Shell Programming and Scripting

In the semaphore method, the script first checks for the presence of a semaphore file and exits if the file is present. If the file is not present the script immediately creates the semaphore file and subseqently deletes the semaphore file on exit.
Some people call this an interlock file (or even a mutex).

This semaphore file also gives you a reference for when the script started so a monitoring process could detect an overrunning process.

Hi Everyone,
I found a method to avoid the 'sh -c' getting displayed in ps result when run in CRON.

The below line works:
ps -d -f | grep ${SCRIPT_NAME} | grep ksh | grep -v grep >> /tmp/instance.tmp

Using a '-d' as an option with ps blocks the 'sh -c' from getting fetched.

Thanks a lot for all the help.

I would also try to use the semaphore method as suggested by methyl.