How to see every cron job that's running

Understanding what cron jobs are running can be helpful when auditing jobs or resolving system resource issues. Luckily you can do this with a single command, and this quick guide will show you how. To inspect a single job, including syslog lines for runs that already exited, use how to check if a cron job is running. Scheduled jobs that are not running right now live in the crontab files covered in where cron jobs are saved.

How can you see all the jobs currently running?

On Linux, list the processes under the cron daemon and the helper it forks for each job:

ps h --ppid "$(pgrep -d, -x cron || pgrep -d, -x crond)"

The daemon does not run your command itself. It forks a helper, and the job's shell runs under that helper. On Debian and Ubuntu, ps shows the helper as CRON, the same label cron uses on the CRON[pid] syslog lines. On Red Hat and Fedora, cronie shows the helper as CROND. The output includes those helper lines along with the jobs.

The helper's command name is still cron on Debian and Ubuntu, so pgrep -x cron matches the daemon and the helpers. -x is an exact match. -d, joins those pids with commas, which is what lets --ppid see the jobs and not only the CRON lines. On Red Hat the daemon is named crond, so the command falls through to pgrep -x crond. A plain pgrep cron also matches other commands whose names merely contain "cron", such as cronitor dash or anacron.

If nothing matches, pgrep prints nothing and ps reports error: list of process IDs must follow --ppid. That means the daemon is not running. The list also leaves out jobs that have already exited, jobs that daemonized and were reparented, and crontab lines that are not processes yet. Those show up in the logs and the crontab, which is what the check-if guide walks through.

If you are a Cronitor user, open Filters on the jobs list and choose Only next to Running. The same control is described in how to check if a cron job is running right now.