.\" Copyright (c) 1988 The Regents of the University of California. .\" All rights reserved. .\" .\" Redistribution and use in source and binary forms are permitted provided .\" that: (1) source distributions retain this entire copyright notice and .\" comment, and (2) distributions including binaries display the following .\" acknowledgement: ``This product includes software developed by the .\" University of California, Berkeley and its contributors'' in the .\" documentation or other materials provided with the distribution and in .\" all advertising materials mentioning features or use of this software. .\" Neither the name of the University nor the names of its contributors may .\" be used to endorse or promote products derived from this software without .\" specific prior written permission. .\" THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED .\" WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF .\" MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. .\" .\" @(#)shutdown.8 6.7 (Berkeley) 6/24/90 .\" .TH SHUTDOWN 8 "June 24, 1990" .UC 4 .SH NAME shutdown \- close down the system at a given time .SH SYNOPSIS .B shutdown [ .B - ] [ .B \-fhkrn ] time [ warning-message ... ] .SH DESCRIPTION .I Shutdown provides an automated shutdown procedure which a super-user can use to notify users nicely when the system is shutting down, saving them from system administrators, hackers, and gurus, who would otherwise not bother with such niceties. .PP .I Time is the time at which \fIshutdown\fP will bring the system down and may be the word \fInow\fP (indicating an immediate shutdown) or specify a future time in one of two formats: \fI+number\fP, or \fIyymmddhhmm\fP, where the year, month, and day may be defaulted to the current system values. The first form brings the system down in \fInumber\fP minutes and the second at the absolute time specified. .PP Any other arguments comprise the warning message that is broadcast to users currently logged into the system; if a single dash (``-'') is supplied as an option, the warning message is read from the standard input. .PP At intervals, which get closer together as apocalypse approaches, starting at ten hours before shutdown, warning messages are displayed at the terminals of all users on the system. Five minutes before shutdown, or immediately if shutdown is in less than 5 minutes, logins are disabled by creating \fI/etc/nologin\fP and copying the warning message there. If this file exists when a user attempts to log in, \fIlogin\fP(1) prints its contents and exits. The file is removed just before \fIshutdown\fP exits. .PP At shutdown time a message is written in the system log, containing the time of shutdown, who ran shutdown and the reason. Then a terminate signal is sent to \fIinit\fP to bring the system down to single-user state. Alternatively, if .B \-r, .B \-h, or .B \-k is used, then .I shutdown will exec .IR reboot (8), .IR halt (8), or avoid shutting the system down (respectively). (If it isn't obvious, .B \-k is to make people .I think the system is going down!) .PP With the .B \-f option, .I shutdown arranges, in the manner of .IR fastboot (8), that when the system is rebooted the file systems will not be checked. The .B \-n option prevents the normal .IR sync (2) before stopping. .PP The time of the shutdown and the warning message are placed in \fI/etc/nologin\fP 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). .SH FILES .TP 15 /etc/nologin tells login not to let anyone log in .TP 15 /fastboot tells /etc/rc not to run fsck when rebooting .SH "SEE ALSO" login(1), wall(1), fastboot(8), halt(8), reboot(8) .SH "BACKWARD COMPATIBILITY" The hours and minutes in the second time format may be separated by a colon (``:'') for backward compatibility.