Run the last executed command as root with sudo !!
No I’m not just super excited about the sudo command, the exclamation points are actually part of the usage of the sudo tool. If you want to quickly run the last command executed but as the root superuser, type the following:sudo !! An example of this would be if you’re trying to edit a system file that you need system privileges for. Instead of re-entering the entire command string preceded with sudo, just type sudo !! and the previous command (!!) will be run under sudo.

!! is not related to sudo. It’s a bash event designator that refers to the last command. !-{n} would refer to the command issued n commands ago. !! is equal to !-1.