1.\" Copyright (c) 1988, 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. All advertising materials mentioning features or use of this software 13.\" must display the following acknowledgement: 14.\" This product includes software developed by the University of 15.\" California, Berkeley and its contributors. 16.\" 4. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" @(#)shutdown.8 8.2 (Berkeley) 4/27/95 33.\" $FreeBSD: src/sbin/shutdown/shutdown.8,v 1.12.2.5 2003/02/23 21:17:43 trhodes Exp $ 34.\" $DragonFly: src/sbin/shutdown/shutdown.8,v 1.3 2006/02/17 19:33:33 swildner Exp $ 35.\" 36.Dd December 11, 1998 37.Dt SHUTDOWN 8 38.Os 39.Sh NAME 40.Nm shutdown 41.Nd "close down the system at a given time" 42.Sh SYNOPSIS 43.Nm 44.Op Fl 45.Oo 46.Fl h | Fl p | 47.Fl r | Fl k 48.Oc 49.Oo 50.Fl o 51.Op Fl n 52.Oc 53.Ar time 54.Op Ar warning-message ... 55.Sh DESCRIPTION 56The 57.Nm 58utility provides an automated shutdown procedure for super-users 59to nicely notify users when the system is shutting down, 60saving them from system administrators, hackers, and gurus, who 61would otherwise not bother with such niceties. 62.Pp 63The following options are available: 64.Bl -tag -width indent 65.It Fl h 66The system is halted at the specified 67.Ar time . 68.It Fl p 69The system is halted and the power is turned off 70(hardware support required) 71at the specified 72.Ar time . 73.It Fl r 74The system is rebooted at the specified 75.Ar time . 76.It Fl k 77Kick everybody off. 78The 79.Fl k 80option 81does not actually halt the system, but leaves the 82system multi-user with logins disabled (for all but super-user). 83.It Fl o 84If one of the 85.Fl h , 86.Fl p 87or 88.Fl r 89is specified, 90.Nm 91will execute 92.Xr halt 8 93or 94.Xr reboot 8 95instead of sending signal to 96.Xr init 8 . 97.It Fl n 98If the 99.Fl o 100is specified, prevent the file system cache from being flushed by passing 101.Fl n 102option to 103.Xr halt 8 104or 105.Xr reboot 8 . 106This option should probably not be used. 107.It Ar time 108.Ar Time 109is the time at which 110.Nm 111will bring the system down and 112may be the word 113.Ar now 114(indicating an immediate shutdown) or 115specify a future time in one of two formats: 116.Ar +number , 117or 118.Ar yymmddhhmm , 119where the year, month, and day may be defaulted 120to the current system values. The first form brings the system down in 121.Ar number 122minutes and the second at the absolute time specified. 123.It Ar warning-message 124Any other arguments comprise the warning message that is broadcast 125to users currently logged into the system. 126.It Fl 127If 128.Sq Fl 129is supplied as an option, the warning message is read from the standard 130input. 131.El 132.Pp 133At intervals, becoming more frequent as apocalypse approaches 134and starting at ten hours before shutdown, warning messages are displayed 135on the terminals of all users logged in. Five minutes before 136shutdown, or immediately if shutdown is in less than 5 minutes, 137logins are disabled by creating 138.Pa /var/run/nologin 139and copying the 140warning message there. If this file exists when a user attempts to 141log in, 142.Xr login 1 143prints its contents and exits. The file is 144removed just before 145.Nm 146exits. 147.Pp 148At shutdown time a message is written to the system log, containing the 149time of shutdown, the person who initiated the shutdown and the reason. 150Corresponding signal is then sent to 151.Xr init 8 152to respectively halt, reboot or bring the system down to single-user state 153(depending on the above options). 154The time of the shutdown and the warning message 155are placed in 156.Pa /var/run/nologin 157and should be used to 158inform the users about when the system will be back up 159and why it is going down (or anything else). 160.Pp 161A scheduled shutdown can be canceled by killing the 162.Nm 163process (a 164.Dv SIGTERM 165should suffice). 166The 167.Pa /var/run/nologin 168file that 169.Nm 170created will be removed automatically. 171.Sh FILES 172.Bl -tag -width /var/run/nologin -compact 173.It Pa /var/run/nologin 174tells login not to let anyone log in 175.El 176.Sh BACKWARD COMPATIBILITY 177The hours and minutes in the second time format may be separated by 178a colon (``:'') for backward compatibility. 179.Sh SEE ALSO 180.Xr kill 1 , 181.Xr login 1 , 182.Xr wall 1 , 183.Xr nologin 5 , 184.Xr halt 8 , 185.Xr init 8 , 186.Xr reboot 8 187.Sh HISTORY 188The 189.Nm 190utility appeared in 191.Bx 4.0 . 192