cron jobs are automated scripts that run at a specified date/time, or on a specified interval.
anything that can be executed in the terminal on the server can be run as a cron job (this includes commands, applications, scripts, etc).
crontab is the command used to create/view/modify/remove cron jobs.
- crontab -l lists all scheduled jobs
- crontab -e allows you to edit jobs
- crontab -r will delete *all* your active jobs!
once the crontab file has been edited the cron daemon will automatically read it and update it's job que to match the file. you should see the message:
crontab: installing new crontab