here we use the randomly chosen
5123.

On host1,
zmodload zsh/net/tcp
ztcp -l 5123
listenfd=$REPLY
ztcp -a $listenfd
fd=$REPLY
The second from last command blocks until there is an incoming
connection.

Now create a connection from host2 (which may, of course, be the same
machine):
zmodload zsh/net/tcp
ztcp host1 5123
fd=$REPLY

Now on each host, $fd contains a file descriptor for talking to the
other. For example, on host1:
print This is a message >&$fd
and on host2:
read -r line <&$fd; print -r - $line
prints `This is a message'.

To tidy up, on host1:
ztcp -c $listenfd
ztcp -c $fd
and on host2
ztcp -c $fd

THE ZSH/TERMCAP MODULE
The zsh/termcap module makes available one builtin command:

echotc cap [ arg ... ]
Output the termcap value corresponding to the capability cap,
with optional arguments.

The zsh/termcap module makes available one parameter:

termcap
An associative array that maps termcap capability codes to their
values.

THE ZSH/TERMINFO MODULE
The zsh/terminfo module makes available one builtin command:

echoti cap [ arg ]
Output the terminfo value corresponding to the capability cap,
instantiated with arg if applicable.

The zsh/terminfo module makes available one parameter:

terminfo
An associative array that maps terminfo capability names to
their values.

THE ZSH/WATCH MODULE
The zsh/watch module can be used to report when specific users log in
or out. This is controlled via the following parameters.

LOGCHECK
The interval in seconds between checks for login/logout activity
using the watch parameter.

watch <S> <Z> (WATCH <S>)
An array (colon-separated list) of login/logout events to
report.

If it contains the single word `all', then all login/logout
events are reported. If it contains the single word `notme',
then all events are reported as with `all' except $USERNAME.

An entry in this list may consist of a username, an `@' followed
by a remote hostname, and a `%' followed by a line (tty). Any
of these may be a pattern (be sure to quote this during the
assignment to watch so that it does not immediately perform file
generation); the setting of the EXTENDED_GLOB option is
respected. Any or all of these components may be present in an
entry; if a login/logout event matches all of them, it is
reported.

For example, with the EXTENDED_GLOB option set, the following:

watch=('^(pws|barts)')

causes reports for activity associated with any user other than
pws or barts.

WATCHFMT
The format of login/logout reports if the watch parameter is
set. Default is `%n has %a %l from %m'. Recognizes the
following escape sequences:

%n The name of the user that logged in/out.

%a The observed action, i.e. "logged on" or "logged off".

%l The line (tty) the user is logged in on.

%M The full hostname of the remote host.

%m The hostname up to the first `.'. If only the IP address
is available or the utmp field contains the name of an
X-windows display, the whole name is printed.

NOTE: The `%m' and `%M' escapes will work only if there
is a host name field in the utmp on your machine.
Otherwise they are treated as ordinary strings.

%F{color} (%f)
Start (stop) using a different foreground color.

%K{color} (%k)
Start (stop) using a different background color.

%S (%s)
Start (stop) standout mode.

%U (%u)
Start (stop) underline mode.

%B (%b)
Start (stop) boldface mode.

%t
%@ The time, in 12-hour, am/pm format.

%T The time, in 24-hour format.

%w The date in `day-dd' format.

%W The date in `mm/dd/yy' format.

%D The date in `yy-mm-dd' format.

%D{string}
The date formatted as string using the strftime function,
with zsh extensions as described by EXPANSION OF PROMPT
SEQUENCES in zshmisc(1).

%(x:true-text:false-text)
Specifies a ternary expression. The character following
the x is arbitrary; the same character is used to
separate the text for the "true" result from that for the
"false" result. Both the separator and the right
parenthesis may be escaped with a backslash. Ternary
expressions may be nested.

The test character x may be any one of `l', `n', `m' or
`M', which indicate a `true' result if the corresponding
escape sequence would return a non-empty value; or it may
be `a', which indicates a `true' result if the watched
user has logged in, or `false' if he has logged out.
Other characters evaluate to neither true nor false; the
entire expression is omitted in this case.

If the result is `true', then the true-text is formatted
according to the rules above and printed, and the
false-text is skipped. If `false', the true-text is
skipped and the false-text is formatted and printed.
Either or both of the branches may be empty, but both
separators must be present in any case.

Furthermore, the zsh/watch module makes available one builtin command:

log List all users currently logged in who are affected by the
current setting of the watch parameter.

THE ZSH/ZFTP MODULE
The zsh/zftp module makes available one builtin command:

zftp subcommand [ args ]
The zsh/zftp module is a client for FTP (file transfer
protocol). It is implemented as a builtin to allow full use of
shell command line editing, file I/O, and job control
mechanisms. Often, users will access it via shell functions
providing a more powerful interface; a set is provided with the
zsh distribution and is described in zshzftpsys(1). However,
the zftp command is entirely usable in its own right.

All commands consist of the command name zftp followed by the
name of a subcommand. These are listed below. The return
status of each subcommand is supposed to reflect the success or
failure of the remote operation. See a description of the
variable ZFTP_VERBOSE for more information on how responses from
the server may be printed.

Subcommands
open host[:port] [ user [ password [ account ] ] ]
Open a new FTP session to host, which may be the name of a
TCP/IP connected host or an IP number in the standard dot
notation. If the argument is in the form host:port, open a
connection to TCP port port instead of the standard FTP port 21.
This may be the name of a TCP service or a number: see the
description of ZFTP_PORT below for more information.

If IPv6 addresses in colon format are used, the host should be
surrounded by quoted square brackets to distinguish it from the
port, for example '[fe80::203:baff:fe02:8b56]'. For consistency
this is allowed with all forms of host.

Remaining arguments are passed to the login subcommand. Note
that if no arguments beyond host are supplied, open will not
automatically call login. If no arguments at all are supplied,
open will use the parameters set by the params subcommand.

After a successful open, the shell variables ZFTP_HOST,
ZFTP_PORT, ZFTP_IP and ZFTP_SYSTEM are available; see
`Variables' below.

login [ name [ password [ account ] ] ]
user [ name [ password [ account ] ] ]
Login the user name with parameters password and account. Any
of the parameters can be omitted, and will be read from standard
input if needed (name is always needed). If standard input is a
terminal, a prompt for each one will be printed on standard
error and password will not be echoed. If any of the parameters
are not used, a warning message is printed.

After a successful login, the shell variables ZFTP_USER,
ZFTP_ACCOUNT and ZFTP_PWD are available; see `Variables' below.

This command may be re-issued when a user is already logged in,
and the server will first be reinitialized for a new user.

params [ host [ user [ password [ account ] ] ] ]
params -
Store the given parameters for a later open command with no
arguments. Only those given on the command line will be
remembered. If no arguments are given, the parameters currently
set are printed, although the password will appear as a line of
stars; the return status is one if no parameters were set, zero
otherwise.

Any of the parameters may be specified as a `?', which may need
to be quoted to protect it from shell expansion. In this case,
the appropriate parameter will be read from stdin as with the
login subcommand, including special handling of password. If
the `?' is followed by a string, that is used as the prompt for
reading the parameter instead of the default message (any
necessary punctuation and whitespace should be included at the
end of the prompt). The first letter of the parameter (only)
may be quoted with a `\'; hence an argument "\\$word" guarantees
that the string from the shell parameter $word will be treated
literally, whether or not it begins with a `?'.

If instead a single `-' is given, the existing parameters, if
any, are deleted. In that case, calling open with no arguments
will cause an error.

The list of parameters is not deleted after a close, however it
will be deleted if the zsh/zftp module is unloaded.

For example,

zftp params ftp.elsewhere.xx juser '?Password for juser: '

will store the host ftp.elsewhere.xx and the user juser and then
prompt the user for the corresponding password with the given
prompt.

test Test the connection; if the server has reported that it has
closed the connection (maybe due to a timeout), return status 2;
if no connection was open anyway, return status 1; else return
status 0. The test subcommand is silent, apart from messages
printed by the $ZFTP_VERBOSE mechanism, or error messages if the
connection closes. There is no network overhead for this test.

The test is only supported on systems with either the select(2)
or poll(2) system calls; otherwise the message `not supported on
this system' is printed instead.

The test subcommand will automatically be called at the start of
any other subcommand for the current session when a connection
is open.

cd directory
Change the remote directory to directory. Also alters the shell
variable ZFTP_PWD.

cdup Change the remote directory to the one higher in the directory
tree. Note that cd .. will also work correctly on non-UNIX
systems.

dir [ arg ... ]
Give a (verbose) listing of the remote directory. The args are
passed directly to the server. The command's behaviour is
implementation dependent, but a UNIX server will typically
interpret args as arguments to the ls command and with no
arguments return the result of `ls -l'. The directory is listed
to standard output.

ls [ arg ... ]
Give a (short) listing of the remote directory. With no arg,
produces a raw list of the files in the directory, one per line.
Otherwise, up to vagaries of the server implementation, behaves
similar to dir.

type [ type ]
Change the type for the transfer to type, or print the current
type if type is absent. The allowed values are `A' (ASCII), `I'
(Image, i.e. binary), or `B' (a synonym for `I').

The FTP default for a transfer is ASCII. However, if zftp finds
that the remote host is a UNIX machine with 8-bit byes, it will
automatically switch to using binary for file transfers upon
open. This can subsequently be overridden.

The transfer type is only passed to the remote host when a data
connection is established; this command involves no network
overhead.

ascii The same as type A.

binary The same as type I.

mode [ S | B ]
Set the mode type to stream (S) or block (B). Stream mode is
the default; block mode is not widely supported.

remote file ...
local [ file ... ]
Print the size and last modification time of the remote or local
files. If there is more than one item on the list, the name of
the file is printed first. The first number is the file size,
the second is the last modification time of the file in the
format CCYYMMDDhhmmSS consisting of year, month, date, hour,
minutes and seconds in GMT. Note that this format, including
the length, is guaranteed, so that time strings can be directly
compared via the [[ builtin's < and > operators, even if they
are too long to be represented as integers.

Not all servers support the commands for retrieving this
information. In that case, the remote command will print
nothing and return status 2, compared with status 1 for a file
not found.

The local command (but not remote) may be used with no
arguments, in which case the information comes from examining
file descriptor zero. This is the same file as seen by a put
command with no further redirection.

get file ...
Retrieve all files from the server, concatenating them and
sending them to standard output.

put file ...
For each file, read a file from standard input and send that to
the remote host with the given name.

append file ...
As put, but if the remote file already exists, data is appended
to it instead of overwriting it.

getat file point
putat file point
appendat file point
Versions of get, put and append which will start the transfer at
the given point in the remote file. This is useful for
appending to an incomplete local file. However, note that this
ability is not universally supported by servers (and is not
quite the behaviour specified by the standard).

delete file ...
Delete the list of files on the server.

mkdir directory
Create a new directory directory on the server.

rmdir directory
Delete the directory directory on the server.

rename old-name new-name
Rename file old-name to new-name on the server.

site arg ...
Send a host-specific command to the server. You will probably
only need this if instructed by the server to use it.

quote arg ...
Send the raw FTP command sequence to the server. You should be
familiar with the FTP command set as defined in RFC959 before
doing this. Useful commands may include STAT and HELP. Note
also the mechanism for returning messages as described for the
variable ZFTP_VERBOSE below, in particular that all messages
from the control connection are sent to standard error.

close
quit Close the current data connection. This unsets the shell
parameters ZFTP_HOST, ZFTP_PORT, ZFTP_IP, ZFTP_SYSTEM,
ZFTP_USER, ZFTP_ACCOUNT, ZFTP_PWD, ZFTP_TYPE and ZFTP_MODE.

session [ sessname ]
Allows multiple FTP sessions to be used at once. The name of
the session is an arbitrary string of characters; the default
session is called `default'. If this command is called without
an argument, it will list all the current sessions; with an
argument, it will either switch to the existing session called
sessname, or create a new session of that name.

Each session remembers the status of the connection, the set of
connection-specific shell parameters (the same set as are unset
when a connection closes, as given in the description of close),
and any user parameters specified with the params subcommand.
Changing to a previous session restores those values; changing
to a new session initialises them in the same way as if zftp had
just been loaded. The name of the current session is given by
the parameter ZFTP_SESSION.

rmsession [ sessname ]
Delete a session; if a name is not given, the current session is
deleted. If the current session is deleted, the earliest
existing session becomes the new current session, otherwise the
current session is not changed. If the session being deleted is
the only one, a new session called `default' is created and
becomes the current session; note that this is a new session
even if the session being deleted is also called `default'. It
is recommended that sessions not be deleted while background
commands which use zftp are still active.

Parameters
The following shell parameters are used by zftp. Currently none of
them are special.

ZFTP_TMOUT
Integer. The time in seconds to wait for a network operation to
complete before returning an error. If this is not set when the
module is loaded, it will be given the default value 60. A
value of zero turns off timeouts. If a timeout occurs on the
control connection it will be closed. Use a larger value if
this occurs too frequently.

ZFTP_IP
Readonly. The IP address of the current connection in dot
notation.

ZFTP_HOST
Readonly. The hostname of the current remote server. If the
host was opened as an IP number, ZFTP_HOST contains that
instead; this saves the overhead for a name lookup, as IP
numbers are most commonly used when a nameserver is unavailable.

ZFTP_PORT
Readonly. The number of the remote TCP port to which the
connection is open (even if the port was originally specified as
a named service). Usually this is the standard FTP port, 21.

In the unlikely event that your system does not have the
appropriate conversion functions, this appears in network byte
order. If your system is little-endian, the port then consists
of two swapped bytes and the standard port will be reported as
5376. In that case, numeric ports passed to zftp open will also
need to be in this format.

ZFTP_SYSTEM
Readonly. The system type string returned by the server in
response to an FTP SYST request. The most interesting case is a
string beginning "UNIX Type: L8", which ensures maximum
compatibility with a local UNIX host.

ZFTP_TYPE
Readonly. The type to be used for data transfers , either `A'
or `I'. Use the type subcommand to change this.

ZFTP_USER
Readonly. The username currently logged in, if any.

ZFTP_ACCOUNT
Readonly. The account name of the current user, if any. Most
servers do not require an account name.

ZFTP_PWD
Readonly. The current directory on the server.

ZFTP_CODE
Readonly. The three digit code of the last FTP reply from the
server as a string. This can still be read after the connection
is closed, and is not changed when the current session changes.

ZFTP_REPLY
Readonly. The last line of the last reply sent by the server.
This can still be read after the connection is closed, and is
not changed when the current session changes.

ZFTP_SESSION
Readonly. The name of the current FTP session; see the
description of the session subcommand.

ZFTP_PREFS
A string of preferences for altering aspects of zftp's
behaviour. Each preference is a single character. The
following are defined:

P Passive: attempt to make the remote server initiate data
transfers. This is slightly more efficient than sendport
mode. If the letter S occurs later in the string, zftp
will use sendport mode if passive mode is not available.

S Sendport: initiate transfers by the FTP PORT command.
If this occurs before any P in the string, passive mode
will never be attempted.

D Dumb: use only the bare minimum of FTP commands. This
prevents the variables ZFTP_SYSTEM and ZFTP_PWD from
being set, and will mean all connections default to ASCII
type. It may prevent ZFTP_SIZE from being set during a
transfer if the server does not send it anyway (many
servers do).

If ZFTP_PREFS is not set when zftp is loaded, it will be set to
a default of `PS', i.e. use passive mode if available, otherwise
fall back to sendport mode.

ZFTP_VERBOSE
A string of digits between 0 and 5 inclusive, specifying which
responses from the server should be printed. All responses go
to standard error. If any of the numbers 1 to 5 appear in the
string, raw responses from the server with reply codes beginning
with that digit will be printed to standard error. The first
digit of the three digit reply code is defined by RFC959 to
correspond to:

1. A positive preliminary reply.

2. A positive completion reply.

3. A positive intermediate reply.

4. A transient negative completion reply.

5. A permanent negative completion reply.

It should be noted that, for unknown reasons, the reply `Service
not available', which forces termination of a connection, is
classified as 421, i.e. `transient negative', an interesting
interpretation of the word `transient'.

The code 0 is special: it indicates that all but the last line
of multiline replies read from the server will be printed to
standard error in a processed format. By convention, servers
use this mechanism for sending information for the user to read.
The appropriate reply code, if it matches the same response,
takes priority.

If ZFTP_VERBOSE is not set when zftp is loaded, it will be set
to the default value 450, i.e., messages destined for the user
and all errors will be printed. A null string is valid and
specifies that no messages should be printed.

Functions
zftp_chpwd
If this function is set by the user, it is called every time the
directory changes on the server, including when a user is logged
in, or when a connection is closed. In the last case, $ZFTP_PWD
will be unset; otherwise it will reflect the new directory.

zftp_progress
If this function is set by the user, it will be called during a
get, put or append operation each time sufficient data has been
received from the host. During a get, the data is sent to
standard output, so it is vital that this function should write
to standard error or directly to the terminal, not to standard
output.

When it is called with a transfer in progress, the following
additional shell parameters are set:

ZFTP_FILE
The name of the remote file being transferred from or to.

ZFTP_TRANSFER
A G for a get operation and a P for a put operation.

ZFTP_SIZE
The total size of the complete file being transferred:
the same as the first value provided by the remote and
local subcommands for a particular file. If the server
cannot supply this value for a remote file being
retrieved, it will not be set. If input is from a pipe
the value may be incorrect and correspond simply to a
full pipe buffer.

ZFTP_COUNT
The amount of data so far transferred; a number between
zero and $ZFTP_SIZE, if that is set. This number is
always available.

The function is initially called with ZFTP_TRANSFER set
appropriately and ZFTP_COUNT set to zero. After the transfer is
finished, the function will be called one more time with
ZFTP_TRANSFER set to GF or PF, in case it wishes to tidy up. It
is otherwise never called twice with the same value of
ZFTP_COUNT.

Sometimes the progress meter may cause disruption. It is up to
the user to decide whether the function should be defined and to
use unfunction when necessary.

Problems
A connection may not be opened in the left hand side of a pipe as this
occurs in a subshell and the file information is not updated in the
main shell. In the case of type or mode changes or closing the
connection in a subshell, the information is returned but variables are
not updated until the next call to zftp. Other status changes in
subshells will not be reflected by changes to the variables (but should
be otherwise harmless).

Deleting sessions while a zftp command is active in the background can
have unexpected effects, even if it does not use the session being
deleted. This is because all shell subprocesses share information on
the state of all connections, and deleting a session changes the
ordering of that information.

On some operating systems, the control connection is not valid after a
fork(), so that operations in subshells, on the left hand side of a
pipeline, or in the background are not possible, as they should be.
This is presumably a bug in the operating system.

THE ZSH/ZLE MODULE
The zsh/zle module contains the Zsh Line Editor. See zshzle(1).

THE ZSH/ZLEPARAMETER MODULE
The zsh/zleparameter module defines two special parameters that can be
used to access internal information of the Zsh Line Editor (see
zshzle(1)).

keymaps
This array contains the names of the keymaps currently defined.

widgets
This associative array contains one entry per widget. The name
of the widget is the key and the value gives information about
the widget. It is either
the string `builtin' for builtin widgets,
a string of the form `user:name' for user-defined widgets,
where name is the name of the shell function implementing
the widget,
a string of the form `completion:type:name'
for completion widgets,
or a null value if the widget is not yet fully defined. In
the penultimate case, type is the name of the builtin widget the
completion widget imitates in its behavior and name is the name
of the shell function implementing the completion widget.

THE ZSH/ZPROF MODULE
When loaded, the zsh/zprof causes shell functions to be profiled. The
profiling results can be obtained with the zprof builtin command made
available by this module. There is no way to turn profiling off other
than unloading the module.

zprof [ -c ]
Without the -c option, zprof lists profiling results to standard
output. The format is comparable to that of commands like
gprof.

At the top there is a summary listing all functions that were
called at least once. This summary is sorted in decreasing
order of the amount of time spent in each. The lines contain
the number of the function in order, which is used in other
parts of the list in suffixes of the form `[num]', then the
number of calls made to the function. The next three columns
list the time in milliseconds spent in the function and its
descendants, the average time in milliseconds spent in the
function and its descendants per call and the percentage of time
spent in all shell functions used in this function and its
descendants. The following three columns give the same
information, but counting only the time spent in the function
itself. The final column shows the name of the function.

After the summary, detailed information about every function
that was invoked is listed, sorted in decreasing order of the
amount of time spent in each function and its descendants. Each
of these entries consists of descriptions for the functions that
called the function described, the function itself, and the
functions that were called from it. The description for the
function itself has the same format as in the summary (and shows
the same information). The other lines don't show the number of
the function at the beginning and have their function named
indented to make it easier to distinguish the line showing the
function described in the section from the surrounding lines.

The information shown in this case is almost the same as in the
summary, but only refers to the call hierarchy being displayed.
For example, for a calling function the column showing the total
running time lists the time spent in the described function and
its descendants only for the times when it was called from that
particular calling function. Likewise, for a called function,
this columns lists the total time spent in the called function
and its descendants only for the times when it was called from
the function described.

Also in this case, the column showing the number of calls to a
function also shows a slash and then the total number of
invocations made to the called function.

As long as the zsh/zprof module is loaded, profiling will be
done and multiple invocations of the zprof builtin command will
show the times and numbers of calls since the module was loaded.
With the -c option, the zprof builtin command will reset its
internal counters and will not show the listing.

THE ZSH/ZPTY MODULE
The zsh/zpty module offers one builtin:

zpty [ -e ] [ -b ] name [ arg ... ]
The arguments following name are concatenated with spaces
between, then executed as a command, as if passed to the eval
builtin. The command runs under a newly assigned
pseudo-terminal; this is useful for running commands
non-interactively which expect an interactive environment. The
name is not part of the command, but is used to refer to this
command in later calls to zpty.

With the -e option, the pseudo-terminal is set up so that input
characters are echoed.

With the -b option, input to and output from the pseudo-terminal
are made non-blocking.

The shell parameter REPLY is set to the file descriptor assigned
to the master side of the pseudo-terminal. This allows the
terminal to be monitored with ZLE descriptor handlers (see
zshzle(1)) or manipulated with sysread and syswrite (see THE
ZSH/SYSTEM MODULE in zshmodules(1)). Warning: Use of sysread
and syswrite is not recommended; use zpty -r and zpty -w unless
you know exactly what you are doing.

zpty -d [ name ... ]
The second form, with the -d option, is used to delete commands
previously started, by supplying a list of their names. If no
name is given, all commands are deleted. Deleting a command
causes the HUP signal to be sent to the corresponding process.

zpty -w [ -n ] name [ string ... ]
The -w option can be used to send the to command name the given
strings as input (separated by spaces). If the -n option is not
given, a newline is added at the end.

If no string is provided, the standard input is copied to the
pseudo-terminal; this may stop before copying the full input if
the pseudo-terminal is non-blocking. The exact input is always
copied: the -n option is not applied.

Note that the command under the pseudo-terminal sees this input
as if it were typed, so beware when sending special tty driver
characters such as word-erase, line-kill, and end-of-file.

zpty -r [ -mt ] name [ param [ pattern ] ]
The -r option can be used to read the output of the command
name. With only a name argument, the output read is copied to
the standard output. Unless the pseudo-terminal is
non-blocking, copying continues until the command under the
pseudo-terminal exits; when non-blocking, only as much output as
is immediately available is copied. The return status is zero
if any output is copied.

When also given a param argument, at most one line is read and
stored in the parameter named param. Less than a full line may
be read if the pseudo-terminal is non-blocking. The return
status is zero if at least one character is stored in param.

If a pattern is given as well, output is read until the whole
string read matches the pattern, even in the non-blocking case.
The return status is zero if the string read matches the
pattern, or if the command has exited but at least one character
could still be read. If the option -m is present, the return
status is zero only if the pattern matches. As of this writing,
a maximum of one megabyte of output can be consumed this way; if
a full megabyte is read without matching the pattern, the return
status is non-zero.

In all cases, the return status is non-zero if nothing could be
read, and is 2 if this is because the command has finished.

If the -r option is combined with the -t option, zpty tests
whether output is available before trying to read. If no output
is available, zpty immediately returns the status 1. When used
with a pattern, the behaviour on a failed poll is similar to
when the command has exited: the return value is zero if at
least one character could still be read even if the pattern
failed to match.

zpty -t name
The -t option without the -r option can be used to test whether
the command name is still running. It returns a zero status if
the command is running and a non-zero value otherwise.

zpty [ -L ]
The last form, without any arguments, is used to list the
commands currently defined. If the -L option is given, this is
done in the form of calls to the zpty builtin.

THE ZSH/ZSELECT MODULE
The zsh/zselect module makes available one builtin command:

zselect [ -rwe ] [ -t timeout ] [ -a array ] [ -A assoc ] [ fd ... ]
The zselect builtin is a front-end to the `select' system call,
which blocks until a file descriptor is ready for reading or
writing, or has an error condition, with an optional timeout.
If this is not available on your system, the command prints an
error message and returns status 2 (normal errors return status
1). For more information, see your system's documentation for
select(3). Note there is no connection with the shell builtin
of the same name.

Arguments and options may be intermingled in any order.
Non-option arguments are file descriptors, which must be decimal
integers. By default, file descriptors are to be tested for
reading, i.e. zselect will return when data is available to be
read from the file descriptor, or more precisely, when a read
operation from the file descriptor will not block. After a -r,
-w and -e, the given file descriptors are to be tested for
reading, writing, or error conditions. These options and an
arbitrary list of file descriptors may be given in any order.

(The presence of an `error condition' is not well defined in the
documentation for many implementations of the select system
call. According to recent versions of the POSIX specification,
it is really an exception condition, of which the only standard
example is out-of-band data received on a socket. So zsh users
are unlikely to find the -e option useful.)

The option `-t timeout' specifies a timeout in hundredths of a
second. This may be zero, in which case the file descriptors
will simply be polled and zselect will return immediately. It
is possible to call zselect with no file descriptors and a
non-zero timeout for use as a finer-grained replacement for
`sleep'; note, however, the return status is always 1 for a
timeout.

The option `-a array' indicates that array should be set to
indicate the file descriptor(s) which are ready. If the option
is not given, the array reply will be used for this purpose.
The array will contain a string similar to the arguments for
zselect. For example,

zselect -t 0 -r 0 -w 1

might return immediately with status 0 and $reply containing `-r
0 -w 1' to show that both file descriptors are ready for the
requested operations.

The option `-A assoc' indicates that the associative array assoc
should be set to indicate the file descriptor(s) which are
ready. This option overrides the option -a, nor will reply be
modified. The keys of assoc are the file descriptors, and the
corresponding values are any of the characters `rwe' to indicate
the condition.

The command returns status 0 if some file descriptors are ready
for reading. If the operation timed out, or a timeout of 0 was
given and no file descriptors were ready, or there was an error,
it returns status 1 and the array will not be set (nor modified
in any way). If there was an error in the select operation the
appropriate error message is printed.

THE ZSH/ZUTIL MODULE
The zsh/zutil module only adds some builtins:

zstyle [ -L [ metapattern [ style ] ] ]
zstyle [ -e | - | -- ] pattern style string ...
zstyle -d [ pattern [ style ... ] ]
zstyle -g name [ pattern [ style ] ]
zstyle -{a|b|s} context style name [ sep ]
zstyle -{T|t} context style [ string ... ]
zstyle -m context style pattern
This builtin command is used to define and lookup styles.
Styles are pairs of names and values, where the values consist
of any number of strings. They are stored together with
patterns and lookup is done by giving a string, called the
`context', which is matched against the patterns. The
definition stored for the most specific pattern that matches
will be returned.

A pattern is considered to be more specific than another if it
contains more components (substrings separated by colons) or if
the patterns for the components are more specific, where simple
strings are considered to be more specific than patterns and
complex patterns are considered to be more specific than the
pattern `*'. A `*' in the pattern will match zero or more
characters in the context; colons are not treated specially in
this regard. If two patterns are equally specific, the tie is
broken in favour of the pattern that was defined first.

Example

For example, a fictional `weather' plugin might state in its
documentation that it looks up the preferred-precipitation style
under the `:weather:continent:day-of-the-week:phase-of-the-moon'
context. According to this, you might set the following in your
zshrc:

zstyle ':weather:europe:*' preferred-precipitation rain
zstyle ':weather:*:Sunday:*' preferred-precipitation snow

Then the plugin would run under the hood a command such as

zstyle -s ":weather:${continent}:${day_of_week}:${moon_phase}" preferred-precipitation REPLY

in order to retrieve your preference into the scalar variable
$REPLY. On Sundays $REPLY would be set to `snow'; in Europe it
would be set to `rain'; and on Sundays in Europe it would be set
to `snow' again, because the patterns `:weather:europe:*' and
`:weather:*:Sunday:*' both match the context argument to zstyle
-s, are equally specific, and the latter is more specific
(because it has more colon-separated components).

Usage

The forms that operate on patterns are the following.

zstyle [ -L [ metapattern [ style ] ] ]
Without arguments, lists style definitions. Styles are
shown in alphabetic order and patterns are shown in the
order zstyle will test them.

If the -L option is given, listing is done in the form of
calls to zstyle. The optional first argument,
metapattern, is a pattern which will be matched against
the string supplied as pattern when the style was
defined. Note: this means, for example, `zstyle -L
":completion:*"' will match any supplied pattern
beginning `:completion:', not just ":completion:*": use
':completion:\*' to match that. The optional second
argument limits the output to a specific style (not a
pattern). -L is not compatible with any other options.

zstyle [ - | -- | -e ] pattern style string ...
Defines the given style for the pattern with the strings
as the value. If the -e option is given, the strings
will be concatenated (separated by spaces) and the
resulting string will be evaluated (in the same way as it
is done by the eval builtin command) when the style is
looked up. In this case the parameter `reply' must be
assigned to set the strings returned after the
evaluation. Before evaluating the value, reply is unset,
and if it is still unset after the evaluation, the style
is treated as if it were not set.

zstyle -d [ pattern [ style ... ] ]
Delete style definitions. Without arguments all
definitions are deleted, with a pattern all definitions
for that pattern are deleted and if any styles are given,
then only those styles are deleted for the pattern.

zstyle -g name [ pattern [ style ] ]
Retrieve a style definition. The name is used as the name
of an array in which the results are stored. Without any
further arguments, all patterns defined are returned.
With a pattern the styles defined for that pattern are
returned and with both a pattern and a style, the value
strings of that combination is returned.

The other forms can be used to look up or test styles for a
given context.

zstyle -s context style name [ sep ]
The parameter name is set to the value of the style
interpreted as a string. If the value contains several
strings they are concatenated with spaces (or with the
sep string if that is given) between them.

Return 0 if the style is set, 1 otherwise.

zstyle -b context style name
The value is stored in name as a boolean, i.e. as the
string `yes' if the value has only one string and that
string is equal to one of `yes', `true', `on', or `1'. If
the value is any other string or has more than one
string, the parameter is set to `no'.

Return 0 if name is set to `yes', 1 otherwise.

zstyle -a context style name
The value is stored in name as an array. If name is
declared as an associative array, the first, third, etc.
strings are used as the keys and the other strings are
used as the values.

Return 0 if the style is set, 1 otherwise.

zstyle -t context style [ string ... ]
zstyle -T context style [ string ... ]
Test the value of a style, i.e. the -t option only
returns a status (sets $?). Without any string the
return status is zero if the style is defined for at
least one matching pattern, has only one string in its
value, and that is equal to one of `true', `yes', `on' or
`1'. If any strings are given the status is zero if and
only if at least one of the strings is equal to at least
one of the strings in the value. If the style is defined
but doesn't match, the return status is 1. If the style
is not defined, the status is 2.

The -T option tests the values of the style like -t, but
it returns status zero (rather than 2) if the style is
not defined for any matching pattern.

zstyle -m context style pattern
Match a value. Returns status zero if the pattern matches
at least one of the strings in the value.

zformat -f param format spec ...
zformat -F param format spec ...
zformat -a array sep spec ...
This builtin provides different forms of formatting. The first
form is selected with the -f option. In this case the format
string will be modified by replacing sequences starting with a
percent sign in it with strings from the specs. Each spec
should be of the form `char:string' which will cause every
appearance of the sequence `%char' in format to be replaced by
the string. The `%' sequence may also contain optional minimum
and maximum field width specifications between the `%' and the
`char' in the form `%min.maxc', i.e. the minimum field width is
given first and if the maximum field width is used, it has to be
preceded by a dot. Specifying a minimum field width makes the
result be padded with spaces to the right if the string is
shorter than the requested width. Padding to the left can be
achieved by giving a negative minimum field width. If a maximum
field width is specified, the string will be truncated after
that many characters. After all `%' sequences for the given
specs have been processed, the resulting string is stored in the
parameter param.

