Subj : Remove Oldest Process Every Minute. How To?
To   : comp.os.linux
From : Juul
Date : Sat Aug 21 2004 11:52 pm

I've build a picturegrabber in PHP that starts every minute from within a
shellscript that runs as a cronjob.

The PHP-script needs about 5 minutes to complete and sometimes it will
hang. That's why I wrote a shellscript for it.

Every minute a new session of the PHP-script starts. There can be more than
1 process of the PHP-script active but not more than 6. So the old
instances can complete when a new instance of the PHP-script starts. When
the 6th process starts then all processes of the PHP-script would be killed
by the shellscript. This is my problem...

By killing all the processes of the PHP-script it kills also the just
started processes and I actually want to kill only the oldest process when
the 6th process starts. How can I do this?

This is the shellscript I use:
==================

#!/bin/sh

PS=/bin/ps
GREP=/bin/grep
WC=/usr/bin/wc
PHP=/usr/bin/php
AWK=/usr/bin/awk
PATH=/local/www/data/cgi-bin

COUNT=`$PS -ef | $GREP checkpictures | $GREP -v grep | $WC -l`

if [ $COUNT -lt 6 ]; then
cd $PATH
$PHP ./checkpictures.php > /local/www/data/logs/checkpictures.log 2>&1
else
kill -9 `$PS -ef | $GREP checkpictures | $AWK '{ print $2 }'`
fi

.