How to disable everything in crontab -l?

Question

I just want to pause everything. Don't execute anything listed on crontab -l.

kubanczyk · Answer 1 · 2022-09-12T09:56:05.600

198

First, back up the crontab:

crontab -l > my_cron_backup.txt

Then you can empty it:

crontab -r

To restore:

crontab my_cron_backup.txt
crontab -l

This works only for the crontab of the user who runs these commands, but it does not empty/restore crontabs of other users. My other answer is about suspending launches from all the users.

edited Sep 12 '22 at 09:56

answered Dec 14 '09 at 22:41

kubanczyk

13,982

2

This is particularly helpful when /tmp is corrupted (and if your crontab -e uses mktemp in /tmp. – Kevin Lee Mar 23 '15 at 15:17
1

If you are running your cronjobs in sudo better make sure you sudo first when backing up so you get the right one. – Cesar Bielich May 24 '22 at 18:15

score 84 · Answer 2 · answered Dec 14 '09 at 22:46

84

Do you have root access? Just pause cron

sudo /etc/init.d/crond stop

Then restart it when you're ready

sudo /etc/init.d/crond start

answered Dec 14 '09 at 22:46

muffinista

1,256

10

That is assuming you want to stop crontab for all users including root. The selected answer, and kubanskamac's answer would do it for just the current (desired?) user. – Kevin K Dec 15 '09 at 00:20
1

our crond service had been stopped. This pointed us in right direction to check whether crond was running, and restart. – Paul May 24 '16 at 12:51
12

If you're on Ubuntu you can use sudo service cron stop – Joel Oct 28 '16 at 11:14
3

On Debian this is /etc/init.d/cron stop. – Faheem Mitha Jul 19 '17 at 05:52
3

@Faheem on Debian nowadays it’s also service cron stop. – Stephen Kitt Jul 19 '17 at 08:42
on centos i did systemctl stop crond.service – Binyamin Feb 02 '21 at 08:02
I get sudo: /etc/init.d/crond: command not found – Black Sep 13 '22 at 10:23

score 82 · Accepted Answer · answered Dec 14 '09 at 22:39

82

crontab -e then comment out each line you don't want to run with #.

answered Dec 14 '09 at 22:39

gregf

1,028

20

Try this with 100 jobs ... – merlin May 19 '20 at 04:40
4

@merlin Use column edit move in vi/vim – whirlwin Jun 08 '20 at 13:33

score 13 · Answer 4 · answered Dec 15 '09 at 10:46

13

If you are using vi as editor, then just enter :%s/^/#/ in command mode. In all lines (%), it substitutes (s///) the begin of line (^) with a hash (#).

answered Dec 15 '09 at 10:46

andunix

131

If you are not using vi as default editor, you can "force" usage of vi like EDITOR=vi; crontab -e, and than you can use the trick above. – Betlista Jan 25 '13 at 11:53
3

To uncomment, command is :%s/^#// – NP01 Aug 14 '13 at 03:18

score 6 · Answer 5 · edited Sep 12 '14 at 11:19

6

Wasn't happy with the options above since they weren't one liners.

To disable crontab -l | perl -nle 's/^([^#])/# $1/;print' | crontab

To enable crontab -l | perl -nle 's/^#\s*([0-9*])/$1/;print' | crontab

usage example ( edited to show it doesn't disable comments)

$ crontab -l
# Comment
0 0 * * 0 /opt/something.sh

$ crontab -l|perl -nle 's/^([^#])/# $1/;print'|crontab
$ crontab -l
# Comment
# 0 0 * * 0 /opt/something.sh

$ crontab -l|perl -nle 's/^#\s*([0-9*])/$1/;print'|crontab
$ crontab -l
# Comment
0 0 * * 0 /opt/something.sh

Tested this on RHEL and AIX , and should work out of the box without anything needed to be installed

edited Sep 12 '14 at 11:19

HBruijn

80,330
24
138
209

answered Sep 12 '14 at 10:31

segaps

81

1

Also can look for specific details in the cronjob crontab -l | perl -nle 's/^#\s([0-1])/$1/;print if /.+mytexttofind.+/' – Jason Nov 06 '16 at 06:10
Could you please explain why comments are not affected? What is the pattern you use to detect them? – Sopalajo de Arrierez Dec 24 '17 at 23:39
Hm, under Debian Jessie I get the following error: crontab: usage error: file name must be specified for replace. It seems you have to specify a file (?) when using crontab without any parameters (which is replace by default). – fritzmg Dec 04 '18 at 14:06
@Sopalajo de Arrierez If the first character after #/space is a digit 0-9, then it should be a cron scheduling, and we have to drop the pound sign. This is because the comments mainly start with a word. Unfortunately, this will fail with a comment like this: "# 2 do the backups". – Fjor Oct 27 '22 at 23:03
@fritzmg I suggest that the pseudo-filename - (dash as standard input) needs to be self-explanatory : [..];print' | crontab - – Alexis-Emmanuel Haeringer Jan 13 '23 at 16:07

score 3 · Answer 6 · answered Oct 13 '14 at 21:23

3

In my limited testing, setting the shell to /bin/false works. You will still see /opt/job.sh executing in your logs, but it will be a noop:

SHELL=/bin/false

*/1 * * * *    root  /some/job.sh

answered Oct 13 '14 at 21:23

ash

31

kubanczyk · Answer 7 · 2022-09-12T09:44:47.867

1

In any flavor of Unix/Linux that I know of (except maybe OpenBSD):

mv /var/spool/cron  /var/spool/cron_is_disabled

This:

disables crontabs of all users
but not system /etc/crontab (/etc/cron.daily. etc.)
persists across a reboot
is a one-liner, duh :)

edited Sep 12 '22 at 09:44

answered Nov 05 '15 at 17:12

kubanczyk

13,982

score 1 · Answer 8 · edited Jun 29 '16 at 18:23

1

I got the idea from the answer provided by @segaps

To disable:

crontab -l | awk '{print "# "$1}' | crontab

To enable:

crontab -l | cut -c 3- | crontab

The only problem with the solution provided by segaps, is that it will uncomment the jobs, that are already commented by the user.

edited Jun 29 '16 at 18:23

Joffrey

2,021

answered Jun 29 '16 at 13:49

Sarvsav Sharma

11

Disable command should be: crontab -l | awk '{print "# "$0}' | crontab – Raymond Chiu Aug 25 '20 at 08:49

score 0 · Answer 9 · answered Apr 15 '20 at 16:47

You can use the following like so:

crondisable
cronenable

crondisable some_other_user
...

The zsh code (put in your .zshrc):

ecerr () {
print -r -- "$@" >&2
}
crondisable() {
        local user="${1:-$(whoami)}"
        local cronpath="/tmp/$user.cron.tmp"
        test -e "$cronpath" && {
        ecerr "There is already a disabled crontab at $cronpath. Remove that manually if you want to proceed."
        return 1
        }
        crontab -l -u $user > "$cronpath"
        crontab -r -u $user
}
cronenable() {
        local user="${1:-$(whoami)}"
        local cronpath="/tmp/$user.cron.tmp"
        test -e "$cronpath" || {
        ecerr "No disabled cron at $cronpath"
        return 1
        }
        crontab -u $user "$cronpath"
        mv "$cronpath" "${cronpath}.bak"
}

score -1 · Answer 10 · answered Dec 13 '17 at 21:32

-1

To do this, using nano as the editor:

sudo env EDITOR=nano crontab -e

then comment out each line you don't want to run with #

answered Dec 13 '17 at 21:32

Jonesome Reinstate Monica

5,505

How to disable everything in crontab -l?

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