- Watch (Unix)
In
Unix , watch runs the specified command repeatedly and displays the output onstdout so you can watch it change over time. By default, the command is run every 2 seconds, although this is adjustable with the-n "secs"argument. Since the command is passed tosh -c, you may need to encase it in quotes for it to run correctly.Syntax
watch ["options"] "command" ["command options"]
Example
watch "
ps aux | grep php"This will generate a list ofprocess es every 2 seconds, filter for all lines that contain the word "php", and display the results on the screen. The output might look something like this:Every 2s: ps aux | grep php Tue Jan 30 14:56:33 2007 reconst 30028 0.0 0.0 7044 2596 ? S Jan23 0:00 vim -r core/html_api.php cinonet 28009 0.0 0.2 20708 11064 ? SN Jan25 0:30 php5.cgi donoiz 23810 0.0 0.2 22740 10996 ? SN Jan27 0:30 php.cgi 43/pdf
The watch command is useful for viewing changes over time, like repeatedly running the
ls -lpsas in the above example to monitor certain processes continuously.Arguments
*
-d– Highlights differences between iterations
*-h– Displays a help message, then exits
*-n "secs"– Specifies the interval between executions of the command in seconds
*-t– Tells watch not to display the header
*-v– Prints version information, then exitsSee also
List of Unix commands External links
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