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.\" 35.Dd December 11, 1998 36.Dt SHUTDOWN 8 37.Os 38.Sh NAME 39.Nm shutdown 40.Nd "close down the system at a given time" 41.Sh SYNOPSIS 42.Nm 43.Op Fl 44.Oo 45.Fl h | Fl p | 46.Fl r | Fl k 47.Oc 48.Oo 49.Fl o 50.Op Fl n 51.Oc 52.Ar time 53.Op Ar warning-message ... 54.Sh DESCRIPTION 55The 56.Nm 57utility provides an automated shutdown procedure for super-users 58to nicely notify users when the system is shutting down, 59saving them from system administrators, hackers, and gurus, who 60would otherwise not bother with such niceties. 61.Pp 62The following options are available: 63.Bl -tag -width indent 64.It Fl h 65The system is halted at the specified 66.Ar time . 67.It Fl p 68The system is halted and the power is turned off 69(hardware support required) 70at the specified 71.Ar time . 72.It Fl r 73The system is rebooted at the specified 74.Ar time . 75.It Fl k 76Kick everybody off. 77The 78.Fl k 79option 80does not actually halt the system, but leaves the 81system multi-user with logins disabled (for all but super-user). 82.It Fl o 83If one of the 84.Fl h , 85.Fl p 86or 87.Fl r 88is specified, 89.Nm 90will execute 91.Xr halt 8 92or 93.Xr reboot 8 94instead of sending signal to 95.Xr init 8 . 96.It Fl n 97If the 98.Fl o 99is specified, prevent the file system cache from being flushed by passing 100.Fl n 101option to 102.Xr halt 8 103or 104.Xr reboot 8 . 105This option should probably not be used. 106.It Ar time 107.Ar Time 108is the time at which 109.Nm 110will bring the system down and 111may be the word 112.Ar now 113(indicating an immediate shutdown) or 114specify a future time in one of two formats: 115.Ar +number , 116or 117.Ar yymmddhhmm , 118where the year, month, and day may be defaulted 119to the current system values. The first form brings the system down in 120.Ar number 121minutes and the second at the absolute time specified. 122.It Ar warning-message 123Any other arguments comprise the warning message that is broadcast 124to users currently logged into the system. 125.It Fl 126If 127.Sq Fl 128is supplied as an option, the warning message is read from the standard 129input. 130.El 131.Pp 132At intervals, becoming more frequent as apocalypse approaches 133and starting at ten hours before shutdown, warning messages are displayed 134on the terminals of all users logged in. Five minutes before 135shutdown, or immediately if shutdown is in less than 5 minutes, 136logins are disabled by creating 137.Pa /var/run/nologin 138and copying the 139warning message there. If this file exists when a user attempts to 140log in, 141.Xr login 1 142prints its contents and exits. The file is 143removed just before 144.Nm 145exits. 146.Pp 147At shutdown time a message is written to the system log, containing the 148time of shutdown, the person who initiated the shutdown and the reason. 149Corresponding signal is then sent to 150.Xr init 8 151to respectively halt, reboot or bring the system down to single-user state 152(depending on the above options). 153The time of the shutdown and the warning message 154are placed in 155.Pa /var/run/nologin 156and should be used to 157inform the users about when the system will be back up 158and why it is going down (or anything else). 159.Pp 160A scheduled shutdown can be canceled by killing the 161.Nm 162process (a 163.Dv SIGTERM 164should suffice). 165The 166.Pa /var/run/nologin 167file that 168.Nm 169created will be removed automatically. 170.Sh FILES 171.Bl -tag -width /var/run/nologin -compact 172.It Pa /var/run/nologin 173tells login not to let anyone log in 174.El 175.Sh SEE ALSO 176.Xr kill 1 , 177.Xr login 1 , 178.Xr wall 1 , 179.Xr nologin 5 , 180.Xr halt 8 , 181.Xr init 8 , 182.Xr reboot 8 183.Sh BACKWARD COMPATIBILITY 184The hours and minutes in the second time format may be separated by 185a colon (``:'') for backward compatibility. 186.Sh HISTORY 187The 188.Nm 189utility appeared in 190.Bx 4.0 . 191