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SINCE(1)                         User Manuals                         SINCE(1)


NAME

       since - display content of a file since the last time


SYNOPSIS

       since [-aefhlmnqvxz] [-d seconds] [-s file] files


DESCRIPTION

       since is a utility designed to monitor log files.  since is similar to
       tail(2) as it also displays information appended to a file.  However
       since only displays the data which has been added since the last time
       since was run. If since is run on a particular file for the first time,
       then the entire file is displayed.


EXAMPLE

       since /var/log/apache/{access,error}_log > /dev/null
       lynx --dump http://localhost/ > /dev/null
       since /var/log/apache/{access,error}_log


OPTIONS

       -a     Make updates to the since state files atomic. This option
              configures since to use a temporary file and a rename(2) instead
              of updating the state file in situ.

       -d seconds
              Specify the number of integer seconds to wait between polling
              files for changes. This option is only relevant in conjunction
              with the -f option and if the inotify mechanism is not being
              used.

       -e     Print the header lines to standard error instead of standard
              output.

       -f     Follow the specified files. This option is analogous to tail -f
              as the files are also polled for changes until the process is
              interrupted.

       -h     Print a terse help message.

       -l     Relaxed mode. If some data files are inaccessible since will not
              fail completely.

       -m     Disable mmap(2), use read(2) instead to access state and data
              files.  Note that for certain smaller io operations read(2) may
              be used even if this option has not been given.

       -n     Do not update the .since file which keeps track of file growth.

       -q     Make the utility operate more quietly.

       -s filename
              Specify the state file explicitly. Using this option will also
              disable the use of fallback state files.

       -v     Increase the verbosity. This option can be given multiple times.

       -x     Ignore file arguments which have compressed extensions.

       -z     Discard output. Similar to redirecting the output to /dev/null,
              but faster. If used in conjunction with the -f option, only the
              initial output will be discarded.


FILES

       .since

              State file recording the length of the previously displayed
              files.  The location of the file can be set on the command line
              using the -s option. If this option is not given, since will
              check the SINCE environment variable for the location of the
              state file. If the SINCE environment variable has not been set
              since will use the HOME environment variable and store the
              information in the file $HOME/.since.  If the HOME variable is
              not set, since will use a getpwuid(3) lookup. If all these fail
              will use the file /tmp/since.


BUGS

       since uses the inode of a file as its key, if that inode is recycled
       since will get confused.  since is not particularly efficient when
       storing or looking up the stat(2) information. Functionality equivalent
       to since can probably be achieved with a number of trivial shell
       scripts.


COPYING

       since may only be used, distributed and modified in accordance with the
       terms of the GPL (GNU General Public License) version 3 or newer as
       published by the FSF (Free Software Foundation).


SEE ALSO

       tail(1), stat(2).

FreeBSD                            JULY 1998                          SINCE(1)

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