As root, how can I list the crontabs for all users?

Question

I have a script being run automatically that I can't find in the crontab for the expected users, so I'd like to search all users' crontabs for it.

Essentially I want to run a crontab -l for all users.

Answer 1

Well depends on the script but easily you can find your crontab as root with

crontab -l -u <user>

Or you can find crontab from spool where is located file for all users

cat /var/spool/cron/crontabs/<user>

To show all users' crontabs with the username printed at the beginning of each line:

cd /var/spool/cron/crontabs/ && grep . *

Answer 2

One liner which lists all users and prints cron for every user:

for user in $(getent passwd | cut -f1 -d: ); do echo $user; crontab -u $user -l; done

This solution:

• Doesn't require knowing a system specific crontab path (e.g. /var/spool/cron/crontabs/ vs /var/spool/cron/
• Won't list "orphan" crons, i.e. crons for users that don't exist anymore (and thus are not executed effectively)

Answer 3

for USER in `cat /etc/passwd | awk -F ":" '{print $1}'`
do
  echo "this crontab for user : $USER"
  crontab -u $USER -l 2>&1
done >> list_all_cron

Strange need to escape chars on this web site. I think copy paste won't work

Well you got the point : loop all users from /etc/passwd + awk and ask for crontab with crontab -u -l

Answer 4

To filter out comments from only active user crontabs:

for user in $(getent passwd | cut -f1 -d: ); do echo $user; crontab -u $user -l | grep -v "^#"; done

or quick and dirty from both common directories:

grep -v "^#" /var/spool/cron/crontabs/* /var/spool/cron/*

Answer 5

In RHEL/OEL you can list the cron jobs created by all users:

#cd /var/spool/cron/
#ls -1
root
oracle
user1

To see root's cronjobs:

#cat root

Answer 6

Using the following command, we findall Cron jobs, on the specified system.

find /etc/cron* -type f -perm -o+w -exec ls -l {} \;