*xss-lock* hooks up your favorite locker to the MIT screen saver extension for
X and also to systemd's login manager. The locker is executed in response to
events from these two sources:
- X signals when screen saver activation is forced or after a period of user
inactivity (as set with `xset s TIMEOUT`). In the latter case, the notifier
command, if specified, is executed first.
- The login manager can also request that the session be locked; as a result of
`loginctl lock-sessions`, for example. Additionally, **xss-lock** uses the
inhibition logic to lock the screen before the system goes to sleep.
*xss-lock* waits for the locker to exit -- or kills it when screen saver
deactivation or session unlocking is forced -- so the command should not fork.
Also, *xss-lock* manages the idle hint on the login session. The idle state of
the session is directly linked to user activity as reported by X (except when
the notifier runs before locking the screen). When all sessions are idle, the
login manager can take action (such as suspending the system) after a