Learn Linux Shell Scripting - Fundamentals of Bash 4.4

Scheduling with at and cron

We've learned about many things in the world of shell scripting so far: variables, conditionals, loops, redirections, and even functions. In this chapter, we'll explain another important concept that is closely related to shell scripting: scheduling.

Simply put, scheduling is making sure your commands or scripts run at certain times, without the need for you to personally start them every time. A classic example can be found in cleaning up logs; often, older logs are no longer useful and take up too much space. For example, you could fix this with a cleanup script that removes logs older than 45 days. However, such a script should probably be run once a day. On a workday, this shouldn't pose the biggest problem, ...