UNIX for Dummies Questions & Answers

I have two scripts:
SCR1 which takes between 5 seconds to 15 minutes and needs to be run every 23 minutes.
SCR2 which needs to be run every 5 minutes but only if SCR1 is not running at that moment.

How can I do this task?

Best Regards
/Hamid

The easy answer is to have SCR1 touch a lock file when it starts and delete it when it finishes. Then have SCR2 test for the presence of the lock file and exit if it exists. I am assuming you know how to schedule the jobs using crontab.

At the beginning of SCR1 below the #!/path/to/shell entry, have something like;
touch /tmp/scr1.lock

Then the last line executed should be;
rm -f /tmp/scr1.lock

At the beginning of SCR2, enter;
if [ -e /tmp/scr1.lock ]
then exit
fi

I hope this helps

I forgot a very important issue in my description of the problem. The solution you gave is very smart, good and easy to understand but the problem is that I am not allowed to modify the scripts SCR1 and SCR2.

Best Regards
/Hamid

Then use a wrapper.
Create another script like launch.scr1;

#!/bin/sh
touch /tmp/scr1.lock
/path/to/SCR1
wait
rm -f /tmp/scr1.lock

------------------
And then create the wrapper for SCR2 called launch.scr2

#!/bin/sh
if [ -e /tmp/scr1.lock ]
then exit
else /path/to/SCR2
fi

------------------
Than change your cron entries to execute the wrapper scripts instead of the actual scripts/executables.


[Edited by 98_1LE on 01-16-2001 at 10:13 AM]