Red Hat Enterprise Linux is pre-configured to run important system tasks to keep the system updated. For example, the locate database used by the locate command is updated daily. A system administrator can use automated tasks to perform periodic backups, monitor the system, run custom scripts, and more.
Red Hat Enterprise Linux comes with several automated tasks utilities: cron, at, and batch.
The cron daemon is a long running process that executes commands at specific dates and times. To schedule one-time only tasks with cron, use at or batch. For commands that need to be executed repeatedly (e.g. hourly, daily or weekly), use crontab, which has the following options:
|crontab filename||Install filename as your crontab file.|
|crontab -e||Edit your crontab file.|
|crontab -l||Show your crontab file.|
|crontab -r||Remove your crontab file.|
|[email protected]||Emails the output to the specified address.|
The crontab command creates a crontab file containing commands and how often cron should execute them. Each entry in a crontab file consists of six fields, specified in the following order:
minute(s) hour(s) day(s) month(s) weekday(s) command(s)
Note: Learn here how to use the Cron jobs in cPanel?