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

       watch - execute a program periodically, showing output fullscreen

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

       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 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

       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.)

       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.

       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)
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