The %-escapes also understand ternary expressions in the form
used by prompts. The % is followed by a `(' and then an
ordinary format specifier character as described above. There
may be a set of digits either before or after the `('; these
specify a test number, which defaults to zero. Negative numbers
are also allowed. An arbitrary delimiter character follows the
format specifier, which is followed by a piece of `true' text,
the delimiter character again, a piece of `false' text, and a
closing parenthesis. The complete expression (without the
digits) thus looks like `%(X.text1.text2)', except that the `.'
character is arbitrary. The value given for the format
specifier in the char:string expressions is evaluated as a
mathematical expression, and compared with the test number. If
they are the same, text1 is output, else text2 is output. A
parenthesis may be escaped in text2 as %). Either of text1 or
text2 may contain nested %-escapes.

For example:

zformat -f REPLY "The answer is '%3(c.yes.no)'." c:3

outputs "The answer is 'yes'." to REPLY since the value for the
format specifier c is 3, agreeing with the digit argument to the
ternary expression.

With -F instead of -f, ternary expressions choose between the
`true' or `false' text on the basis of whether the format
specifier is present and non-empty. A test number indicates a
minimum width for the value given in the format specifier.
Negative numbers reverse this, so the test is for whether the
value exceeds a maximum width.

The form, using the -a option, can be used for aligning strings.
Here, the specs are of the form `left:right' where `left' and
`right' are arbitrary strings. These strings are modified by
replacing the colons by the sep string and padding the left
strings with spaces to the right so that the sep strings in the
result (and hence the right strings after them) are all aligned
if the strings are printed below each other. All strings
without a colon are left unchanged and all strings with an empty
right string have the trailing colon removed. In both cases the
lengths of the strings are not used to determine how the other
strings are to be aligned. A colon in the left string can be
escaped with a backslash. The resulting strings are stored in
the array.

zregexparse
This implements some internals of the _regex_arguments function.

zparseopts [ -D -E -F -K -M ] [ -a array ] [ -A assoc ] [ - ] spec ...
This builtin simplifies the parsing of options in positional
parameters, i.e. the set of arguments given by $*. Each spec
describes one option and must be of the form `opt[=array]'. If
an option described by opt is found in the positional parameters
it is copied into the array specified with the -a option; if the
optional `=array' is given, it is instead copied into that
array, which should be declared as a normal array and never as
an associative array.

Note that it is an error to give any spec without an `=array'
unless one of the -a or -A options is used.

Unless the -E option is given, parsing stops at the first string
that isn't described by one of the specs. Even with -E, parsing
always stops at a positional parameter equal to `-' or `--'. See
also -F.

The opt description must be one of the following. Any of the
special characters can appear in the option name provided it is
preceded by a backslash.

name
name* The name is the name of the option without the leading
`-'. To specify a GNU-style long option, one of the
usual two leading `-' must be included in name; for
example, a `--file' option is represented by a name of
`-file'.

If a `*' appears after name, the option is appended to
array each time it is found in the positional parameters;
without the `*' only the last occurrence of the option is
preserved.

If one of these forms is used, the option takes no
argument, so parsing stops if the next positional
parameter does not also begin with `-' (unless the -E
option is used).

name:
name:-
name:: If one or two colons are given, the option takes an
argument; with one colon, the argument is mandatory and
with two colons it is optional. The argument is appended
to the array after the option itself.

An optional argument is put into the same array element
as the option name (note that this makes empty strings as
arguments indistinguishable). A mandatory argument is
added as a separate element unless the `:-' form is used,
in which case the argument is put into the same element.

A `*' as described above may appear between the name and
the first colon.

In all cases, option-arguments must appear either immediately
following the option in the same positional parameter or in the
next one. Even an optional argument may appear in the next
parameter, unless it begins with a `-'. There is no special
handling of `=' as with GNU-style argument parsers; given the
spec `-foo:', the positional parameter `--foo=bar' is parsed as
`--foo' with an argument of `=bar'.

When the names of two options that take no arguments overlap,
the longest one wins, so that parsing for the specs `-foo
-foobar' (for example) is unambiguous. However, due to the
aforementioned handling of option-arguments, ambiguities may
arise when at least one overlapping spec takes an argument, as
in `-foo: -foobar'. In that case, the last matching spec wins.

The options of zparseopts itself cannot be stacked because, for
example, the stack `-DEK' is indistinguishable from a spec for
the GNU-style long option `--DEK'. The options of zparseopts
itself are:

-a array
As described above, this names the default array in which
to store the recognised options.

-A assoc
If this is given, the options and their values are also
put into an associative array with the option names as
keys and the arguments (if any) as the values.

-D If this option is given, all options found are removed
from the positional parameters of the calling shell or
shell function, up to but not including any not described
by the specs. If the first such parameter is `-' or
`--', it is removed as well. This is similar to using
the shift builtin.

-E This changes the parsing rules to not stop at the first
string that isn't described by one of the specs. It can
be used to test for or (if used together with -D) extract
options and their arguments, ignoring all other options
and arguments that may be in the positional parameters.
As indicated above, parsing still stops at the first `-'
or `--' not described by a spec, but it is not removed
when used with -D.

-F If this option is given, zparseopts immediately stops at
the first option-like parameter not described by one of
the specs, prints an error message, and returns status 1.
Removal (-D) and extraction (-E) are not performed, and
option arrays are not updated. This provides basic
validation for the given options.

Note that the appearance in the positional parameters of
an option without its required argument always aborts
parsing and returns an error as described above
regardless of whether this option is used.

-K With this option, the arrays specified with the -a option
and with the `=array' forms are kept unchanged when none
of the specs for them is used. Otherwise the entire
array is replaced when any of the specs is used.
Individual elements of associative arrays specified with
the -A option are preserved by -K. This allows
assignment of default values to arrays before calling
zparseopts.

-M This changes the assignment rules to implement a map
among equivalent option names. If any spec uses the
`=array' form, the string array is interpreted as the
name of another spec, which is used to choose where to
store the values. If no other spec is found, the values
are stored as usual. This changes only the way the
values are stored, not the way $* is parsed, so results
may be unpredictable if the `name*' specifier is used
inconsistently.

For example,

set -- -a -bx -c y -cz baz -cend
zparseopts a=foo b:=bar c+:=bar

will have the effect of

foo=(-a)
bar=(-b x -c y -c z)

The arguments from `baz' on will not be used.

As an example for the -E option, consider:

set -- -a x -b y -c z arg1 arg2
zparseopts -E -D b:=bar

will have the effect of

bar=(-b y)
set -- -a x -c z arg1 arg2

I.e., the option -b and its arguments are taken from the
positional parameters and put into the array bar.

The -M option can be used like this:

set -- -a -bx -c y -cz baz -cend
zparseopts -A bar -M a=foo b+: c:=b

to have the effect of

foo=(-a)
bar=(-a '' -b xyz)

NAME
zshcalsys - zsh calendar system

DESCRIPTION
The shell is supplied with a series of functions to replace and enhance
the traditional Unix calendar programme, which warns the user of
imminent or future events, details of which are stored in a text file
(typically calendar in the user's home directory). The version
provided here includes a mechanism for alerting the user when an event
is due.

In addition functions age, before and after are provided that can be
used in a glob qualifier; they allow files to be selected based on
their modification times.

The format of the calendar file and the dates used there in and in the
age function are described first, then the functions that can be called
to examine and modify the calendar file.

The functions here depend on the availability of the zsh/datetime
module which is usually installed with the shell. The library function
strptime() must be available; it is present on most recent operating
systems.

FILE AND DATE FORMATS
Calendar File Format
The calendar file is by default ~/calendar. This can be configured by
the calendar-file style, see the section STYLES below. The basic
format consists of a series of separate lines, with no indentation,
each including a date and time specification followed by a description
of the event.

Various enhancements to this format are supported, based on the syntax
of Emacs calendar mode. An indented line indicates a continuation line
that continues the description of the event from the preceding line
(note the date may not be continued in this way). An initial ampersand
(&) is ignored for compatibility.

An indented line on which the first non-whitespace character is # is
not displayed with the calendar entry, but is still scanned for
information. This can be used to hide information useful to the
calendar system but not to the user, such as the unique identifier used
by calendar_add.

The Emacs extension that a date with no description may refer to a
number of succeeding events at different times is not supported.

Unless the done-file style has been altered, any events which have been
processed are appended to the file with the same name as the calendar
file with the suffix .done, hence ~/calendar.done by default.

An example is shown below.

Date Format
The format of the date and time is designed to allow flexibility
without admitting ambiguity. (The words `date' and `time' are both
used in the documentation below; except where specifically noted this
implies a string that may include both a date and a time
specification.) Note that there is no localization support; month and
day names must be in English and separator characters are fixed.
Matching is case insensitive, and only the first three letters of the
names are significant, although as a special case a form beginning
"month" does not match "Monday". Furthermore, time zones are not
handled; all times are assumed to be local.

It is recommended that, rather than exploring the intricacies of the
system, users find a date format that is natural to them and stick to
it. This will avoid unexpected effects. Various key facts should be
noted.

o In particular, note the confusion between month/day/year and
day/month/year when the month is numeric; these formats should
be avoided if at all possible. Many alternatives are available.

o The year must be given in full to avoid confusion, and only
years from 1900 to 2099 inclusive are matched.

The following give some obvious examples; users finding here a format
they like and not subject to vagaries of style may skip the full
description. As dates and times are matched separately (even though
the time may be embedded in the date), any date format may be mixed
with any format for the time of day provide the separators are clear
(whitespace, colons, commas).

2007/04/03 13:13
2007/04/03:13:13
2007/04/03 1:13 pm
3rd April 2007, 13:13
April 3rd 2007 1:13 p.m.
Apr 3, 2007 13:13
Tue Apr 03 13:13:00 2007
13:13 2007/apr/3

More detailed rules follow.

Times are parsed and extracted before dates. They must use colons to
separate hours and minutes, though a dot is allowed before seconds if
they are present. This limits time formats to the following:

o HH:MM[:SS[.FFFFF]] [am|pm|a.m.|p.m.]

o HH:MM.SS[.FFFFF] [am|pm|a.m.|p.m.]

Here, square brackets indicate optional elements, possibly with
alternatives. Fractions of a second are recognised but ignored. For
absolute times (the normal format require by the calendar file and the
age, before and after functions) a date is mandatory but a time of day
is not; the time returned is at the start of the date. One variation
is allowed: if a.m. or p.m. or one of their variants is present, an
hour without a minute is allowed, e.g. 3 p.m..

Time zones are not handled, though if one is matched following a time
specification it will be removed to allow a surrounding date to be
parsed. This only happens if the format of the timezone is not too
unusual. The following are examples of forms that are understood:

+0100
GMT
GMT-7
CET+1CDT

Any part of the timezone that is not numeric must have exactly three
capital letters in the name.

Dates suffer from the ambiguity between DD/MM/YYYY and MM/DD/YYYY. It
is recommended this form is avoided with purely numeric dates, but use
of ordinals, eg. 3rd/04/2007, will resolve the ambiguity as the ordinal
is always parsed as the day of the month. Years must be four digits
(and the first two must be 19 or 20); 03/04/08 is not recognised.
Other numbers may have leading zeroes, but they are not required. The
following are handled:

o YYYY/MM/DD

o YYYY-MM-DD

o YYYY/MNM/DD

o YYYY-MNM-DD

o DD[th|st|rd] MNM[,] [ YYYY ]

o MNM DD[th|st|rd][,] [ YYYY ]

o DD[th|st|rd]/MM[,] YYYY

o DD[th|st|rd]/MM/YYYY

o MM/DD[th|st|rd][,] YYYY

o MM/DD[th|st|rd]/YYYY

Here, MNM is at least the first three letters of a month name, matched
case-insensitively. The remainder of the month name may appear but its
contents are irrelevant, so janissary, febrile, martial, apricot,
maybe, junta, etc. are happily handled.

Where the year is shown as optional, the current year is assumed.
There are only two such cases, the form Jun 20 or 14 September (the
only two commonly occurring forms, apart from a "the" in some forms of
English, which isn't currently supported). Such dates will of course
become ambiguous in the future, so should ideally be avoided.

Times may follow dates with a colon, e.g. 1965/07/12:09:45; this is in
order to provide a format with no whitespace. A comma and whitespace
are allowed, e.g. 1965/07/12, 09:45. Currently the order of these
separators is not checked, so illogical formats such as 1965/07/12, :
,09:45 will also be matched. For simplicity such variations are not
shown in the list above. Otherwise, a time is only recognised as being
associated with a date if there is only whitespace in between, or if
the time was embedded in the date.

Days of the week are not normally scanned, but will be ignored if they
occur at the start of the date pattern only. However, in contexts
where it is useful to specify dates relative to today, days of the week
with no other date specification may be given. The day is assumed to
be either today or within the past week. Likewise, the words
yesterday, today and tomorrow are handled. All matches are
case-insensitive. Hence if today is Monday, then Sunday is equivalent
to yesterday, Monday is equivalent to today, but Tuesday gives a date
six days ago. This is not generally useful within the calendar file.
Dates in this format may be combined with a time specification; for
example Tomorrow, 8 p.m..

For example, the standard date format:

Fri Aug 18 17:00:48 BST 2006

is handled by matching HH:MM:SS and removing it together with the
matched (but unused) time zone. This leaves the following:

Fri Aug 18 2006

Fri is ignored and the rest is matched according to the standard rules.

Relative Time Format
In certain places relative times are handled. Here, a date is not
allowed; instead a combination of various supported periods are
allowed, together with an optional time. The periods must be in order
from most to least significant.

In some cases, a more accurate calculation is possible when there is an
anchor date: offsets of months or years pick the correct day, rather
than being rounded, and it is possible to pick a particular day in a
month as `(1st Friday)', etc., as described in more detail below.

Anchors are available in the following cases. If one or two times are
passed to the function calendar, the start time acts an anchor for the
end time when the end time is relative (even if the start time is
implicit). When examining calendar files, the scheduled event being
examined anchors the warning time when it is given explicitly by means
of the WARN keyword; likewise, the scheduled event anchors a repetition
period when given by the RPT keyword, so that specifications such as
RPT 2 months, 3rd Thursday are handled properly. Finally, the -R
argument to calendar_scandate directly provides an anchor for relative
calculations.

The periods handled, with possible abbreviations are:

Years years, yrs, ys, year, yr, y, yearly. A year is 365.25 days
unless there is an anchor.

Months months, mons, mnths, mths, month, mon, mnth, mth, monthly. Note
that m, ms, mn, mns are ambiguous and are not handled. A month
is a period of 30 days rather than a calendar month unless there
is an anchor.

Weeks weeks, wks, ws, week, wk, w, weekly

Days days, dys, ds, day, dy, d, daily

Hours hours, hrs, hs, hour, hr, h, hourly

Minutes
minutes, mins, minute, min, but not m, ms, mn or mns

Seconds
seconds, secs, ss, second, sec, s

Spaces between the numbers are optional, but are required between
items, although a comma may be used (with or without spaces).

The forms yearly to hourly allow the number to be omitted; it is
assumed to be 1. For example, 1 d and daily are equivalent. Note that
using those forms with plurals is confusing; 2 yearly is the same as 2
years, not twice yearly, so it is recommended they only be used without
numbers.

When an anchor time is present, there is an extension to handle regular
events in the form of the nth someday of the month. Such a
specification must occur immediately after any year and month
specification, but before any time of day, and must be in the form
n(th|st|rd) day, for example 1st Tuesday or 3rd Monday. As in other
places, days are matched case insensitively, must be in English, and
only the first three letters are significant except that a form
beginning `month' does not match `Monday'. No attempt is made to
sanitize the resulting date; attempts to squeeze too many occurrences
into a month will push the day into the next month (but in the obvious
fashion, retaining the correct day of the week).

Here are some examples:

30 years 3 months 4 days 3:42:41
14 days 5 hours
Monthly, 3rd Thursday
4d,10hr

Example
Here is an example calendar file. It uses a consistent date format, as
recommended above.

Feb 1, 2006 14:30 Pointless bureaucratic meeting
Mar 27, 2006 11:00 Mutual recrimination and finger pointing
Bring water pistol and waterproofs
Mar 31, 2006 14:00 Very serious managerial pontification
# UID 12C7878A9A50
Apr 10, 2006 13:30 Even more pointless blame assignment exercise WARN 30 mins
May 18, 2006 16:00 Regular moaning session RPT monthly, 3rd Thursday

The second entry has a continuation line. The third entry has a
continuation line that will not be shown when the entry is displayed,
but the unique identifier will be used by the calendar_add function
when updating the event. The fourth entry will produce a warning 30
minutes before the event (to allow you to equip yourself
appropriately). The fifth entry repeats after a month on the 3rd
Thursday, i.e. June 15, 2006, at the same time.

USER FUNCTIONS
This section describes functions that are designed to be called
directly by the user. The first part describes those functions
associated with the user's calendar; the second part describes the use
in glob qualifiers.

Calendar system functions

calendar [ -abdDsv ] [ -C calfile ] [ -n num ] [ -S showprog ]
[ [ start ] end ]
calendar -r [ -abdDrsv ] [ -C calfile ] [ -n num ] [ -S showprog ]
[ start ]
Show events in the calendar.

With no arguments, show events from the start of today until the
end of the next working day after today. In other words, if
today is Friday, Saturday, or Sunday, show up to the end of the
following Monday, otherwise show today and tomorrow.

If end is given, show events from the start of today up to the
time and date given, which is in the format described in the
previous section. Note that if this is a date the time is
assumed to be midnight at the start of the date, so that
effectively this shows all events before the given date.

end may start with a *, in which case the remainder of the
specification is a relative time format as described in the
previous section indicating the range of time from the start
time that is to be included.

If start is also given, show events starting from that time and
date. The word now can be used to indicate the current time.

To implement an alert when events are due, include calendar -s
in your ~/.zshrc file.

Options:

-a Show all items in the calendar, regardless of the start
and end.

-b Brief: don't display continuation lines (i.e. indented
lines following the line with the date/time), just the
first line.

-B lines
Brief: display at most the first lines lines of the
calendar entry. `-B 1' is equivalent to `-b'.

-C calfile
Explicitly specify a calendar file instead of the value
of the calendar-file style or the default ~/calendar.

-d Move any events that have passed from the calendar file
to the "done" file, as given by the done-file style or
the default which is the calendar file with .done
appended. This option is implied by the -s option.

-D Turns off the option -d, even if the -s option is also
present.

-n num, -num
Show at least num events, if present in the calendar
file, regardless of the start and end.

-r Show all the remaining options in the calendar, ignoring
the given end time. The start time is respected; any
argument given is treated as a start time.

-s Use the shell's sched command to schedule a timed event
that will warn the user when an event is due. Note that
the sched command only runs if the shell is at an
interactive prompt; a foreground task blocks the
scheduled task from running until it is finished.

The timed event usually runs the programme calendar_show
to show the event, as described in the section UTILITY
FUNCTIONS below.

By default, a warning of the event is shown five minutes
before it is due. The warning period can be configured
by the style warn-time or for a single calendar entry by
including WARN reltime in the first line of the entry,
where reltime is one of the usual relative time formats.

A repeated event may be indicated by including RPT
reldate in the first line of the entry. After the
scheduled event has been displayed it will be re-entered
into the calendar file at a time reldate after the
existing event. Note that this is currently the only use
made of the repeat count, so that it is not possible to
query the schedule for a recurrence of an event in the
calendar until the previous event has passed.

If RPT is used, it is also possible to specify that
certain recurrences of an event are rescheduled or
cancelled. This is done with the OCCURRENCE keyword,
followed by whitespace and the date and time of the
occurrence in the regular sequence, followed by
whitespace and either the date and time of the
rescheduled event or the exact string CANCELLED. In this
case the date and time must be in exactly the "date with
local time" format used by the text/calendar MIME type
(RFC 2445), <YYYY><MM><DD>T<hh><mm><ss> (note the
presence of the literal character T). The first word
(the regular recurrence) may be something other than a
proper date/time to indicate that the event is additional
to the normal sequence; a convention that retains the
formatting appearance is XXXXXXXXTXXXXXX.

Furthermore, it is useful to record the next regular
recurrence (as then the displayed date may be for a
rescheduled event so cannot be used for calculating the
regular sequence). This is specified by RECURRENCE and a
time or date in the same format. calendar_add adds such
an indication when it encounters a recurring event that
does not include one, based on the headline date/time.

If calendar_add is used to update occurrences the UID
keyword described there should be present in both the
existing entry and the added occurrence in order to
identify recurring event sequences.

For example,

Thu May 6, 2010 11:00 Informal chat RPT 1 week
# RECURRENCE 20100506T110000
# OCCURRENCE 20100513T110000 20100513T120000
# OCCURRENCE 20100520T110000 CANCELLED

The event that occurs at 11:00 on 13th May 2010 is
rescheduled an hour later. The event that occurs a week
later is cancelled. The occurrences are given on a
continuation line starting with a # character so will not
usually be displayed as part of the event. As elsewhere,
no account of time zones is taken with the times. After
the next event occurs the headline date/time will be `Thu
May 13, 2010 12:00' while the RECURRENCE date/time will
be `20100513T110000' (note that cancelled and moved
events are not taken account of in the RECURRENCE, which
records what the next regular recurrence is, but they are
accounted for in the headline date/time).

It is safe to run calendar -s to reschedule an existing
event (if the calendar file has changed, for example),
and also to have it running in multiples instances of the
shell since the calendar file is locked when in use.

By default, expired events are moved to the "done" file;
see the -d option. Use -D to prevent this.

-S showprog
Explicitly specify a programme to be used for showing
events instead of the value of the show-prog style or the
default calendar_show.

-v Verbose: show more information about stages of
processing. This is useful for confirming that the
function has successfully parsed the dates in the
calendar file.

calendar_add [ -BL ] event ...
Adds a single event to the calendar in the appropriate location.
The event can contain multiple lines, as described in the
section `Calendar File Format' above. Using this function
ensures that the calendar file is sorted in date and time order.
It also makes special arrangements for locking the file while it
is altered. The old calendar is left in a file with the suffix
.old.

The option -B indicates that backing up the calendar file will
be handled by the caller and should not be performed by
calendar_add. The option -L indicates that calendar_add does
not need to lock the calendar file as it is already locked.
These options will not usually be needed by users.

If the style reformat-date is true, the date and time of the new
entry will be rewritten into the standard date format: see the
descriptions of this style and the style date-format.

The function can use a unique identifier stored with each event
to ensure that updates to existing events are treated correctly.
The entry should contain the word UID, followed by whitespace,
followed by a word consisting entirely of hexadecimal digits of
arbitrary length (all digits are significant, including leading
zeroes). As the UID is not directly useful to the user, it is
convenient to hide it on an indented continuation line starting
with a #, for example:

Aug 31, 2007 09:30 Celebrate the end of the holidays
# UID 045B78A0

The second line will not be shown by the calendar function.

It is possible to specify the RPT keyword followed by CANCELLED
instead of a relative time. This causes any matched event or
series of events to be cancelled (the original event does not
have to be marked as recurring in order to be cancelled by this
method). A UID is required in order to match an existing event
in the calendar.

calendar_add will attempt to manage recurrences and occurrences
of repeating events as described for event scheduling by
calendar -s above. To reschedule or cancel a single event
calendar_add should be called with an entry that includes the
correct UID but does not include the RPT keyword as this is
taken to mean the entry applies to a series of repeating events
and hence replaces all existing information. Each rescheduled
or cancelled occurrence must have an OCCURRENCE keyword in the
entry passed to calendar_add which will be merged into the
calendar file. Any existing reference to the occurrence is
replaced. An occurrence that does not refer to a valid existing
event is added as a one-off occurrence to the same calendar
entry.

calendar_edit
This calls the user's editor to edit the calendar file. If
there are arguments, they are taken as the editor to use (the
file name is appended to the commands); otherwise, the editor is
given by the variable VISUAL, if set, else the variable EDITOR.

If the calendar scheduler was running, then after editing the
file calendar -s is called to update it.

This function locks out the calendar system during the edit.
Hence it should be used to edit the calendar file if there is
any possibility of a calendar event occurring meanwhile. Note
this can lead to another shell with calendar functions enabled
hanging waiting for a lock, so it is necessary to quit the
editor as soon as possible.

calendar_parse calendar-entry
This is the internal function that analyses the parts of a
calendar entry, which is passed as the only argument. The
function returns status 1 if the argument could not be parsed as
a calendar entry and status 2 if the wrong number of arguments
were passed; it also sets the parameter reply to an empty
associative array. Otherwise, it returns status 0 and sets
elements of the associative array reply as follows:

time The time as a string of digits in the same units as
$EPOCHSECONDS
schedtime
The regularly scheduled time. This may differ from the
actual event time time if this is a recurring event and
the next occurrence has been rescheduled. Then time
gives the actual time and schedtime the time of the
regular recurrence before modification.
text1 The text from the line not including the date and time of
the event, but including any WARN or RPT keywords and
values.
warntime
Any warning time given by the WARN keyword as a string of
digits containing the time at which to warn in the same
units as $EPOCHSECONDS. (Note this is an absolute time,
not the relative time passed down.) Not set no WARN
keyword and value were matched.
warnstr
The raw string matched after the WARN keyword, else
unset.
rpttime
Any recurrence time given by the RPT keyword as a string
of digits containing the time of the recurrence in the
same units as $EPOCHSECONDS. (Note this is an absolute
time.) Not set if no RPT keyword and value were matched.
schedrpttime
The next regularly scheduled occurrence of a recurring
event before modification. This may differ from rpttime,
which is the actual time of the event that may have been
rescheduled from the regular time.
rptstr The raw string matched after the RPT keyword, else unset.
text2 The text from the line after removal of the date and any
keywords and values.

calendar_showdate [ -r ] [ -f fmt ] date-spec ...
The given date-spec is interpreted and the corresponding date
and time printed. If the initial date-spec begins with a * or -
it is treated as relative to the current time; date-specs after
the first are treated as relative to the date calculated so far
and a leading * is optional in that case. This allows one to
use the system as a date calculator. For example,
calendar_showdate '+1 month, 1st Friday' shows the date of the
first Friday of next month.

With the option -r nothing is printed but the value of the date
and time in seconds since the epoch is stored in the parameter
REPLY.

With the option -f fmt the given date/time conversion format is
passed to strftime; see notes on the date-format style below.

In order to avoid ambiguity with negative relative date
specifications, options must occur in separate words; in other
words, -r and -f should not be combined in the same word.

calendar_sort
Sorts the calendar file into date and time order. The old
calendar is left in a file with the suffix .old.

Glob qualifiers
age The function age can be autoloaded and use separately from the
calendar system, although it uses the function calendar_scandate
for date formatting. It requires the zsh/stat builtin, but uses
only the builtin zstat.

age selects files having a given modification time for use as a
glob qualifier. The format of the date is the same as that
understood by the calendar system, described in the section FILE
AND DATE FORMATS above.

The function can take one or two arguments, which can be
supplied either directly as command or arguments, or separately
as shell parameters.

print *(e:age 2006/10/04 2006/10/09:)

The example above matches all files modified between the start
of those dates. The second argument may alternatively be a
relative time introduced by a *:

print *(e:age 2006/10/04 +5d:)

The example above is equivalent to the previous example.

In addition to the special use of days of the week, today and
yesterday, times with no date may be specified; these apply to
today. Obviously such uses become problematic around midnight.

print *(e-age 12:00 13:30-)

The example above shows files modified between 12:00 and 13:00
today.

print *(e:age 2006/10/04:)

The example above matches all files modified on that date. If
the second argument is omitted it is taken to be exactly 24
hours after the first argument (even if the first argument
contains a time).

print *(e-age 2006/10/04:10:15 2006/10/04:10:45-)

The example above supplies times. Note that whitespace within
the time and date specification must be quoted to ensure age
receives the correct arguments, hence the use of the additional
colon to separate the date and time.

AGEREF=2006/10/04:10:15
AGEREF2=2006/10/04:10:45
print *(+age)

This shows the same example before using another form of
argument passing. The dates and times in the parameters AGEREF
and AGEREF2 stay in effect until unset, but will be overridden
if any argument is passed as an explicit argument to age. Any
explicit argument causes both parameters to be ignored.

Instead of an explicit date and time, it's possible to use the
modification time of a file as the date and time for either
argument by introducing the file name with a colon:

print *(e-age :file1-)

matches all files created on the same day (24 hours starting
from midnight) as file1.

print *(e-age :file1 :file2-)

matches all files modified no earlier than file1 and no later
than file2; precision here is to the nearest second.

after
before The functions after and before are simpler versions of age that
take just one argument. The argument is parsed similarly to an
argument of age; if it is not given the variable AGEREF is
consulted. As the names of the functions suggest, a file
matches if its modification time is after or before the time and
date specified. If a time only is given the date is today.

The two following examples are therefore equivalent:
print *(e-after 12:00-)
print *(e-after today:12:00-)

STYLES
The zsh style mechanism using the zstyle command is describe in
zshmodules(1). This is the same mechanism used in the completion
system.

The styles below are all examined in the context :datetime:function:,
for example :datetime:calendar:.

calendar-file
The location of the main calendar. The default is ~/calendar.

date-format
A strftime format string (see strftime(3)) with the zsh
extensions providing various numbers with no leading zero or
space if the number is a single digit as described for the
%D{string} prompt format in the section EXPANSION OF PROMPT
SEQUENCES in zshmisc(1).

This is used for outputting dates in calendar, both to support
the -v option and when adding recurring events back to the
calendar file, and in calendar_showdate as the final output
format.

If the style is not set, the default used is similar the
standard system format as output by the date command (also known
as `ctime format'): `%a %b %d %H:%M:%S %Z %Y'.

done-file
The location of the file to which events which have passed are
appended. The default is the calendar file location with the
suffix .done. The style may be set to an empty string in which
case a "done" file will not be maintained.

reformat-date
Boolean, used by calendar_add. If it is true, the date and time
of new entries added to the calendar will be reformatted to the
format given by the style date-format or its default. Only the
date and time of the event itself is reformatted; any subsidiary
dates and times such as those associated with repeat and warning
times are left alone.

show-prog
The programme run by calendar for showing events. It will be
passed the start time and stop time of the events requested in
seconds since the epoch followed by the event text. Note that
calendar -s uses a start time and stop time equal to one another
to indicate alerts for specific events.

The default is the function calendar_show.

warn-time
The time before an event at which a warning will be displayed,
if the first line of the event does not include the text EVENT
reltime. The default is 5 minutes.

UTILITY FUNCTIONS
calendar_lockfiles
Attempt to lock the files given in the argument. To prevent
problems with network file locking this is done in an ad hoc
fashion by attempting to create a symbolic link to the file with
the name file.lockfile. No other system level functions are
used for locking, i.e. the file can be accessed and modified by
any utility that does not use this mechanism. In particular,
the user is not prevented from editing the calendar file at the
same time unless calendar_edit is used.

Three attempts are made to lock the file before giving up. If
the module zsh/zselect is available, the times of the attempts
are jittered so that multiple instances of the calling function
are unlikely to retry at the same time.

The files locked are appended to the array lockfiles, which
should be local to the caller.

If all files were successfully locked, status zero is returned,
else status one.

This function may be used as a general file locking function,
although this will only work if only this mechanism is used to
lock files.

calendar_read
This is a backend used by various other functions to parse the
calendar file, which is passed as the only argument. The array
calendar_entries is set to the list of events in the file; no
pruning is done except that ampersands are removed from the
start of the line. Each entry may contain multiple lines.

calendar_scandate
This is a generic function to parse dates and times that may be
used separately from the calendar system. The argument is a
date or time specification as described in the section FILE AND
DATE FORMATS above. The parameter REPLY is set to the number of
seconds since the epoch corresponding to that date or time. By
default, the date and time may occur anywhere within the given
argument.

