SHUTDOWN(8)                                           SHUTDOWN(8)

          shutdown - Halt, power-off or reboot the machine

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

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

          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-off the machine (the default).

          -r, --reboot
              Reboot the machine.

              Equivalent to --poweroff, unless --halt is specified.

              Do not halt, power-off, reboot, just write wall message.

     Page 1                     systemd 247          (printed 5/24/22)

     SHUTDOWN(8)                                           SHUTDOWN(8)

              Do not send wall message before halt, power-off, 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".

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

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

     Page 2                     systemd 247          (printed 5/24/22)