How do I check active crons?

Question

I'm trying to hunt down a cron job (or the equivalent) which I know is running, but I can't find it in the default cron files for my system (FreeBSD / Linux / BSD). How can I tell which ones are actually being initialized?

Solution 1

crontab can be used to override the files that are used by default. As such you can remove and add your own cron lists, or just single cron jobs.

crontab -l

That will list the cron jobs/lists/tabs that are currently initialized, their frequency, directory and file location, and a few other small details.

Also in FreeBSD you can look in /var/cron/tabs and for Ubuntu/Linux look in /var/spool/cron/crontabs for user-specific crontabs.

Solution 2

Linux based distributions can also use various multiple locations for crontabs:

/etc/cron.d/
/etc/cron.daily/
/etc/cron.hourly/
/etc/cron.monthly/
/etc/crontab
/etc/cron.weekly/