topic Re: CRON Help Needed. in Operating System - HP-UX

CRON Help Needed.

William McElvain — Fri, 09 Jan 2004 10:31:25 GMT

I want to set my cron to run a script on the first Friday of the month at 7:01 and only on the first Friday of the month. I have tried to set it using the following crontab line
01 7 1-7 * 5 /scriptname
However, instead of only running the script on a Friday that is also the 1st, 2nd, 3rd, 4th, 5th, 6th, or 7th of the month, it will run it every Friday and also every day of the month between the 1st and 7th.

Re: CRON Help Needed.

Pete Randall — Fri, 09 Jan 2004 10:33:31 GMT

William,

The easiest way to accomplish this would be to put the logic inside your script to determine if it's Friday or not. Cron has no mechanism for this.

Pete

Re: CRON Help Needed.

Dave Johnson_1 — Fri, 09 Jan 2004 10:34:47 GMT

Another option is to run it every friday and test to see if todays date is <= 7.

-Dave

Re: CRON Help Needed.

Mark Grant — Fri, 09 Jan 2004 10:36:52 GMT

Yep, cron can't do this

You should get cron to run the thing every Friday but add the following to the top of the script

[ `date +%d` -gt 6 ] && exit

Re: CRON Help Needed.

A. Clay Stephenson — Fri, 09 Jan 2004 10:48:23 GMT

Your fundamental problem is that cron's logic is OR'ing your request and you really need an AND. Cron won't do this on its own but my solution for all things date related is caljd.sh.

In your case, the fix is to have cron run your script every Friday and then add a test within the script itself to determine if this is the 1st (or 2nd, 3rd) ...

if [[ $(caljd.sh -N) -eq 1 ]]
then
echo "First Friday; Do your thing"
else
echo "It ain't, exit"
fi

Re: CRON Help Needed.

William McElvain — Fri, 09 Jan 2004 11:00:27 GMT

Thanks for the help. I kind of figured that the wasn't a way to set it up in the cron. I'll just schedule it for every Friday and have my script exit if the date isn't with in the 1st through 7th range. Thanks again everyone.