Provided by: systemd_229-4ubuntu21.31_amd64 bug


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







       systemd-suspend.service is a system service that is pulled in by and is
       responsible for the actual system suspend. Similarly, systemd-hibernate.service is pulled
       in by to execute the actual hibernation. Finally,
       systemd-hybrid-sleep.service is pulled in by 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
       /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 /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 or a sleep.conf.d file. See systemd-


       systemd-sleep understands the following commands:

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

           Print a short version string and exit.

       suspend, hibernate, hybrid-sleep
           Suspend, hibernate, or put the system to hybrid sleep.


       systemd-sleep.conf(5), systemd(1), systemctl(1), systemd.special(7), systemd-