Execute a command in a regular interval - watch Linux command

You may have heard about cron jobs, that executes a given command in a given interval, this is useful when you want the job to continue in the time, but if you need to execute a command only for this session, or for some hours, and not each time you log into the system, then watch maybe your best bet.

Watch lets you execute a given command in a regular interval, and will show you the output in the screen, so it is very useful for those commands like free, or uptime, or some like those, that change its output contantly but it does not stay in the screen like top for example.

This article lets you lear a little about watch.