Returns status zero if the date and time were successfully
parsed, else one.

Options:
-a The date and time are anchored to the start of the
argument; they will not be matched if there is preceding
text.

-A The date and time are anchored to both the start and end
of the argument; they will not be matched if the is any
other text in the argument.

-d Enable additional debugging output.

-m Minus. When -R anchor_time is also given the relative
time is calculated backwards from anchor_time.

-r The argument passed is to be parsed as a relative time.

-R anchor_time
The argument passed is to be parsed as a relative time.
The time is relative to anchor_time, a time in seconds
since the epoch, and the returned value is the absolute
time corresponding to advancing anchor_time by the
relative time given. This allows lengths of months to be
correctly taken into account. If the final day does not
exist in the given month, the last day of the final month
is given. For example, if the anchor time is during 31st
January 2007 and the relative time is 1 month, the final
time is the same time of day during 28th February 2007.

-s In addition to setting REPLY, set REPLY2 to the remainder
of the argument after the date and time have been
stripped. This is empty if the option -A was given.

-t Allow a time with no date specification. The date is
assumed to be today. The behaviour is unspecified if the
iron tongue of midnight is tolling twelve.

calendar_show
The function used by default to display events. It accepts a
start time and end time for events, both in epoch seconds, and
an event description.

The event is always printed to standard output. If the command
line editor is active (which will usually be the case) the
command line will be redisplayed after the output.

If the parameter DISPLAY is set and the start and end times are
the same (indicating a scheduled event), the function uses the
command xmessage to display a window with the event details.

BUGS
As the system is based entirely on shell functions (with a little
support from the zsh/datetime module) the mechanisms used are not as
robust as those provided by a dedicated calendar utility. Consequently
the user should not rely on the shell for vital alerts.

There is no calendar_delete function.

There is no localization support for dates and times, nor any support
for the use of time zones.

Relative periods of months and years do not take into account the
variable number of days.

The calendar_show function is currently hardwired to use xmessage for
displaying alerts on X Window System displays. This should be
configurable and ideally integrate better with the desktop.

calendar_lockfiles hangs the shell while waiting for a lock on a file.
If called from a scheduled task, it should instead reschedule the event
that caused it.

NAME
zshtcpsys - zsh tcp system

DESCRIPTION
A module zsh/net/tcp is provided to provide network I/O over TCP/IP
from within the shell; see its description in zshmodules(1). This
manual page describes a function suite based on the module. If the
module is installed, the functions are usually installed at the same
time, in which case they will be available for autoloading in the
default function search path. In addition to the zsh/net/tcp module,
the zsh/zselect module is used to implement timeouts on read
operations. For troubleshooting tips, consult the corresponding advice
for the zftp functions described in zshzftpsys(1).

There are functions corresponding to the basic I/O operations open,
close, read and send, named tcp_open etc., as well as a function
tcp_expect for pattern match analysis of data read as input. The
system makes it easy to receive data from and send data to multiple
named sessions at once. In addition, it can be linked with the shell's
line editor in such a way that input data is automatically shown at the
terminal. Other facilities available including logging, filtering and
configurable output prompts.

To use the system where it is available, it should be enough to
`autoload -U tcp_open' and run tcp_open as documented below to start a
session. The tcp_open function will autoload the remaining functions.

TCP USER FUNCTIONS
Basic I/O
tcp_open [ -qz ] host port [ sess ]
tcp_open [ -qz ] [ -s sess | -l sess[,...] ] ...
tcp_open [ -qz ] [ -a fd | -f fd ] [ sess ]
Open a new session. In the first and simplest form, open a TCP
connection to host host at port port; numeric and symbolic forms
are understood for both.

If sess is given, this becomes the name of the session which can
be used to refer to multiple different TCP connections. If sess
is not given, the function will invent a numeric name value
(note this is not the same as the file descriptor to which the
session is attached). It is recommended that session names not
include `funny' characters, where funny characters are not
well-defined but certainly do not include alphanumerics or
underscores, and certainly do include whitespace.

In the second case, one or more sessions to be opened are given
by name. A single session name is given after -s and a
comma-separated list after -l; both options may be repeated as
many times as necessary. A failure to open any session causes
tcp_open to abort. The host and port are read from the file
.ztcp_sessions in the same directory as the user's zsh
initialisation files, i.e. usually the home directory, but
$ZDOTDIR if that is set. The file consists of lines each giving
a session name and the corresponding host and port, in that
order (note the session name comes first, not last), separated
by whitespace.

The third form allows passive and fake TCP connections. If the
option -a is used, its argument is a file descriptor open for
listening for connections. No function front-end is provided to
open such a file descriptor, but a call to `ztcp -l port' will
create one with the file descriptor stored in the parameter
$REPLY. The listening port can be closed with `ztcp -c fd'. A
call to `tcp_open -a fd' will block until a remote TCP
connection is made to port on the local machine. At this point,
a session is created in the usual way and is largely
indistinguishable from an active connection created with one of
the first two forms.

If the option -f is used, its argument is a file descriptor
which is used directly as if it were a TCP session. How well
the remainder of the TCP function system copes with this depends
on what actually underlies this file descriptor. A regular file
is likely to be unusable; a FIFO (pipe) of some sort will work
better, but note that it is not a good idea for two different
sessions to attempt to read from the same FIFO at once.

If the option -q is given with any of the three forms, tcp_open
will not print informational messages, although it will in any
case exit with an appropriate status.

If the line editor (zle) is in use, which is typically the case
if the shell is interactive, tcp_open installs a handler inside
zle which will check for new data at the same time as it checks
for keyboard input. This is convenient as the shell consumes no
CPU time while waiting; the test is performed by the operating
system. Giving the option -z to any of the forms of tcp_open
prevents the handler from being installed, so data must be read
explicitly. Note, however, this is not necessary for executing
complete sets of send and read commands from a function, as zle
is not active at this point. Generally speaking, the handler is
only active when the shell is waiting for input at a command
prompt or in the vared builtin. The option has no effect if zle
is not active; `[[ -o zle]]' will test for this.

The first session to be opened becomes the current session and
subsequent calls to tcp_open do not change it. The current
session is stored in the parameter $TCP_SESS; see below for more
detail about the parameters used by the system.

The function tcp_on_open, if defined, is called when a session
is opened. See the description below.

tcp_close [ -qn ] [ -a | -l sess[,...] | sess ... ]
Close the named sessions, or the current session if none is
given, or all open sessions if -a is given. The options -l and
-s are both handled for consistency with tcp_open, although the
latter is redundant.

If the session being closed is the current one, $TCP_SESS is
unset, leaving no current session, even if there are other
sessions still open.

If the session was opened with tcp_open -f, the file descriptor
is closed so long as it is in the range 0 to 9 accessible
directly from the command line. If the option -n is given, no
attempt will be made to close file descriptors in this case.
The -n option is not used for genuine ztcp session; the file
descriptors are always closed with the session.

If the option -q is given, no informational messages will be
printed.

tcp_read [ -bdq ] [ -t TO ] [ -T TO ]
[ -a | -u fd[,...] | -l sess[,...] | -s sess ... ]
Perform a read operation on the current session, or on a list of
sessions if any are given with -u, -l or -s, or all open
sessions if the option -a is given. Any of the -u, -l or -s
options may be repeated or mixed together. The -u option
specifies a file descriptor directly (only those managed by this
system are useful), the other two specify sessions as described
for tcp_open above.

The function checks for new data available on all the sessions
listed. Unless the -b option is given, it will not block
waiting for new data. Any one line of data from any of the
available sessions will be read, stored in the parameter
$TCP_LINE, and displayed to standard output unless $TCP_SILENT
contains a non-empty string. When printed to standard output
the string $TCP_PROMPT will be shown at the start of the line;
the default form for this includes the name of the session being
read. See below for more information on these parameters. In
this mode, tcp_read can be called repeatedly until it returns
status 2 which indicates all pending input from all specified
sessions has been handled.

With the option -b, equivalent to an infinite timeout, the
function will block until a line is available to read from one
of the specified sessions. However, only a single line is
returned.

The option -d indicates that all pending input should be
drained. In this case tcp_read may process multiple lines in
the manner given above; only the last is stored in $TCP_LINE,
but the complete set is stored in the array $tcp_lines. This is
cleared at the start of each call to tcp_read.

The options -t and -T specify a timeout in seconds, which may be
a floating point number for increased accuracy. With -t the
timeout is applied before each line read. With -T, the timeout
applies to the overall operation, possibly including multiple
read operations if the option -d is present; without this
option, there is no distinction between -t and -T.

The function does not print informational messages, but if the
option -q is given, no error message is printed for a
non-existent session.

A return status of 2 indicates a timeout or no data to read.
Any other non-zero return status indicates some error condition.

See tcp_log for how to control where data is sent by tcp_read.

tcp_send [ -cnq ] [ -s sess | -l sess[,...] ] data ...
tcp_send [ -cnq ] -a data ...
Send the supplied data strings to all the specified sessions in
turn. The underlying operation differs little from a `print -r'
to the session's file descriptor, although it attempts to
prevent the shell from dying owing to a SIGPIPE caused by an
attempt to write to a defunct session.

The option -c causes tcp_send to behave like cat. It reads
lines from standard input until end of input and sends them in
turn to the specified session(s) exactly as if they were given
as data arguments to individual tcp_send commands.

The option -n prevents tcp_send from putting a newline at the
end of the data strings.

The remaining options all behave as for tcp_read.

The data arguments are not further processed once they have been
passed to tcp_send; they are simply passed down to print -r.

If the parameter $TCP_OUTPUT is a non-empty string and logging
is enabled then the data sent to each session will be echoed to
the log file(s) with $TCP_OUTPUT in front where appropriate,
much in the manner of $TCP_PROMPT.

Session Management
tcp_alias [ -q ] alias=sess ...
tcp_alias [ -q ] [ alias ... ]
tcp_alias -d [ -q ] alias ...
This function is not particularly well tested.

The first form creates an alias for a session name; alias can
then be used to refer to the existing session sess. As many
aliases may be listed as required.

The second form lists any aliases specified, or all aliases if
none.

The third form deletes all the aliases listed. The underlying
sessions are not affected.

The option -q suppresses an inconsistently chosen subset of
error messages.

tcp_log [ -asc ] [ -n | -N ] [ logfile ]
With an argument logfile, all future input from tcp_read will be
logged to the named file. Unless -a (append) is given, this
file will first be truncated or created empty. With no
arguments, show the current status of logging.

With the option -s, per-session logging is enabled. Input from
tcp_read is output to the file logfile.sess. As the session is
automatically discriminated by the filename, the contents are
raw (no $TCP_PROMPT). The option -a applies as above.
Per-session logging and logging of all data in one file are not
mutually exclusive.

The option -c closes all logging, both complete and per-session
logs.

The options -n and -N respectively turn off or restore output of
data read by tcp_read to standard output; hence `tcp_log -cn'
turns off all output by tcp_read.

The function is purely a convenient front end to setting the
parameters $TCP_LOG, $TCP_LOG_SESS, $TCP_SILENT, which are
described below.

tcp_rename old new
Rename session old to session new. The old name becomes
invalid.

tcp_sess [ sess [ command [ arg ... ] ] ]
With no arguments, list all the open sessions and associated
file descriptors. The current session is marked with a star.
For use in functions, direct access to the parameters
$tcp_by_name, $tcp_by_fd and $TCP_SESS is probably more
convenient; see below.

With a sess argument, set the current session to sess. This is
equivalent to changing $TCP_SESS directly.

With additional arguments, temporarily set the current session
while executing `command arg ...'. command is re-evaluated so
as to expand aliases etc., but the remaining args are passed
through as that appear to tcp_sess. The original session is
restored when tcp_sess exits.

Advanced I/O
tcp_command send-option ... send-argument ...
This is a convenient front-end to tcp_send. All arguments are
passed to tcp_send, then the function pauses waiting for data.
While data is arriving at least every $TCP_TIMEOUT (default 0.3)
seconds, data is handled and printed out according to the
current settings. Status 0 is always returned.

This is generally only useful for interactive use, to prevent
the display becoming fragmented by output returned from the
connection. Within a programme or function it is generally
better to handle reading data by a more explicit method.

tcp_expect [ -q ] [ -p var | -P var ] [ -t TO | -T TO ]
[ -a | -s sess | -l sess[,...] ] pattern ...
Wait for input matching any of the given patterns from any of
the specified sessions. Input is ignored until an input line
matches one of the given patterns; at this point status zero is
returned, the matching line is stored in $TCP_LINE, and the full
set of lines read during the call to tcp_expect is stored in the
array $tcp_expect_lines.

Sessions are specified in the same way as tcp_read: the default
is to use the current session, otherwise the sessions specified
by -a, -s, or -l are used.

Each pattern is a standard zsh extended-globbing pattern; note
that it needs to be quoted to avoid it being expanded
immediately by filename generation. It must match the full
line, so to match a substring there must be a `*' at the start
and end. The line matched against includes the $TCP_PROMPT
added by tcp_read. It is possible to include the globbing flags
`#b' or `#m' in the patterns to make backreferences available in
the parameters $MATCH, $match, etc., as described in the base
zsh documentation on pattern matching.

Unlike tcp_read, the default behaviour of tcp_expect is to block
indefinitely until the required input is found. This can be
modified by specifying a timeout with -t or -T; these function
as in tcp_read, specifying a per-read or overall timeout,
respectively, in seconds, as an integer or floating-point
number. As tcp_read, the function returns status 2 if a timeout
occurs.

The function returns as soon as any one of the patterns given
match. If the caller needs to know which of the patterns
matched, the option -p var can be used; on return, $var is set
to the number of the pattern using ordinary zsh indexing, i.e.
the first is 1, and so on. Note the absence of a `$' in front
of var. To avoid clashes, the parameter cannot begin with
`_expect'. The index -1 is used if there is a timeout and 0 if
there is no match.

The option -P var works similarly to -p, but instead of
numerical indexes the regular arguments must begin with a prefix
followed by a colon: that prefix is then used as a tag to which
var is set when the argument matches. The tag timeout is used
if there is a timeout and the empty string if there is no match.
Note it is acceptable for different arguments to start with the
same prefix if the matches do not need to be distinguished.

The option -q is passed directly down to tcp_read.

As all input is done via tcp_read, all the usual rules about
output of lines read apply. One exception is that the parameter
$tcp_lines will only reflect the line actually matched by
tcp_expect; use $tcp_expect_lines for the full set of lines read
during the function call.

tcp_proxy
This is a simple-minded function to accept a TCP connection and
execute a command with I/O redirected to the connection.
Extreme caution should be taken as there is no security
whatsoever and this can leave your computer open to the world.
Ideally, it should only be used behind a firewall.

The first argument is a TCP port on which the function will
listen.

The remaining arguments give a command and its arguments to
execute with standard input, standard output and standard error
redirected to the file descriptor on which the TCP session has
been accepted. If no command is given, a new zsh is started.
This gives everyone on your network direct access to your
account, which in many cases will be a bad thing.

The command is run in the background, so tcp_proxy can then
accept new connections. It continues to accept new connections
until interrupted.

tcp_spam [ -ertv ] [ -a | -s sess | -l sess[,...] ] cmd [ arg ... ]
Execute `cmd [ arg ... ]' for each session in turn. Note this
executes the command and arguments; it does not send the command
line as data unless the -t (transmit) option is given.

The sessions may be selected explicitly with the standard -a, -s
or -l options, or may be chosen implicitly. If none of the
three options is given the rules are: first, if the array
$tcp_spam_list is set, this is taken as the list of sessions,
otherwise all sessions are taken. Second, any sessions given in
the array $tcp_no_spam_list are removed from the list of
sessions.

Normally, any sessions added by the `-a' flag or when all
sessions are chosen implicitly are spammed in alphabetic order;
sessions given by the $tcp_spam_list array or on the command
line are spammed in the order given. The -r flag reverses the
order however it was arrived it.

The -v flag specifies that a $TCP_PROMPT will be output before
each session. This is output after any modification to TCP_SESS
by the user-defined tcp_on_spam function described below.
(Obviously that function is able to generate its own output.)

If the option -e is present, the line given as `cmd [ arg ... ]'
is executed using eval, otherwise it is executed without any
further processing.

tcp_talk
This is a fairly simple-minded attempt to force input to the
line editor to go straight to the default TCP_SESS.

An escape string, $TCP_TALK_ESCAPE, default `:', is used to
allow access to normal shell operation. If it is on its own at
the start of the line, or followed only by whitespace, the line
editor returns to normal operation. Otherwise, the string and
any following whitespace are skipped and the remainder of the
line executed as shell input without any change of the line
editor's operating mode.

The current implementation is somewhat deficient in terms of use
of the command history. For this reason, many users will prefer
to use some form of alternative approach for sending data easily
to the current session. One simple approach is to alias some
special character (such as `%') to `tcp_command --'.

tcp_wait
The sole argument is an integer or floating point number which
gives the seconds to delay. The shell will do nothing for that
period except wait for input on all TCP sessions by calling
tcp_read -a. This is similar to the interactive behaviour at
the command prompt when zle handlers are installed.

`One-shot' file transfer
tcp_point port
tcp_shoot host port
This pair of functions provide a simple way to transfer a file
between two hosts within the shell. Note, however, that bulk
data transfer is currently done using cat. tcp_point reads any
data arriving at port and sends it to standard output; tcp_shoot
connects to port on host and sends its standard input. Any
unused port may be used; the standard mechanism for picking a
port is to think of a random four-digit number above 1024 until
one works.

To transfer a file from host woodcock to host springes, on
springes:

tcp_point 8091 >output_file

and on woodcock:

tcp_shoot springes 8091 <input_file

As these two functions do not require tcp_open to set up a TCP
connection first, they may need to be autoloaded separately.

TCP USER-DEFINED FUNCTIONS
Certain functions, if defined by the user, will be called by the
function system in certain contexts. This facility depends on the
module zsh/parameter, which is usually available in interactive shells
as the completion system depends on it. None of the functions need be
defined; they simply provide convenient hooks when necessary.

Typically, these are called after the requested action has been taken,
so that the various parameters will reflect the new state.

tcp_on_alias alias fd
When an alias is defined, this function will be called with two
arguments: the name of the alias, and the file descriptor of the
corresponding session.

tcp_on_awol sess fd
If the function tcp_fd_handler is handling input from the line
editor and detects that the file descriptor is no longer
reusable, by default it removes it from the list of file
descriptors handled by this method and prints a message. If the
function tcp_on_awol is defined it is called immediately before
this point. It may return status 100, which indicates that the
normal handling should still be performed; any other return
status indicates that no further action should be taken and the
tcp_fd_handler should return immediately with the given status.
Typically the action of tcp_on_awol will be to close the
session.

The variable TCP_INVALIDATE_ZLE will be a non-empty string if it
is necessary to invalidate the line editor display using `zle
-I' before printing output from the function.

(`AWOL' is military jargon for `absent without leave' or some
variation. It has no pre-existing technical meaning known to
the author.)

tcp_on_close sess fd
This is called with the name of a session being closed and the
file descriptor which corresponded to that session. Both will
be invalid by the time the function is called.

tcp_on_open sess fd
This is called after a new session has been defined with the
session name and file descriptor as arguments. If it returns a
non-zero status, opening the session is assumed to fail and the
session is closed again; however, tcp_open will continue to
attempt to open any remaining sessions given on the command
line.

tcp_on_rename oldsess fd newsess
This is called after a session has been renamed with the three
arguments old session name, file descriptor, new session name.

tcp_on_spam sess command ...
This is called once for each session spammed, just before a
command is executed for a session by tcp_spam. The arguments
are the session name followed by the command list to be
executed. If tcp_spam was called with the option -t, the first
command will be tcp_send.

This function is called after $TCP_SESS is set to reflect the
session to be spammed, but before any use of it is made. Hence
it is possible to alter the value of $TCP_SESS within this
function. For example, the session arguments to tcp_spam could
include extra information to be stripped off and processed in
tcp_on_spam.

If the function sets the parameter $REPLY to `done', the command
line is not executed; in addition, no prompt is printed for the
-v option to tcp_spam.

tcp_on_unalias alias fd
This is called with the name of an alias and the corresponding
session's file descriptor after an alias has been deleted.

TCP UTILITY FUNCTIONS
The following functions are used by the TCP function system but will
rarely if ever need to be called directly.

tcp_fd_handler
This is the function installed by tcp_open for handling input
from within the line editor, if that is required. It is in the
format documented for the builtin `zle -F' in zshzle(1) .

While active, the function sets the parameter TCP_HANDLER_ACTIVE
to 1. This allows shell code called internally (for example, by
setting tcp_on_read) to tell if is being called when the shell
is otherwise idle at the editor prompt.

tcp_output [ -q ] -P prompt -F fd -S sess
This function is used for both logging and handling output to
standard output, from within tcp_read and (if $TCP_OUTPUT is
set) tcp_send.

The prompt to use is specified by -P; the default is the empty
string. It can contain:
%c Expands to 1 if the session is the current session,
otherwise 0. Used with ternary expressions such as
`%(c.-.+)' to output `*' for the current session and `-'
otherwise.

%f Replaced by the session's file descriptor.

%s Replaced by the session name.

%% Replaced by a single `%'.

The option -q suppresses output to standard output, but not to
any log files which are configured.

The -S and -F options are used to pass in the session name and
file descriptor for possible replacement in the prompt.

TCP USER PARAMETERS
Parameters follow the usual convention that uppercase is used for
scalars and integers, while lowercase is used for normal and
associative array. It is always safe for user code to read these
parameters. Some parameters may also be set; these are noted
explicitly. Others are included in this group as they are set by the
function system for the user's benefit, i.e. setting them is typically
not useful but is benign.

It is often also useful to make settable parameters local to a
function. For example, `local TCP_SILENT=1' specifies that data read
during the function call will not be printed to standard output,
regardless of the setting outside the function. Likewise, `local
TCP_SESS=sess' sets a session for the duration of a function, and
`local TCP_PROMPT=' specifies that no prompt is used for input during
the function.

tcp_expect_lines
Array. The set of lines read during the last call to
tcp_expect, including the last ($TCP_LINE).

tcp_filter
Array. May be set directly. A set of extended globbing patterns
which, if matched in tcp_output, will cause the line not to be
printed to standard output. The patterns should be defined as
described for the arguments to tcp_expect. Output of line to
log files is not affected.

TCP_HANDLER_ACTIVE
Scalar. Set to 1 within tcp_fd_handler to indicate to functions
called recursively that they have been called during an editor
session. Otherwise unset.

TCP_LINE
The last line read by tcp_read, and hence also tcp_expect.

TCP_LINE_FD
The file descriptor from which $TCP_LINE was read.
${tcp_by_fd[$TCP_LINE_FD]} will give the corresponding session
name.

tcp_lines
Array. The set of lines read during the last call to tcp_read,
including the last ($TCP_LINE).

TCP_LOG
May be set directly, although it is also controlled by tcp_log.
The name of a file to which output from all sessions will be
sent. The output is proceeded by the usual $TCP_PROMPT. If it
is not an absolute path name, it will follow the user's current
directory.

TCP_LOG_SESS
May be set directly, although it is also controlled by tcp_log.
The prefix for a set of files to which output from each session
separately will be sent; the full filename is
${TCP_LOG_SESS}.sess. Output to each file is raw; no prompt is
added. If it is not an absolute path name, it will follow the
user's current directory.

tcp_no_spam_list
Array. May be set directly. See tcp_spam for how this is used.

TCP_OUTPUT
May be set directly. If a non-empty string, any data sent to a
session by tcp_send will be logged. This parameter gives the
prompt to be used in a file specified by $TCP_LOG but not in a
file generated from $TCP_LOG_SESS. The prompt string has the
same format as TCP_PROMPT and the same rules for its use apply.

TCP_PROMPT
May be set directly. Used as the prefix for data read by
tcp_read which is printed to standard output or to the log file
given by $TCP_LOG, if any. Any `%s', `%f' or `%%' occurring in
the string will be replaced by the name of the session, the
session's underlying file descriptor, or a single `%',
respectively. The expression `%c' expands to 1 if the session
being read is the current session, else 0; this is most useful
in ternary expressions such as `%(c.-.+)' which outputs `*' if
the session is the current one, else `-'.

If the prompt starts with %P, this is stripped and the complete
result of the previous stage is passed through standard prompt
%-style formatting before being output.

TCP_READ_DEBUG
May be set directly. If this has non-zero length, tcp_read will
give some limited diagnostics about data being read.

TCP_SECONDS_START
This value is created and initialised to zero by tcp_open.

The functions tcp_read and tcp_expect use the shell's SECONDS
parameter for their own timing purposes. If that parameter is
not of floating point type on entry to one of the functions, it
will create a local parameter SECONDS which is floating point
and set the parameter TCP_SECONDS_START to the previous value of
$SECONDS. If the parameter is already floating point, it is
used without a local copy being created and TCP_SECONDS_START is
not set. As the global value is zero, the shell elapsed time is
guaranteed to be the sum of $SECONDS and $TCP_SECONDS_START.

This can be avoided by setting SECONDS globally to a floating
point value using `typeset -F SECONDS'; then the TCP functions
will never make a local copy and never set TCP_SECONDS_START to
a non-zero value.

TCP_SESS
May be set directly. The current session; must refer to one of
the sessions established by tcp_open.

TCP_SILENT
May be set directly, although it is also controlled by tcp_log.
If of non-zero length, data read by tcp_read will not be written
to standard output, though may still be written to a log file.

tcp_spam_list
Array. May be set directly. See the description of the
function tcp_spam for how this is used.

TCP_TALK_ESCAPE
May be set directly. See the description of the function
tcp_talk for how this is used.

TCP_TIMEOUT
May be set directly. Currently this is only used by the
function tcp_command, see above.

TCP USER-DEFINED PARAMETERS
The following parameters are not set by the function system, but have a
special effect if set by the user.

tcp_on_read
This should be an associative array; if it is not, the behaviour
is undefined. Each key is the name of a shell function or other
command, and the corresponding value is a shell pattern (using
EXTENDED_GLOB). Every line read from a TCP session directly or
indirectly using tcp_read (which includes lines read by
tcp_expect) is compared against the pattern. If the line
matches, the command given in the key is called with two
arguments: the name of the session from which the line was read,
and the line itself.

If any function called to handle a line returns a non-zero
status, the line is not output. Thus a tcp_on_read handler
containing only the instruction `return 1' can be used to
suppress output of particular lines (see, however, tcp_filter
above). However, the line is still stored in TCP_LINE and
tcp_lines; this occurs after all tcp_on_read processing.

TCP UTILITY PARAMETERS
These parameters are controlled by the function system; they may be
read directly, but should not usually be set by user code.

tcp_aliases
Associative array. The keys are the names of sessions
established with tcp_open; each value is a space-separated list
of aliases which refer to that session.

tcp_by_fd
Associative array. The keys are session file descriptors; each
value is the name of that session.

tcp_by_name
Associative array. The keys are the names of sessions; each
value is the file descriptor associated with that session.

TCP EXAMPLES
Here is a trivial example using a remote calculator.

To create a calculator server on port 7337 (see the dc manual page for
quite how infuriating the underlying command is):

tcp_proxy 7337 dc

To connect to this from the same host with a session also named `dc':

tcp_open localhost 7337 dc

To send a command to the remote session and wait a short while for
output (assuming dc is the current session):

tcp_command 2 4 * p

To close the session:

tcp_close

The tcp_proxy needs to be killed to be stopped. Note this will not
usually kill any connections which have already been accepted, and also
that the port is not immediately available for reuse.

The following chunk of code puts a list of sessions into an xterm
header, with the current session followed by a star.

print -n "\033]2;TCP:" ${(k)tcp_by_name:/$TCP_SESS/$TCP_SESS\*} "\a"

TCP BUGS
The function tcp_read uses the shell's normal read builtin. As this
reads a complete line at once, data arriving without a terminating
newline can cause the function to block indefinitely.

Though the function suite works well for interactive use and for data
arriving in small amounts, the performance when large amounts of data
are being exchanged is likely to be extremely poor.

NAME
zshzftpsys - zftp function front-end

DESCRIPTION
This describes the set of shell functions supplied with the source
distribution as an interface to the zftp builtin command, allowing you
to perform FTP operations from the shell command line or within
functions or scripts. The interface is similar to a traditional FTP
client (e.g. the ftp command itself, see ftp(1)), but as it is entirely
done within the shell all the familiar completion, editing and globbing
features, and so on, are present, and macros are particularly simple to
write as they are just ordinary shell functions.

The prerequisite is that the zftp command, as described in
zshmodules(1) , must be available in the version of zsh installed at
your site. If the shell is configured to load new commands at run
time, it probably is: typing `zmodload zsh/zftp' will make sure (if
that runs silently, it has worked). If this is not the case, it is
possible zftp was linked into the shell anyway: to test this, type
`which zftp' and if zftp is available you will get the message `zftp:
shell built-in command'.

Commands given directly with zftp builtin may be interspersed between
the functions in this suite; in a few cases, using zftp directly may
cause some of the status information stored in shell parameters to
become invalid. Note in particular the description of the variables
$ZFTP_TMOUT, $ZFTP_PREFS and $ZFTP_VERBOSE for zftp.

INSTALLATION
You should make sure all the functions from the Functions/Zftp
directory of the source distribution are available; they all begin with
the two letters `zf'. They may already have been installed on your
system; otherwise, you will need to find them and copy them. The
directory should appear as one of the elements of the $fpath array
(this should already be the case if they were installed), and at least
the function zfinit should be autoloaded; it will autoload the rest.
Finally, to initialize the use of the system you need to call the
zfinit function. The following code in your .zshrc will arrange for
this; assume the functions are stored in the directory ~/myfns:

fpath=(~/myfns $fpath)
autoload -U zfinit
zfinit

Note that zfinit assumes you are using the zmodload method to load the
zftp command. If it is already built into the shell, change zfinit to
zfinit -n. It is helpful (though not essential) if the call to zfinit
appears after any code to initialize the new completion system, else
unnecessary compctl commands will be given.

FUNCTIONS
The sequence of operations in performing a file transfer is essentially
the same as that in a standard FTP client. Note that, due to a quirk
of the shell's getopts builtin, for those functions that handle options
you must use `--' rather than `-' to ensure the remaining arguments are
treated literally (a single `-' is treated as an argument).

Opening a connection
zfparams [ host [ user [ password ... ] ] ]
Set or show the parameters for a future zfopen with no
arguments. If no arguments are given, the current parameters
are displayed (the password will be shown as a line of
asterisks). If a host is given, and either the user or password
is not, they will be prompted for; also, any parameter given as
`?' will be prompted for, and if the `?' is followed by a
string, that will be used as the prompt. As zfopen calls
zfparams to store the parameters, this usually need not be
called directly.

A single argument `-' will delete the stored parameters. This
will also cause the memory of the last directory (and so on) on
the other host to be deleted.

zfopen [ -1 ] [ host [ user [ password [ account ] ] ] ]
If host is present, open a connection to that host under
username user with password password (and, on the rare occasions
when it is necessary, account account). If a necessary
parameter is missing or given as `?' it will be prompted for.
If host is not present, use a previously stored set of
parameters.

If the command was successful, and the terminal is compatible
with xterm or is sun-cmd, a summary will appear in the title
bar, giving the local host:directory and the remote
host:directory; this is handled by the function zftp_chpwd,
described below.

Normally, the host, user and password are internally recorded
for later re-opening, either by a zfopen with no arguments, or
automatically (see below). With the option `-1', no information
is stored. Also, if an open command with arguments failed, the
parameters will not be retained (and any previous parameters
will also be deleted). A zfopen on its own, or a zfopen -1,
never alters the stored parameters.

Both zfopen and zfanon (but not zfparams) understand URLs of the
form ftp://host/path... as meaning to connect to the host, then
change directory to path (which must be a directory, not a
file). The `ftp://' can be omitted; the trailing `/' is enough
to trigger recognition of the path. Note prefixes other than
`ftp:' are not recognized, and that all characters after the
first slash beyond host are significant in path.

zfanon [ -1 ] host
Open a connection host for anonymous FTP. The username used is
`anonymous'. The password (which will be reported the first
time) is generated as user@host; this is then stored in the
shell parameter $EMAIL_ADDR which can alternatively be set
manually to a suitable string.

