Mac OS X in a Nutshell

Name

shutdown

Synopsis

shutdown [options] when [message]

Terminate all processing. when may be a specific time (in hh:mm format), a number of minutes to wait (in + m format), or now. A broadcast message notifies all users to log off the system. Processes are signaled with SIGTERM, to allow them to exit gracefully. Only privileged users can execute the shutdown command. Broadcast messages, default or defined, are displayed at regular intervals during the grace period; the closer the shutdown time, the more frequent the message.

Options

-c

Cancel a shutdown in progress.

-f

Reboot fast, by suppressing the normal call to fsck when rebooting.

-h

Halt the system when shutdown is complete.

-k

Print the warning message, but suppress actual shutdown.

-n

Perform shutdown without a call to sync.

-r

Reboot the system when shutdown is complete.