topic Re: Crontab query in Operating System - Linux

Crontab query

Becke — Tue, 16 Mar 2010 06:02:40 GMT

Hi Folks

I have setup simple a job in root crontab to change permission on a file every 5 minutes forever but the cron doesn't execute the script successfully, I have tried with the below entries and refreshed cron but no difference.

*/5 * * * * /script.changowner > /outputfile 2>&1

and with

0-59/5 * * * * /script.changeonwer >outputfile 2>&1

Have i got the first entry incorrect in crontab ? and what would be the correct entry ?

Thanks in advance

Re: Crontab query

Matti_Kurkela — Tue, 16 Mar 2010 06:45:08 GMT

When a cron job fails (or when it produces any output that is not redirected elsewhere), cron sends email to the user that owns the cron job.

So, your root account should have received email about each failed attempt. These emails might contain error messages or other clues about the failure reason.

You did not specify the name of the Linux distribution you're using, but assuming your distribution uses the Vixie Cron like most common distributions, your crontab line syntax seems OK.

However, have you really placed the script to the root directory (/) as your crontab lines seem to indicate? The recommended place to put locally-created sysadmin scripts would be /usr/local/sbin. Of course you can choose to ignore this recommendation if you have your reasons for it.

MK

Re: Crontab query

Kapil Jha — Tue, 16 Mar 2010 08:38:14 GMT

you need to check a couple of things

ls -lrt /script.changeonwer
does it have execute permission.

you may out it like

*/5 **** sh /script.changowner > /outputfile 2>/tmp/test

this test file would tell you the exact error and then u can move ahead to resolve the issue.

BR,
Kapil+

Re: Crontab query

Horia Chirculescu — Tue, 16 Mar 2010 09:10:16 GMT

Hello,

Have you established a correct environment for the script you are using? Maybe your script fail to execute because of this.

Horia.

Re: Crontab query

Steven Schweda — Tue, 16 Mar 2010 12:07:03 GMT

> [...] the cron doesn't execute the script
> successfully [...]

What, exactly, does that mean?

ls -l /script.changeonwer

cat outputfile

> ls -lrt /script.changeonwer

"rt"? Why?

Re: Crontab query

Raynald Boucher — Wed, 17 Mar 2010 11:47:59 GMT

I don't know which distribution of linux you are using or if it makes a difference.

Did you try adding the user in the cron command such as:

*/5 * * * * root /script.changowner > /outputfile 2>&1

RayB

Re: Crontab query

Victor Semaska_3 — Wed, 17 Mar 2010 13:36:47 GMT

The user field is allowed only in the system-wide crontab /etc/crontab.

Re: Crontab query

bullz — Thu, 18 Mar 2010 15:39:22 GMT

firstly chk log in /var/log/cron

and make sure your file has execute permission for files.