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

     shutdown -- close down the	system at a given time

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

     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	sup-
	     port 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
	     system, but leaves	the system multi-user with logins disabled
	     (for all but super-user).

     -o	     If	one of the -h, -p or -r	is specified, shutdown will execute
	     halt(8) or	reboot(8) instead of sending signal to init(8).

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

     time    Time is the time at which shutdown	will bring the system down and
	     may be the	word now (indicating an	immediate shutdown) or specify
	     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.

	     Any other arguments comprise the warning message that is broad-
	     cast 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 start-
     ing at ten	hours before shutdown, warning messages	are displayed on the
     terminals of all users logged in.	Five minutes before shutdown, or imme-
     diately 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 exists when a	user attempts to log in, login(1) prints its contents
     and exits.	 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.
     Corresponding signal is then sent to init(8) to respectively halt,	reboot
     or	bring the system down to single-user state (depending on the above op-
     tions).  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
     system 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.

     /var/run/nologin  tells login not to let anyone log in

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

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

     The shutdown utility appeared in 4.0BSD.

BSD			       December	11, 1998			   BSD


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