There may come a time when you might want a task to run automatically at particular intervals, without your involvement being needed. Linux features cron, a utility for doing just that. A cron task is called a job, so you may hear the combined term, cron job, in the Linux community. Cron may seem rather complex at first, but it's surprisingly simple once it is broken down.

The first thing to note is that each user has his or her crontab, which is the term used for the configuration file that contains one or more cron jobs. By default, no user has any jobs created; thus, each user has an empty cron job. Inside a user's crontab, you place cron jobs in their own separate line, with a specific command to be run. This means that each user may have their own tasks to be automatically completed at specific times. For system administration purposes, administrators will often use the root user or a dedicated service account to run cron jobs.

To get started with this...