I can see cronjobs owned by root by
You can use following command to see user’s crons
crontab -u username -l
User’s cron jobs reside in /var/spool/cron/ you can see them there also.
You would have to run this as root
for user in $(cut -f1 -d: /etc/passwd); do echo $user; crontab -u $user -l; done
will loop over each user name listing out their crontab. The crontabs are owned by the respective users so you won’t be able to see another user’s crontab w/o being them or root.
If you wished to have a script named /root/backup.sh run every day at 3am, your crontab entry would look like as follows. First, install your cronjob by running the following command:
# crontab -e
Append the following entry:
0 3 * * * /root/backup.sh
Save and close the file.
Cron Easy to remember format:
* * * * * command to be executed - - - - - | | | | | | | | | ----- Day of week (0 - 7) (Sunday=0 or 7) | | | ------- Month (1 - 12) | | --------- Day of month (1 - 31) | ----------- Hour (0 - 23) ------------- Minute (0 - 59)
If you wish to edit a users cronjob, following command would be used :
# crontab -u username -e