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
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 "
referring to the specified number of minutes m from now.
now" is an alias for "
for triggering an immediate shutdown. If no time argument is
+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:
Halt the machine.
Power-off the machine (the default).
Reboot the machine.
--halt is specified.
Do not halt, power-off, reboot, just write wall message.
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
On success, 0 is returned, a non-zero failure code otherwise.