Directory management
zfcd [ dir ]
zfcd -
zfcd old new
Change the current directory on the remote server: this is
implemented to have many of the features of the shell builtin
cd.

In the first form with dir present, change to the directory dir.
The command `zfcd ..' is treated specially, so is guaranteed to
work on non-UNIX servers (note this is handled internally by
zftp). If dir is omitted, has the effect of `zfcd ~'.

The second form changes to the directory previously current.

The third form attempts to change the current directory by
replacing the first occurrence of the string old with the string
new in the current directory.

Note that in this command, and indeed anywhere a remote filename
is expected, the string which on the local host corresponds to
`~' is converted back to a `~' before being passed to the remote
machine. This is convenient because of the way expansion is
performed on the command line before zfcd receives a string.
For example, suppose the command is `zfcd ~/foo'. The shell
will expand this to a full path such as `zfcd
/home/user2/pws/foo'. At this stage, zfcd recognises the
initial path as corresponding to `~' and will send the directory
to the remote host as ~/foo, so that the `~' will be expanded by
the server to the correct remote host directory. Other named
directories of the form `~name' are not treated in this fashion.

zfhere Change directory on the remote server to the one corresponding
to the current local directory, with special handling of `~' as
in zfcd. For example, if the current local directory is
~/foo/bar, then zfhere performs the effect of `zfcd ~/foo/bar'.

zfdir [ -rfd ] [ - ] [ dir-options ] [ dir ]
Produce a long directory listing. The arguments dir-options and
dir are passed directly to the server and their effect is
implementation dependent, but specifying a particular remote
directory dir is usually possible. The output is passed through
a pager given by the environment variable $PAGER, or `more' if
that is not set.

The directory is usually cached for re-use. In fact, two caches
are maintained. One is for use when there is no dir-options or
dir, i.e. a full listing of the current remote directory; it is
flushed when the current remote directory changes. The other is
kept for repeated use of zfdir with the same arguments; for
example, repeated use of `zfdir /pub/gnu' will only require the
directory to be retrieved on the first call. Alternatively,
this cache can be re-viewed with the -r option. As relative
directories will confuse zfdir, the -f option can be used to
force the cache to be flushed before the directory is listed.
The option -d will delete both caches without showing a
directory listing; it will also delete the cache of file names
in the current remote directory, if any.

zfls [ ls-options ] [ dir ]
List files on the remote server. With no arguments, this will
produce a simple list of file names for the current remote
directory. Any arguments are passed directly to the server. No
pager and no caching is used.

Status commands
zftype [ type ]
With no arguments, show the type of data to be transferred,
usually ASCII or binary. With an argument, change the type: the
types `A' or `ASCII' for ASCII data and `B' or `BINARY', `I' or
`IMAGE' for binary data are understood case-insensitively.

zfstat [ -v ]
Show the status of the current or last connection, as well as
the status of some of zftp's status variables. With the -v
option, a more verbose listing is produced by querying the
server for its version of events, too.

Retrieving files
The commands for retrieving files all take at least two options. -G
suppresses remote filename expansion which would otherwise be performed
(see below for a more detailed description of that). -t attempts to
set the modification time of the local file to that of the remote file:
see the description of the function zfrtime below for more information.

zfget [ -Gtc ] file1 ...
Retrieve all the listed files file1 ... one at a time from the
remote server. If a file contains a `/', the full name is
passed to the remote server, but the file is stored locally
under the name given by the part after the final `/'. The
option -c (cat) forces all files to be sent as a single stream
to standard output; in this case the -t option has no effect.

zfuget [ -Gvst ] file1 ...
As zfget, but only retrieve files where the version on the
remote server is newer (has a later modification time), or where
the local file does not exist. If the remote file is older but
the files have different sizes, or if the sizes are the same but
the remote file is newer, the user will usually be queried.
With the option -s, the command runs silently and will always
retrieve the file in either of those two cases. With the option
-v, the command prints more information about the files while it
is working out whether or not to transfer them.

zfcget [ -Gt ] file1 ...
As zfget, but if any of the local files exists, and is shorter
than the corresponding remote file, the command assumes that it
is the result of a partially completed transfer and attempts to
transfer the rest of the file. This is useful on a poor
connection which keeps failing.

Note that this requires a commonly implemented, but
non-standard, version of the FTP protocol, so is not guaranteed
to work on all servers.

zfgcp [ -Gt ] remote-file local-file
zfgcp [ -Gt ] rfile1 ... ldir
This retrieves files from the remote server with arguments
behaving similarly to the cp command.

In the first form, copy remote-file from the server to the local
file local-file.

In the second form, copy all the remote files rfile1 ... into
the local directory ldir retaining the same basenames. This
assumes UNIX directory semantics.

Sending files
zfput [ -r ] file1 ...
Send all the file1 ... given separately to the remote server.
If a filename contains a `/', the full filename is used locally
to find the file, but only the basename is used for the remote
file name.

With the option -r, if any of the files are directories they are
sent recursively with all their subdirectories, including files
beginning with `.'. This requires that the remote machine
understand UNIX file semantics, since `/' is used as a directory
separator.

zfuput [ -vs ] file1 ...
As zfput, but only send files which are newer than their remote
equivalents, or if the remote file does not exist. The logic is
the same as for zfuget, but reversed between local and remote
files.

zfcput file1 ...
As zfput, but if any remote file already exists and is shorter
than the local equivalent, assume it is the result of an
incomplete transfer and send the rest of the file to append to
the existing part. As the FTP append command is part of the
standard set, this is in principle more likely to work than
zfcget.

zfpcp local-file remote-file
zfpcp lfile1 ... rdir
This sends files to the remote server with arguments behaving
similarly to the cp command.

With two arguments, copy local-file to the server as
remote-file.

With more than two arguments, copy all the local files lfile1
... into the existing remote directory rdir retaining the same
basenames. This assumes UNIX directory semantics.

A problem arises if you attempt to use zfpcp lfile1 rdir, i.e.
the second form of copying but with two arguments, as the
command has no simple way of knowing if rdir corresponds to a
directory or a filename. It attempts to resolve this in various
ways. First, if the rdir argument is `.' or `..' or ends in a
slash, it is assumed to be a directory. Secondly, if the
operation of copying to a remote file in the first form failed,
and the remote server sends back the expected failure code 553
and a reply including the string `Is a directory', then zfpcp
will retry using the second form.

Closing the connection
zfclose
Close the connection.

Session management
zfsession [ -lvod ] [ sessname ]
Allows you to manage multiple FTP sessions at once. By default,
connections take place in a session called `default'; by giving
the command `zfsession sessname' you can change to a new or
existing session with a name of your choice. The new session
remembers its own connection, as well as associated shell
parameters, and also the host/user parameters set by zfparams.
Hence you can have different sessions set up to connect to
different hosts, each remembering the appropriate host, user and
password.

With no arguments, zfsession prints the name of the current
session; with the option -l it lists all sessions which
currently exist, and with the option -v it gives a verbose list
showing the host and directory for each session, where the
current session is marked with an asterisk. With -o, it will
switch to the most recent previous session.

With -d, the given session (or else the current one) is removed;
everything to do with it is completely forgotten. If it was the
only session, a new session called `default' is created and made
current. It is safest not to delete sessions while background
commands using zftp are active.

zftransfer sess1:file1 sess2:file2
Transfer files between two sessions; no local copy is made. The
file is read from the session sess1 as file1 and written to
session sess2 as file file2; file1 and file2 may be relative to
the current directories of the session. Either sess1 or sess2
may be omitted (though the colon should be retained if there is
a possibility of a colon appearing in the file name) and
defaults to the current session; file2 may be omitted or may end
with a slash, in which case the basename of file1 will be added.
The sessions sess1 and sess2 must be distinct.

The operation is performed using pipes, so it is required that
the connections still be valid in a subshell, which is not the
case under versions of some operating systems, presumably due to
a system bug.

Bookmarks
The two functions zfmark and zfgoto allow you to `bookmark' the present
location (host, user and directory) of the current FTP connection for
later use. The file to be used for storing and retrieving bookmarks is
given by the parameter $ZFTP_BMFILE; if not set when one of the two
functions is called, it will be set to the file .zfbkmarks in the
directory where your zsh startup files live (usually ~).

zfmark [ bookmark ]
If given an argument, mark the current host, user and directory
under the name bookmark for later use by zfgoto. If there is no
connection open, use the values for the last connection
immediately before it was closed; it is an error if there was
none. Any existing bookmark under the same name will be
silently replaced.

If not given an argument, list the existing bookmarks and the
points to which they refer in the form user@host:directory; this
is the format in which they are stored, and the file may be
edited directly.

zfgoto [ -n ] bookmark
Return to the location given by bookmark, as previously set by
zfmark. If the location has user `ftp' or `anonymous', open the
connection with zfanon, so that no password is required. If the
user and host parameters match those stored for the current
session, if any, those will be used, and again no password is
required. Otherwise a password will be prompted for.

With the option -n, the bookmark is taken to be a nickname
stored by the ncftp program in its bookmark file, which is
assumed to be ~/.ncftp/bookmarks. The function works
identically in other ways. Note that there is no mechanism for
adding or modifying ncftp bookmarks from the zftp functions.

Other functions
Mostly, these functions will not be called directly (apart from
zfinit), but are described here for completeness. You may wish to
alter zftp_chpwd and zftp_progress, in particular.

zfinit [ -n ]
As described above, this is used to initialize the zftp function
system. The -n option should be used if the zftp command is
already built into the shell.

zfautocheck [ -dn ]
This function is called to implement automatic reopening
behaviour, as described in more detail below. The options must
appear in the first argument; -n prevents the command from
changing to the old directory, while -d prevents it from setting
the variable do_close, which it otherwise does as a flag for
automatically closing the connection after a transfer. The host
and directory for the last session are stored in the variable
$zflastsession, but the internal host/user/password parameters
must also be correctly set.

zfcd_match prefix suffix
This performs matching for completion of remote directory names.
If the remote server is UNIX, it will attempt to persuade the
server to list the remote directory with subdirectories marked,
which usually works but is not guaranteed. On other hosts it
simply calls zfget_match and hence completes all files, not just
directories. On some systems, directories may not even look
like filenames.

zfget_match prefix suffix
This performs matching for completion of remote filenames. It
caches files for the current directory (only) in the shell
parameter $zftp_fcache. It is in the form to be called by the
-K option of compctl, but also works when called from a
widget-style completion function with prefix and suffix set
appropriately.

zfrglob varname
Perform remote globbing, as describes in more detail below.
varname is the name of a variable containing the pattern to be
expanded; if there were any matches, the same variable will be
set to the expanded set of filenames on return.

zfrtime lfile rfile [ time ]
Set the local file lfile to have the same modification time as
the remote file rfile, or the explicit time time in FTP format
CCYYMMDDhhmmSS for the GMT timezone. This uses the shell's
zsh/datetime module to perform the conversion from GMT to local
time.

zftp_chpwd
This function is called every time a connection is opened, or
closed, or the remote directory changes. This version alters
the title bar of an xterm-compatible or sun-cmd terminal
emulator to reflect the local and remote hostnames and current
directories. It works best when combined with the function
chpwd. In particular, a function of the form

chpwd() {
if [[ -n $ZFTP_USER ]]; then
zftp_chpwd
else
# usual chpwd e.g put host:directory in title bar
fi
}

fits in well.

zftp_progress
This function shows the status of the transfer. It will not
write anything unless the output is going to a terminal;
however, if you transfer files in the background, you should
turn off progress reports by hand using `zstyle ':zftp:*'
progress none'. Note also that if you alter it, any output must
be to standard error, as standard output may be a file being
received. The form of the progress meter, or whether it is used
at all, can be configured without altering the function, as
described in the next section.

zffcache
This is used to implement caching of files in the current
directory for each session separately. It is used by
zfget_match and zfrglob.

MISCELLANEOUS FEATURES
Configuration
Various styles are available using the standard shell style mechanism,
described in zshmodules(1). Briefly, the command `zstyle ':zftp:*'
style value ...'. defines the style to have value value; more than one
value may be given, although that is not useful in the cases described
here. These values will then be used throughout the zftp function
system. For more precise control, the first argument, which gives a
pattern that matches contexts in which the style applies, can be
modified to include a particular function, as for example
`:zftp:zfget': the style will then have the given value only in the
zfget function, and will override styles set under `:zftp:*'. Note
that only the top level function name, as called by the user, is used;
calling of lower level functions is transparent to the user. Hence
modifications to the title bar in zftp_chpwd use the contexts
:zftp:zfopen, :zftp:zfcd, etc., depending where it was called from.
The following styles are understood:

progress
Controls the way that zftp_progress reports on the progress of a
transfer. If empty, unset, or `none', no progress report is
made; if `bar' a growing bar of inverse video is shown; if
`percent' (or any other string, though this may change in
future), the percentage of the file transferred is shown. The
bar meter requires that the width of the terminal be available
via the $COLUMNS parameter (normally this is set automatically).
If the size of the file being transferred is not available, bar
and percent meters will simply show the number of bytes
transferred so far.

When zfinit is run, if this style is not defined for the context
:zftp:*, it will be set to `bar'.

update Specifies the minimum time interval between updates of the
progress meter in seconds. No update is made unless new data
has been received, so the actual time interval is limited only
by $ZFTP_TIMEOUT.

As described for progress, zfinit will force this to default to
1.

remote-glob
If set to `1', `yes' or `true', filename generation (globbing)
is performed on the remote machine instead of by zsh itself; see
below.

titlebar
If set to `1', `yes' or `true', zftp_chpwd will put the remote
host and remote directory into the titlebar of terminal
emulators such as xterm or sun-cmd that allow this.

As described for progress, zfinit will force this to default to
1.

chpwd If set to `1' `yes' or `true', zftp_chpwd will call the function
chpwd when a connection is closed. This is useful if the remote
host details were put into the terminal title bar by zftp_chpwd
and your usual chpwd also modifies the title bar.

When zfinit is run, it will determine whether chpwd exists and
if so it will set the default value for the style to 1 if none
exists already.

Note that there is also an associative array zfconfig which contains
values used by the function system. This should not be modified or
overwritten.

Remote globbing
The commands for retrieving files usually perform filename generation
(globbing) on their arguments; this can be turned off by passing the
option -G to each of the commands. Normally this operates by
retrieving a complete list of files for the directory in question, then
matching these locally against the pattern supplied. This has the
advantage that the full range of zsh patterns (respecting the setting
of the option EXTENDED_GLOB) can be used. However, it means that the
directory part of a filename will not be expanded and must be given
exactly. If the remote server does not support the UNIX directory
semantics, directory handling is problematic and it is recommended that
globbing only be used within the current directory. The list of files
in the current directory, if retrieved, will be cached, so that
subsequent globs in the same directory without an intervening zfcd are
much faster.

If the remote-glob style (see above) is set, globbing is instead
performed on the remote host: the server is asked for a list of
matching files. This is highly dependent on how the server is
implemented, though typically UNIX servers will provide support for
basic glob patterns. This may in some cases be faster, as it avoids
retrieving the entire list of directory contents.

Automatic and temporary reopening
As described for the zfopen command, a subsequent zfopen with no
parameters will reopen the connection to the last host (this includes
connections made with the zfanon command). Opened in this fashion, the
connection starts in the default remote directory and will remain open
until explicitly closed.

Automatic re-opening is also available. If a connection is not
currently open and a command requiring a connection is given, the last
connection is implicitly reopened. In this case the directory which
was current when the connection was closed again becomes the current
directory (unless, of course, the command given changes it). Automatic
reopening will also take place if the connection was close by the
remote server for whatever reason (e.g. a timeout). It is not
available if the -1 option to zfopen or zfanon was used.

Furthermore, if the command issued is a file transfer, the connection
will be closed after the transfer is finished, hence providing a
one-shot mode for transfers. This does not apply to directory changing
or listing commands; for example a zfdir may reopen a connection but
will leave it open. Also, automatic closure will only ever happen in
the same command as automatic opening, i.e a zfdir directly followed by
a zfget will never close the connection automatically.

Information about the previous connection is given by the zfstat
function. So, for example, if that reports:

Session: default
Not connected.
Last session: ftp.bar.com:/pub/textfiles

then the command zfget file.txt will attempt to reopen a connection to
ftp.bar.com, retrieve the file /pub/textfiles/file.txt, and immediately
close the connection again. On the other hand, zfcd .. will open the
connection in the directory /pub and leave it open.

Note that all the above is local to each session; if you return to a
previous session, the connection for that session is the one which will
be reopened.

Completion
Completion of local and remote files, directories, sessions and
bookmarks is supported. The older, compctl-style completion is defined
when zfinit is called; support for the new widget-based completion
system is provided in the function Completion/Zsh/Command/_zftp, which
should be installed with the other functions of the completion system
and hence should automatically be available.

NAME
zshcontrib - user contributions to zsh

DESCRIPTION
The Zsh source distribution includes a number of items contributed by
the user community. These are not inherently a part of the shell, and
some may not be available in every zsh installation. The most
significant of these are documented here. For documentation on other
contributed items such as shell functions, look for comments in the
function source files.

UTILITIES
Accessing On-Line Help
The key sequence ESC h is normally bound by ZLE to execute the run-help
widget (see zshzle(1)). This invokes the run-help command with the
command word from the current input line as its argument. By default,
run-help is an alias for the man command, so this often fails when the
command word is a shell builtin or a user-defined function. By
redefining the run-help alias, one can improve the on-line help
provided by the shell.

The helpfiles utility, found in the Util directory of the distribution,
is a Perl program that can be used to process the zsh manual to produce
a separate help file for each shell builtin and for many other shell
features as well. The autoloadable run-help function, found in
Functions/Misc, searches for these helpfiles and performs several other
tests to produce the most complete help possible for the command.

Help files are installed by default to a subdirectory of /usr/share/zsh
or /usr/local/share/zsh.

To create your own help files with helpfiles, choose or create a
directory where the individual command help files will reside. For
example, you might choose ~/zsh_help. If you unpacked the zsh
distribution in your home directory, you would use the commands:

mkdir ~/zsh_help
perl ~/zsh-5.9/Util/helpfiles ~/zsh_help

The HELPDIR parameter tells run-help where to look for the help files.
When unset, it uses the default installation path. To use your own set
of help files, set this to the appropriate path in one of your startup
files:

HELPDIR=~/zsh_help

To use the run-help function, you need to add lines something like the
following to your .zshrc or equivalent startup file:

unalias run-help
autoload run-help

Note that in order for `autoload run-help' to work, the run-help file
must be in one of the directories named in your fpath array (see
zshparam(1)). This should already be the case if you have a standard
zsh installation; if it is not, copy Functions/Misc/run-help to an
appropriate directory.

Recompiling Functions
If you frequently edit your zsh functions, or periodically update your
zsh installation to track the latest developments, you may find that
function digests compiled with the zcompile builtin are frequently out
of date with respect to the function source files. This is not usually
a problem, because zsh always looks for the newest file when loading a
function, but it may cause slower shell startup and function loading.
Also, if a digest file is explicitly used as an element of fpath, zsh
won't check whether any of its source files has changed.

The zrecompile autoloadable function, found in Functions/Misc, can be
used to keep function digests up to date.

zrecompile [ -qt ] [ name ... ]
zrecompile [ -qt ] -p arg ... [ -- arg ... ]
This tries to find *.zwc files and automatically re-compile them
if at least one of the original files is newer than the compiled
file. This works only if the names stored in the compiled files
are full paths or are relative to the directory that contains
the .zwc file.

In the first form, each name is the name of a compiled file or a
directory containing *.zwc files that should be checked. If no
arguments are given, the directories and *.zwc files in fpath
are used.

When -t is given, no compilation is performed, but a return
status of zero (true) is set if there are files that need to be
re-compiled and non-zero (false) otherwise. The -q option
quiets the chatty output that describes what zrecompile is
doing.

Without the -t option, the return status is zero if all files
that needed re-compilation could be compiled and non-zero if
compilation for at least one of the files failed.

If the -p option is given, the args are interpreted as one or
more sets of arguments for zcompile, separated by `--'. For
example:

zrecompile -p \
-R ~/.zshrc -- \
-M ~/.zcompdump -- \
~/zsh/comp.zwc ~/zsh/Completion/*/_*

This compiles ~/.zshrc into ~/.zshrc.zwc if that doesn't exist
or if it is older than ~/.zshrc. The compiled file will be
marked for reading instead of mapping. The same is done for
~/.zcompdump and ~/.zcompdump.zwc, but this compiled file is
marked for mapping. The last line re-creates the file
~/zsh/comp.zwc if any of the files matching the given pattern is
newer than it.

Without the -p option, zrecompile does not create function
digests that do not already exist, nor does it add new functions
to the digest.

The following shell loop is an example of a method for creating
function digests for all functions in your fpath, assuming that you
have write permission to the directories:

for ((i=1; i <= $#fpath; ++i)); do
dir=$fpath[i]
zwc=${dir:t}.zwc
if [[ $dir == (.|..) || $dir == (.|..)/* ]]; then
continue
fi
files=($dir/*(N-.))
if [[ -w $dir:h && -n $files ]]; then
files=(${${(M)files%/*/*}#/})
if ( cd $dir:h &&
zrecompile -p -U -z $zwc $files ); then
fpath[i]=$fpath[i].zwc
fi
fi
done

The -U and -z options are appropriate for functions in the default zsh
installation fpath; you may need to use different options for your
personal function directories.

Once the digests have been created and your fpath modified to refer to
them, you can keep them up to date by running zrecompile with no
arguments.

Keyboard Definition
The large number of possible combinations of keyboards, workstations,
terminals, emulators, and window systems makes it impossible for zsh to
have built-in key bindings for every situation. The zkbd utility,
found in Functions/Misc, can help you quickly create key bindings for
your configuration.

Run zkbd either as an autoloaded function, or as a shell script:

zsh -f ~/zsh-5.9/Functions/Misc/zkbd

When you run zkbd, it first asks you to enter your terminal type; if
the default it offers is correct, just press return. It then asks you
to press a number of different keys to determine characteristics of
your keyboard and terminal; zkbd warns you if it finds anything out of
the ordinary, such as a Delete key that sends neither ^H nor ^?.

The keystrokes read by zkbd are recorded as a definition for an
associative array named key, written to a file in the subdirectory
.zkbd within either your HOME or ZDOTDIR directory. The name of the
file is composed from the TERM, VENDOR and OSTYPE parameters, joined by
hyphens.

You may read this file into your .zshrc or another startup file with
the `source' or `.' commands, then reference the key parameter in
bindkey commands, like this:

source ${ZDOTDIR:-$HOME}/.zkbd/$TERM-$VENDOR-$OSTYPE
[[ -n ${key[Left]} ]] && bindkey "${key[Left]}" backward-char
[[ -n ${key[Right]} ]] && bindkey "${key[Right]}" forward-char
# etc.

Note that in order for `autoload zkbd' to work, the zkdb file must be
in one of the directories named in your fpath array (see zshparam(1)).
This should already be the case if you have a standard zsh
installation; if it is not, copy Functions/Misc/zkbd to an appropriate
directory.

Dumping Shell State
Occasionally you may encounter what appears to be a bug in the shell,
particularly if you are using a beta version of zsh or a development
release. Usually it is sufficient to send a description of the problem
to one of the zsh mailing lists (see zsh(1)), but sometimes one of the
zsh developers will need to recreate your environment in order to track
the problem down.

The script named reporter, found in the Util directory of the
distribution, is provided for this purpose. (It is also possible to
autoload reporter, but reporter is not installed in fpath by default.)
This script outputs a detailed dump of the shell state, in the form of
another script that can be read with `zsh -f' to recreate that state.

To use reporter, read the script into your shell with the `.' command
and redirect the output into a file:

. ~/zsh-5.9/Util/reporter > zsh.report

You should check the zsh.report file for any sensitive information such
as passwords and delete them by hand before sending the script to the
developers. Also, as the output can be voluminous, it's best to wait
for the developers to ask for this information before sending it.

You can also use reporter to dump only a subset of the shell state.
This is sometimes useful for creating startup files for the first time.
Most of the output from reporter is far more detailed than usually is
necessary for a startup file, but the aliases, options, and zstyles
states may be useful because they include only changes from the
defaults. The bindings state may be useful if you have created any of
your own keymaps, because reporter arranges to dump the keymap creation
commands as well as the bindings for every keymap.

As is usual with automated tools, if you create a startup file with
reporter, you should edit the results to remove unnecessary commands.
Note that if you're using the new completion system, you should not
dump the functions state to your startup files with reporter; use the
compdump function instead (see zshcompsys(1)).

reporter [ state ... ]
Print to standard output the indicated subset of the current
shell state. The state arguments may be one or more of:

all Output everything listed below.
aliases
Output alias definitions.
bindings
Output ZLE key maps and bindings.
completion
Output old-style compctl commands. New completion is
covered by functions and zstyles.
functions
Output autoloads and function definitions.
limits Output limit commands.
options
Output setopt commands.
styles Same as zstyles.
variables
Output shell parameter assignments, plus export commands
for any environment variables.
zstyles
Output zstyle commands.

If the state is omitted, all is assumed.

With the exception of `all', every state can be abbreviated by any
prefix, even a single letter; thus a is the same as aliases, z is the
same as zstyles, etc.

Manipulating Hook Functions
add-zsh-hook [ -L | -dD ] [ -Uzk ] hook function
Several functions are special to the shell, as described in the
section SPECIAL FUNCTIONS, see zshmisc(1), in that they are
automatically called at specific points during shell execution.
Each has an associated array consisting of names of functions to
be called at the same point; these are so-called `hook
functions'. The shell function add-zsh-hook provides a simple
way of adding or removing functions from the array.

hook is one of chpwd, periodic, precmd, preexec, zshaddhistory,
zshexit, or zsh_directory_name, the special functions in
question. Note that zsh_directory_name is called in a different
way from the other functions, but may still be manipulated as a
hook.

function is name of an ordinary shell function. If no options
are given this will be added to the array of functions to be
executed in the given context. Functions are invoked in the
order they were added.

If the option -L is given, the current values for the hook
arrays are listed with typeset.

If the option -d is given, the function is removed from the
array of functions to be executed.

If the option -D is given, the function is treated as a pattern
and any matching names of functions are removed from the array
of functions to be executed.

The options -U, -z and -k are passed as arguments to autoload
for function. For functions contributed with zsh, the options
-Uz are appropriate.

add-zle-hook-widget [ -L | -dD ] [ -Uzk ] hook widgetname
Several widget names are special to the line editor, as
described in the section Special Widgets, see zshzle(1), in that
they are automatically called at specific points during editing.
Unlike function hooks, these do not use a predefined array of
other names to call at the same point; the shell function
add-zle-hook-widget maintains a similar array and arranges for
the special widget to invoke those additional widgets.

hook is one of isearch-exit, isearch-update, line-pre-redraw,
line-init, line-finish, history-line-set, or keymap-select,
corresponding to each of the special widgets zle-isearch-exit,
etc. The special widget names are also accepted as the hook
argument.

widgetname is the name of a ZLE widget. If no options are given
this is added to the array of widgets to be invoked in the given
hook context. Widgets are invoked in the order they were added,
with
zle widgetname -Nw -f "nolast" -- "$@"

Note that this means that the `WIDGET' special parameter tracks
the widgetname when the widget function is called, rather than
tracking the name of the corresponding special hook widget.

If the option -d is given, the widgetname is removed from the
array of widgets to be executed.

If the option -D is given, the widgetname is treated as a
pattern and any matching names of widgets are removed from the
array.

If widgetname does not name an existing widget when added to the
array, it is assumed that a shell function also named widgetname
is meant to provide the implementation of the widget. This name
is therefore marked for autoloading, and the options -U, -z and
-k are passed as arguments to autoload as with add-zsh-hook.
The widget is also created with `zle -N widgetname' to cause the
corresponding function to be loaded the first time the hook is
called.

The arrays of widgetname are currently maintained in zstyle
contexts, one for each hook context, with a style of `widgets'.
If the -L option is given, this set of styles is listed with
`zstyle -L'. This implementation may change, and the special
widgets that refer to the styles are created only if
add-zle-hook-widget is called to add at least one widget, so if
this function is used for any hooks, then all hooks should be
managed only via this function.

REMEMBERING RECENT DIRECTORIES
The function cdr allows you to change the working directory to a
previous working directory from a list maintained automatically. It is
similar in concept to the directory stack controlled by the pushd, popd
and dirs builtins, but is more configurable, and as it stores all
entries in files it is maintained across sessions and (by default)
between terminal emulators in the current session. Duplicates are
automatically removed, so that the list reflects the single most recent
use of each directory.

Note that the pushd directory stack is not actually modified or used by
cdr unless you configure it to do so as described in the configuration
section below.

Installation
The system works by means of a hook function that is called every time
the directory changes. To install the system, autoload the required
functions and use the add-zsh-hook function described above:

autoload -Uz chpwd_recent_dirs cdr add-zsh-hook
add-zsh-hook chpwd chpwd_recent_dirs

Now every time you change directly interactively, no matter which
command you use, the directory to which you change will be remembered
in most-recent-first order.

Use
All direct user interaction is via the cdr function.

The argument to cdr is a number N corresponding to the Nth most
recently changed-to directory. 1 is the immediately preceding
directory; the current directory is remembered but is not offered as a
destination. Note that if you have multiple windows open 1 may refer
to a directory changed to in another window; you can avoid this by
having per-terminal files for storing directory as described for the
recent-dirs-file style below.

If you set the recent-dirs-default style described below cdr will
behave the same as cd if given a non-numeric argument, or more than one
argument. The recent directory list is updated just the same however
you change directory.

If the argument is omitted, 1 is assumed. This is similar to pushd's
behaviour of swapping the two most recent directories on the stack.

Completion for the argument to cdr is available if compinit has been
run; menu selection is recommended, using:

zstyle ':completion:*:*:cdr:*:*' menu selection

to allow you to cycle through recent directories; the order is
preserved, so the first choice is the most recent directory before the
current one. The verbose style is also recommended to ensure the
directory is shown; this style is on by default so no action is
required unless you have changed it.

Options
The behaviour of cdr may be modified by the following options.

-l lists the numbers and the corresponding directories in
abbreviated form (i.e. with ~ substitution reapplied), one per
line. The directories here are not quoted (this would only be
an issue if a directory name contained a newline). This is used
by the completion system.

-r sets the variable reply to the current set of directories.
Nothing is printed and the directory is not changed.

-e allows you to edit the list of directories, one per line. The
list can be edited to any extent you like; no sanity checking is
performed. Completion is available. No quoting is necessary
(except for newlines, where I have in any case no sympathy);
directories are in unabbreviated form and contain an absolute
path, i.e. they start with /. Usually the first entry should be
left as the current directory.

-p 'pattern'
Prunes any items in the directory list that match the given
extended glob pattern; the pattern needs to be quoted from
immediate expansion on the command line. The pattern is matched
against each completely expanded file name in the list; the full
string must match, so wildcards at the end (e.g. '*removeme*')
are needed to remove entries with a given substring.

If output is to a terminal, then the function will print the new
list after pruning and prompt for confirmation by the user.
This output and confirmation step can be skipped by using -P
instead of -p.

Configuration
Configuration is by means of the styles mechanism that should be
familiar from completion; if not, see the description of the zstyle
command in see zshmodules(1). The context for setting styles should be
':chpwd:*' in case the meaning of the context is extended in future,
for example:

zstyle ':chpwd:*' recent-dirs-max 0

sets the value of the recent-dirs-max style to 0. In practice the
style name is specific enough that a context of '*' should be fine.

An exception is recent-dirs-insert, which is used exclusively by the
completion system and so has the usual completion system context
(':completion:*' if nothing more specific is needed), though again '*'
should be fine in practice.

recent-dirs-default
If true, and the command is expecting a recent directory index,
and either there is more than one argument or the argument is
not an integer, then fall through to "cd". This allows the lazy
to use only one command for directory changing. Completion
recognises this, too; see recent-dirs-insert for how to control
completion when this option is in use.

recent-dirs-file
The file where the list of directories is saved. The default is
${ZDOTDIR:-$HOME}/.chpwd-recent-dirs, i.e. this is in your home
directory unless you have set the variable ZDOTDIR to point
somewhere else. Directory names are saved in $'...' quoted
form, so each line in the file can be supplied directly to the
shell as an argument.

