cron script for all users

r_jr · 11-21-2011, 12:07 PM

I was wondering how to setup cron to execute a script for all users. Or do I have to set it up for each individual user.

Doc CPU · 11-21-2011, 12:50 PM

Hi there,

Quote:

Originally Posted by r_jr

I was wondering how to setup cron to execute a script for all users.

simply by editing the global cron job table /etc/crontab.

Quote:

Originally Posted by r_jr

Or do I have to set it up for each individual user.

No. Actually, for quite a long time I didn't know that cron jobs can be set per user. I only new the global /etc/crontab.

[X] Doc CPU

r_jr · 11-23-2011, 02:40 PM

Quote:

Originally Posted by Doc CPU

Hi there,

simply by editing the global cron job table /etc/crontab.

No. Actually, for quite a long time I didn't know that cron jobs can be set per user. I only new the global /etc/crontab.

[X] Doc CPU

Well, I tried adding the job to the /etc/crontab file, but now it does not run at all.

lithos · 11-23-2011, 03:34 PM

Where did you find/read about the option to add jobs to /etc/crontab file ?

It's the directory /etc/cron.daily or /etc/cron.hourly or whichever you want to put the script into
so that executes at desired intervals.
Check the /etc/cron.daily files within and make your script as that inside.
Put your script there and it will run (presuming service crond is running?)

Another way of doing it is edit the crontab file from Root account
with: crontab -e
and putting the line for executing your script at desired time/intervals.

Doc CPU · 11-23-2011, 03:56 PM

Hi there,

Quote:

Originally Posted by lithos

Where did you find/read about the option to add jobs to /etc/crontab file ?

I don't remember - it's the way I've always done it. For years. And it has worked ever since. Simplest method of all, IMHO.

Quote:

Originally Posted by lithos

Another way of doing it is edit the crontab file from Root account
with: crontab -e
and putting the line for executing your script at desired time/intervals.

Yea, but in effect, that does nothing else than editing /etc/crontab. [EDIT: Yes, it does something else: It edits user root's crontab, rather than the global one.] So why do it more complicated than necessary? Why not directly edit the config file?

[X] Doc CPU

lithos · 11-24-2011, 06:14 AM

Quote:

Originally Posted by Doc CPU

Yea, but in effect, that does nothing else than editing /etc/crontab. So why do it more complicated than necessary? Why not directly edit the config file?

Have you tried to run command:

Code:

crontab -l

what does it show you ?
Mine is:

Code:

root@~#>crontab -l
# This set of options gives you additonal mail options
# If any dont apply to you, please remove from list.
#!mail(yes),noticenotrun(yes)

# All mails will be sent to root
#!mailto(root)

SHELL=/bin/bash
PATH=/sbin:/bin:/usr/bin:/usr/sbin:/usr/local/bin

# Run-parts
01 * * * * run-parts /etc/cron.hourly
02 0 * * * run-parts /etc/cron.daily
22 0 * * 0 run-parts /etc/cron.weekly
42 0 1 * * run-parts /etc/cron.monthly

# * */8 * * * htpdate -s -l www.linux.org
# * */6 * * * hwclock --systohc

And if you look at your file: /etc/crontab ?

Code:

cat /etc/crontab

Mine is:

Code:

root@~#>cat /etc/crontab 
SHELL=/bin/bash
PATH=/sbin:/bin:/usr/sbin:/usr/bin
MAILTO=root
HOME=/

# run-parts
01 * * * * root run-parts /etc/cron.hourly
02 4 * * * root run-parts /etc/cron.daily
22 4 * * 0 root run-parts /etc/cron.weekly
42 4 1 * * root run-parts /etc/cron.monthly

Are the outputs the same ?

Can you please tell me the difference now (besides the Root's crontab is different than /etc/crontab, because ROOT runs some scripts) ?

Doc CPU · 11-24-2011, 06:37 AM

Hi there,

Quote:

Originally Posted by lithos

Have you tried to run command:

Code:

crontab -l

what does it show you ?

it tells me:

Code:

no crontab for root

And that's logical, in a way, because I didn't create a crontab for the root user, only the global, non-user-specific one that was automatically created during the system setup.

Quote:

Originally Posted by lithos

And if you look at your file: /etc/crontab ?

Then I see a list of all the system-wide cron jobs, plus the generic cron.hourly, cron.daily etc:

Code:

root@spine / :cat /etc/crontab
# for vixie cron
# $Header: /var/cvsroot/gentoo-x86/sys-process/vixie-cron/files/crontab-3.0.1-r4,v 1.2 2009/05/12 09:13:46 bangert Exp $

# Global variables
SHELL=/bin/bash
PATH=/sbin:/bin:/usr/sbin:/usr/bin
MAILTO=root
HOME=/

# check scripts in cron.hourly, cron.daily, cron.weekly and cron.monthly
59   *  * * *  root  rm -f /var/spool/cron/lastrun/cron.hourly
9    3  * * *  root  rm -f /var/spool/cron/lastrun/cron.daily
19   4  * * 6  root  rm -f /var/spool/cron/lastrun/cron.weekly
29   5  1 * *  root  rm -f /var/spool/cron/lastrun/cron.monthly
*/10 *  * * *  root  test -x /usr/sbin/run-crons && /usr/sbin/run-crons
*/15 *  * * *  root  fetchmail -f /etc/fetchmail-gmx-net-rc      >> /server/mail/gmx.net.log
  [ more cron jobs listed ]
root@spine / :

That's quite similar to your sample.

Quote:

Originally Posted by lithos

Are the outputs the same ?

Of course they're not.

Quote:

Originally Posted by lithos

Can you please tell me the difference now (besides the Root's crontab is different than /etc/crontab, because ROOT runs some scripts) ?

The difference is that one is user-specific by design (albeit for root), the other isn't. That's why, for example, the system-wide crontab has a field for each cron job that specifies the user under which the job shall execute, while the user-specific crontabs don't have that field.

[X] Doc CPU

lithos · 11-24-2011, 12:40 PM

thank you, now I know how sys/wide and user cron's.