I wanted to add a command to crontab so that it is executed every time Linux boots so that I do not have to enter the command manually. I wanted to turn off the red light on my microphone outlet in Ubuntu.
Crontab command is used to edit crontab files. These files have a list of commands that are to be executed on a particular day at a given time. They are most useful when you want to run some tests or some cleanup commands or something that needs to be run regularly – say weekly or monthly. The commands specified are executed automatically and logs can also be collected from those commands, along with an email that will be sent to the user. I had not used this feature until recently when I was asked to use them at my job. These crontab files are maintained per user, so each user can configure his own commands to be run.