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

NAME

       watch - execute a program periodically, showing output fullscreen

SYNOPSIS

       watch [-dhv] [-n <seconds>] [--differences[=cumulative]] [--help] [--interval=<seconds>] [--version] <command>

DESCRIPTION

       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.

       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 watch itself.

EXAMPLES

       To watch for mail, you might do

	      watch -n 60 from

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

	      watch -d ls -l

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

	      watch -d 'ls -l | fgrep joe'

       To see the effects of quoting, try these out

	      watch echo $$

	      watch echo '$$'

	      watch echo "'"'$$'"'"

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

	      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.

								    1999 Apr 3								  WATCH(1)