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. "
is an alias for "
+0", i.e. for
triggering an immediate shutdown. If no time argument
is specified, "
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
The following options are understood:
Halt the machine.
Power-off the machine (the default).
Reboot the machine.
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 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.