The value of this style may be an array. In this case, the
first file in the list will always be used for saving
directories while any other files are left untouched. When
reading the recent directory list, if there are fewer than the
maximum number of entries in the first file, the contents of
later files in the array will be appended with duplicates
removed from the list shown. The contents of the two files are
not sorted together, i.e. all the entries in the first file are
shown first. The special value * can appear in the list to
indicate the default file should be read at that point. This
allows effects like the following:

zstyle ':chpwd:*' recent-dirs-file \
~/.chpwd-recent-dirs-${TTY##*/} *

Recent directories are read from a file numbered according to
the terminal. If there are insufficient entries the list is
supplemented from the default file.

It is possible to use zstyle -e to make the directory
configurable at run time:

zstyle -e ':chpwd:*' recent-dirs-file pick-recent-dirs-file
pick-recent-dirs-file() {
if [[ $PWD = ~/text/writing(|/*) ]]; then
reply=(~/.chpwd-recent-dirs-writing)
else
reply=(+)
fi
}

In this example, if the current directory is ~/text/writing or a
directory under it, then use a special file for saving recent
directories, else use the default.

recent-dirs-insert
Used by completion. If recent-dirs-default is true, then
setting this to true causes the actual directory, rather than
its index, to be inserted on the command line; this has the same
effect as using the corresponding index, but makes the history
clearer and the line easier to edit. With this setting, if part
of an argument was already typed, normal directory completion
rather than recent directory completion is done; this is because
recent directory completion is expected to be done by cycling
through entries menu fashion.

If the value of the style is always, then only recent
directories will be completed; in that case, use the cd command
when you want to complete other directories.

If the value is fallback, recent directories will be tried
first, then normal directory completion is performed if recent
directory completion failed to find a match.

Finally, if the value is both then both sets of completions are
presented; the usual tag mechanism can be used to distinguish
results, with recent directories tagged as recent-dirs. Note
that the recent directories inserted are abbreviated with
directory names where appropriate.

recent-dirs-max
The maximum number of directories to save to the file. If this
is zero or negative there is no maximum. The default is 20.
Note this includes the current directory, which isn't offered,
so the highest number of directories you will be offered is one
less than the maximum.

recent-dirs-prune
This style is an array determining what directories should (or
should not) be added to the recent list. Elements of the array
can include:

parent Prune parents (more accurately, ancestors) from the
recent list. If present, changing directly down by any
number of directories causes the current directory to be
overwritten. For example, changing from ~pws to
~pws/some/other/dir causes ~pws not to be left on the
recent directory stack. This only applies to direct
changes to descendant directories; earlier directories on
the list are not pruned. For example, changing from
~pws/yet/another to ~pws/some/other/dir does not cause
~pws to be pruned.

pattern:pattern
Gives a zsh pattern for directories that should not be
added to the recent list (if not already there). This
element can be repeated to add different patterns. For
example, 'pattern:/tmp(|/*)' stops /tmp or its
descendants from being added. The EXTENDED_GLOB option
is always turned on for these patterns.

recent-dirs-pushd
If set to true, cdr will use pushd instead of cd to change the
directory, so the directory is saved on the directory stack. As
the directory stack is completely separate from the list of
files saved by the mechanism used in this file there is no
obvious reason to do this.

Use with dynamic directory naming
It is possible to refer to recent directories using the dynamic
directory name syntax by using the supplied function
zsh_directory_name_cdr a hook:

autoload -Uz add-zsh-hook
add-zsh-hook -Uz zsh_directory_name zsh_directory_name_cdr

When this is done, ~[1] will refer to the most recent directory other
than $PWD, and so on. Completion after ~[... also works.

Details of directory handling
This section is for the curious or confused; most users will not need
to know this information.

Recent directories are saved to a file immediately and hence are
preserved across sessions. Note currently no file locking is applied:
the list is updated immediately on interactive commands and nowhere
else (unlike history), and it is assumed you are only going to change
directory in one window at once. This is not safe on shared accounts,
but in any case the system has limited utility when someone else is
changing to a different set of directories behind your back.

To make this a little safer, only directory changes instituted from the
command line, either directly or indirectly through shell function
calls (but not through subshells, evals, traps, completion functions
and the like) are saved. Shell functions should use cd -q or pushd -q
to avoid side effects if the change to the directory is to be invisible
at the command line. See the contents of the function
chpwd_recent_dirs for more details.

ABBREVIATED DYNAMIC REFERENCES TO DIRECTORIES
The dynamic directory naming system is described in the subsection
Dynamic named directories of the section Filename Expansion in
zshexpn(1). In this, a reference to ~[...] is expanded by a function
found by the hooks mechanism.

The contributed function zsh_directory_name_generic provides a system
allowing the user to refer to directories with only a limited amount of
new code. It supports all three of the standard interfaces for
directory naming: converting from a name to a directory, converting in
the reverse direction to find a short name, and completion of names.

The main feature of this function is a path-like syntax, combining
abbreviations at multiple levels separated by ":". As an example,
~[g:p:s] might specify:
g The top level directory for your git area. This first component
has to match, or the function will return indicating another
directory name hook function should be tried.

p The name of a project within your git area.

s The source area within that project. This allows you to
collapse references to long hierarchies to a very compact form,
particularly if the hierarchies are similar across different
areas of the disk.

Name components may be completed: if a description is shown at the top
of the list of completions, it includes the path to which previous
components expand, while the description for an individual completion
shows the path segment it would add. No additional configuration is
needed for this as the completion system is aware of the dynamic
directory name mechanism.

Usage
To use the function, first define a wrapper function for your specific
case. We'll assume it's to be autoloaded. This can have any name but
we'll refer to it as zdn_mywrapper. This wrapper function will define
various variables and then call this function with the same arguments
that the wrapper function gets. This configuration is described below.

Then arrange for the wrapper to be run as a zsh_directory_name hook:

autoload -Uz add-zsh-hook zsh_directory_name_generic zdn_mywrapper
add-zsh-hook -U zsh_directory_name zdn_mywrapper

Configuration
The wrapper function should define a local associative array zdn_top.
Alternatively, this can be set with a style called mapping. The
context for the style is :zdn:wrapper-name where wrapper-name is the
function calling zsh_directory_name_generic; for example:

zstyle :zdn:zdn_mywrapper: mapping zdn_mywrapper_top

The keys in this associative array correspond to the first component of
the name. The values are matching directories. They may have an
optional suffix with a slash followed by a colon and the name of a
variable in the same format to give the next component. (The slash
before the colon is to disambiguate the case where a colon is needed in
the path for a drive. There is otherwise no syntax for escaping this,
so path components whose names start with a colon are not supported.)
A special component :default: specifies a variable in the form /:var
(the path section is ignored and so is usually empty) that will be used
for the next component if no variable is given for the path. Variables
referred to within zdn_top have the same format as zdn_top itself, but
contain relative paths.

For example,

local -A zdn_top=(
g ~/git
ga ~/alternate/git
gs /scratch/$USER/git/:second2
:default: /:second1
)

This specifies the behaviour of a directory referred to as ~[g:...] or
~[ga:...] or ~[gs:...]. Later path components are optional; in that
case ~[g] expands to ~/git, and so on. gs expands to
/scratch/$USER/git and uses the associative array second2 to match the
second component; g and ga use the associative array second1 to match
the second component.

When expanding a name to a directory, if the first component is not g
or ga or gs, it is not an error; the function simply returns 1 so that
a later hook function can be tried. However, matching the first
component commits the function, so if a later component does not match,
an error is printed (though this still does not stop later hooks from
being executed).

For components after the first, a relative path is expected, but note
that multiple levels may still appear. Here is an example of second1:

local -A second1=(
p myproject
s somproject
os otherproject/subproject/:third
)

The path as found from zdn_top is extended with the matching directory,
so ~[g:p] becomes ~/git/myproject. The slash between is added
automatically (it's not possible to have a later component modify the
name of a directory already matched). Only os specifies a variable for
a third component, and there's no :default:, so it's an error to use a
name like ~[g:p:x] or ~[ga:s:y] because there's nowhere to look up the
x or y.

The associative arrays need to be visible within this function; the
generic function therefore uses internal variable names beginning _zdn_
in order to avoid clashes. Note that the variable reply needs to be
passed back to the shell, so should not be local in the calling
function.

The function does not test whether directories assembled by component
actually exist; this allows the system to work across automounted file
systems. The error from the command trying to use a non-existent
directory should be sufficient to indicate the problem.

Complete example
Here is a full fictitious but usable autoloadable definition of the
example function defined by the code above. So ~[gs:p:s] expands to
/scratch/$USER/git/myscratchproject/top/srcdir (with $USER also
expanded).

local -A zdn_top=(
g ~/git
ga ~/alternate/git
gs /scratch/$USER/git/:second2
:default: /:second1
)

local -A second1=(
p myproject
s somproject
os otherproject/subproject/:third
)

local -A second2=(
p myscratchproject
s somescratchproject
)

local -A third=(
s top/srcdir
d top/documentation
)

# autoload not needed if you did this at initialisation...
autoload -Uz zsh_directory_name_generic
zsh_directory_name_generic "$@

It is also possible to use global associative arrays, suitably named,
and set the style for the context of your wrapper function to refer to
this. Then your set up code would contain the following:

typeset -A zdn_mywrapper_top=(...)
# ... and so on for other associative arrays ...
zstyle ':zdn:zdn_mywrapper:' mapping zdn_mywrapper_top
autoload -Uz add-zsh-hook zsh_directory_name_generic zdn_mywrapper
add-zsh-hook -U zsh_directory_name zdn_mywrapper

and the function zdn_mywrapper would contain only the following:

zsh_directory_name_generic "$@"

GATHERING INFORMATION FROM VERSION CONTROL SYSTEMS
In a lot of cases, it is nice to automatically retrieve information
from version control systems (VCSs), such as subversion, CVS or git, to
be able to provide it to the user; possibly in the user's prompt. So
that you can instantly tell which branch you are currently on, for
example.

In order to do that, you may use the vcs_info function.

The following VCSs are supported, showing the abbreviated name by which
they are referred to within the system:
Bazaar (bzr)
https://bazaar.canonical.com/
Codeville (cdv)
http://freecode.com/projects/codeville/
Concurrent Versioning System (cvs)
https://www.nongnu.org/cvs/
Darcs (darcs)
http://darcs.net/
Fossil (fossil)
https://fossil-scm.org/
Git (git)
https://git-scm.com/
GNU arch (tla)
https://www.gnu.org/software/gnu-arch/
Mercurial (hg)
https://www.mercurial-scm.org/
Monotone (mtn)
https://monotone.ca/
Perforce (p4)
https://www.perforce.com/
Subversion (svn)
https://subversion.apache.org/
SVK (svk)
https://svk.bestpractical.com/

There is also support for the patch management system quilt
(https://savannah.nongnu.org/projects/quilt). See Quilt Support below
for details.

To load vcs_info:

autoload -Uz vcs_info

It can be used in any existing prompt, because it does not require any
specific $psvar entries to be available.

Quickstart
To get this feature working quickly (including colors), you can do the
following (assuming, you loaded vcs_info properly - see above):

zstyle ':vcs_info:*' actionformats \
'%F{5}(%f%s%F{5})%F{3}-%F{5}[%F{2}%b%F{3}|%F{1}%a%F{5}]%f '
zstyle ':vcs_info:*' formats \
'%F{5}(%f%s%F{5})%F{3}-%F{5}[%F{2}%b%F{5}]%f '
zstyle ':vcs_info:(sv[nk]|bzr):*' branchformat '%b%F{1}:%F{3}%r'
precmd () { vcs_info }
PS1='%F{5}[%F{2}%n%F{5}] %F{3}%3~ ${vcs_info_msg_0_}%f%# '

Obviously, the last two lines are there for demonstration. You need to
call vcs_info from your precmd function. Once that is done you need a
single quoted '${vcs_info_msg_0_}' in your prompt.

To be able to use '${vcs_info_msg_0_}' directly in your prompt like
this, you will need to have the PROMPT_SUBST option enabled.

Now call the vcs_info_printsys utility from the command line:

% vcs_info_printsys
## list of supported version control backends:
## disabled systems are prefixed by a hash sign (#)
bzr
cdv
cvs
darcs
fossil
git
hg
mtn
p4
svk
svn
tla
## flavours (cannot be used in the enable or disable styles; they
## are enabled and disabled with their master [git-svn -> git])
## they *can* be used in contexts: ':vcs_info:git-svn:*'.
git-p4
git-svn
hg-git
hg-hgsubversion
hg-hgsvn

You may not want all of these because there is no point in running the
code to detect systems you do not use. So there is a way to disable
some backends altogether:

zstyle ':vcs_info:*' disable bzr cdv darcs mtn svk tla

You may also pick a few from that list and enable only those:

zstyle ':vcs_info:*' enable git cvs svn

If you rerun vcs_info_printsys after one of these commands, you will
see the backends listed in the disable style (or backends not in the
enable style - if you used that) marked as disabled by a hash sign.
That means the detection of these systems is skipped completely. No
wasted time there.

Configuration
The vcs_info feature can be configured via zstyle.

First, the context in which we are working:
:vcs_info:vcs-string:user-context:repo-root-name

vcs-string
is one of: git, git-svn, git-p4, hg, hg-git, hg-hgsubversion,
hg-hgsvn, darcs, bzr, cdv, mtn, svn, cvs, svk, tla, p4 or
fossil. This is followed by `.quilt-quilt-mode' in Quilt mode
(see Quilt Support for details) and by `*hook-name' while hooks
are active (see Hooks in vcs_info for details).

Currently, hooks in quilt mode don't add the `.quilt-quilt-mode'
information. This may change in the future.

user-context
is a freely configurable string, assignable by the user as the
first argument to vcs_info (see its description below).

repo-root-name
is the name of a repository in which you want a style to match.
So, if you want a setting specific to /usr/src/zsh, with that
being a CVS checkout, you can set repo-root-name to zsh to make
it so.

There are three special values for vcs-string: The first is named
-init-, that is in effect as long as there was no decision what VCS
backend to use. The second is -preinit-; it is used before vcs_info is
run, when initializing the data exporting variables. The third special
value is formats and is used by the vcs_info_lastmsg for looking up its
styles.

The initial value of repo-root-name is -all- and it is replaced with
the actual name, as soon as it is known. Only use this part of the
context for defining the formats, actionformats or branchformat styles,
as it is guaranteed that repo-root-name is set up correctly for these
only. For all other styles, just use '*' instead.

There are two pre-defined values for user-context:
default
the one used if none is specified
command
used by vcs_info_lastmsg to lookup its styles

You can of course use ':vcs_info:*' to match all VCSs in all
user-contexts at once.

This is a description of all styles that are looked up.

formats
A list of formats, used when actionformats is not used (which is
most of the time).

actionformats
A list of formats, used if there is a special action going on in
your current repository; like an interactive rebase or a merge
conflict.

branchformat
Some backends replace %b in the formats and actionformats styles
above, not only by a branch name but also by a revision number.
This style lets you modify how that string should look.

nvcsformats
These "formats" are set when we didn't detect a version control
system for the current directory or vcs_info was disabled. This
is useful if you want vcs_info to completely take over the
generation of your prompt. You would do something like
PS1='${vcs_info_msg_0_}' to accomplish that.

hgrevformat
hg uses both a hash and a revision number to reference a
specific changeset in a repository. With this style you can
format the revision string (see branchformat) to include either
or both. It's only useful when get-revision is true. Note, the
full 40-character revision id is not available (except when
using the use-simple option) because executing hg more than once
per prompt is too slow; you may customize this behavior using
hooks.

max-exports
Defines the maximum number of vcs_info_msg_*_ variables vcs_info
will set.

enable A list of backends you want to use. Checked in the -init-
context. If this list contains an item called NONE no backend is
used at all and vcs_info will do nothing. If this list contains
ALL, vcs_info will use all known backends. Only with ALL in
enable will the disable style have any effect. ALL and NONE are
case insensitive.

disable
A list of VCSs you don't want vcs_info to test for repositories
(checked in the -init- context, too). Only used if enable
contains ALL.

disable-patterns
A list of patterns that are checked against $PWD. If a pattern
matches, vcs_info will be disabled. This style is checked in the
:vcs_info:-init-:*:-all- context.

Say, ~/.zsh is a directory under version control, in which you
do not want vcs_info to be active, do:
zstyle ':vcs_info:*' disable-patterns "${(b)HOME}/.zsh(|/*)"

use-quilt
If enabled, the quilt support code is active in `addon' mode.
See Quilt Support for details.

quilt-standalone
If enabled, `standalone' mode detection is attempted if no VCS
is active in a given directory. See Quilt Support for details.

quilt-patch-dir
Overwrite the value of the $QUILT_PATCHES environment variable.
See Quilt Support for details.

quiltcommand
When quilt itself is called in quilt support, the value of this
style is used as the command name.

check-for-changes
If enabled, this style causes the %c and %u format escapes to
show when the working directory has uncommitted changes. The
strings displayed by these escapes can be controlled via the
stagedstr and unstagedstr styles. The only backends that
currently support this option are git, hg, and bzr (the latter
two only support unstaged).

For this style to be evaluated with the hg backend, the
get-revision style needs to be set and the use-simple style
needs to be unset. The latter is the default; the former is not.

With the bzr backend, lightweight checkouts only honor this
style if the use-server style is set.

Note, the actions taken if this style is enabled are potentially
expensive (read: they may be slow, depending on how big the
current repository is). Therefore, it is disabled by default.

check-for-staged-changes
This style is like check-for-changes, but it never checks the
worktree files, only the metadata in the .${vcs} dir.
Therefore, this style initializes only the %c escape (with
stagedstr) but not the %u escape. This style is faster than
check-for-changes.

In the git backend, this style checks for changes in the index.
Other backends do not currently implement this style.

This style is disabled by default.

stagedstr
This string will be used in the %c escape if there are staged
changes in the repository.

unstagedstr
This string will be used in the %u escape if there are unstaged
changes in the repository.

command
This style causes vcs_info to use the supplied string as the
command to use as the VCS's binary. Note, that setting this in
':vcs_info:*' is not a good idea.

If the value of this style is empty (which is the default), the
used binary name is the name of the backend in use (e.g. svn is
used in an svn repository).

The repo-root-name part in the context is always the default
-all- when this style is looked up.

For example, this style can be used to use binaries from
non-default installation directories. Assume, git is installed
in /usr/bin but your sysadmin installed a newer version in
/usr/local/bin. Instead of changing the order of your $PATH
parameter, you can do this:
zstyle ':vcs_info:git:*:-all-' command /usr/local/bin/git

use-server
This is used by the Perforce backend (p4) to decide if it should
contact the Perforce server to find out if a directory is
managed by Perforce. This is the only reliable way of doing
this, but runs the risk of a delay if the server name cannot be
found. If the server (more specifically, the host:port pair
describing the server) cannot be contacted, its name is put into
the associative array vcs_info_p4_dead_servers and is not
contacted again during the session until it is removed by hand.
If you do not set this style, the p4 backend is only usable if
you have set the environment variable P4CONFIG to a file name
and have corresponding files in the root directories of each
Perforce client. See comments in the function
VCS_INFO_detect_p4 for more detail.

The Bazaar backend (bzr) uses this to permit contacting the
server about lightweight checkouts, see the check-for-changes
style.

use-simple
If there are two different ways of gathering information, you
can select the simpler one by setting this style to true; the
default is to use the not-that-simple code, which is potentially
a lot slower but might be more accurate in all possible cases.
This style is used by the bzr, hg, and git backends. In the case
of hg it will invoke the external hexdump program to parse the
binary dirstate cache file; this method will not return the
local revision number.

get-revision
If set to true, vcs_info goes the extra mile to figure out the
revision of a repository's work tree (currently for the git and
hg backends, where this kind of information is not always
vital). For git, the hash value of the currently checked out
commit is available via the %i expansion. With hg, the local
revision number and the corresponding global hash are available
via %i.

get-mq If set to true, the hg backend will look for a Mercurial Queue
(mq) patch directory. Information will be available via the `%m'
replacement.

get-bookmarks
If set to true, the hg backend will try to get a list of current
bookmarks. They will be available via the `%m' replacement.

The default is to generate a comma-separated list of all
bookmark names that refer to the currently checked out revision.
If a bookmark is active, its name is suffixed an asterisk and
placed first in the list.

use-prompt-escapes
Determines if we assume that the assembled string from vcs_info
includes prompt escapes. (Used by vcs_info_lastmsg.)

debug Enable debugging output to track possible problems. Currently
this style is only used by vcs_info's hooks system.

hooks A list style that defines hook-function names. See Hooks in
vcs_info below for details.

patch-format
nopatch-format
This pair of styles format the patch information used by the %m
expando in formats and actionformats for the git and hg
backends. The value is subject to certain %-expansions
described below. The expanded value is made available in the
global backend_misc array as ${backend_misc[patches]} (also if a
set-patch-format hook is used).

get-unapplied
This boolean style controls whether a backend should attempt to
gather a list of unapplied patches (for example with Mercurial
Queue patches).

Used by the quilt, hg, and git backends.

The default values for these styles in all contexts are:

formats
" (%s)-[%b]%u%c-"
actionformats
" (%s)-[%b|%a]%u%c-"
branchformat
"%b:%r" (for bzr, svn, svk and hg)
nvcsformats
""
hgrevformat
"%r:%h"
max-exports
2
enable ALL
disable
(empty list)
disable-patterns
(empty list)
check-for-changes
false
check-for-staged-changes
false
stagedstr
(string: "S")
unstagedstr
(string: "U")
command
(empty string)
use-server
false
use-simple
false
get-revision
false
get-mq true
get-bookmarks
false
use-prompt-escapes
true
debug false
hooks (empty list)
use-quilt
false
quilt-standalone
false
quilt-patch-dir
empty - use $QUILT_PATCHES
quiltcommand
quilt
patch-format
backend dependent
nopatch-format
backend dependent
get-unapplied
false

In normal formats and actionformats the following replacements are
done:

%s The VCS in use (git, hg, svn, etc.).
%b Information about the current branch.
%a An identifier that describes the action. Only makes sense in
actionformats.
%i The current revision number or identifier. For hg the
hgrevformat style may be used to customize the output.
%c The string from the stagedstr style if there are staged changes
in the repository.
%u The string from the unstagedstr style if there are unstaged
changes in the repository.
%R The base directory of the repository.
%r The repository name. If %R is /foo/bar/repoXY, %r is repoXY.
%S A subdirectory within a repository. If $PWD is
/foo/bar/repoXY/beer/tasty, %S is beer/tasty.
%m A "misc" replacement. It is at the discretion of the backend to
decide what this replacement expands to.

The hg and git backends use this expando to display patch
information. hg sources patch information from the mq
extensions; git from in-progress rebase and cherry-pick
operations and from the stgit extension. The patch-format and
nopatch-format styles control the generated string. The former
is used when at least one patch from the patch queue has been
applied, and the latter otherwise.

The hg backend displays bookmark information in this expando (in
addition to mq information). See the get-mq and get-bookmarks
styles. Both of these styles may be enabled at the same time.
If both are enabled, both resulting strings will be shown
separated by a semicolon (that cannot currently be customized).

The quilt `standalone' backend sets this expando to the same
value as the %Q expando.

%Q Quilt series information. When quilt is used (either in `addon'
mode or as a `standalone' backend), this expando is set to the
quilt series' patch-format string. The set-patch-format hook
and nopatch-format style are honoured.

See Quilt Support below for details.

In branchformat these replacements are done:

%b The branch name. For hg, the branch name can include a topic
name.
%r The current revision number or the hgrevformat style for hg.

In hgrevformat these replacements are done:

%r The current local revision number.
%h The current global revision identifier.

In patch-format and nopatch-format these replacements are done:

%p The name of the top-most applied patch; may be overridden by the
applied-string hook.
%u The number of unapplied patches; may be overridden by the
unapplied-string hook.
%n The number of applied patches.
%c The number of unapplied patches.
%a The number of all patches (%a = %n * %c).
%g The names of active mq guards (hg backend).
%G The number of active mq guards (hg backend).

Not all VCS backends have to support all replacements. For nvcsformats
no replacements are performed at all, it is just a string.

Oddities
If you want to use the %b (bold off) prompt expansion in formats, which
expands %b itself, use %%b. That will cause the vcs_info expansion to
replace %%b with %b, so that zsh's prompt expansion mechanism can
handle it. Similarly, to hand down %b from branchformat, use %%%%b.
Sorry for this inconvenience, but it cannot be easily avoided. Luckily
we do not clash with a lot of prompt expansions and this only needs to
be done for those.

When one of the gen-applied-string, gen-unapplied-string, and
set-patch-format hooks is defined, applying %-escaping
(`foo=${foo//'%'/%%}') to the interpolated values for use in the prompt
is the responsibility of those hooks (jointly); when neither of those
hooks is defined, vcs_info handles escaping by itself. We regret this
coupling, but it was required for backwards compatibility.

Quilt Support
Quilt is not a version control system, therefore this is not
implemented as a backend. It can help keeping track of a series of
patches. People use it to keep a set of changes they want to use on top
of software packages (which is tightly integrated into the package
build process - the Debian project does this for a large number of
packages). Quilt can also help individual developers keep track of
their own patches on top of real version control systems.

The vcs_info integration tries to support both ways of using quilt by
having two slightly different modes of operation: `addon' mode and
`standalone' mode).

Quilt integration is off by default; to enable it, set the use-quilt
style, and add %Q to your formats or actionformats style:
zstyle ':vcs_info:*' use-quilt true

Styles looked up from the Quilt support code include
`.quilt-quilt-mode' in the vcs-string part of the context, where
quilt-mode is either addon or standalone. Example:
:vcs_info:git.quilt-addon:default:repo-root-name.

For `addon' mode to become active vcs_info must have already detected a
real version control system controlling the directory. If that is the
case, a directory that holds quilt's patches needs to be found. That
directory is configurable via the `QUILT_PATCHES' environment variable.
If that variable exists its value is used, otherwise the value
`patches' is assumed. The value from $QUILT_PATCHES can be overwritten
using the `quilt-patch-dir' style. (Note: you can use vcs_info to keep
the value of $QUILT_PATCHES correct all the time via the post-quilt
hook).

When the directory in question is found, quilt is assumed to be active.
To gather more information, vcs_info looks for a directory called
`.pc'; Quilt uses that directory to track its current state. If this
directory does not exist we know that quilt has not done anything to
the working directory (read: no patches have been applied yet).

If patches are applied, vcs_info will try to find out which. If you
want to know which patches of a series are not yet applied, you need to
activate the get-unapplied style in the appropriate context.

vcs_info allows for very detailed control over how the gathered
information is presented (see the Configuration and Hooks in vcs_info
sections), all of which are documented below. Note there are a number
of other patch tracking systems that work on top of a certain version
control system (like stgit for git, or mq for hg); the configuration
for systems like that are generally configured the same way as the
quilt support.

If the quilt support is working in `addon' mode, the produced string is
available as a simple format replacement (%Q to be precise), which can
be used in formats and actionformats; see below for details).

If, on the other hand, the support code is working in `standalone'
mode, vcs_info will pretend as if quilt were an actual version control
system. That means that the version control system identifier (which
otherwise would be something like `svn' or `cvs') will be set to
`-quilt-'. This has implications on the used style context where this
identifier is the second element. vcs_info will have filled in a proper
value for the "repository's" root directory and the string containing
the information about quilt's state will be available as the `misc'
replacement (and %Q for compatibility with `addon' mode).

What is left to discuss is how `standalone' mode is detected. The
detection itself is a series of searches for directories. You can have
this detection enabled all the time in every directory that is not
otherwise under version control. If you know there is only a limited
set of trees where you would like vcs_info to try and look for Quilt in
`standalone' mode to minimise the amount of searching on every call to
vcs_info, there are a number of ways to do that:

Essentially, `standalone' mode detection is controlled by a style
called `quilt-standalone'. It is a string style and its value can have
different effects. The simplest values are: `always' to run detection
every time vcs_info is run, and `never' to turn the detection off
entirely.

If the value of quilt-standalone is something else, it is interpreted
differently. If the value is the name of a scalar variable the value of
that variable is checked and that value is used in the same
`always'/`never' way as described above.

If the value of quilt-standalone is an array, the elements of that
array are used as directory names under which you want the detection to
be active.

If quilt-standalone is an associative array, the keys are taken as
directory names under which you want the detection to be active, but
only if the corresponding value is the string `true'.

Last, but not least, if the value of quilt-standalone is the name of a
function, the function is called without arguments and the return value
decides whether detection should be active. A `0' return value is true;
a non-zero return value is interpreted as false.

Note, if there is both a function and a variable by the name of
quilt-standalone, the function will take precedence.

Function Descriptions (Public API)
vcs_info [user-context]
The main function, that runs all backends and assembles all data
into ${vcs_info_msg_*_}. This is the function you want to call
from precmd if you want to include up-to-date information in
your prompt (see Variable Description below). If an argument is
given, that string will be used instead of default in the
user-context field of the style context.

vcs_info_hookadd
Statically registers a number of functions to a given hook. The
hook needs to be given as the first argument; what follows is a
list of hook-function names to register to the hook. The `+vi-'
prefix needs to be left out here. See Hooks in vcs_info below
for details.

vcs_info_hookdel
Remove hook-functions from a given hook. The hook needs to be
given as the first non-option argument; what follows is a list
of hook-function names to un-register from the hook. If `-a' is
used as the first argument, all occurrences of the functions are
unregistered. Otherwise only the last occurrence is removed (if
a function was registered to a hook more than once). The `+vi-'
prefix needs to be left out here. See Hooks in vcs_info below
for details.

vcs_info_lastmsg
Outputs the current values of ${vcs_info_msg_*_}. Takes into
account the value of the use-prompt-escapes style in
':vcs_info:formats:command:-all-'. It also only prints
max-exports values.

vcs_info_printsys [user-context]
Prints a list of all supported version control systems. Useful
to find out possible contexts (and which of them are enabled) or
values for the disable style.

vcs_info_setsys
Initializes vcs_info's internal list of available backends. With
this function, you can add support for new VCSs without
restarting the shell.

All functions named VCS_INFO_* are for internal use only.

Variable Description
${vcs_info_msg_N_} (Note the trailing underscore)
Where N is an integer, e.g., vcs_info_msg_0_. These variables
are the storage for the informational message the last vcs_info
call has assembled. These are strongly connected to the formats,
actionformats and nvcsformats styles described above. Those
styles are lists. The first member of that list gets expanded
into ${vcs_info_msg_0_}, the second into ${vcs_info_msg_1_} and
the Nth into ${vcs_info_msg_N-1_}. (See the max-exports style
above.)

All variables named VCS_INFO_* are for internal use only.

Hooks in vcs_info
Hooks are places in vcs_info where you can run your own code. That code
can communicate with the code that called it and through that, change
the system's behaviour.

For configuration, hooks change the style context:
:vcs_info:vcs-string*hook-name:user-context:repo-root-name

To register functions to a hook, you need to list them in the hooks
style in the appropriate context.

Example:
zstyle ':vcs_info:*+foo:*' hooks bar baz

This registers functions to the hook `foo' for all backends. In order
to avoid namespace problems, all registered function names are
prepended by a `+vi-', so the actual functions called for the `foo'
hook are `+vi-bar' and `+vi-baz'.

If you would like to register a function to a hook regardless of the
current context, you may use the vcs_info_hookadd function. To remove a
function that was added like that, the vcs_info_hookdel function can be
used.

If something seems weird, you can enable the `debug' boolean style in
the proper context and the hook-calling code will print what it tried
to execute and whether the function in question existed.

When you register more than one function to a hook, all functions are
executed one after another until one function returns non-zero or until
all functions have been called. Context-sensitive hook functions are
executed before statically registered ones (the ones added by
vcs_info_hookadd).

