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WATCH(1)                      Linux User's Manual                     WATCH(1)


NAME

       gnu-watch - execute a program periodically, showing output fullscreen


SYNOPSIS

       gnu-watch [-dhvt] [-n <seconds>] [--differences[=cumulative]] [--help]
       [--interval=<seconds>] [--no-title] [--version] <command>


DESCRIPTION

       gnu-watch runs command repeatedly, displaying its output (the first
       screenfull).  This allows you to watch the program output change over
       time.  By default, the program is run every 2 seconds; use -n or
       --interval to specify a different interval.

       The -d or --differences flag will highlight the differences between
       successive updates.  The --cumulative option makes highlighting
       "sticky", presenting a running display of all positions that have ever
       changed.  The -t or --no-title option turns off the header showing the
       interval, command, and current time at the top of the display, as well
       as the following blank line.

       gnu-watch will run until interrupted.


NOTE

       Note that command is given to "sh -c" which means that you may need to
       use extra quoting to get the desired effect.

       Note that POSIX option processing is used (i.e., option processing
       stops at the first non-option argument).  This means that flags after
       command don't get interpreted by gnu-watch itself.


EXAMPLES

       To watch for mail, you might do

              gnu-watch -n 60 from

       To watch the contents of a directory change, you could use

              gnu-watch -d ls -l

       If you're only interested in files owned by user joe, you might use

              gnu-watch -d 'ls -l | fgrep joe'

       To see the effects of quoting, try these out

              gnu-watch echo $$

              gnu-watch echo '$$'

              gnu-watch echo "'"'$$'"'"

       You can watch for your administrator to install the latest kernel with

              gnu-watch uname -r

       (Just kidding.)


BUGS

       Upon terminal resize, the screen will not be correctly repainted until
       the next scheduled update.  All --differences highlighting is lost on
       that update as well.

       Non-printing characters are stripped from program output.  Use "cat -v"
       as part of the command pipeline if you want to see them.


AUTHORS

       The original watch was written by Tony Rems <rembo@unisoft.com> in
       1991, with mods and corrections by Francois Pinard.  It was reworked
       and new features added by Mike Coleman <mkc@acm.org> in 1999. In 2005
       it was modified for FreeBSD by Emanuel Haupt <ehaupt@critical.ch>.

                                  1999 Apr 3                          WATCH(1)

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