A friend had an interesting problem for me to solve; he wanted to know how to turn off his laptop’s monitor without shutting down the system or waiting for it to go off. He wanted to leave it working during the night on the desk in his room, without the light from the LCD bothering him while he slept.
Luckily there is a Linux command to do just about anything. To turn off your monitor from a terminal, run this command:
sleep 1 && xset dpms force off
Moving the mouse or pressing a key will turn the monitor back on.