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.\" 4. Neither the name of the University nor the names of its contributors 13.\" may be used to endorse or promote products derived from this software 14.\" without specific prior written permission. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.\" @(#)shutdown.8 8.2 (Berkeley) 4/27/95 29.\" $FreeBSD$ 30.\" 31.Dd December 11, 1998 32.Dt SHUTDOWN 8 33.Os 34.Sh NAME 35.Nm shutdown 36.Nd "close down the system at a given time" 37.Sh SYNOPSIS 38.Nm 39.Op Fl 40.Oo 41.Fl h | Fl p | 42.Fl r | Fl k 43.Oc 44.Oo 45.Fl o 46.Op Fl n 47.Oc 48.Ar time 49.Op Ar warning-message ... 50.Sh DESCRIPTION 51The 52.Nm 53utility provides an automated shutdown procedure for super-users 54to nicely notify users when the system is shutting down, 55saving them from system administrators, hackers, and gurus, who 56would otherwise not bother with such niceties. 57.Pp 58The following options are available: 59.Bl -tag -width indent 60.It Fl h 61The system is halted at the specified 62.Ar time . 63.It Fl p 64The system is halted and the power is turned off 65(hardware support required) 66at the specified 67.Ar time . 68.It Fl r 69The system is rebooted at the specified 70.Ar time . 71.It Fl k 72Kick everybody off. 73The 74.Fl k 75option 76does not actually halt the system, but leaves the 77system multi-user with logins disabled (for all but super-user). 78.It Fl o 79If one of the 80.Fl h , 81.Fl p 82or 83.Fl r 84is specified, 85.Nm 86will execute 87.Xr halt 8 88or 89.Xr reboot 8 90instead of sending signal to 91.Xr init 8 . 92.It Fl n 93If the 94.Fl o 95is specified, prevent the file system cache from being flushed by passing 96.Fl n 97option to 98.Xr halt 8 99or 100.Xr reboot 8 . 101This option should probably not be used. 102.It Ar time 103.Ar Time 104is the time at which 105.Nm 106will bring the system down and 107may be the word 108.Ar now 109(indicating an immediate shutdown) or 110specify a future time in one of two formats: 111.Ar +number , 112or 113.Ar yymmddhhmm , 114where the year, month, and day may be defaulted 115to the current system values. 116The first form brings the system down in 117.Ar number 118minutes and the second at the absolute time specified. 119.It Ar warning-message 120Any other arguments comprise the warning message that is broadcast 121to users currently logged into the system. 122.It Fl 123If 124.Sq Fl 125is supplied as an option, the warning message is read from the standard 126input. 127.El 128.Pp 129At intervals, becoming more frequent as apocalypse approaches 130and starting at ten hours before shutdown, warning messages are displayed 131on the terminals of all users logged in. 132Five minutes before 133shutdown, or immediately if shutdown is in less than 5 minutes, 134logins are disabled by creating 135.Pa /var/run/nologin 136and copying the 137warning message there. 138If this file exists when a user attempts to 139log in, 140.Xr login 1 141prints its contents and exits. 142The 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 COMPATIBILITY 176The hours and minutes in the second time format may be separated by 177a colon (``:'') for backward compatibility. 178.Sh SEE ALSO 179.Xr kill 1 , 180.Xr login 1 , 181.Xr wall 1 , 182.Xr nologin 5 , 183.Xr halt 8 , 184.Xr init 8 , 185.Xr reboot 8 186.Sh HISTORY 187The 188.Nm 189utility appeared in 190.Bx 4.0 . 191