Provided by: systemd-sysv_252.5-2ubuntu3_amd64 bug


       shutdown - Halt, power off or reboot the machine


       shutdown [OPTIONS...] [TIME] [WALL...]


       shutdown may be used to halt, power off, or reboot the machine.

       The first argument may be a time string (which is usually "now"). Optionally, this may be
       followed by a wall message to be sent to all logged-in users before going down.

       The time string may either be in the format "hh:mm" for hour/minutes specifying the time
       to execute the shutdown at, specified in 24h clock format. Alternatively it may be in the
       syntax "+m" referring to the specified number of minutes m from now.  "now" is an alias
       for "+0", i.e. for triggering an immediate shutdown. If no time argument is specified,
       "+1" is implied.

       Note that to specify a wall message you must specify a time argument, too.

       If the time argument is used, 5 minutes before the system goes down the /run/nologin file
       is created to ensure that further logins shall not be allowed.


       The following options are understood:

           Print a short help text and exit.

       -H, --halt
           Halt the machine.

       -P, --poweroff
           Power the machine off (the default).

       -r, --reboot
           Reboot the machine.

           The same as --poweroff, but does not override the action to take if it is "halt". E.g.
           shutdown --reboot -h means "poweroff", but shutdown --halt -h means "halt".

           Do not halt, power off, or reboot, but just write the wall message.

           Do not send wall message before halt, power off, or reboot.

           Cancel a pending shutdown. This may be used to cancel the effect of an invocation of
           shutdown with a time argument that is not "+0" or "now".

           Show a pending shutdown action and time if there is any.


       On success, 0 is returned, a non-zero failure code otherwise.


        shutdown command in previous init systems (including sysvinit) defaulted to single-user
       mode instead of powering off the machine. To change into single-user mode, use systemctl
       rescue instead.


       systemd(1), systemctl(1), halt(8), wall(1)