You may pass data between functions via an associative array,
user_data. For example:

+vi-git-myfirsthook(){
user_data[myval]=$myval
}
+vi-git-mysecondhook(){
# do something with ${user_data[myval]}
}

There are a number of variables that are special in hook contexts:

ret The return value that the hooks system will return to the
caller. The default is an integer `zero'. If and how a changed
ret value changes the execution of the caller depends on the
specific hook. See the hook documentation below for details.

hook_com
An associated array which is used for bidirectional
communication from the caller to hook functions. The used keys
depend on the specific hook.

context
The active context of the hook. Functions that wish to change
this variable should make it local scope first.

vcs The current VCS after it was detected. The same values as in the
enable/disable style are used. Available in all hooks except
start-up.

Finally, the full list of currently available hooks:

start-up
Called after starting vcs_info but before the VCS in this
directory is determined. It can be used to deactivate vcs_info
temporarily if necessary. When ret is set to 1, vcs_info aborts
and does nothing; when set to 2, vcs_info sets up everything as
if no version control were active and exits.

pre-get-data
Same as start-up but after the VCS was detected.

gen-hg-bookmark-string
Called in the Mercurial backend when a bookmark string is
generated; the get-revision and get-bookmarks styles must be
true.

This hook gets the names of the Mercurial bookmarks that
vcs_info collected from `hg'.

If a bookmark is active, the key ${hook_com[hg-active-bookmark]}
is set to its name. The key is otherwise unset.

When setting ret to non-zero, the string in
${hook_com[hg-bookmark-string]} will be used in the %m escape in
formats and actionformats and will be available in the global
backend_misc array as ${backend_misc[bookmarks]}.

gen-applied-string
Called in the git (with stgit or during rebase or merge), and hg
(with mq) backends and in quilt support when the applied-string
is generated; the use-quilt zstyle must be true for quilt (the
mq and stgit backends are active by default).

The arguments to this hook describe applied patches in the
opposite order, which means that the first argument is the
top-most patch and so forth.

When the patches' log messages can be extracted, those are
embedded within each argument after a space, so each argument is
of the form `patch-name first line of the log message', where
patch-name contains no whitespace. The mq backend passes
arguments of the form `patch name', with possible embedded
spaces, but without extracting the patch's log message.

When setting ret to non-zero, the string in
${hook_com[applied-string]} will be available as %p in the
patch-format and nopatch-format styles. This hook is, in
concert with set-patch-format, responsible for %-escaping that
value for use in the prompt. (See the Oddities section.)

The quilt backend passes to this hook the inputs
${hook_com[quilt-patches-dir]} and, if it has been determined,
${hook_com[quilt-pc-dir]}.

gen-unapplied-string
Called in the git (with stgit or during rebase), and hg (with
mq) backend and in quilt support when the unapplied-string is
generated; the get-unapplied style must be true.

This hook gets the names of all unapplied patches which vcs_info
in order, which means that the first argument is the patch
next-in-line to be applied and so forth.

The format of each argument is as for gen-applied-string, above.

When setting ret to non-zero, the string in
${hook_com[unapplied-string]} will be available as %u in the
patch-format and nopatch-format styles. This hook is, in
concert with set-patch-format, responsible for %-escaping that
value for use in the prompt. (See the Oddities section.)

The quilt backend passes to this hook the inputs
${hook_com[quilt-patches-dir]} and, if it has been determined,
${hook_com[quilt-pc-dir]}.

gen-mqguards-string
Called in the hg backend when guards-string is generated; the
get-mq style must be true (default).

This hook gets the names of any active mq guards.

When setting ret to non-zero, the string in
${hook_com[guards-string]} will be used in the %g escape in the
patch-format and nopatch-format styles.

no-vcs This hooks is called when no version control system was
detected.

The `hook_com' parameter is not used.

post-backend
Called as soon as the backend has finished collecting
information.

The `hook_com' keys available are as for the set-message hook.

post-quilt
Called after the quilt support is done. The following
information is passed as arguments to the hook: 1. the
quilt-support mode (`addon' or `standalone'); 2. the directory
that contains the patch series; 3. the directory that holds
quilt's status information (the `.pc' directory) or the string
"-nopc-" if that directory wasn't found.

The `hook_com' parameter is not used.

set-branch-format
Called before `branchformat' is set. The only argument to the
hook is the format that is configured at this point.

The `hook_com' keys considered are `branch' and `revision'.
They are set to the values figured out so far by vcs_info and
any change will be used directly when the actual replacement is
done.

If ret is set to non-zero, the string in
${hook_com[branch-replace]} will be used unchanged as the `%b'
replacement in the variables set by vcs_info.

set-hgrev-format
Called before a `hgrevformat' is set. The only argument to the
hook is the format that is configured at this point.

The `hook_com' keys considered are `hash' and `localrev'. They
are set to the values figured out so far by vcs_info and any
change will be used directly when the actual replacement is
done.

If ret is set to non-zero, the string in
${hook_com[rev-replace]} will be used unchanged as the `%i'
replacement in the variables set by vcs_info.

pre-addon-quilt
This hook is used when vcs_info's quilt functionality is active
in "addon" mode (quilt used on top of a real version control
system). It is activated right before any quilt specific action
is taken.

Setting the `ret' variable in this hook to a non-zero value
avoids any quilt specific actions from being run at all.

set-patch-format
This hook is used to control some of the possible expansions in
patch-format and nopatch-format styles with patch queue systems
such as quilt, mqueue and the like.

This hook is used in the git, hg and quilt backends.

The hook allows the control of the %p (${hook_com[applied]}) and
%u (${hook_com[unapplied]}) expansion in all backends that use
the hook. With the mercurial backend, the %g
(${hook_com[guards]}) expansion is controllable in addition to
that.

If ret is set to non-zero, the string in
${hook_com[patch-replace]} will be used unchanged instead of an
expanded format from patch-format or nopatch-format.

This hook is, in concert with the gen-applied-string or
gen-unapplied-string hooks if they are defined, responsible for
%-escaping the final patch-format value for use in the prompt.
(See the Oddities section.)

The quilt backend passes to this hook the inputs
${hook_com[quilt-patches-dir]} and, if it has been determined,
${hook_com[quilt-pc-dir]}.

set-message
Called each time before a `vcs_info_msg_N_' message is set. It
takes two arguments; the first being the `N' in the message
variable name, the second is the currently configured formats or
actionformats.

There are a number of `hook_com' keys, that are used here:
`action', `branch', `base', `base-name', `subdir', `staged',
`unstaged', `revision', `misc', `vcs' and one `miscN' entry for
each backend-specific data field (N starting at zero). They are
set to the values figured out so far by vcs_info and any change
will be used directly when the actual replacement is done.

Since this hook is triggered multiple times (once for each
configured formats or actionformats), each of the `hook_com'
keys mentioned above (except for the miscN entries) has an
`_orig' counterpart, so even if you changed a value to your
liking you can still get the original value in the next run.
Changing the `_orig' values is probably not a good idea.

If ret is set to non-zero, the string in ${hook_com[message]}
will be used unchanged as the message by vcs_info.

If all of this sounds rather confusing, take a look at the Examples
section below and also in the Misc/vcs_info-examples file in the Zsh
source. They contain some explanatory code.

Examples
Don't use vcs_info at all (even though it's in your prompt):
zstyle ':vcs_info:*' enable NONE

Disable the backends for bzr and svk:
zstyle ':vcs_info:*' disable bzr svk

Disable everything but bzr and svk:
zstyle ':vcs_info:*' enable bzr svk

Provide a special formats for git:
zstyle ':vcs_info:git:*' formats ' GIT, BABY! [%b]'
zstyle ':vcs_info:git:*' actionformats ' GIT ACTION! [%b|%a]'

All %x expansion in all sorts of formats (formats, actionformats,
branchformat, you name it) are done using the `zformat' builtin from
the `zsh/zutil' module. That means you can do everything with these %x
items what zformat supports. In particular, if you want something that
is really long to have a fixed width, like a hash in a mercurial
branchformat, you can do this: %12.12i. That'll shrink the 40 character
hash to its 12 leading characters. The form is actually `%min.maxx'.
More is possible. See the section `The zsh/zutil Module' in
zshmodules(1) for details.

Use the quicker bzr backend
zstyle ':vcs_info:bzr:*' use-simple true

If you do use use-simple, please report if it does
`the-right-thing[tm]'.

Display the revision number in yellow for bzr and svn:
zstyle ':vcs_info:(svn|bzr):*' \
branchformat '%b%%F{yellow}:%r'

The doubled percent sign is explained in the Oddities section.

Alternatively, one can use the raw colour codes directly:

zstyle ':vcs_info:(svn|bzr):*' \
branchformat '%b%{'${fg[yellow]}'%}:%r'

Normally when a variable is interpolated into a format string, the
variable needs to be %-escaped. In this example we skipped that because
we assume the value of ${fg[yellow]} doesn't contain any % signs.

Make sure you enclose the color codes in %{...%} if you want to use the
string provided by vcs_info in prompts.

Here is how to print the VCS information as a command (not in a
prompt):
vcsi() { vcs_info interactive; vcs_info_lastmsg }

This way, you can even define different formats for output via
vcs_info_lastmsg in the ':vcs_info:*:interactive:*' namespace.

Now as promised, some code that uses hooks: say, you'd like to replace
the string `svn' by `subversion' in vcs_info's %s formats replacement.

First, we will tell vcs_info to call a function when populating the
message variables with the gathered information:
zstyle ':vcs_info:*+set-message:*' hooks svn2subversion

Nothing happens. Which is reasonable, since we didn't define the actual
function yet. To see what the hooks subsystem is trying to do, enable
the `debug' style:
zstyle ':vcs_info:*+*:*' debug true

That should give you an idea what is going on. Specifically, the
function that we are looking for is `+vi-svn2subversion'. Note, the
`+vi-' prefix. So, everything is in order, just as documented. When you
are done checking out the debugging output, disable it again:
zstyle ':vcs_info:*+*:*' debug false

Now, let's define the function:

function +vi-svn2subversion() {
[[ ${hook_com[vcs_orig]} == svn ]] && hook_com[vcs]=subversion
}

Simple enough. And it could have even been simpler, if only we had
registered our function in a less generic context. If we do it only in
the `svn' backend's context, we don't need to test which the active
backend is:
zstyle ':vcs_info:svn+set-message:*' hooks svn2subversion

function +vi-svn2subversion() {
hook_com[vcs]=subversion
}

And finally a little more elaborate example, that uses a hook to create
a customised bookmark string for the hg backend.

Again, we start off by registering a function:
zstyle ':vcs_info:hg+gen-hg-bookmark-string:*' hooks hgbookmarks

And then we define the `+vi-hgbookmarks' function:

function +vi-hgbookmarks() {
# The default is to connect all bookmark names by
# commas. This mixes things up a little.
# Imagine, there's one type of bookmarks that is
# special to you. Say, because it's *your* work.
# Those bookmarks look always like this: "sh/*"
# (because your initials are sh, for example).
# This makes the bookmarks string use only those
# bookmarks. If there's more than one, it
# concatenates them using commas.
# The bookmarks returned by `hg' are available in
# the function's positional parameters.
local s="${(Mj:,:)@:#sh/*}"
# Now, the communication with the code that calls
# the hook functions is done via the hook_com[]
# hash. The key at which the `gen-hg-bookmark-string'
# hook looks is `hg-bookmark-string'. So:
hook_com[hg-bookmark-string]=$s
# And to signal that we want to use the string we
# just generated, set the special variable `ret' to
# something other than the default zero:
ret=1
return 0
}

Some longer examples and code snippets which might be useful are
available in the examples file located at Misc/vcs_info-examples in the
Zsh source directory.

This concludes our guided tour through zsh's vcs_info.

PROMPT THEMES
Installation
You should make sure all the functions from the Functions/Prompts
directory of the source distribution are available; they all begin with
the string `prompt_' except for the special function `promptinit'. You
also need the `colors' and `add-zsh-hook' functions from
Functions/Misc. All these functions may already be installed on your
system; if not, you will need to find them and copy them. The
directory should appear as one of the elements of the fpath array (this
should already be the case if they were installed), and at least the
function promptinit should be autoloaded; it will autoload the rest.
Finally, to initialize the use of the system you need to call the
promptinit function. The following code in your .zshrc will arrange
for this; assume the functions are stored in the directory ~/myfns:

fpath=(~/myfns $fpath)
autoload -U promptinit
promptinit

Theme Selection
Use the prompt command to select your preferred theme. This command
may be added to your .zshrc following the call to promptinit in order
to start zsh with a theme already selected.

prompt [ -c | -l ]
prompt [ -p | -h ] [ theme ... ]
prompt [ -s ] theme [ arg ... ]
Set or examine the prompt theme. With no options and a theme
argument, the theme with that name is set as the current theme.
The available themes are determined at run time; use the -l
option to see a list. The special theme `random' selects at
random one of the available themes and sets your prompt to that.

In some cases the theme may be modified by one or more
arguments, which should be given after the theme name. See the
help for each theme for descriptions of these arguments.

Options are:

-c Show the currently selected theme and its parameters, if
any.
-l List all available prompt themes.
-p Preview the theme named by theme, or all themes if no
theme is given.
-h Show help for the theme named by theme, or for the prompt
function if no theme is given.
-s Set theme as the current theme and save state.

prompt_theme_setup
Each available theme has a setup function which is called by the
prompt function to install that theme. This function may define
other functions as necessary to maintain the prompt, including
functions used to preview the prompt or provide help for its
use. You should not normally call a theme's setup function
directly.

Utility Themes
prompt off
The theme `off' sets all the prompt variables to minimal values
with no special effects.

prompt default
The theme `default' sets all prompt variables to the same state
as if an interactive zsh was started with no initialization
files.

prompt restore
The special theme `restore' erases all theme settings and sets
prompt variables to their state before the first time the
`prompt' function was run, provided each theme has properly
defined its cleanup (see below).

Note that you can undo `prompt off' and `prompt default' with
`prompt restore', but a second restore does not undo the first.

Writing Themes
The first step for adding your own theme is to choose a name for it,
and create a file `prompt_name_setup' in a directory in your fpath,
such as ~/myfns in the example above. The file should at minimum
contain assignments for the prompt variables that your theme wishes to
modify. By convention, themes use PS1, PS2, RPS1, etc., rather than
the longer PROMPT and RPROMPT.

The file is autoloaded as a function in the current shell context, so
it may contain any necessary commands to customize your theme,
including defining additional functions. To make some complex tasks
easier, your setup function may also do any of the following:

Assign prompt_opts
The array prompt_opts may be assigned any of "bang", "cr",
"percent", "sp", and/or "subst" as values. The corresponding
setopts (promptbang, etc.) are turned on, all other
prompt-related options are turned off. The prompt_opts array
preserves setopts even beyond the scope of localoptions, should
your function need that.

Modify hooks
Use of add-zsh-hook and add-zle-hook-widget is recommended (see
the Manipulating Hook Functions section above). All hooks that
follow the naming pattern prompt_theme_hook are automatically
removed when the prompt theme changes or is disabled.

Declare cleanup
If your function makes any other changes that should be undone
when the theme is disabled, your setup function may call

prompt_cleanup command

where command should be suitably quoted. If your theme is ever
disabled or replaced by another, command is executed with eval.
You may declare more than one such cleanup hook.

Define preview
Define or autoload a function prompt_name_preview to display a
simulated version of your prompt. A simple default previewer is
defined by promptinit for themes that do not define their own.
This preview function is called by `prompt -p'.

Provide help
Define or autoload a function prompt_name_help to display
documentation or help text for your theme. This help function
is called by `prompt -h'.

ZLE FUNCTIONS
Widgets
These functions all implement user-defined ZLE widgets (see zshzle(1))
which can be bound to keystrokes in interactive shells. To use them,
your .zshrc should contain lines of the form

autoload function
zle -N function

followed by an appropriate bindkey command to associate the function
with a key sequence. Suggested bindings are described below.

bash-style word functions
If you are looking for functions to implement moving over and
editing words in the manner of bash, where only alphanumeric
characters are considered word characters, you can use the
functions described in the next section. The following is
sufficient:

autoload -U select-word-style
select-word-style bash

forward-word-match, backward-word-match
kill-word-match, backward-kill-word-match
transpose-words-match, capitalize-word-match
up-case-word-match, down-case-word-match
delete-whole-word-match, select-word-match
select-word-style, match-word-context, match-words-by-style
The first eight `-match' functions are drop-in replacements for
the builtin widgets without the suffix. By default they behave
in a similar way. However, by the use of styles and the
function select-word-style, the way words are matched can be
altered. select-word-match is intended to be used as a text
object in vi mode but with custom word styles. For comparison,
the widgets described in zshzle(1) under Text Objects use fixed
definitions of words, compatible with the vim editor.

The simplest way of configuring the functions is to use
select-word-style, which can either be called as a normal
function with the appropriate argument, or invoked as a
user-defined widget that will prompt for the first character of
the word style to be used. The first time it is invoked, the
first eight -match functions will automatically replace the
builtin versions, so they do not need to be loaded explicitly.

The word styles available are as follows. Only the first
character is examined.

bash Word characters are alphanumeric characters only.

normal As in normal shell operation: word characters are
alphanumeric characters plus any characters present in
the string given by the parameter $WORDCHARS.

shell Words are complete shell command arguments, possibly
including complete quoted strings, or any tokens special
to the shell.

whitespace
Words are any set of characters delimited by whitespace.

default
Restore the default settings; this is usually the same as
`normal'.

All but `default' can be input as an upper case character, which
has the same effect but with subword matching turned on. In
this case, words with upper case characters are treated
specially: each separate run of upper case characters, or an
upper case character followed by any number of other characters,
is considered a word. The style subword-range can supply an
alternative character range to the default `[:upper:]'; the
value of the style is treated as the contents of a `[...]'
pattern (note that the outer brackets should not be supplied,
only those surrounding named ranges).

More control can be obtained using the zstyle command, as
described in zshmodules(1). Each style is looked up in the
context :zle:widget where widget is the name of the user-defined
widget, not the name of the function implementing it, so in the
case of the definitions supplied by select-word-style the
appropriate contexts are :zle:forward-word, and so on. The
function select-word-style itself always defines styles for the
context `:zle:*' which can be overridden by more specific
(longer) patterns as well as explicit contexts.

The style word-style specifies the rules to use. This may have
the following values.

normal Use the standard shell rules, i.e. alphanumerics and
$WORDCHARS, unless overridden by the styles word-chars or
word-class.

specified
Similar to normal, but only the specified characters, and
not also alphanumerics, are considered word characters.

unspecified
The negation of specified. The given characters are
those which will not be considered part of a word.

shell Words are obtained by using the syntactic rules for
generating shell command arguments. In addition, special
tokens which are never command arguments such as `()' are
also treated as words.

whitespace
Words are whitespace-delimited strings of characters.

The first three of those rules usually use $WORDCHARS, but the
value in the parameter can be overridden by the style
word-chars, which works in exactly the same way as $WORDCHARS.
In addition, the style word-class uses character class syntax to
group characters and takes precedence over word-chars if both
are set. The word-class style does not include the surrounding
brackets of the character class; for example, `-:[:alnum:]' is a
valid word-class to include all alphanumerics plus the
characters `-' and `:'. Be careful including `]', `^' and `-'
as these are special inside character classes.

word-style may also have `-subword' appended to its value to
turn on subword matching, as described above.

The style skip-chars is mostly useful for transpose-words and
similar functions. If set, it gives a count of characters
starting at the cursor position which will not be considered
part of the word and are treated as space, regardless of what
they actually are. For example, if

zstyle ':zle:transpose-words' skip-chars 1

has been set, and transpose-words-match is called with the
cursor on the X of fooXbar, where X can be any character, then
the resulting expression is barXfoo.

Finer grained control can be obtained by setting the style
word-context to an array of pairs of entries. Each pair of
entries consists of a pattern and a subcontext. The shell
argument the cursor is on is matched against each pattern in
turn until one matches; if it does, the context is extended by a
colon and the corresponding subcontext. Note that the test is
made against the original word on the line, with no stripping of
quotes. Special handling is done between words: the current
context is examined and if it contains the string between the
word is set to a single space; else if it is contains the string
back, the word before the cursor is considered, else the word
after cursor is considered. Some examples are given below.

The style skip-whitespace-first is only used with the
forward-word widget. If it is set to true, then forward-word
skips any non-word-characters, followed by any
non-word-characters: this is similar to the behaviour of other
word-orientated widgets, and also that used by other editors,
however it differs from the standard zsh behaviour. When using
select-word-style the widget is set in the context :zle:* to
true if the word style is bash and false otherwise. It may be
overridden by setting it in the more specific context
:zle:forward-word*.

It is possible to create widgets with specific behaviour by
defining a new widget implemented by the appropriate generic
function, then setting a style for the context of the specific
widget. For example, the following defines a widget
backward-kill-space-word using backward-kill-word-match, the
generic widget implementing backward-kill-word behaviour, and
ensures that the new widget always implements space-delimited
behaviour.

zle -N backward-kill-space-word backward-kill-word-match
zstyle :zle:backward-kill-space-word word-style space

The widget backward-kill-space-word can now be bound to a key.

Here are some further examples of use of the styles, actually
taken from the simplified interface in select-word-style:

zstyle ':zle:*' word-style standard
zstyle ':zle:*' word-chars ''

Implements bash-style word handling for all widgets, i.e. only
alphanumerics are word characters; equivalent to setting the
parameter WORDCHARS empty for the given context.

style ':zle:*kill*' word-style space

Uses space-delimited words for widgets with the word `kill' in
the name. Neither of the styles word-chars nor word-class is
used in this case.

Here are some examples of use of the word-context style to
extend the context.

zstyle ':zle:*' word-context \
"*/*" filename "[[:space:]]" whitespace
zstyle ':zle:transpose-words:whitespace' word-style shell
zstyle ':zle:transpose-words:filename' word-style normal
zstyle ':zle:transpose-words:filename' word-chars ''

This provides two different ways of using transpose-words
depending on whether the cursor is on whitespace between words
or on a filename, here any word containing a /. On whitespace,
complete arguments as defined by standard shell rules will be
transposed. In a filename, only alphanumerics will be
transposed. Elsewhere, words will be transposed using the
default style for :zle:transpose-words.

The word matching and all the handling of zstyle settings is
actually implemented by the function match-words-by-style. This
can be used to create new user-defined widgets. The calling
function should set the local parameter curcontext to
:zle:widget, create the local parameter matched_words and call
match-words-by-style with no arguments. On return,
matched_words will be set to an array with the elements: (1) the
start of the line (2) the word before the cursor (3) any
non-word characters between that word and the cursor (4) any
non-word character at the cursor position plus any remaining
non-word characters before the next word, including all
characters specified by the skip-chars style, (5) the word at or
following the cursor (6) any non-word characters following that
word (7) the remainder of the line. Any of the elements may be
an empty string; the calling function should test for this to
decide whether it can perform its function.

If the variable matched_words is defined by the caller to
match-words-by-style as an associative array (local -A
matched_words), then the seven values given above should be
retrieved from it as elements named start, word-before-cursor,
ws-before-cursor, ws-after-cursor, word-after-cursor,
ws-after-word, and end. In addition the element is-word-start
is 1 if the cursor is on the start of a word or subword, or on
white space before it (the cases can be distinguished by testing
the ws-after-cursor element) and 0 otherwise. This form is
recommended for future compatibility.

It is possible to pass options with arguments to
match-words-by-style to override the use of styles. The options
are:
-w word-style
-s skip-chars
-c word-class
-C word-chars
-r subword-range

For example, match-words-by-style -w shell -c 0 may be used to
extract the command argument around the cursor.

The word-context style is implemented by the function
match-word-context. This should not usually need to be called
directly.

bracketed-paste-magic
The bracketed-paste widget (see the subsection `Miscellaneous'
in zshzle(1)) inserts pasted text literally into the editor
buffer rather than interpret it as keystrokes. This disables
some common usages where the self-insert widget is replaced in
order to accomplish some extra processing. An example is the
contributed url-quote-magic widget described below.

The bracketed-paste-magic widget is meant to replace
bracketed-paste with a wrapper that re-enables these self-insert
actions, and other actions as selected by zstyles. Therefore
this widget is installed with

autoload -Uz bracketed-paste-magic
zle -N bracketed-paste bracketed-paste-magic

Other than enabling some widget processing,
bracketed-paste-magic attempts to replicate bracketed-paste as
faithfully as possible.

The following zstyles may be set to control processing of pasted
text. All are looked up in the context
`:bracketed-paste-magic'.

active-widgets
A list of patterns matching widget names that should be
activated during the paste. All other key sequences are
processed as self-insert-unmeta. The default is `self-*'
so any user-defined widgets named with that prefix are
active along with the builtin self-insert.

If this style is not set (explicitly deleted) or set to
an empty value, no widgets are active and the pasted text
is inserted literally. If the value includes
`undefined-key', any unknown sequences are discarded from
the pasted text.

inactive-keys
The inverse of active-widgets, a list of key sequences
that always use self-insert-unmeta even when bound to an
active widget. Note that this is a list of literal key
sequences, not patterns.

paste-init
A list of function names, called in widget context (but
not as widgets). The functions are called in order until
one of them returns a non-zero status. The parameter
`PASTED' contains the initial state of the pasted text.
All other ZLE parameters such as `BUFFER' have their
normal values and side-effects, and full history is
available, so for example paste-init functions may move
words from BUFFER into PASTED to make those words visible
to the active-widgets.

A non-zero return from a paste-init function does not
prevent the paste itself from proceeding.

Loading bracketed-paste-magic defines
backward-extend-paste, a helper function for use in
paste-init.

zstyle :bracketed-paste-magic paste-init \
backward-extend-paste

When a paste would insert into the middle of a word or
append text to a word already on the line,
backward-extend-paste moves the prefix from LBUFFER into
PASTED so that the active-widgets see the full word so
far. This may be useful with url-quote-magic.

paste-finish
Another list of function names called in order until one
returns non-zero. These functions are called after the
pasted text has been processed by the active-widgets, but
before it is inserted into `BUFFER'. ZLE parameters have
their normal values and side-effects.

A non-zero return from a paste-finish function does not
prevent the paste itself from proceeding.

Loading bracketed-paste-magic also defines quote-paste, a
helper function for use in paste-finish.

zstyle :bracketed-paste-magic paste-finish \
quote-paste
zstyle :bracketed-paste-magic:finish quote-style \
qqq

When the pasted text is inserted into BUFFER, it is
quoted per the quote-style value. To forcibly turn off
the built-in numeric prefix quoting of bracketed-paste,
use:

zstyle :bracketed-paste-magic:finish quote-style \
none

Important: During active-widgets processing of the paste (after
paste-init and before paste-finish), BUFFER starts empty and
history is restricted, so cursor motions, etc., may not pass
outside of the pasted content. Text assigned to BUFFER by the
active widgets is copied back into PASTED before paste-finish.

copy-earlier-word
This widget works like a combination of insert-last-word and
copy-prev-shell-word. Repeated invocations of the widget
retrieve earlier words on the relevant history line. With a
numeric argument N, insert the Nth word from the history line; N
may be negative to count from the end of the line.

If insert-last-word has been used to retrieve the last word on a
previous history line, repeated invocations will replace that
word with earlier words from the same line.

Otherwise, the widget applies to words on the line currently
being edited. The widget style can be set to the name of
another widget that should be called to retrieve words. This
widget must accept the same three arguments as insert-last-word.

cycle-completion-positions
After inserting an unambiguous string into the command line, the
new function based completion system may know about multiple
places in this string where characters are missing or differ
from at least one of the possible matches. It will then place
the cursor on the position it considers to be the most
interesting one, i.e. the one where one can disambiguate between
as many matches as possible with as little typing as possible.

This widget allows the cursor to be easily moved to the other
interesting spots. It can be invoked repeatedly to cycle
between all positions reported by the completion system.

delete-whole-word-match
This is another function which works like the -match functions
described immediately above, i.e. using styles to decide the
word boundaries. However, it is not a replacement for any
existing function.

The basic behaviour is to delete the word around the cursor.
There is no numeric argument handling; only the single word
around the cursor is considered. If the widget contains the
string kill, the removed text will be placed in the cutbuffer
for future yanking. This can be obtained by defining
kill-whole-word-match as follows:

zle -N kill-whole-word-match delete-whole-word-match

and then binding the widget kill-whole-word-match.

up-line-or-beginning-search, down-line-or-beginning-search
These widgets are similar to the builtin functions
up-line-or-search and down-line-or-search: if in a multiline
buffer they move up or down within the buffer, otherwise they
search for a history line matching the start of the current
line. In this case, however, they search for a line which
matches the current line up to the current cursor position, in
the manner of history-beginning-search-backward and -forward,
rather than the first word on the line.

edit-command-line
Edit the command line using your visual editor, as in ksh.

bindkey -M vicmd v edit-command-line

The editor to be used can also be specified using the editor
style in the context of the widget. It is specified as an array
of command and arguments:

zstyle :zle:edit-command-line editor gvim -f

expand-absolute-path
Expand the file name under the cursor to an absolute path,
resolving symbolic links. Where possible, the initial path
segment is turned into a named directory or reference to a
user's home directory.

history-search-end
This function implements the widgets
history-beginning-search-backward-end and
history-beginning-search-forward-end. These commands work by
first calling the corresponding builtin widget (see `History
Control' in zshzle(1)) and then moving the cursor to the end of
the line. The original cursor position is remembered and
restored before calling the builtin widget a second time, so
that the same search is repeated to look farther through the
history.

Although you autoload only one function, the commands to use it
are slightly different because it implements two widgets.

zle -N history-beginning-search-backward-end \
history-search-end
zle -N history-beginning-search-forward-end \
history-search-end
bindkey '\e^P' history-beginning-search-backward-end
bindkey '\e^N' history-beginning-search-forward-end

history-beginning-search-menu
This function implements yet another form of history searching.
The text before the cursor is used to select lines from the
history, as for history-beginning-search-backward except that
all matches are shown in a numbered menu. Typing the
appropriate digits inserts the full history line. Note that
leading zeroes must be typed (they are only shown when necessary
for removing ambiguity). The entire history is searched; there
is no distinction between forwards and backwards.

With a numeric argument, the search is not anchored to the start
of the line; the string typed by the use may appear anywhere in
the line in the history.

If the widget name contains `-end' the cursor is moved to the
end of the line inserted. If the widget name contains `-space'
any space in the text typed is treated as a wildcard and can
match anything (hence a leading space is equivalent to giving a
numeric argument). Both forms can be combined, for example:

zle -N history-beginning-search-menu-space-end \
history-beginning-search-menu

history-pattern-search
The function history-pattern-search implements widgets which
prompt for a pattern with which to search the history backwards
or forwards. The pattern is in the usual zsh format, however
the first character may be ^ to anchor the search to the start
of the line, and the last character may be $ to anchor the
search to the end of the line. If the search was not anchored
to the end of the line the cursor is positioned just after the
pattern found.

The commands to create bindable widgets are similar to those in
the example immediately above:

autoload -U history-pattern-search
zle -N history-pattern-search-backward history-pattern-search
zle -N history-pattern-search-forward history-pattern-search

incarg Typing the keystrokes for this widget with the cursor placed on
or to the left of an integer causes that integer to be
incremented by one. With a numeric argument, the number is
incremented by the amount of the argument (decremented if the
numeric argument is negative). The shell parameter incarg may
be set to change the default increment to something other than
one.

bindkey '^X+' incarg

incremental-complete-word
This allows incremental completion of a word. After starting
this command, a list of completion choices can be shown after
every character you type, which you can delete with ^H or DEL.
Pressing return accepts the completion so far and returns you to
normal editing (that is, the command line is not immediately
executed). You can hit TAB to do normal completion, ^G to abort
back to the state when you started, and ^D to list the matches.

This works only with the new function based completion system.

bindkey '^Xi' incremental-complete-word

insert-composed-char
This function allows you to compose characters that don't appear
on the keyboard to be inserted into the command line. The
command is followed by two keys corresponding to ASCII
characters (there is no prompt). For accented characters, the
two keys are a base character followed by a code for the accent,
while for other special characters the two characters together
form a mnemonic for the character to be inserted. The
two-character codes are a subset of those given by RFC 1345 (see
for example http://www.faqs.org/rfcs/rfc1345.html).

The function may optionally be followed by up to two characters
which replace one or both of the characters read from the
keyboard; if both characters are supplied, no input is read.
For example, insert-composed-char a: can be used within a widget
to insert an a with umlaut into the command line. This has the
advantages over use of a literal character that it is more
portable.

