Provided by: systemd_204-5ubuntu20.31_amd64 

NAME
systemd-suspend.service, systemd-hibernate.service, systemd-hybrid-sleep.service, systemd-sleep - System
sleep state logic
SYNOPSIS
systemd-suspend.service
systemd-hibernate.service
systemd-hybrid-sleep.service
/usr/lib/systemd/systemd-sleep
DESCRIPTION
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.
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", or
"hybrid-sleep" 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 be notified of system suspend/hibernation and
resume there are much nicer interfaces available.
Note that systemd-suspend.service, systemd-hibernate.service, and systemd-hybrid-sleep.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. See systemd-sleep.conf(5).
OPTIONS
systemd-sleep understands the following commands:
-h, --help
Print a short help text and exit.
--version
Print the systemd version identifier and exit.
suspend, hibernate, hybrid-sleep
Suspend, hibernate, or put the system to hybrid sleep.
SEE ALSO
systemd-sleep.conf(5), systemd(1), systemctl(1), systemd.special(7), systemd-halt.service(8)
systemd 204 SYSTEMD-SUSPEND.SERVICE(8)