Simple X display locker. This is the simplest X screen locker we are aware of. It is stable and quite a lot of people in our community are using it every day when they are out with friends or fetching some food from the local pub.


slock is configured via config.h like most other software. Per default it will turn the screen red on any keyboard press, if you are less paranoid and turning red on failed login attempts suffices for you, set failonclear = 0 in config.h.


You can browse its source code repository or get a copy using the following command:

git clone



slock can be started after a specific period of user inactivity using xautolock. The command syntax is:

xautolock -time 10 -locker slock

Simpler alternatives to xautolock might be xssstate or xss.