Index for Section 8

Alphabetical listing for S

shutdown(8)
NAME
  shutdown - Ends system operation

SYNOPSIS
  /usr/sbin/shutdown [-bfhknr] time [warning-message ...]

DESCRIPTION
  The shutdown command provides an automated shutdown procedure.  You must be
  root to use this command.

  The time argument specifies when shutdown will bring the system down.	 You
  can use the word now (indicating an immediate shutdown) or specify a future
  time in one of two formats: +number or hhmm.	The first form brings the
  system down in number minutes.  The second form brings the system down at
  the hours and minutes specified.  The hours and minutes in the second time
  format may be separated by a colon (:) for backward compatibility.

  Any other arguments comprise the warning message that is broadcast to users
  currently logged into the system.  Prior to shutdown, warning messages are
  displayed at the terminals of all users on the system.  Messages are sent
  at intervals which get closer together as shutdown approaches.

  Five minutes before shutdown (or immediately, if shutdown is in less than
  five minutes) logins are disabled by creating the /etc/nologin file and
  copying the warning message there.  If this file exists when a user
  attempts to log in, the login program prints its contents and exits.	The
  nologin file is removed just before shutdown exits.  If the shutdown is
  canceled or aborted, the nologin file may remain, and then must then be
  removed by the superuser after determining that the system is safe for
  users.  If you cancel the shutdown during the grace period by using the
  kill shutdown_process_id command, the shutdown is cancelled and the nologin
  file is removed.  A shutdown process should not be aborted once the grace
  period ends and shutdown actually begins.

  At shutdown time a message is written in the system log, containing the
  time of shutdown, who ran shutdown and the reason.  A terminate signal is
  then sent to init to bring the system down to the single-user state.
  Alternatively, if you invoke shutdown with the -r, -h, or -k flag, the
  command executes the reboot command or the halt command, or avoids shutting
  the system down.  Note that the -h and -r flags use a broadcast kill signal
  and not the run level transition scripts.  To use the run level transition
  scripts, execute the shutdown command without the -h or -r flag.  This will
  bring the system down to single user mode.  From single user mode, execute
  shutdown with the -h or -r flag.  Alternatively, you can execute init 0
  which will bring the system from level 3 to the console prompt.

  If you invoke the command with the -f flag, shutdown shuts down the system
  quickly (in the manner of the fastboot or the fasthalt program); the system
  halts or reboots without checking the file systems.  For example, the
  shutdown -f time command brings the system to single user and creates the
  /fastboot file; when the system reboots to multiuser, it does not invoke
  fsck.	 The shutdown -f -r time command causes the system to shut down,
  create the /fastboot file, then immediately reboot.  The shutdown -f -h
  time command causes the system to halt and create the /fastboot file.

  The -n flag prevents the normal syncing of disks before stopping the
  system.  The -n and -f flags together on the command line are incompatible.

  The time of the shutdown and the warning message are placed in the nologin
  file and can be used to inform the users about when the system will be back
  up and why it is going down.

FLAGS
  -b	    Sends a shutdown message to the rwalld daemon on all remote
	    client hosts that have NFS file systems mounted from this system.

  -f	    Causes a fast shutdown, bypassing the messages to other users and
	    bringing the system down as quickly as possible.

  -h	    Causes the system to shutdown and halt using a broadcast kill
	    signal.

  -k	    Causes shutdown messages to be sent to users, warning them of an
	    impending shutdown.	 The system does not actually shut down.  The
	    /etc/nologin file is not created.

  -n	    Causes a shutdown without syncing the disks.

  -r	    Causes the system to shutdown using a broadcast kill signal and
	    automatically reboot.

FILES
  /usr/sbin/shutdown
	    Specifies the command path

  /etc/nologin
	    Location of the nologin file.

RELATED INFORMATION
  Commands:  login(1), wall(1), fastboot(8), fasthalt(8), halt(8), reboot(8)