How can I set cron to run certain commands every one and a half hours?
+1
A:
Is there a good reason why you can't use 1 hour or 2 hours? It would be simpler for sure.
I haven't tried this personally, but you can find some info here on getting cron to run every 90 minutes: http://keithdevens.com/weblog/archive/2004/May/05/cron
An excert from the above link:
0 0,3,6,9,12,15,18,21 * * * <commands>
30 1,4,7,10,13,16,19,22 * * * <commands>
vfilby
2008-10-29 17:16:34
down-voted because it ignores the requirement
Alnitak
2008-10-29 17:21:11
Which requirement? First sentence questions the necessity of 1.5 hours, the second provides a blog post with information on how to do it every 1.5 hours.
vfilby
2008-10-29 17:24:21
Upvoted because the blog post answers the question correctly.
Paul Tomblin
2008-10-29 17:32:00
It didn't clearly reference that when I down-voted it. It has been edited since to make it clear that the link is to a potential solution for the 90 minute question.
Alnitak
2008-10-29 17:35:37
Aye, I clarified the post.
vfilby
2008-10-29 17:46:37
+13
A:
That's not possible with a single expression in normal cron.
The best you could do without modifying the code is:
0 0,3,6,9,12,15,18,21 * * * [cmd]
30 1,4,7,10,13,16,19,22 * * * [cmd]
These might be compressible, depending on the version of cron you have to:
0 */3 * * * [cmd]
30 1-23/3 * * * [cmd]
Alnitak
2008-10-29 17:17:03
+1
A:
Two lines in the crontab. Along the lines of:
0 0,3,6,9,12,15,18,21 * * * /usr/bin/foo
30 1,4,7,10,13,16,19,22 * * * /usr/bin/foo
ConcernedOfTunbridgeWells
2008-10-29 17:17:11
+1
A:
You could do it with two crontab entries. Each runs every three hours and they are offset by 90 minutes something like this:
0 0,3,6,9,12,15,18,21 * * *
30 1,4,7,10,13,16,19,22 * * *
Thomas DeGan
2008-10-29 17:17:55
A:
You could also use fcron which also accepts more complex time specifications such as :
@ 01h30 my_cmd
Christian Lescuyer
2008-10-29 17:47:56