topic crontab in suse linux in Operating System - Linux

crontab in suse linux

senthil_kumar_1 — Fri, 15 May 2009 10:47:33 GMT

Hi

I am using Suse linux.

I issued following command to view the crontab entries.

>crontab -l

# DO NOT EDIT THIS FILE - edit the master and reinstall.
# (/tmp/crontab.10132 installed on Fri Feb 27 13:40:47 2009)
# (Cron version -- $Id: crontab.c,v 2.13 1994/01/17 03:20:37 vixie Exp $)
# DO NOT EDIT THIS FILE - edit the master and reinstall.
# (/tmp/crontab.1933 installed on Tue Jun 17 14:49:55 2008)
# (Cron version -- $Id: crontab.c,v 2.13 1994/01/17 03:20:37 vixie Exp $)

What is the meaning of "DO NOT EDIT THIS FILE - edit the master and reinstall."

pls explain me.

Re: crontab in suse linux

Suraj K Sankari — Fri, 15 May 2009 11:18:38 GMT

Hi,

>>What is the meaning of "DO NOT EDIT THIS FILE - edit the master and reinstall."

It means do not edit thil file using vi editor.

remember always use "crontab -e" to edit crontab entries

suraj

Re: crontab in suse linux

Jozef_Novak — Fri, 15 May 2009 11:53:39 GMT

Yes, you should edit crobjobs with crontab -e. That's basically what the message tells you.
I am not sure about SUSE, but HPUX used to have a tool called cronedit, which did basically crontab -e, but placed a lock on the crontab file, making sure that only one user at a time was changing it.

J.

Re: crontab in suse linux

Matti_Kurkela — Fri, 15 May 2009 12:35:00 GMT

The cron implementation in SuSE Linux is probably called "Vixie Cron".

Debian uses this too, but it adds this comment to the man page of the crontab command:

-------------
DEBIAN SPECIFIC

The "out-of-the-box" behaviour for crontab -l is to display the three line "DO NOT EDIT THIS FILE" header that is placed at the beginning of the crontab when it is installed. The problem is that it makes the sequence

crontab -l | crontab -

non-idempotent -- you keep adding copies of the header. This causes pain to scripts that use sed to edit a crontab.
-------------

In other words, your crontab has probably been edited by a script. Maybe an installation script of some application?

MK

Re: crontab in suse linux

Taifur — Sat, 16 May 2009 03:18:47 GMT

Hi Senthil,

>>meaning of "DO NOT EDIT THIS FILE
You can not edit this file by vi editor.

For adding anything, you have to use
#crontab -e
then save the the file.

Check below link for details.

http://www-uxsup.csx.cam.ac.uk/pub/doc/suse/suse9.3/suselinux-adminguide_en/cha.suse.html

If it helps , pls assign point.

Rgds//
Taifur

Re: crontab in suse linux

Dennis Handly — Sat, 16 May 2009 04:26:10 GMT

>suraj: remember always use "crontab -e" to edit crontab entries

It would suggest if that's what it meant, it should have said that.

Re: crontab in suse linux

James R. Ferguson — Mon, 18 May 2009 13:13:31 GMT

Hi Senthil:

The 'Vixie' implementation (and more about the history of the crontab) is discussed here:

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

Regards!

...JRF...

Re: crontab in suse linux

Kranti Mahmud — Tue, 19 May 2009 04:47:42 GMT

Hi Senthil,

What is the meaning of "DO NOT EDIT THIS FILE - edit the master and reinstall."

It means do not edit thil file using vi editor.

For editing or other operation of cron, please read the belo links:

http://docs.huihoo.com/opensolaris/system-administration-guide-advanced-administration/html/ch15s04.html

http://www.adminschoice.com/docs/crontab.htm

Rgds-Kranti