For best results zsh should have been built with support for
multibyte characters (configured with --enable-multibyte);
however, the function works for the limited range of characters
available in single-byte character sets such as ISO-8859-1.

The character is converted into the local representation and
inserted into the command line at the cursor position. (The
conversion is done within the shell, using whatever facilities
the C library provides.) With a numeric argument, the character
and its code are previewed in the status line

The function may be run outside zle in which case it prints the
character (together with a newline) to standard output. Input
is still read from keystrokes.

See insert-unicode-char for an alternative way of inserting
Unicode characters using their hexadecimal character number.

The set of accented characters is reasonably complete up to
Unicode character U+0180, the set of special characters less so.
However, it is very sporadic from that point. Adding new
characters is easy, however; see the function
define-composed-chars. Please send any additions to
zsh-workers@zsh.org.

The codes for the second character when used to accent the first
are as follows. Note that not every character can take every
accent.
! Grave.
' Acute.
> Circumflex.
? Tilde. (This is not ~ as RFC 1345 does not assume that
character is present on the keyboard.)
- Macron. (A horizontal bar over the base character.)
( Breve. (A shallow dish shape over the base character.)
. Dot above the base character, or in the case of i no dot,
or in the case of L and l a centered dot.
: Diaeresis (Umlaut).
c Cedilla.
_ Underline, however there are currently no underlined
characters.
/ Stroke through the base character.
" Double acute (only supported on a few letters).
; Ogonek. (A little forward facing hook at the bottom
right of the character.)
< Caron. (A little v over the letter.)
0 Circle over the base character.
2 Hook over the base character.
9 Horn over the base character.

The most common characters from the Arabic, Cyrillic, Greek and
Hebrew alphabets are available; consult RFC 1345 for the
appropriate sequences. In addition, a set of two letter codes
not in RFC 1345 are available for the double-width characters
corresponding to ASCII characters from ! to ~ (0x21 to 0x7e) by
preceding the character with ^, for example ^A for a
double-width A.

The following other two-character sequences are understood.

ASCII characters
These are already present on most keyboards:
<( Left square bracket
// Backslash (solidus)
)> Right square bracket
(! Left brace (curly bracket)
!! Vertical bar (pipe symbol)
!) Right brace (curly bracket)
'? Tilde

Special letters
Characters found in various variants of the Latin
alphabet:
ss Eszett (scharfes S)
D-, d- Eth
TH, th Thorn
kk Kra
'n 'n
NG, ng Ng
OI, oi Oi
yr yr
ED ezh

Currency symbols
Ct Cent
Pd Pound sterling (also lira and others)
Cu Currency
Ye Yen
Eu Euro (N.B. not in RFC 1345)

Punctuation characters
References to "right" quotes indicate the shape (like a 9
rather than 6) rather than their grammatical use. (For
example, a "right" low double quote is used to open
quotations in German.)
!I Inverted exclamation mark
BB Broken vertical bar
SE Section
Co Copyright
-a Spanish feminine ordinal indicator
<< Left guillemet
-- Soft hyphen
Rg Registered trade mark
PI Pilcrow (paragraph)
-o Spanish masculine ordinal indicator
>> Right guillemet
?I Inverted question mark
-1 Hyphen
-N En dash
-M Em dash
-3 Horizontal bar
:3 Vertical ellipsis
.3 Horizontal midline ellipsis
!2 Double vertical line
=2 Double low line
'6 Left single quote
'9 Right single quote
.9 "Right" low quote
9' Reversed "right" quote
"6 Left double quote
"9 Right double quote
:9 "Right" low double quote
9" Reversed "right" double quote
/- Dagger
/= Double dagger

Mathematical symbols
DG Degree
-2, +-, -+
- sign, +/- sign, -/+ sign
2S Superscript 2
3S Superscript 3
1S Superscript 1
My Micro
.M Middle dot
14 Quarter
12 Half
34 Three quarters
*X Multiplication
-: Division
%0 Per mille
FA, TE, /0
For all, there exists, empty set
dP, DE, NB
Partial derivative, delta (increment), del (nabla)
(-, -) Element of, contains
*P, +Z Product, sum
*-, Ob, Sb
Asterisk, ring, bullet
RT, 0(, 00
Root sign, proportional to, infinity

Other symbols
cS, cH, cD, cC
Card suits: spades, hearts, diamonds, clubs
Md, M8, M2, Mb, Mx, MX
Musical notation: crotchet (quarter note), quaver (eighth
note), semiquavers (sixteenth notes), flag sign, natural
sign, sharp sign
Fm, Ml Female, male

Accents on their own
'> Circumflex (same as caret, ^)
'! Grave (same as backtick, `)
', Cedilla
': Diaeresis (Umlaut)
'm Macron
'' Acute

insert-files
This function allows you type a file pattern, and see the
results of the expansion at each step. When you hit return, all
expansions are inserted into the command line.

bindkey '^Xf' insert-files

insert-unicode-char
When first executed, the user inputs a set of hexadecimal
digits. This is terminated with another call to
insert-unicode-char. The digits are then turned into the
corresponding Unicode character. For example, if the widget is
bound to ^XU, the character sequence `^XU 4 c ^XU' inserts L
(Unicode U+004c).

See insert-composed-char for a way of inserting characters using
a two-character mnemonic.

narrow-to-region [ -p pre ] [ -P post ]
[ -S statepm | -R statepm | [ -l lbufvar ] [ -r
rbufvar ] ]
[ -n ] [ start end ]
narrow-to-region-invisible
Narrow the editable portion of the buffer to the region between
the cursor and the mark, which may be in either order. The
region may not be empty.

narrow-to-region may be used as a widget or called as a function
from a user-defined widget; by default, the text outside the
editable area remains visible. A recursive-edit is performed
and the original widening status is then restored. Various
options and arguments are available when it is called as a
function.

The options -p pretext and -P posttext may be used to replace
the text before and after the display for the duration of the
function; either or both may be an empty string.

If the option -n is also given, pretext or posttext will only be
inserted if there is text before or after the region
respectively which will be made invisible.

Two numeric arguments may be given which will be used instead of
the cursor and mark positions.

The option -S statepm is used to narrow according to the other
options while saving the original state in the parameter with
name statepm, while the option -R statepm is used to restore the
state from the parameter; note in both cases the name of the
parameter is required. In the second case, other options and
arguments are irrelevant. When this method is used, no
recursive-edit is performed; the calling widget should call this
function with the option -S, perform its own editing on the
command line or pass control to the user via `zle
recursive-edit', then call this function with the option -R.
The argument statepm must be a suitable name for an ordinary
parameter, except that parameters beginning with the prefix
_ntr_ are reserved for use within narrow-to-region. Typically
the parameter will be local to the calling function.

The options -l lbufvar and -r rbufvar may be used to specify
parameters where the widget will store the resulting text from
the operation. The parameter lbufvar will contain LBUFFER and
rbufvar will contain RBUFFER. Neither of these two options may
be used with -S or -R.

narrow-to-region-invisible is a simple widget which calls
narrow-to-region with arguments which replace any text outside
the region with `...'. It does not take any arguments.

The display is restored (and the widget returns) upon any zle
command which would usually cause the line to be accepted or
aborted. Hence an additional such command is required to accept
or abort the current line.

The return status of both widgets is zero if the line was
accepted, else non-zero.

Here is a trivial example of a widget using this feature.
local state
narrow-to-region -p $'Editing restricted region\n' \
-P '' -S state
zle recursive-edit
narrow-to-region -R state

predict-on
This set of functions implements predictive typing using history
search. After predict-on, typing characters causes the editor
to look backward in the history for the first line beginning
with what you have typed so far. After predict-off, editing
returns to normal for the line found. In fact, you often don't
even need to use predict-off, because if the line doesn't match
something in the history, adding a key performs standard
completion, and then inserts itself if no completions were
found. However, editing in the middle of a line is liable to
confuse prediction; see the toggle style below.

With the function based completion system (which is needed for
this), you should be able to type TAB at almost any point to
advance the cursor to the next ``interesting'' character
position (usually the end of the current word, but sometimes
somewhere in the middle of the word). And of course as soon as
the entire line is what you want, you can accept with return,
without needing to move the cursor to the end first.

The first time predict-on is used, it creates several additional
widget functions:

delete-backward-and-predict
Replaces the backward-delete-char widget. You do not
need to bind this yourself.
insert-and-predict
Implements predictive typing by replacing the self-insert
widget. You do not need to bind this yourself.
predict-off
Turns off predictive typing.

Although you autoload only the predict-on function, it is
necessary to create a keybinding for predict-off as well.

zle -N predict-on
zle -N predict-off
bindkey '^X^Z' predict-on
bindkey '^Z' predict-off

read-from-minibuffer
This is most useful when called as a function from inside a
widget, but will work correctly as a widget in its own right.
It prompts for a value below the current command line; a value
may be input using all of the standard zle operations (and not
merely the restricted set available when executing, for example,
execute-named-cmd). The value is then returned to the calling
function in the parameter $REPLY and the editing buffer restored
to its previous state. If the read was aborted by a keyboard
break (typically ^G), the function returns status 1 and $REPLY
is not set.

If one argument is supplied to the function it is taken as a
prompt, otherwise `? ' is used. If two arguments are supplied,
they are the prompt and the initial value of $LBUFFER, and if a
third argument is given it is the initial value of $RBUFFER.
This provides a default value and starting cursor placement.
Upon return the entire buffer is the value of $REPLY.

One option is available: `-k num' specifies that num characters
are to be read instead of a whole line. The line editor is not
invoked recursively in this case, so depending on the terminal
settings the input may not be visible, and only the input keys
are placed in $REPLY, not the entire buffer. Note that unlike
the read builtin num must be given; there is no default.

The name is a slight misnomer, as in fact the shell's own
minibuffer is not used. Hence it is still possible to call
executed-named-cmd and similar functions while reading a value.

replace-argument, replace-argument-edit
The function replace-argument can be used to replace a command
line argument in the current command line or, if the current
command line is empty, in the last command line executed (the
new command line is not executed). Arguments are as delimited
by standard shell syntax,

If a numeric argument is given, that specifies the argument to
be replaced. 0 means the command name, as in history expansion.
A negative numeric argument counts backward from the last word.

If no numeric argument is given, the current argument is
replaced; this is the last argument if the previous history line
is being used.

The function prompts for a replacement argument.

If the widget contains the string edit, for example is defined
as

zle -N replace-argument-edit replace-argument

then the function presents the current value of the argument for
editing, otherwise the editing buffer for the replacement is
initially empty.

replace-string, replace-pattern
replace-string-again, replace-pattern-again
The function replace-string implements three widgets. If
defined under the same name as the function, it prompts for two
strings; the first (source) string will be replaced by the
second everywhere it occurs in the line editing buffer.

If the widget name contains the word `pattern', for example by
defining the widget using the command `zle -N replace-pattern
replace-string', then the matching is performed using zsh
patterns. All zsh extended globbing patterns can be used in the
source string; note that unlike filename generation the pattern
does not need to match an entire word, nor do glob qualifiers
have any effect. In addition, the replacement string can
contain parameter or command substitutions. Furthermore, a `&'
in the replacement string will be replaced with the matched
source string, and a backquoted digit `\N' will be replaced by
the Nth parenthesised expression matched. The form `\{N}' may
be used to protect the digit from following digits.

If the widget instead contains the word `regex' (or `regexp'),
then the matching is performed using regular expressions,
respecting the setting of the option RE_MATCH_PCRE (see the
description of the function regexp-replace below). The special
replacement facilities described above for pattern matching are
available.

By default the previous source or replacement string will not be
offered for editing. However, this feature can be activated by
setting the style edit-previous in the context :zle:widget (for
example, :zle:replace-string) to true. In addition, a positive
numeric argument forces the previous values to be offered, a
negative or zero argument forces them not to be.

The function replace-string-again can be used to repeat the
previous replacement; no prompting is done. As with
replace-string, if the name of the widget contains the word
`pattern' or `regex', pattern or regular expression matching is
performed, else a literal string replacement. Note that the
previous source and replacement text are the same whether
pattern, regular expression or string matching is used.

In addition, replace-string shows the previous replacement above
the prompt, so long as there was one during the current session;
if the source string is empty, that replacement will be repeated
without the widget prompting for a replacement string.

For example, starting from the line:

print This line contains fan and fond

and invoking replace-pattern with the source string `f(?)n' and
the replacement string `c\1r' produces the not very useful line:

print This line contains car and cord

The range of the replacement string can be limited by using the
narrow-to-region-invisible widget. One limitation of the
current version is that undo will cycle through changes to the
replacement and source strings before undoing the replacement
itself.

send-invisible
This is similar to read-from-minibuffer in that it may be called
as a function from a widget or as a widget of its own, and
interactively reads input from the keyboard. However, the input
being typed is concealed and a string of asterisks (`*') is
shown instead. The value is saved in the parameter $INVISIBLE
to which a reference is inserted into the editing buffer at the
restored cursor position. If the read was aborted by a keyboard
break (typically ^G) or another escape from editing such as
push-line, $INVISIBLE is set to empty and the original buffer is
restored unchanged.

If one argument is supplied to the function it is taken as a
prompt, otherwise `Non-echoed text: ' is used (as in emacs). If
a second and third argument are supplied they are used to begin
and end the reference to $INVISIBLE that is inserted into the
buffer. The default is to open with ${, then INVISIBLE, and
close with }, but many other effects are possible.

smart-insert-last-word
This function may replace the insert-last-word widget, like so:

zle -N insert-last-word smart-insert-last-word

With a numeric argument, or when passed command line arguments
in a call from another widget, it behaves like insert-last-word,
except that words in comments are ignored when
INTERACTIVE_COMMENTS is set.

Otherwise, the rightmost ``interesting'' word from the previous
command is found and inserted. The default definition of
``interesting'' is that the word contains at least one
alphabetic character, slash, or backslash. This definition may
be overridden by use of the match style. The context used to
look up the style is the widget name, so usually the context is
:insert-last-word. However, you can bind this function to
different widgets to use different patterns:

zle -N insert-last-assignment smart-insert-last-word
zstyle :insert-last-assignment match '[[:alpha:]][][[:alnum:]]#=*'
bindkey '\e=' insert-last-assignment

If no interesting word is found and the auto-previous style is
set to a true value, the search continues upward through the
history. When auto-previous is unset or false (the default),
the widget must be invoked repeatedly in order to search earlier
history lines.

transpose-lines
Only useful with a multi-line editing buffer; the lines here are
lines within the current on-screen buffer, not history lines.
The effect is similar to the function of the same name in Emacs.

Transpose the current line with the previous line and move the
cursor to the start of the next line. Repeating this (which can
be done by providing a positive numeric argument) has the effect
of moving the line above the cursor down by a number of lines.

With a negative numeric argument, requires two lines above the
cursor. These two lines are transposed and the cursor moved to
the start of the previous line. Using a numeric argument less
than -1 has the effect of moving the line above the cursor up by
minus that number of lines.

url-quote-magic
This widget replaces the built-in self-insert to make it easier
to type URLs as command line arguments. As you type, the input
character is analyzed and, if it may need quoting, the current
word is checked for a URI scheme. If one is found and the
current word is not already in quotes, a backslash is inserted
before the input character.

Styles to control quoting behavior:

url-metas
This style is looked up in the context
`:url-quote-magic:scheme' (where scheme is that of the
current URL, e.g. "ftp"). The value is a string listing
the characters to be treated as globbing metacharacters
when appearing in a URL using that scheme. The default
is to quote all zsh extended globbing characters,
excluding '<' and '>' but including braces (as in brace
expansion). See also url-seps.

url-seps
Like url-metas, but lists characters that should be
considered command separators, redirections, history
references, etc. The default is to quote the standard
set of shell separators, excluding those that overlap
with the extended globbing characters, but including '<'
and '>' and the first character of $histchars.

url-globbers
This style is looked up in the context
`:url-quote-magic'. The values form a list of command
names that are expected to do their own globbing on the
URL string. This implies that they are aliased to use
the `noglob' modifier. When the first word on the line
matches one of the values and the URL refers to a local
file (see url-local-schema), only the url-seps characters
are quoted; the url-metas are left alone, allowing them
to affect command-line parsing, completion, etc. The
default values are a literal `noglob' plus (when the
zsh/parameter module is available) any commands aliased
to the helper function `urlglobber' or its alias
`globurl'.

url-local-schema
This style is always looked up in the context
`:urlglobber', even though it is used by both
url-quote-magic and urlglobber. The values form a list
of URI schema that should be treated as referring to
local files by their real local path names, as opposed to
files which are specified relative to a
web-server-defined document root. The defaults are "ftp"
and "file".

url-other-schema
Like url-local-schema, but lists all other URI schema
upon which urlglobber and url-quote-magic should act. If
the URI on the command line does not have a scheme
appearing either in this list or in url-local-schema, it
is not magically quoted. The default values are "http",
"https", and "ftp". When a scheme appears both here and
in url-local-schema, it is quoted differently depending
on whether the command name appears in url-globbers.

Loading url-quote-magic also defines a helper function
`urlglobber' and aliases `globurl' to `noglob urlglobber'. This
function takes a local URL apart, attempts to pattern-match the
local file portion of the URL path, and then puts the results
back into URL format again.

vi-pipe
This function reads a movement command from the keyboard and
then prompts for an external command. The part of the buffer
covered by the movement is piped to the external command and
then replaced by the command's output. If the movement command
is bound to vi-pipe, the current line is used.

The function serves as an example for reading a vi movement
command from within a user-defined widget.

which-command
This function is a drop-in replacement for the builtin widget
which-command. It has enhanced behaviour, in that it correctly
detects whether or not the command word needs to be expanded as
an alias; if so, it continues tracing the command word from the
expanded alias until it reaches the command that will be
executed.

The style whence is available in the context :zle:$WIDGET; this
may be set to an array to give the command and options that will
be used to investigate the command word found. The default is
whence -c.

zcalc-auto-insert
This function is useful together with the zcalc function
described in the section `Mathematical Functions'. It should be
bound to a key representing a binary operator such as `*', `-',
`*' or `/'. When running in zcalc, if the key occurs at the
start of the line or immediately following an open parenthesis,
the text "ans " is inserted before the representation of the key
itself. This allows easy use of the answer from the previous
calculation in the current line. The text to be inserted before
the symbol typed can be modified by setting the variable
ZCALC_AUTO_INSERT_PREFIX.

Hence, for example, typing `+12' followed by return adds 12 to
the previous result.

If zcalc is in RPN mode (-r option) the effect of this binding
is automatically suppressed as operators alone on a line are
meaningful.

When not in zcalc, the key simply inserts the symbol itself.

Utility Functions
These functions are useful in constructing widgets. They should be
loaded with `autoload -U function' and called as indicated from
user-defined widgets.

split-shell-arguments
This function splits the line currently being edited into shell
arguments and whitespace. The result is stored in the array
reply. The array contains all the parts of the line in order,
starting with any whitespace before the first argument, and
finishing with any whitespace after the last argument. Hence
(so long as the option KSH_ARRAYS is not set) whitespace is
given by odd indices in the array and arguments by even indices.
Note that no stripping of quotes is done; joining together all
the elements of reply in order is guaranteed to produce the
original line.

The parameter REPLY is set to the index of the word in reply
which contains the character after the cursor, where the first
element has index 1. The parameter REPLY2 is set to the index
of the character under the cursor in that word, where the first
character has index 1.

Hence reply, REPLY and REPLY2 should all be made local to the
enclosing function.

See the function modify-current-argument, described below, for
an example of how to call this function.

modify-current-argument [ expr-using-$ARG | func ]
This function provides a simple method of allowing user-defined
widgets to modify the command line argument under the cursor (or
immediately to the left of the cursor if the cursor is between
arguments).

The argument can be an expression which when evaluated operates
on the shell parameter ARG, which will have been set to the
command line argument under the cursor. The expression should
be suitably quoted to prevent it being evaluated too early.

Alternatively, if the argument does not contain the string ARG,
it is assumed to be a shell function, to which the current
command line argument is passed as the only argument. The
function should set the variable REPLY to the new value for the
command line argument. If the function returns non-zero status,
so does the calling function.

For example, a user-defined widget containing the following code
converts the characters in the argument under the cursor into
all upper case:

modify-current-argument '${(U)ARG}'

The following strips any quoting from the current word (whether
backslashes or one of the styles of quotes), and replaces it
with single quoting throughout:

modify-current-argument '${(qq)${(Q)ARG}}'

The following performs directory expansion on the command line
argument and replaces it by the absolute path:

expand-dir() {
REPLY=${~1}
REPLY=${REPLY:a}
}
modify-current-argument expand-dir

In practice the function expand-dir would probably not be
defined within the widget where modify-current-argument is
called.

Styles
The behavior of several of the above widgets can be controlled by the
use of the zstyle mechanism. In particular, widgets that interact with
the completion system pass along their context to any completions that
they invoke.

break-keys
This style is used by the incremental-complete-word widget. Its
value should be a pattern, and all keys matching this pattern
will cause the widget to stop incremental completion without the
key having any further effect. Like all styles used directly by
incremental-complete-word, this style is looked up using the
context `:incremental'.

completer
The incremental-complete-word and insert-and-predict widgets set
up their top-level context name before calling completion. This
allows one to define different sets of completer functions for
normal completion and for these widgets. For example, to use
completion, approximation and correction for normal completion,
completion and correction for incremental completion and only
completion for prediction one could use:

zstyle ':completion:*' completer \
_complete _correct _approximate
zstyle ':completion:incremental:*' completer \
_complete _correct
zstyle ':completion:predict:*' completer \
_complete

It is a good idea to restrict the completers used in prediction,
because they may be automatically invoked as you type. The
_list and _menu completers should never be used with prediction.
The _approximate, _correct, _expand, and _match completers may
be used, but be aware that they may change characters anywhere
in the word behind the cursor, so you need to watch carefully
that the result is what you intended.

cursor The insert-and-predict widget uses this style, in the context
`:predict', to decide where to place the cursor after completion
has been tried. Values are:

complete
The cursor is left where it was when completion finished,
but only if it is after a character equal to the one just
inserted by the user. If it is after another character,
this value is the same as `key'.

key The cursor is left after the nth occurrence of the
character just inserted, where n is the number of times
that character appeared in the word before completion was
attempted. In short, this has the effect of leaving the
cursor after the character just typed even if the
completion code found out that no other characters need
to be inserted at that position.

Any other value for this style unconditionally leaves the cursor
at the position where the completion code left it.

list When using the incremental-complete-word widget, this style says
if the matches should be listed on every key press (if they fit
on the screen). Use the context prefix
`:completion:incremental'.

The insert-and-predict widget uses this style to decide if the
completion should be shown even if there is only one possible
completion. This is done if the value of this style is the
string always. In this case the context is `:predict' (not
`:completion:predict').

match This style is used by smart-insert-last-word to provide a
pattern (using full EXTENDED_GLOB syntax) that matches an
interesting word. The context is the name of the widget to
which smart-insert-last-word is bound (see above). The default
behavior of smart-insert-last-word is equivalent to:

zstyle :insert-last-word match '*[[:alpha:]/\\]*'

However, you might want to include words that contain spaces:

zstyle :insert-last-word match '*[[:alpha:][:space:]/\\]*'

Or include numbers as long as the word is at least two
characters long:

zstyle :insert-last-word match '*([[:digit:]]?|[[:alpha:]/\\])*'

The above example causes redirections like "2>" to be included.

prompt The incremental-complete-word widget shows the value of this
style in the status line during incremental completion. The
string value may contain any of the following substrings in the
manner of the PS1 and other prompt parameters:

%c Replaced by the name of the completer function that
generated the matches (without the leading underscore).

%l When the list style is set, replaced by `...' if the list
of matches is too long to fit on the screen and with an
empty string otherwise. If the list style is `false' or
not set, `%l' is always removed.

%n Replaced by the number of matches generated.

%s Replaced by `-no match-', `-no prefix-', or an empty
string if there is no completion matching the word on the
line, if the matches have no common prefix different from
the word on the line, or if there is such a common
prefix, respectively.

%u Replaced by the unambiguous part of all matches, if there
is any, and if it is different from the word on the line.

Like `break-keys', this uses the `:incremental' context.

stop-keys
This style is used by the incremental-complete-word widget. Its
value is treated similarly to the one for the break-keys style
(and uses the same context: `:incremental'). However, in this
case all keys matching the pattern given as its value will stop
incremental completion and will then execute their usual
function.

toggle This boolean style is used by predict-on and its related widgets
in the context `:predict'. If set to one of the standard `true'
values, predictive typing is automatically toggled off in
situations where it is unlikely to be useful, such as when
editing a multi-line buffer or after moving into the middle of a
line and then deleting a character. The default is to leave
prediction turned on until an explicit call to predict-off.

verbose
This boolean style is used by predict-on and its related widgets
in the context `:predict'. If set to one of the standard `true'
values, these widgets display a message below the prompt when
the predictive state is toggled. This is most useful in
combination with the toggle style. The default does not display
these messages.

widget This style is similar to the command style: For widget functions
that use zle to call other widgets, this style can sometimes be
used to override the widget which is called. The context for
this style is the name of the calling widget (not the name of
the calling function, because one function may be bound to
multiple widget names).

zstyle :copy-earlier-word widget smart-insert-last-word

Check the documentation for the calling widget or function to
determine whether the widget style is used.

EXCEPTION HANDLING
Two functions are provided to enable zsh to provide exception handling
in a form that should be familiar from other languages.

throw exception
The function throw throws the named exception. The name is an
arbitrary string and is only used by the throw and catch
functions. An exception is for the most part treated the same
as a shell error, i.e. an unhandled exception will cause the
shell to abort all processing in a function or script and to
return to the top level in an interactive shell.

catch exception-pattern
The function catch returns status zero if an exception was
thrown and the pattern exception-pattern matches its name.
Otherwise it returns status 1. exception-pattern is a standard
shell pattern, respecting the current setting of the
EXTENDED_GLOB option. An alias catch is also defined to prevent
the argument to the function from matching filenames, so
patterns may be used unquoted. Note that as exceptions are not
fundamentally different from other shell errors it is possible
to catch shell errors by using an empty string as the exception
name. The shell variable CAUGHT is set by catch to the name of
the exception caught. It is possible to rethrow an exception by
calling the throw function again once an exception has been
caught.

The functions are designed to be used together with the always
construct described in zshmisc(1). This is important as only this
construct provides the required support for exceptions. A typical
example is as follows.

{
# "try" block
# ... nested code here calls "throw MyExcept"
} always {
# "always" block
if catch MyExcept; then
print "Caught exception MyExcept"
elif catch ''; then
print "Caught a shell error. Propagating..."
throw ''
fi
# Other exceptions are not handled but may be caught further
# up the call stack.
}

If all exceptions should be caught, the following idiom might be
preferable.

{
# ... nested code here throws an exception
} always {
if catch *; then
case $CAUGHT in
(MyExcept)
print "Caught my own exception"
;;
(*)
print "Caught some other exception"
;;
esac
fi
}

In common with exception handling in other languages, the exception may
be thrown by code deeply nested inside the `try' block. However, note
that it must be thrown inside the current shell, not in a subshell
forked for a pipeline, parenthesised current-shell construct, or some
form of command or process substitution.

The system internally uses the shell variable EXCEPTION to record the
name of the exception between throwing and catching. One drawback of
this scheme is that if the exception is not handled the variable
EXCEPTION remains set and may be incorrectly recognised as the name of
an exception if a shell error subsequently occurs. Adding unset
EXCEPTION at the start of the outermost layer of any code that uses
exception handling will eliminate this problem.

MIME FUNCTIONS
Three functions are available to provide handling of files recognised
by extension, for example to dispatch a file text.ps when executed as a
command to an appropriate viewer.

zsh-mime-setup [ -fv ] [ -l [ suffix ... ] ]
zsh-mime-handler [ -l ] command argument ...
These two functions use the files ~/.mime.types and
/etc/mime.types, which associate types and extensions, as well
as ~/.mailcap and /etc/mailcap files, which associate types and
the programs that handle them. These are provided on many
systems with the Multimedia Internet Mail Extensions.

To enable the system, the function zsh-mime-setup should be
autoloaded and run. This allows files with extensions to be
treated as executable; such files be completed by the function
completion system. The function zsh-mime-handler should not
need to be called by the user.

The system works by setting up suffix aliases with `alias -s'.
Suffix aliases already installed by the user will not be
overwritten.

For suffixes defined in lower case, upper case variants will
also automatically be handled (e.g. PDF is automatically handled
if handling for the suffix pdf is defined), but not vice versa.

Repeated calls to zsh-mime-setup do not override the existing
mapping between suffixes and executable files unless the option
-f is given. Note, however, that this does not override
existing suffix aliases assigned to handlers other than
zsh-mime-handler.

Calling zsh-mime-setup with the option -l lists the existing
mappings without altering them. Suffixes to list (which may
contain pattern characters that should be quoted from immediate
interpretation on the command line) may be given as additional
arguments, otherwise all suffixes are listed.

Calling zsh-mime-setup with the option -v causes verbose output
to be shown during the setup operation.

The system respects the mailcap flags needsterminal and
copiousoutput; see mailcap(4) or mailcap(5) (the man page's name
varies across platforms).

The functions use the following styles, which are defined with
the zstyle builtin command (see zshmodules(1)). They should be
defined before zsh-mime-setup is run. The contexts used all
start with :mime:, with additional components in some cases. It
is recommended that a trailing * (suitably quoted) be appended
to style patterns in case the system is extended in future.
Some examples are given below.

For files that have multiple suffixes, e.g. .pdf.gz, where the
context includes the suffix it will be looked up starting with
the longest possible suffix until a match for the style is
found. For example, if .pdf.gz produces a match for the
handler, that will be used; otherwise the handler for .gz will
be used. Note that, owing to the way suffix aliases work, it is
always required that there be a handler for the shortest
possible suffix, so in this example .pdf.gz can only be handled
if .gz is also handled (though not necessarily in the same way).
Alternatively, if no handling for .gz on its own is needed,
simply adding the command

alias -s gz=zsh-mime-handler

to the initialisation code is sufficient; .gz will not be
handled on its own, but may be in combination with other
suffixes.

current-shell
If this boolean style is true, the mailcap handler for
the context in question is run using the eval builtin
instead of by starting a new sh process. This is more
efficient, but may not work in the occasional cases where
the mailcap handler uses strict POSIX syntax.

disown If this boolean style is true, mailcap handlers started
in the background will be disowned, i.e. not subject to
job control within the parent shell. Such handlers
nearly always produce their own windows, so the only
likely harmful side effect of setting the style is that
it becomes harder to kill jobs from within the shell.

execute-as-is
This style gives a list of patterns to be matched against
files passed for execution with a handler program. If
the file matches the pattern, the entire command line is
executed in its current form, with no handler. This is
useful for files which might have suffixes but
nonetheless be executable in their own right. If the
style is not set, the pattern *(*) *(/) is used; hence
executable files are executed directly and not passed to
a handler, and the option AUTO_CD may be used to change
to directories that happen to have MIME suffixes.

execute-never
This style is useful in combination with execute-as-is.
It is set to an array of patterns corresponding to full
paths to files that should never be treated as
executable, even if the file passed to the MIME handler
matches execute-as-is. This is useful for file systems
that don't handle execute permission or that contain
executables from another operating system. For example,
if /mnt/windows is a Windows mount, then

zstyle ':mime:*' execute-never '/mnt/windows/*'

will ensure that any files found in that area will be
executed as MIME types even if they are executable. As
this example shows, the complete file name is matched
against the pattern, regardless of how the file was
passed to the handler. The file is resolved to a full
path using the :P modifier described in the subsection
`Modifiers' in zshexpn(1); this means that symbolic links
are resolved where possible, so that links into other
file systems behave in the correct fashion.

file-path
Used if the style find-file-in-path is true for the same
context. Set to an array of directories that are used
for searching for the file to be handled; the default is
the command path given by the special parameter path.
The shell option PATH_DIRS is respected; if that is set,
the appropriate path will be searched even if the name of
the file to be handled as it appears on the command line
contains a `/'. The full context is :mime:.suffix:, as
described for the style handler.

find-file-in-path
If set, allows files whose names do not contain absolute
paths to be searched for in the command path or the path
specified by the file-path style. If the file is not
found in the path, it is looked for locally (whether or
not the current directory is in the path); if it is not
found locally, the handler will abort unless the
handle-nonexistent style is set. Files found in the path
are tested as described for the style execute-as-is. The
full context is :mime:.suffix:, as described for the
style handler.

flags Defines flags to go with a handler; the context is as for
the handler style, and the format is as for the flags in
mailcap.

handle-nonexistent
By default, arguments that don't correspond to files are
not passed to the MIME handler in order to prevent it
from intercepting commands found in the path that happen
to have suffixes. This style may be set to an array of
extended glob patterns for arguments that will be passed
to the handler even if they don't exist. If it is not
explicitly set it defaults to [[:alpha:]]#:/* which
allows URLs to be passed to the MIME handler even though
they don't exist in that format in the file system. The
full context is :mime:.suffix:, as described for the
style handler.

handler
Specifies a handler for a suffix; the suffix is given by
the context as :mime:.suffix:, and the format of the
handler is exactly that in mailcap. Note in particular
the `.' and trailing colon to distinguish this use of the
context. This overrides any handler specified by the
mailcap files. If the handler requires a terminal, the
flags style should be set to include the word
needsterminal, or if the output is to be displayed
through a pager (but not if the handler is itself a
pager), it should include copiousoutput.

mailcap
A list of files in the format of ~/.mailcap and
/etc/mailcap to be read during setup, replacing the
default list which consists of those two files. The
context is :mime:. A * in the list will be replaced by
the default files.

mailcap-priorities
This style is used to resolve multiple mailcap entries
for the same MIME type. It consists of an array of the
following elements, in descending order of priority;
later entries will be used if earlier entries are unable
to resolve the entries being compared. If none of the
tests resolve the entries, the first entry encountered is
retained.

files The order of files (entries in the mailcap style)
read. Earlier files are preferred. (Note this
does not resolve entries in the same file.)

priority
The priority flag from the mailcap entry. The
priority is an integer from 0 to 9 with the
default value being 5.

flags The test given by the mailcap-prio-flags option is
used to resolve entries.

place Later entries are preferred; as the entries are
strictly ordered, this test always succeeds.

