Crontab question (Every few minutes after a certain time)

Norwood · 03-08-2010, 09:34 AM

Hi all,

I am able to get a job to run every x amount of minutes but what I need is to be able to get thsi job to run every x amount of minutes after, say 9am on a certain day.

The only part I'm struggling with is the "after 9am" part. All the other things like day of week and the actual command all work perfectly.

troop · 03-08-2010, 09:37 AM

*/x 9-24 certain_day * * job

Norwood · 03-08-2010, 09:54 AM

So I have:

Code:

*/5 9-11 * * 5 command

That will execute the command every five minutes on Fridays?

troop · 03-08-2010, 11:17 AM

Yes. Two hours between 09 and 11 am. 24 times.

nuwen52 · 03-08-2010, 01:20 PM

Actually, I ran a quick test on that because I wanted to know what would happen...

crontab entry:

Code:

*/5 11-12 * * * root /home/tests/test0.sh

test0.sh

Code:

#!/bin/sh
DATECODE=`date +%H:%M:%S`
echo $DATECODE >> /tmp/cron_junk.txt

output of cron_junk.txt:

Code:

...
11:50:01
11:55:01
12:00:01
12:05:01
12:10:02
12:15:01
...
12:55:01

As you can see, it actually went until (5 minutes before) 13:00 even though it was expected to end at 12:00. So, what it seems to be is that for every hour that starts with the number specified in the range, the command runs. So, I would expect that "*/5 9-11 * * 5 command" would run every 5 minutes until 12:00, which may not be the desired affect. (Unless I had done something incorrectly.)

Norwood · 03-08-2010, 02:41 PM

Gotcha, and that actually makes sense now that I think about it.

Man I love this place!