3.7.2.1 Xorg

If you use Xorg, you can use the utility xss-lock to lock the screen of your session. xss-lock is triggered by DPMS which since Xorg 1.8 is auto-detected and enabled if ACPI is also enabled at kernel runtime.

To use xss-lock, you can simple execute it and put it into the background before you start your window manager from e.g. your ~/.xsession:

xss-lock -- slock &
exec stumpwm

In this example, xss-lock uses slock to do the actual locking of the screen when it determines it’s appropriate, like when you suspend your device.

For slock to be allowed to be a screen locker for the graphical session, it needs to be made setuid-root so it can authenticate users, and it needs a PAM service. This can be achieved by adding the following service to your config.scm:

(service screen-locker-service-type
         (screen-locker-configuration
          (name "slock")
          (program (file-append slock "/bin/slock"))))

If you manually lock your screen, e.g. by directly calling slock when you want to lock your screen but not suspend it, it’s a good idea to notify xss-lock about this so no confusion occurs. This can be done by executing xset s activate immediately before you execute slock.