NAME

       systemd-suspend.service, systemd-hibernate.service, systemd-hybrid-sleep.service, systemd-
       suspend-then-hibernate.service, systemd-sleep - System sleep state logic

SYNOPSIS

       systemd-suspend.service

       systemd-hibernate.service

       systemd-hybrid-sleep.service

       systemd-suspend-then-hibernate.service

       /lib/systemd/system-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 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
       /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 /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[1].

       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 systemd-
       sleep.conf(5).

OPTIONS

       systemd-sleep understands the following commands:

       -h, --help
           Print a short help text and exit.

       --version
           Print a short version string and exit.

       suspend, hibernate, hybrid-sleep, suspend-then-hibernate
           Suspend, hibernate, suspend then 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)

NOTES

        1. Inhibitor interface
           https://www.freedesktop.org/wiki/Software/systemd/inhibit