systemd-sleep - System sleep state logic
systemd-suspend.service is a system service that is pulled in by suspend.target
and is responsible for the actual system suspend. Similarly,
systemd-hibernate.service is pulled in by hibernate.target to execute the
actual hibernation. Finally, systemd-hybrid-sleep.service is pulled in by
hybrid-sleep.target to execute hybrid hibernation with system suspend and
pulled in by suspend-then-hibernate.target to execute system suspend with a
timeout that will activate hibernate later.
Immediately before entering system suspend and/or hibernation
systemd-suspend.service (and the other mentioned units, respectively) will run
all executables in /usr/lib/systemd/system-sleep/ and pass two arguments to
them. The first argument will be "pre", the second either
"suspend", "hibernate", "hybrid-sleep", or
"suspend-then-hibernate" depending on the chosen action. Immediately
after leaving system suspend and/or hibernation the same executables are run,
but the first argument is now "post". All executables in this
directory are executed in parallel, and execution of the action is not
continued until all executables have finished.
Note that scripts or binaries dropped in /usr/lib/systemd/system-sleep/ are
intended for local use only and should be considered hacks. If applications
want to react to system suspend/hibernation and resume, they should rather use
the Inhibitor interface
Note that systemd-suspend.service, systemd-hibernate.service, and
systemd-hybrid-sleep.service systemd-suspend-then-hibernate.service should
never be executed directly. Instead, trigger system sleep states with a
command such as "systemctl suspend" or similar.
Internally, this service will echo a string like "mem" into
/sys/power/state, to trigger the actual system suspend. What exactly is
written where can be configured in the "[Sleep]" section of
/etc/systemd/sleep.conf or a sleep.conf.d file. See
understands the following commands:
Print a short help text and exit.
Print a short version string and exit.
Suspend, hibernate, suspend then hibernate, or
put the system to hybrid sleep.
- Inhibitor interface