simple cron question

Lleb_KCir · 03-02-2005, 11:06 PM

if i set a crontab -e job to look as follows will it run the service every 30min?

30 * * * * command -cron

???

i hope that is simple. i basically need to run something every 30min, if this is not how it is done, please advise me. i looked here:

http://www.unixgeeks.org/security/ne...ix/cron-1.html

but could not get the */30 * * * to work that gave me an error:

Quote:

Cron also supports 'step' values.
A value of */2 in the dom field would mean the command runs every two days
and likewise, */5 in the hours field would mean the command runs every
5 hours.
e.g.
* 12 10-16/2 * * root backup.sh
is the same as:
* 12 10,12,14,16 * * root backup.sh

*/15 9-17 * * * root connection.test
Will run connection.test every 15 mins between the hours or 9am and 5pm

i was trying to get something like the last line example there to run.

homey · 03-02-2005, 11:10 PM

Quote:

if i set a crontab -e job to look as follows will it run the service every 30min?

30 * * * * command -cron

No, that would run at 30 minutes past every hour.

*/30 * * * * command -cron This will run every 30 minutes.

Lleb_KCir · 03-03-2005, 01:02 AM

ok, then i must of done something wrong the first time around to get an error.

*/30 * * * * svc -t /service/imapssl -cron

that would reset the imapssl server every 30min is that correct?

homey · 03-03-2005, 08:17 AM

Quote:

*/30 * * * * svc -t /service/imapssl -cron

That's the correct time setup. I don't know about your command though. I don't seem to have a command called svc on FC3 . Normally, to restart a service I use the command like this...
service smb restart. You do want to use the full path in a cron job so that would look like this..
*/30 * * * * /sbin/service smb restart ## example

Lleb_KCir · 03-03-2005, 09:55 AM

yes that would be true, but IMAPssl is one of those funky servies:

Code:

(root@mail) 1 ~ # svc -t /service/imapssl/
(root@mail) 2 ~ # service imapssl restart
imapssl: unrecognized service
(root@mail) 3 ~ # services imapssl restart
services: Command not found.
(root@mail) 4 ~ # service
Usage: service < option > | --status-all | [ service_name [ command | --full-restart ] ]
(root@mail) 5 ~ # service imapssl restart
imapssl: unrecognized service

according to this URL about qmail:

http://cr.yp.to/qmail/faq/admin.html the svc -t /service/SERVICE_HERE is the proper way to reset something for qmail like the imapssl server.

why is it that cron is telling me that svc -t does not exsist, yet as you can seei can type it in exactly as i have it in my cron job and it works flawlessly.

homey · 03-03-2005, 10:35 AM

Cron probably can't find the path to svc. Try to find it with the command: whereis svc
Put the path which it shows in the cron job.

Lleb_KCir · 03-03-2005, 11:04 AM

ok so the full path will be:

Code:

/usr/local/bin/svc -t /service/imapssl

and look like */30 * * * * /usr/local/bin/svc -t /service/imapssl/

Lleb_KCir · 03-03-2005, 11:05 AM

ok that did not work either. just got this error from cron (its set to send me an e-mail every time it has an error

Quote:

svc: warning: unable to chdir to service/imap*: file does not exist

homey · 03-03-2005, 11:30 AM

Do a whereis service and use the full path to that also.

Lleb_KCir · 03-03-2005, 12:33 PM

turned out that crontab -e is the user cron job and does not have the same PATH$ as the user does. in my case root.

i had to call someone on my LUG to get help, but the bottom line was he created a sh script that told the cron job were to find the svc -t /service/imapssl and to run that.

after he did that cron liked what it was told as it now had the information for the PATH$ thanks to the script.

thank you for all the help.