DragonFly On-Line Manual Pages
TOP(1) DragonFly General Commands Manual TOP(1)
top - display and update information about the top cpu processes
top [-CIMSTabcinqtuv] [-d count] [-m mode] [-o field] [-s time]
[-U username] [number]
top displays the top processes on the system and periodically updates
this information. Raw cpu percentage is used to rank the processes.
top makes a distinction between terminals that support advanced
capabilities and those that do not. This distinction affects the choice
of defaults for certain options. In the remainder of this document, an
"intelligent" terminal is one that supports cursor addressing, clear
screen, and clear to end of line. Conversely, a "dumb" terminal is one
that does not support such features. If the output of top is redirected
to a file, it acts as if it were being run on a dumb terminal.
-C Turn off the use of color in the display.
-I Do not display idle processes. By default, top
displays both active and idle processes.
-M Enable multi-CPU display.
-S Show system processes in the display. Normally,
system processes such as the pager and the swapper are
not shown. This option makes them visible.
-T List all available color tags and the current set of
tests used for color highlighting, then exit.
-a Show all processes for as long as possible. This is
shorthand for "-d all all". This option is especially
handy in batch mode.
-b Use "batch" mode. In this mode, all input from the
terminal is ignored. Interrupt characters (such as ^C
and ^\) still have an effect. This is the default on
a dumb terminal, or when the output is not a terminal.
-c Show the full command line for each process. Default
is to show just the command name. This option is not
supported on all platforms.
-i Use "interactive" mode. In this mode, any input is
immediately read for processing. See the subsection
on INTERACTIVE MODE for an explanation of which keys
perform what functions. After the command is
processed, the screen will immediately be updated,
even if the command was not understood. This mode is
the default when standard output is an intelligent
-q Renice top to -20 so that it will run faster. This
can be used when the system is being very sluggish to
improve the possibility of discovering the problem.
This option can only be used by root.
-t Show individual threads on separate lines. By
default, on systems which support threading, each
process is shown with a count of the number of
threads. This option shows each thread on a separate
line. This option is not supported on all platforms.
-u Do not take the time to map uid numbers to usernames.
Normally, top will read as much of the file
/etc/passwd as is necessary to map all the user id
numbers it encounters into login names. This option
disables all that, while possibly decreasing execution
time. The uid numbers are displayed instead of the
-v Write version number information to stderr then exit
immediately. No other processing takes place when
this option is used. To see current revision
information while top is running, use the help command
-d count Show only count displays, then exit. A display is
considered to be one update of the screen. This
option allows the user to select the number of
displays he wants to see before top automatically
exits. Any proper prefix of the words `infinity',
`maximum', or `all' can be used to indicate an
infinite number of displays. The default for
intelligent terminals is `infinity'. The default for
dumb terminals is `1'.
-m mode Start the display in an alternate mode. Some
platforms support multiple process displays to show
additional process information. The value of mode is
a number indicating which mode to display. The
default is `0'. On platforms that do not have
multiple display modes this option has no effect.
-o field Sort the process display area on the specified field.
The field name is the name of the column as seen in
the output, but in lower case. Likely values are
`cpu', `size', `res', and `time', but may vary on
different operating systems. Note that not all
operating systems support this option.
-s time Set the delay between screen updates to time seconds.
The default delay between updates is 5 seconds.
-U username Show only those processes owned by username. This
option currently only accepts usernames and will not
understand uid numbers.
If number is given, then the top number processes will be displayed
instead of the default. Both count and number fields can be specified as
`infinite', indicating that they can stretch as far as possible. This is
accomplished by using any proper prefix of the keywords `infinity',
`maximum', or `all'. The default for count on an intelligent terminal
is, in fact, `infinity'.
When top is running in "interactive mode", it reads commands from the
terminal and acts upon them accordingly. In this mode, the terminal is
put in "CBREAK", so that a character will be processed as soon as it is
typed. Almost always, a key will be pressed when top is between
displays; that is, while it is waiting for time seconds to elapse. If
this is the case, the command will be processed and the display will be
updated immediately thereafter (reflecting any changes that the command
may have specified). This happens even if the command was incorrect. If
a key is pressed while top is in the middle of updating the display, it
will finish the update and then process the command. Some commands
require additional information, and the user will be prompted
accordingly. While typing this information in, the user's erase and kill
keys (as set up by the command stty(1)) are recognized, and a newline
terminates the input. Note that a control-L (^L) always redraws the
current screen and a space forces an immediate update to the screen using
These commands are currently recognized:
h or ? Display a summary of the commands (help screen). Version
information is included in this display.
C Toggle the use of color in the display.
c Display only processes whose commands match the specified
string. An empty string will display all processes. This
command is not supported on all platforms.
d Change the number of displays to show (prompt for new
number). Remember that the next display counts as one, so
typing "d1" will make top show one final display and then
f Toggle the display of the full command line.
H Toggle the display of threads on separate lines. By
default, on systems which support threading, each process
is shown with a count of the number of threads. This
command shows each thread on a separate line. This command
is not supported on all platforms.
i or I Toggle the display of idle processes.
k Send a signal ( "kill" by default) to a list of processes.
This acts similarly to the command kill(1).
M Sort display by memory usage. Shorthand for "-o size".
m Change to a different process display mode. Some systems
provide multiple display modes for the process display
which shows different information. This command toggles
between the available modes. This command is not supported
on all platforms.
