Linux Verify crond Daemon And Cronjobs Are Running

Q. How do I verify or check cronjob is running or not under CentOS / RHEL / Fedora Linux from a shell prompt?

A. cron / crond is daemon to execute scheduled commands (Vixie Cron). Usually, it is started automatically from /etc/init.d on entering multi-user runlevels.

RHEL / CentOS / Fedora Linux Verify Cron Service

You can simply use any one of the following command to see if crond is running or not, enter:
# pgrep crond
OR
# service crond status
Sample output:

crond (pid 4370) is running...

If it is not running type the following two command to start crond:
# chkconfig crond on # service crond start
Verify cron is running by viewing log file, enter:
# tail -f /var/log/cron

A note about Debian / Ubuntu Linux Cron service

Under Debian and Ububtu Linux cron logs its action logged to the syslog facility i.e. use /var/log/messages file:
# tail -f /var/log/messages
Find out if cron daemon is running or not, enter:
# pgrep cron

See Debian / Linux service management for more information.