Note that as this style is handled during initialisation,
the context is always :mime:, with no discrimination by
suffix.

mailcap-prio-flags
This style is used when the keyword flags is encountered
in the list of tests specified by the mailcap-priorities
style. It should be set to a list of patterns, each of
which is tested against the flags specified in the
mailcap entry (in other words, the sets of assignments
found with some entries in the mailcap file). Earlier
patterns in the list are preferred to later ones, and
matched patterns are preferred to unmatched ones.

mime-types
A list of files in the format of ~/.mime.types and
/etc/mime.types to be read during setup, replacing the
default list which consists of those two files. The
context is :mime:. A * in the list will be replaced by
the default files.

never-background
If this boolean style is set, the handler for the given
context is always run in the foreground, even if the
flags provided in the mailcap entry suggest it need not
be (for example, it doesn't require a terminal).

pager If set, will be used instead of $PAGER or more to handle
suffixes where the copiousoutput flag is set. The
context is as for handler, i.e. :mime:.suffix: for
handling a file with the given suffix.

Examples:

zstyle ':mime:*' mailcap ~/.mailcap /usr/local/etc/mailcap
zstyle ':mime:.txt:' handler less %s
zstyle ':mime:.txt:' flags needsterminal

When zsh-mime-setup is subsequently run, it will look for
mailcap entries in the two files given. Files of suffix .txt
will be handled by running `less file.txt'. The flag
needsterminal is set to show that this program must run attached
to a terminal.

As there are several steps to dispatching a command, the
following should be checked if attempting to execute a file by
extension .ext does not have the expected effect.

The command `alias -s ext' should show `ps=zsh-mime-handler'.
If it shows something else, another suffix alias was already
installed and was not overwritten. If it shows nothing, no
handler was installed: this is most likely because no handler
was found in the .mime.types and mailcap combination for .ext
files. In that case, appropriate handling should be added to
~/.mime.types and mailcap.

If the extension is handled by zsh-mime-handler but the file is
not opened correctly, either the handler defined for the type is
incorrect, or the flags associated with it are in appropriate.
Running zsh-mime-setup -l will show the handler and, if there
are any, the flags. A %s in the handler is replaced by the file
(suitably quoted if necessary). Check that the handler program
listed lists and can be run in the way shown. Also check that
the flags needsterminal or copiousoutput are set if the handler
needs to be run under a terminal; the second flag is used if the
output should be sent to a pager. An example of a suitable
mailcap entry for such a program is:

text/html; /usr/bin/lynx '%s'; needsterminal

Running `zsh-mime-handler -l command line' prints the command
line that would be executed, simplified to remove the effect of
any flags, and quoted so that the output can be run as a
complete zsh command line. This is used by the completion
system to decide how to complete after a file handled by
zsh-mime-setup.

pick-web-browser
This function is separate from the two MIME functions described
above and can be assigned directly to a suffix:

autoload -U pick-web-browser
alias -s html=pick-web-browser

It is provided as an intelligent front end to dispatch a web
browser. It may be run as either a function or a shell script.
The status 255 is returned if no browser could be started.

Various styles are available to customize the choice of
browsers:

browser-style
The value of the style is an array giving preferences in
decreasing order for the type of browser to use. The
values of elements may be

running
Use a GUI browser that is already running when an
X Window display is available. The browsers
listed in the x-browsers style are tried in order
until one is found; if it is, the file will be
displayed in that browser, so the user may need to
check whether it has appeared. If no running
browser is found, one is not started. Browsers
other than Firefox, Opera and Konqueror are
assumed to understand the Mozilla syntax for
opening a URL remotely.

x Start a new GUI browser when an X Window display
is available. Search for the availability of one
of the browsers listed in the x-browsers style and
start the first one that is found. No check is
made for an already running browser.

tty Start a terminal-based browser. Search for the
availability of one of the browsers listed in the
tty-browsers style and start the first one that is
found.

If the style is not set the default running x tty is
used.

x-browsers
An array in decreasing order of preference of browsers to
use when running under the X Window System. The array
consists of the command name under which to start the
browser. They are looked up in the context :mime: (which
may be extended in future, so appending `*' is
recommended). For example,

zstyle ':mime:*' x-browsers opera konqueror firefox

specifies that pick-web-browser should first look for a
running instance of Opera, Konqueror or Firefox, in that
order, and if it fails to find any should attempt to
start Opera. The default is firefox mozilla netscape
opera konqueror.

tty-browsers
An array similar to x-browsers, except that it gives
browsers to use when no X Window display is available.
The default is elinks links lynx.

command
If it is set this style is used to pick the command used
to open a page for a browser. The context is
:mime:browser:new:$browser: to start a new browser or
:mime:browser:running:$browser: to open a URL in a
browser already running on the current X display, where
$browser is the value matched in the x-browsers or
tty-browsers style. The escape sequence %b in the
style's value will be replaced by the browser, while %u
will be replaced by the URL. If the style is not set,
the default for all new instances is equivalent to %b %u
and the defaults for using running browsers are
equivalent to the values kfmclient openURL %u for
Konqueror, firefox -new-tab %u for Firefox, opera
-newpage %u for Opera, and %b -remote "openUrl(%u)" for
all others.

MATHEMATICAL FUNCTIONS
zcalc [ -erf ] [ expression ... ]
A reasonably powerful calculator based on zsh's arithmetic
evaluation facility. The syntax is similar to that of formulae
in most programming languages; see the section `Arithmetic
Evaluation' in zshmisc(1) for details.

Non-programmers should note that, as in many other programming
languages, expressions involving only integers (whether
constants without a `.', variables containing such constants as
strings, or variables declared to be integers) are by default
evaluated using integer arithmetic, which is not how an ordinary
desk calculator operates. To force floating point operation,
pass the option -f; see further notes below.

If the file ~/.zcalcrc exists it will be sourced inside the
function once it is set up and about to process the command
line. This can be used, for example, to set shell options;
emulate -L zsh and setopt extendedglob are in effect at this
point. Any failure to source the file if it exists is treated
as fatal. As with other initialisation files, the directory
$ZDOTDIR is used instead of $HOME if it is set.

The mathematical library zsh/mathfunc will be loaded if it is
available; see the section `The zsh/mathfunc Module' in
zshmodules(1). The mathematical functions correspond to the raw
system libraries, so trigonometric functions are evaluated using
radians, and so on.

Each line typed is evaluated as an expression. The prompt shows
a number, which corresponds to a positional parameter where the
result of that calculation is stored. For example, the result
of the calculation on the line preceded by `4> ' is available as
$4. The last value calculated is available as ans. Full
command line editing, including the history of previous
calculations, is available; the history is saved in the file
~/.zcalc_history. To exit, enter a blank line or type `:q' on
its own (`q' is allowed for historical compatibility).

A line ending with a single backslash is treated in the same
fashion as it is in command line editing: the backslash is
removed, the function prompts for more input (the prompt is
preceded by `...' to indicate this), and the lines are combined
into one to get the final result. In addition, if the input so
far contains more open than close parentheses zcalc will prompt
for more input.

If arguments are given to zcalc on start up, they are used to
prime the first few positional parameters. A visual indication
of this is given when the calculator starts.

The constants PI (3.14159...) and E (2.71828...) are provided.
Parameter assignment is possible, but note that all parameters
will be put into the global namespace unless the :local special
command is used. The function creates local variables whose
names start with _, so users should avoid doing so. The
variables ans (the last answer) and stack (the stack in RPN
mode) may be referred to directly; stack is an array but
elements of it are numeric. Various other special variables are
used locally with their standard meaning, for example
compcontext, match, mbegin, mend, psvar.

The output base can be initialised by passing the option
`-#base', for example `zcalc -#16' (the `#' may have to be
quoted, depending on the globbing options set).

If the option `-e' is set, the function runs non-interactively:
the arguments are treated as expressions to be evaluated as if
entered interactively line by line.

If the option `-f' is set, all numbers are treated as floating
point, hence for example the expression `3/4' evaluates to 0.75
rather than 0. Options must appear in separate words.

If the option `-r' is set, RPN (Reverse Polish Notation) mode is
entered. This has various additional properties:
Stack Evaluated values are maintained in a stack; this is
contained in an array named stack with the most recent
value in ${stack[1]}.

Operators and functions
If the line entered matches an operator (*, -, *, /, **,
^, | or &) or a function supplied by the zsh/mathfunc
library, the bottom element or elements of the stack are
popped to use as the argument or arguments. The higher
elements of stack (least recent) are used as earlier
arguments. The result is then pushed into ${stack[1]}.

Expressions
Other expressions are evaluated normally, printed, and
added to the stack as numeric values. The syntax within
expressions on a single line is normal shell arithmetic
(not RPN).

Stack listing
If an integer follows the option -r with no space, then
on every evaluation that many elements of the stack,
where available, are printed instead of just the most
recent result. Hence, for example, zcalc -r4 shows
$stack[4] to $stack[1] each time results are printed.

Duplication: =
The pseudo-operator = causes the most recent element of
the stack to be duplicated onto the stack.

pop The pseudo-function pop causes the most recent element of
the stack to be popped. A `>' on its own has the same
effect.

>ident The expression > followed (with no space) by a shell
identifier causes the most recent element of the stack to
be popped and assigned to the variable with that name.
The variable is local to the zcalc function.

<ident The expression < followed (with no space) by a shell
identifier causes the value of the variable with that
name to be pushed onto the stack. ident may be an
integer, in which case the previous result with that
number (as shown before the > in the standard zcalc
prompt) is put on the stack.

Exchange: xy
The pseudo-function xy causes the most recent two
elements of the stack to be exchanged. `<>' has the same
effect.

The prompt is configurable via the parameter ZCALCPROMPT, which
undergoes standard prompt expansion. The index of the current
entry is stored locally in the first element of the array psvar,
which can be referred to in ZCALCPROMPT as `%1v'. The default
prompt is `%1v> '.

The variable ZCALC_ACTIVE is set within the function and can be
tested by nested functions; it has the value rpn if RPN mode is
active, else 1.

A few special commands are available; these are introduced by a
colon. For backward compatibility, the colon may be omitted for
certain commands. Completion is available if compinit has been
run.

The output precision may be specified within zcalc by special
commands familiar from many calculators.
:norm The default output format. It corresponds to the printf
%g specification. Typically this shows six decimal
digits.

:sci digits
Scientific notation, corresponding to the printf %g
output format with the precision given by digits. This
produces either fixed point or exponential notation
depending on the value output.

:fix digits
Fixed point notation, corresponding to the printf %f
output format with the precision given by digits.

:eng digits
Exponential notation, corresponding to the printf %E
output format with the precision given by digits.

:raw Raw output: this is the default form of the output from
a math evaluation. This may show more precision than the
number actually possesses.

Other special commands:
:!line...
Execute line... as a normal shell command line. Note
that it is executed in the context of the function, i.e.
with local variables. Space is optional after :!.

:local arg ...
Declare variables local to the function. Other variables
may be used, too, but they will be taken from or put into
the global scope.

:function name [ body ]
Define a mathematical function or (with no body) delete
it. :function may be abbreviated to :func or simply :f.
The name may contain the same characters as a shell
function name. The function is defined using
zmathfuncdef, see below.

Note that zcalc takes care of all quoting. Hence for
example:

:f cube $1 * $1 * $1

defines a function to cube the sole argument. Functions
so defined, or indeed any functions defined directly or
indirectly using functions -M, are available to execute
by typing only the name on the line in RPN mode; this
pops the appropriate number of arguments off the stack to
pass to the function, i.e. 1 in the case of the example
cube function. If there are optional arguments only the
mandatory arguments are supplied by this means.

[#base]
This is not a special command, rather part of normal
arithmetic syntax; however, when this form appears on a
line by itself the default output radix is set to base.
Use, for example, `[#16]' to display hexadecimal output
preceded by an indication of the base, or `[##16]' just
to display the raw number in the given base. Bases
themselves are always specified in decimal. `[#]'
restores the normal output format. Note that setting an
output base suppresses floating point output; use `[#]'
to return to normal operation.

$var Print out the value of var literally; does not affect the
calculation. To use the value of var, omit the leading
`$'.

See the comments in the function for a few extra tips.

min(arg, ...)
max(arg, ...)
sum(arg, ...)
zmathfunc
The function zmathfunc defines the three mathematical functions
min, max, and sum. The functions min and max take one or more
arguments. The function sum takes zero or more arguments.
Arguments can be of different types (ints and floats).

Not to be confused with the zsh/mathfunc module, described in
the section `The zsh/mathfunc Module' in zshmodules(1).

zmathfuncdef [ mathfunc [ body ] ]
A convenient front end to functions -M.

With two arguments, define a mathematical function named
mathfunc which can be used in any form of arithmetic evaluation.
body is a mathematical expression to implement the function. It
may contain references to position parameters $1, $2, ... to
refer to mandatory parameters and ${1:-defvalue} ... to refer
to optional parameters. Note that the forms must be strictly
adhered to for the function to calculate the correct number of
arguments. The implementation is held in a shell function named
zsh_math_func_mathfunc; usually the user will not need to refer
to the shell function directly. Any existing function of the
same name is silently replaced.

With one argument, remove the mathematical function mathfunc as
well as the shell function implementation.

With no arguments, list all mathfunc functions in a form
suitable for restoring the definition. The functions have not
necessarily been defined by zmathfuncdef.

USER CONFIGURATION FUNCTIONS
The zsh/newuser module comes with a function to aid in configuring
shell options for new users. If the module is installed, this function
can also be run by hand. It is available even if the module's default
behaviour, namely running the function for a new user logging in
without startup files, is inhibited.

zsh-newuser-install [ -f ]
The function presents the user with various options for
customizing their initialization scripts. Currently only
~/.zshrc is handled. $ZDOTDIR/.zshrc is used instead if the
parameter ZDOTDIR is set; this provides a way for the user to
configure a file without altering an existing .zshrc.

By default the function exits immediately if it finds any of the
files .zshenv, .zprofile, .zshrc, or .zlogin in the appropriate
directory. The option -f is required in order to force the
function to continue. Note this may happen even if .zshrc
itself does not exist.

As currently configured, the function will exit immediately if
the user has root privileges; this behaviour cannot be
overridden.

Once activated, the function's behaviour is supposed to be
self-explanatory. Menus are present allowing the user to alter
the value of options and parameters. Suggestions for
improvements are always welcome.

When the script exits, the user is given the opportunity to save
the new file or not; changes are not irreversible until this
point. However, the script is careful to restrict changes to
the file only to a group marked by the lines `# Lines configured
by zsh-newuser-install' and `# End of lines configured by
zsh-newuser-install'. In addition, the old version of .zshrc is
saved to a file with the suffix .zni appended.

If the function edits an existing .zshrc, it is up to the user
to ensure that the changes made will take effect. For example,
if control usually returns early from the existing .zshrc the
lines will not be executed; or a later initialization file may
override options or parameters, and so on. The function itself
does not attempt to detect any such conflicts.

OTHER FUNCTIONS
There are a large number of helpful functions in the Functions/Misc
directory of the zsh distribution. Most are very simple and do not
require documentation here, but a few are worthy of special mention.

Descriptions
colors This function initializes several associative arrays to map
color names to (and from) the ANSI standard eight-color terminal
codes. These are used by the prompt theme system (see above).
You seldom should need to run colors more than once.

The eight base colors are: black, red, green, yellow, blue,
magenta, cyan, and white. Each of these has codes for
foreground and background. In addition there are seven
intensity attributes: bold, faint, standout, underline, blink,
reverse, and conceal. Finally, there are seven codes used to
negate attributes: none (reset all attributes to the defaults),
normal (neither bold nor faint), no-standout, no-underline,
no-blink, no-reverse, and no-conceal.

Some terminals do not support all combinations of colors and
intensities.

The associative arrays are:

color
colour Map all the color names to their integer codes, and
integer codes to the color names. The eight base names
map to the foreground color codes, as do names prefixed
with `fg-', such as `fg-red'. Names prefixed with `bg-',
such as `bg-blue', refer to the background codes. The
reverse mapping from code to color yields base name for
foreground codes and the bg- form for backgrounds.

Although it is a misnomer to call them `colors', these
arrays also map the other fourteen attributes from names
to codes and codes to names.

fg
fg_bold
fg_no_bold
Map the eight basic color names to ANSI terminal escape
sequences that set the corresponding foreground text
properties. The fg sequences change the color without
changing the eight intensity attributes.

bg
bg_bold
bg_no_bold
Map the eight basic color names to ANSI terminal escape
sequences that set the corresponding background
properties. The bg sequences change the color without
changing the eight intensity attributes.

In addition, the scalar parameters reset_color and bold_color
are set to the ANSI terminal escapes that turn off all
attributes and turn on bold intensity, respectively.

fned [ -x num ] name
Same as zed -f. This function does not appear in the zsh
distribution, but can be created by linking zed to the name fned
in some directory in your fpath.

histed [ [ name ] size ]
Same as zed -h. This function does not appear in the zsh
distribution, but can be created by linking zed to the name
histed in some directory in your fpath.

is-at-least needed [ present ]
Perform a greater-than-or-equal-to comparison of two strings
having the format of a zsh version number; that is, a string of
numbers and text with segments separated by dots or dashes. If
the present string is not provided, $ZSH_VERSION is used.
Segments are paired left-to-right in the two strings with
leading non-number parts ignored. If one string has fewer
segments than the other, the missing segments are considered
zero.

This is useful in startup files to set options and other state
that are not available in all versions of zsh.

is-at-least 3.1.6-15 && setopt NO_GLOBAL_RCS
is-at-least 3.1.0 && setopt HIST_REDUCE_BLANKS
is-at-least 2.6-17 || print "You can't use is-at-least here."

nslookup [ arg ... ]
This wrapper function for the nslookup command requires the
zsh/zpty module (see zshmodules(1)). It behaves exactly like
the standard nslookup except that it provides customizable
prompts (including a right-side prompt) and completion of
nslookup commands, host names, etc. (if you use the
function-based completion system). Completion styles may be set
with the context prefix `:completion:nslookup'.

See also the pager, prompt and rprompt styles below.

regexp-replace var regexp replace
Use regular expressions to perform a global search and replace
operation on a variable. POSIX extended regular expressions
(ERE) are used, unless the option RE_MATCH_PCRE has been set, in
which case Perl-compatible regular expressions are used (this
requires the shell to be linked against the pcre library).

var is the name of the variable containing the string to be
matched. The variable will be modified directly by the
function. The variables MATCH, MBEGIN, MEND, match, mbegin,
mend should be avoided as these are used by the regular
expression code.

regexp is the regular expression to match against the string.

replace is the replacement text. This can contain parameter,
command and arithmetic expressions which will be replaced: in
particular, a reference to $MATCH will be replaced by the text
matched by the pattern.

The return status is 0 if at least one match was performed, else
1.

Note that if using POSIX EREs, the ^ or word boundary operators
(where available) may not work properly.

run-help cmd
This function is designed to be invoked by the run-help ZLE
widget, in place of the default alias. See `Accessing On-Line
Help' above for setup instructions.

In the discussion which follows, if cmd is a file system path,
it is first reduced to its rightmost component (the file name).

Help is first sought by looking for a file named cmd in the
directory named by the HELPDIR parameter. If no file is found,
an assistant function, alias, or command named run-help-cmd is
sought. If found, the assistant is executed with the rest of
the current command line (everything after the command name cmd)
as its arguments. When neither file nor assistant is found, the
external command `man cmd' is run.

An example assistant for the "ssh" command:

run-help-ssh() {
emulate -LR zsh
local -a args
# Delete the "-l username" option
zparseopts -D -E -a args l:
# Delete other options, leaving: host command
args=(${@:#-*})
if [[ ${#args} -lt 2 ]]; then
man ssh
else
run-help $args[2]
fi
}

Several of these assistants are provided in the Functions/Misc
directory. These must be autoloaded, or placed as executable
scripts in your search path, in order to be found and used by
run-help.

run-help-btrfs
run-help-git
run-help-ip
run-help-openssl
run-help-p4
run-help-sudo
run-help-svk
run-help-svn
Assistant functions for the btrfs, git, ip, openssl, p4,
sudo, svk, and svn, commands.

tetris Zsh was once accused of not being as complete as Emacs, because
it lacked a Tetris game. This function was written to refute
this vicious slander.

This function must be used as a ZLE widget:

autoload -U tetris
zle -N tetris
bindkey keys tetris

To start a game, execute the widget by typing the keys.
Whatever command line you were editing disappears temporarily,
and your keymap is also temporarily replaced by the Tetris
control keys. The previous editor state is restored when you
quit the game (by pressing `q') or when you lose.

If you quit in the middle of a game, the next invocation of the
tetris widget will continue where you left off. If you lost, it
will start a new game.

tetriscurses
This is a port of the above to zcurses. The input handling is
improved a bit so that moving a block sideways doesn't
automatically advance a timestep, and the graphics use unicode
block graphics.

This version does not save the game state between invocations,
and is not invoked as a widget, but rather as:

autoload -U tetriscurses
tetriscurses

zargs [ option ... -- ] [ input ... ] [ -- command [ arg ... ] ]
This function has a similar purpose to GNU xargs. Instead of
reading lines of arguments from the standard input, it takes
them from the command line. This is useful because zsh,
especially with recursive glob operators, often can construct a
command line for a shell function that is longer than can be
accepted by an external command.

The option list represents options of the zargs command itself,
which are the same as those of xargs. The input list is the
collection of strings (often file names) that become the
arguments of the command, analogous to the standard input of
xargs. Finally, the arg list consists of those arguments
(usually options) that are passed to the command each time it
runs. The arg list precedes the elements from the input list in
each run. If no command is provided, then no arg list may be
provided, and in that event the default command is `print' with
arguments `-r --'.

For example, to get a long ls listing of all non-hidden plain
files in the current directory or its subdirectories:

autoload -U zargs
zargs -- **/*(.) -- ls -ld --

The first and third occurrences of `--' are used to mark the end
of options for zargs and ls respectively to guard against
filenames starting with `-', while the second is used to
separate the list of files from the command to run (`ls -ld
--').

The first `--' would also be needed if there was a chance the
list might be empty as in:

zargs -r -- ./*.back(#qN) -- rm -f

In the event that the string `--' is or may be an input, the -e
option may be used to change the end-of-inputs marker. Note
that this does not change the end-of-options marker. For
example, to use `..' as the marker:

zargs -e.. -- **/*(.) .. ls -ld --

This is a good choice in that example because no plain file can
be named `..', but the best end-marker depends on the
circumstances.

The options -i, -I, -l, -L, and -n differ slightly from their
usage in xargs. There are no input lines for zargs to count, so
-l and -L count through the input list, and -n counts the number
of arguments passed to each execution of command, including any
arg list. Also, any time -i or -I is used, each input is
processed separately as if by `-L 1'.

For details of the other zargs options, see the xargs(1) man
page (but note the difference in function between zargs and
xargs) or run zargs with the --help option.

zed [ -f [ -x num ] ] name
zed [ -h [ name ] size ]
zed -b This function uses the ZLE editor to edit a file or function.

Only one name argument is allowed. If the -f option is given,
the name is taken to be that of a function; if the function is
marked for autoloading, zed searches for it in the fpath and
loads it. Note that functions edited this way are installed
into the current shell, but not written back to the autoload
file. In this case the -x option specifies that leading tabs
indenting the function according to syntax should be converted
into the given number of spaces; `-x 2' is consistent with the
layout of functions distributed with the shell.

Without -f, name is the path name of the file to edit, which
need not exist; it is created on write, if necessary. With -h,
the file is presumed to contain history events.

When no file name is provided for -h the current shell history
is edited in place. The history is renumbered when zed exits
successfully.

When editing history, multi-line events must have a trailing
backslash on every line before the last.

While editing, the function sets the main keymap to zed and the
vi command keymap to zed-vicmd. These will be copied from the
existing main and vicmd keymaps if they do not exist the first
time zed is run. They can be used to provide special key
bindings used only in zed.

If it creates the keymap, zed rebinds the return key to insert a
line break and `^X^W' to accept the edit in the zed keymap, and
binds `ZZ' to accept the edit in the zed-vicmd keymap.

The bindings alone can be installed by running `zed -b'. This
is suitable for putting into a startup file. Note that, if
rerun, this will overwrite the existing zed and zed-vicmd
keymaps.

Completion is available, and styles may be set with the context
prefix `:completion:zed:'.

A zle widget zed-set-file-name is available. This can be called
by name from within zed using `\ex zed-set-file-name' or can be
bound to a key in either of the zed or zed-vicmd keymaps after
`zed -b' has been run. When the widget is called, it prompts
for a new name for the file being edited. When zed exits the
file will be written under that name and the original file will
be left alone. The widget has no effect when invoked from `zed
-f'. The completion context is changed to
`:completion:zed-set-file-name:'. When editing the current
history with `zed -h', the history is first updated and then the
file is written, but the global setting of HISTFILE is not
altered.

While zed-set-file-name is running, zed uses the keymap
zed-normal-keymap, which is linked from the main keymap in
effect at the time zed initialised its bindings. (This is to
make the return key operate normally.) The result is that if
the main keymap has been changed, the widget won't notice. This
is not a concern for most users.

zcp [ -finqQvwW ] srcpat dest
zln [ -finqQsvwW ] srcpat dest
Same as zmv -C and zmv -L, respectively. These functions do not
appear in the zsh distribution, but can be created by linking
zmv to the names zcp and zln in some directory in your fpath.

zkbd See `Keyboard Definition' above.

zmv [ -finqQsvwW ] [ -C | -L | -M | -{p|P} program ] [ -o optstring ]
srcpat dest
Move (usually, rename) files matching the pattern srcpat to
corresponding files having names of the form given by dest,
where srcpat contains parentheses surrounding patterns which
will be replaced in turn by $1, $2, ... in dest. For example,

zmv '(*).lis' '$1.txt'

renames `foo.lis' to `foo.txt', `my.old.stuff.lis' to
`my.old.stuff.txt', and so on.

The pattern is always treated as an EXTENDED_GLOB pattern. Any
file whose name is not changed by the substitution is simply
ignored. Any error (a substitution resulted in an empty string,
two substitutions gave the same result, the destination was an
existing regular file and -f was not given) causes the entire
function to abort without doing anything.

In addition to pattern replacement, the variable $f can be
referred to in the second (replacement) argument. This makes it
possible to use variable substitution to alter the argument; see
examples below.

Options:

-f Force overwriting of destination files. Not currently
passed down to the mv/cp/ln command due to vagaries of
implementations (but you can use -o-f to do that).
-i Interactive: show each line to be executed and ask the
user whether to execute it. `Y' or `y' will execute it,
anything else will skip it. Note that you just need to
type one character.
-n No execution: print what would happen, but don't do it.
-q Turn bare glob qualifiers off: now assumed by default, so
this has no effect.
-Q Force bare glob qualifiers on. Don't turn this on unless
you are actually using glob qualifiers in a pattern.
-s Symbolic, passed down to ln; only works with -L.
-v Verbose: print each command as it's being executed.
-w Pick out wildcard parts of the pattern, as described
above, and implicitly add parentheses for referring to
them.
-W Just like -w, with the addition of turning wildcards in
the replacement pattern into sequential ${1} .. ${N}
references.
-C
-L
-M Force cp, ln or mv, respectively, regardless of the name
of the function.
-p program
Call program instead of cp, ln or mv. Whatever it does,
it should at least understand the form `program --
oldname newname' where oldname and newname are filenames
generated by zmv. program will be split into words, so
might be e.g. the name of an archive tool plus a copy or
rename subcommand.
-P program
As -p program, except that program does not accept a
following -- to indicate the end of options. In this
case filenames must already be in a sane form for the
program in question.
-o optstring
The optstring is split into words and passed down
verbatim to the cp, ln or mv command called to perform
the work. It should probably begin with a `-'.

Further examples:

zmv -v '(* *)' '${1// /_}'

For any file in the current directory with at least one space in
the name, replace every space by an underscore and display the
commands executed.

zmv -v '* *' '${f// /_}'

This does exactly the same by referring to the file name stored
in $f.

For more complete examples and other implementation details, see
the zmv source file, usually located in one of the directories
named in your fpath, or in Functions/Misc/zmv in the zsh
distribution.

zrecompile
See `Recompiling Functions' above.

zstyle+ context style value [ * subcontext style value ... ]
This makes defining styles a bit simpler by using a single `*'
as a special token that allows you to append a context name to
the previously used context name. Like this:

zstyle+ ':foo:bar' style1 value1 \
+':baz' style2 value2 \
+':frob' style3 value3

This defines style1 with value1 for the context :foo:bar as
usual, but it also defines style2 with value2 for the context
:foo:bar:baz and style3 with value3 for :foo:bar:frob. Any
subcontext may be the empty string to re-use the first context
unchanged.

Styles
insert-tab
The zed function sets this style in context `:completion:zed:*'
to turn off completion when TAB is typed at the beginning of a
line. You may override this by setting your own value for this
context and style.

pager The nslookup function looks up this style in the context
`:nslookup' to determine the program used to display output that
does not fit on a single screen.

prompt
rprompt
The nslookup function looks up this style in the context
`:nslookup' to set the prompt and the right-side prompt,
respectively. The usual expansions for the PS1 and RPS1
parameters may be used (see EXPANSION OF PROMPT SEQUENCES in
zshmisc(1)).

FILES
$ZDOTDIR/.zshenv
$ZDOTDIR/.zprofile
$ZDOTDIR/.zshrc
$ZDOTDIR/.zlogin
$ZDOTDIR/.zlogout
${TMPPREFIX}* (default is /tmp/zsh*)
/etc/zshenv
/etc/zprofile
/etc/zshrc
/etc/zlogin
/etc/zlogout (installation-specific - /etc is the default)

SEE ALSO
sh(1), csh(1), tcsh(1), rc(1), bash(1), ksh(1)

IEEE Standard for information Technology - Portable Operating System
Interface (POSIX) - Part 2: Shell and Utilities, IEEE Inc, 1993, ISBN
1-55937-255-9.

zsh 5.9 May 14, 2022 ZSHALL(1)