CRON Question

[AzteK]

How can I run cron on the 1st hr, 2nd hr, 4th hr...in a 24 hour period, everyday, every month, every year?

[signupdamnit]

http://en.wikipedia.org/wiki/Cron

Generally by using @hourly or "0 * * * *" in your crontab file.

The "0" says "every time the minute is :00" which of course works out to hourly. But if you want to run it 30 minutes past the hour every hour you might do "30 * * * *", for example.

See the wiki article for more details.

[AzteK]

I found my answer there!!

0 */2 * * * /home/user/jim/test.pl
0 */3 * * * /home/user/jim/test.pl
0 */4 * * * /home/user/jim/test.pl

Thanks!!

[signupdamnit]

Oh that's what you wanted?

Just to make sure it is:

I found my answer there!!

0 */2 * * * /home/user/jim/test.pl

Means every other hour.

0 */3 * * * /home/user/jim/test.pl

Every 3 hours.

0 */4 * * * /home/user/jim/test.pl

Every 4 hours.

[AzteK]

The following line causes the user program test.pl – possibly a Perl script – to be run every two hours, namely at midnight, 2am, 4am, 6am, 8am, and so on:

0 */2 * * * /home/user/jim/test.pl


oh no I guess it's not what I wanted... :L

I need it to run like this:

1:00 /home/user/jim/test.pl
2:00 /home/user/jim/test2.pl
3:00 /home/user/jim/test3.pl
4:00 /home/user/jim/test4.pl

and so forth

[AzteK]

so would it be like this?

0 0/1 * * * /home/user/jim/test.pl
0 0/2 * * * /home/user/jim/test2.pl
0 0/3 * * * /home/user/jim/test3.pl

[signupdamnit]

oh no I guess it's not what I wanted... :L

I need it to run like this:

1:00 /home/user/jim/test.pl
2:00 /home/user/jim/test2.pl
3:00 /home/user/jim/test3.pl
4:00 /home/user/jim/test4.pl

and so forth

so would it be like this?

0 0/1 * * * /home/user/jim/test.pl
0 0/2 * * * /home/user/jim/test2.pl
0 0/3 * * * /home/user/jim/test3.pl

Just three different scripts then? There are different ways to go but in a pinch perhaps this might work:

0 1 * * * /home/user/jim/test.pl
0 2 * * * /home/user/jim/test2.pl
0 3 * * * /home/user/jim/test3.pl
0 4 * * * /home/user/jim/test.pl
0 5 * * * /home/user/jim/test2.pl

and so on.

In this example:

test.pl would run at 1am and 4am.
test2.pl would run at 2am and 5am
test3.pl would run at 3am.

Another way of doing the above (same thing) would be:

0 1,4 * * * /home/user/jim/test.pl
0 2,5 * * * /home/user/jim/test2.pl
0 3 * * * /home/user/jim/test3.pl

... but there are all sorts of ways to do it.

You'll probably want to redirect the output in some way too.

Also see this: http://www.tutorial5.com/content/view/95/51/
It's a decent tutorial which may be of some help.

You can type 'man crontab' at the command line to see the man page as well.

[signupdamnit]

And to make it more clear if you were just wanting a different script for each hour of the day I guess you could do something like:

0 1 * * * /home/user/jim/test.pl >/dev/null 2>&1
0 2 * * * /home/user/jim/test2.pl >/dev/null 2>&1
0 3 * * * /home/user/jim/test3.pl >/dev/null 2>&1

...

0 23 * * * /home/user/jim/test23.pl >/dev/null 2>&1

The ">/dev/null 2>&1" at the end says to discard the output so that it doesn't email it to you for each hour.

Hope this helps.

[AzteK]

And to make it more clear if you were just wanting a different script for each hour of the day I guess you could do something like:

0 1 * * * /home/user/jim/test.pl >/dev/null 2>&1
0 2 * * * /home/user/jim/test2.pl >/dev/null 2>&1
0 3 * * * /home/user/jim/test3.pl >/dev/null 2>&1

...

0 23 * * * /home/user/jim/test23.pl >/dev/null 2>&1

The ">/dev/null 2>&1" at the end says to discard the output so that it doesn't email it to you for each hour.

Hope this helps.

That's exactly what I want it to do, to run different scripts every hour of the day. I'll give it a shot. Thank you!