User-defined tasks can be done by executing a script at startup and shutdown for Linux. To execute script at startup of Ubuntu, the rc.local can be modified to include additional commands. To execute script when rebooting Ubuntu, the script has to be copied to the relevant directory. Once the permissions of the script have been changed to executable, it will run when rebooting the Linux operating system. Scripts are run in the alphabetical order in the directories and the scripts should be named following the nomenclature rules when executing a script at startup and shutdown with all distributions of Linux.