78

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

10 Answers 10

68

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

| improve this answer | |
  • Try this with 100 jobs ... – merlin May 19 at 4:40
151

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
| improve this answer | |
  • 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
    +1 Finally, this is what worked for me. Thank you – Pavan Jun 4 '15 at 23:25
  • @alex This should be the accepted answer – Luis Ferrao Sep 7 '18 at 8:52
  • 1
    crontab -r is what I was looking for. Thanks ! – forzagreen Feb 26 '19 at 13:48
68

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
| improve this answer | |
  • 6
    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 0:20
  • 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
  • 4
    If you're on Ubuntu you can use sudo service cron stop – Joel Oct 28 '16 at 11:14
  • 1
    On Debian this is /etc/init.d/cron stop. – Faheem Mitha Jul 19 '17 at 5:52
  • 2
    @Faheem on Debian nowadays it’s also service cron stop. – Stephen Kitt Jul 19 '17 at 8:42
11

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 (#).

| improve this answer | |
  • 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
  • 2
    To uncomment, command is :%s/^#// – NP01 Aug 14 '13 at 3:18
4

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

| improve this answer | |
  • 1
    Also can look for specific details in the cronjob crontab -l | perl -nle 's/^#\s*([0-1*])/$1/;print if /.+mytexttofind.+/' – Jason Nov 6 '16 at 6:10
  • 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 4 '18 at 14:06
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
| improve this answer | |
1

In any flavor of Unix/Linux that I know of:

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 :)
| improve this answer | |
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.

| improve this answer | |
0

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 #

| improve this answer | |
0

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"
}
| improve this answer | |

Not the answer you're looking for? Browse other questions tagged or ask your own question.