Scheduling with a cron
The GNU/Linux system supports several utilities for scheduling tasks. The cron utility is the most widely supported. It allows you to schedule tasks to be run in the background at regular intervals. The cron utility uses a table (crontab) with a list of scripts or commands to be executed and the time when they are to be executed.
Cron is used to schedule system housekeeping tasks, such as performing backups, synchronizing the system clocking with ntpdate, and removing temporary files.
A regular user might use cron to schedule Internet downloads to happen late at night when their ISP allows drop caps and the available bandwidth is higher.
Getting ready
The cron scheduling utility comes with all GNU/Linux distributions. It scans the cron tables to determine whether a command is due to be run. Each user has their own cron table, which is a plain text file. The crontab command manipulates the cron table.
How to do it...
A crontab entry specifies the time to execute a command...
