I fail to see how:

Code:

isRunning=`ps -ef | grep -v grep | grep /home/unispool/bin/main`

(which sets the variable isRunning to the lines reported by ps that contain the string /home/unispool/bin/main (not the number of line that contain that string; the actual lines themselves) would ever be a string that is a numeric string equal in value to the number 3. The same thing can be sad for the other two ps pipelines. So, this script is logically equivalent to:

Code:

#!/bin/ksh
while true ; do
      echo "not running"
      mailx -s "Main process not running correctly" biswajit.nitd@yahoo.in < /dev/null
      echo "not running"
      mailx -s "Cserver process not running correctly" biswajit.nitd@yahoo.in < /dev/null
      echo "not running"
      mailx -s "ciserver process not running correctly" biswajit.nitd@yahoo.in < /dev/null
done

which will mostly just fill your mailbox with meaningless messages as fast as your system can run ps, grep twice, and mailx.

If you're trying to count the number of lines produced by ps as filtered by grep in those pipelines, you need to either add a wc -l to the end of the pipeline or add a -c option to the last grep command in the pipeline. (I strongly prefer the latter option since it uses fewer system resources and will run faster.)

But, I fail to see how draining system resources with a continuous loop to slow down your system when it is working well (and to further slow it down and fill up your mailbox rapidly when something isn't running as expected) is a good idea.

Have you considered putting a sleep in your loop (so your system can perform some meaningful work in addition to looking for an imbalance in the three things you seem to think are the only things that matter on your system)?

Have you considered exiting your loop once mail has been sent so you can find one message in your mailbox, fix the problem, and then restart the loop to wait for the next occurrence of a problem?