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SHUTDOWN(8)		     System Manager's Manual		     SHUTDOWN(8)

NAME
     shutdown, poweroff -- close down the system at a given time

SYNOPSIS
     shutdown [-] [-h | -p | -r | -k] [-o [-n]] time [warning-message ...]
     poweroff

DESCRIPTION
     The  shutdown  utility  provides an automated shutdown procedure for super-
     users to nicely notify users when the system is shutting down, saving  them
     from  system  administrators,  hackers,  and gurus, who would otherwise not
     bother with such niceties.

     The following options are available:

     -h      The system is halted at the specified time.

     -p      The system is halted and the power is turned off (hardware  support
	     required) at the specified time.

     -r      The system is rebooted at the specified time.

     -k      Kick  everybody off.  The -k option does not actually halt the sys-
	     tem, but leaves the system multi-user with logins disabled (for all
	     but super-user).

     -o      If one of the -h, -p or -r options are specified, shutdown will ex-
	     ecute halt(8) or reboot(8) instead of sending a signal to init(8).

     -n      If the -o option is specified, prevent the file system  cache  from
	     being  flushed  by passing -n to halt(8) or reboot(8).  This option
	     should probably not be used.

     time    Time is the time at which shutdown will bring the system  down  and
	     may be the case-insensitive word now (indicating an immediate shut-
	     down)  or	a  future  time  in  one  of  two  formats:  +number, or
	     yymmddhhmm, where the year, month, and day may be defaulted to  the
	     current  system  values.	The first form brings the system down in
	     number minutes and the second at the absolute time specified.

     warning-message
	     Any other arguments comprise the warning message that is  broadcast
	     to users currently logged into the system.

     -	     If  `-'  is supplied as an option, the warning message is read from
	     the standard input.

     At intervals, becoming more frequent as apocalypse approaches and	starting
     at  ten hours before shutdown, warning messages are displayed on the termi-
     nals of all users logged in.  Five minutes before shutdown, or  immediately
     if  shutdown  is  in  less  than 5 minutes, logins are disabled by creating
     /var/run/nologin and copying the warning message there.  If this  file  ex-
     ists  when  a user attempts to log in, login(1) prints its contents and ex-
     its.  The file is removed just before shutdown exits.

     At shutdown time a message is written to the  system  log,  containing  the
     time  of  shutdown,  the  person who initiated the shutdown and the reason.
     The corresponding signal is then sent to init(8) to respectively halt,  re-
     boot  or bring the system down to single-user state (depending on the above
     options).	The time of the shutdown and the warning message are  placed  in
     /var/run/nologin and should be used to inform the users about when the sys-
     tem will be back up and why it is going down (or anything else).

     A	scheduled  shutdown  can  be canceled by killing the shutdown process (a
     SIGTERM should suffice).  The /var/run/nologin file that  shutdown  created
     will be removed automatically.

     When  run	without options, the shutdown utility will place the system into
     single user mode at the time specified.

     Calling "poweroff" is equivalent to running:

	   shutdown -p now

FILES
     /var/run/nologin  tells login(1) not to let anyone log in

COMPATIBILITY
     The hours and minutes in the second time format may be separated by a colon
     (``:'') for backward compatibility.

SEE ALSO
     kill(1), login(1), wall(1), nologin(5), halt(8), init(8), reboot(8)

HISTORY
     The shutdown utility appeared in 4.0BSD.

FreeBSD 9.0			  July 13, 2011 		     SHUTDOWN(8)
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