N Sort by process id. Shorthand for "-o pid".
n or # Change the number of processes to display (prompt for new
o Change the order in which the display is sorted. This
command is not available on all systems. The sort key
names vary fron system to system, but usually include:
`cpu', `res', `size', and `time'. The default is `cpu'.
P Sort by CPU usage. Shorthand for "-o cpu".
q Quit top.
r Change the priority (the niceness) of a list of processes.
This acts similarly to the command renice(8).
s Change the number of seconds to delay between displays
(prompt for new number).
T Sort by CPU time. Shorthand for "-o time".
U Toggle between displaying usernames and uids.
u Display only processes owned by a specific username (prompt
for username). If the username specified is simply "+",
then processes belonging to all users will be displayed.
The actual display varies depending on the specific variant of Unix that
the machine is running. This description may not exactly match what is
seen by top running on this particular machine. Differences are listed
at the end of this manual entry.
The top lines of the display show general information about the state of
the system. The first line shows (on some systems) the last process id
assigned to a process, the three load averages, the system uptime, and
the current time. The second line displays the total number of processes
followed by a breakdown of processes per state. Examples of states
common to Unix systems are sleeping, running, starting, stopped, zombie,
and dumping (i.e., generating a core). The next line displays a
percentage of time spent in each of the processor states (user, nice,
system, interrupt, idle). These percentages show the processor activity
during the time since the last update. For multi-processor systems, this
information is an average of all processors. The next line shows kernel-
related activity (not available on all systems). The numbers shown on
this line are per-second rates sampled since the last update. The exact
information displayed varies between systems, but some examples are:
context switches, interrupts, traps, forks, and page faults.
The last two lines show a summary of memory and swap activity. The
fields are as follows:
Active: number of pages active
Inact: number of pages inactive
Wired: number of pages wired down, including cached file data
Cache: number of pages used for VM-level disk caching
Buf: number of pages used for BIO-level disk caching
Free: number of pages free
Total: total available swap usage
Free: total free swap usage
Inuse: swap usage
In: pages paged in from swap devices (last interval)
Out: pages paged out to swap devices (last interval)
The remainder of the screen displays information about individual
processes. This display is similar in spirit to ps(1), but it is not
exactly the same. The columns displayed by top will differ slightly
between operating systems. Generally, the following fields are
PID The process id.
USERNAME Username of the process's owner (if -u is specified, a
UID column will be substituted for USERNAME).
NICE Nice amount in the range -20 to 20, as established by the
use of the command nice(1).
SIZE Total size of the process (text, data, and stack) given
RES Resident memory: current amount of process memory that
resides in physical memory, given in kilobytes, megabytes
or gigabytes depending on the size to be reported.
STATE Current state, may be: `START', `RUN' (shown as `CPUn' on
SMP systems), `SLEEP' (generally shown as the event on
which the process waits), `STOP', `ZOMBIE', or `DUMP'.
C Number of CPU the process is currently running on (only
on multi-CPU machines).
TIME Number of system and user cpu seconds that the process
CTIME The cumulated CPU time of the process and its exited
children. This value is similar to what ps(1) displays
as CPU time when run with the -S option.
CPU Percentage of available cpu time used by this process.
COMMAND Name of the command that the process is currently
Top supports the use of ANSI color in its output. By default, color is
available but not used. The environment variable TOPCOLORS specifies
colors to use and conditions for which they should be used. At the
present time, only numbers in the summary display area can be colored.
In a future version it will be possible to highlight numbers in the
process display area as well. The environment variable is the only way
to specify color: there is no equivalent command line option. Note that
the environment variable TOPCOLOURS is also understood. The British
spelling takes precedence. The use of color only works on terminals that
understand and process ANSI color escape sequences.
You can see a list of color codes recognized by this installation of top
with the -T option. This will also show the current set of tests used
for color highligting, as specified in the environment.
The following environment variables affect the execution of top:
TOP The environment variable TOP is examined for options before
the command line is scanned. This enables a user to set his
or her own defaults. The number of processes to display can
also be specified in the environment variable TOP. The
options "-C", "-I", "-S", and "-u" are actually toggles. A
second specification of any of these options will negate the
first. Thus a user who has the environment variable TOP set
to "-I" may use the command "top -I" to see idle processes.
TOPCOLORS The environment variable is a sequence of color
specifications, separated by colons. Each specification takes
the form tag=min,max#code where tag is the name of the value
to check, min and max specify a range for the value, and code
is an ANSI color code. Multiple color codes can be listed and
separated with semi-colons. A missing min implies the lowest
possible value (usually 0) and a missing max implies infinity.
The comma must always be present. When specifying numbers for
load averages, they should be multiplied by 100. For example,
the specification 1min=500,1000#31 indicates that a 1 minute
load average between 5 and 10 should be displayed in red.
Color attributes can be combined. For example, the
specification 5min=1000,#37;41 indicates that a 5 minute load
average higher than 10 should be displayed with white
characters on a red background. A special tag named header is
used to control the color of the header for process display.
It should be specified with no lower and upper limits,
specifically header=,# followed by the ANSI color code.
kill(1), ps(1), stty(1), mem(4), renice(8)
As with ps(1), things can change while top is collecting information for
an update. The picture it gives is only a close approximation to
DragonFly 6.5-DEVELOPMENT February 15, 2023 DragonFly 6.5-DEVELOPMENT