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 8.1 (Berkeley) 6/5/93 33.\" $Id$ 34.\" 35.Dd June 5, 1993 36.Dt SHUTDOWN 8 37.Os BSD 4 38.Sh NAME 39.Nm shutdown 40.Nd "close down the system at a given time" 41.Sh SYNOPSIS 42.Nm shutdown 43.Op Fl 44.Op Fl hkrn 45.Ar time 46.Op Ar warning-message ... 47.Sh DESCRIPTION 48.Nm Shutdown 49provides an automated shutdown procedure for super-users 50to nicely notify users when the system is shutting down, 51saving them from system administrators, hackers, and gurus, who 52would otherwise not bother with such niceties. 53.Pp 54The following options are available: 55.Bl -tag -width indent 56.It Fl h 57The system is halted at the specified 58.Ar time 59when 60.Nm 61executes 62.Xr halt 8 . 63.It Fl k 64Kick every body off. 65The 66.Fl k 67option 68does not actually halt the system, but leaves the 69system multi-user with logins disabled (for all but super-user). 70.It Fl n 71Prevent the normal 72.Xr sync 2 73before stopping. 74.It Fl r 75.Nm Shutdown 76executes 77.Xr reboot 8 78at the specified 79.Ar time . 80.It Ar time 81.Ar Time 82is the time at which 83.Nm 84will bring the system down and 85may be the word 86.Ar now 87(indicating an immediate shutdown) or 88specify a future time in one of two formats: 89.Ar +number , 90or 91.Ar yymmddhhmm , 92where the year, month, and day may be defaulted 93to the current system values. The first form brings the system down in 94.Ar number 95minutes and the second at the absolute time specified. 96.It Ar warning-message 97Any other arguments comprise the warning message that is broadcast 98to users currently logged into the system. 99.It Fl 100If 101.Ql Fl 102is supplied as an option, the warning message is read from the standard 103input. 104.El 105.Pp 106At intervals, becoming more frequent as apocalypse approaches 107and starting at ten hours before shutdown, warning messages are displayed 108on the terminals of all users logged in. Five minutes before 109shutdown, or immediately if shutdown is in less than 5 minutes, 110logins are disabled by creating 111.Pa /etc/nologin 112and copying the 113warning message there. If this file exists when a user attempts to 114log in, 115.Xr login 1 116prints its contents and exits. The file is 117removed just before 118.Nm 119exits. 120.Pp 121At shutdown time a message is written in the system log, containing the 122time of shutdown, who initiated the shutdown and the reason. 123A terminate 124signal is then sent to 125.Xr init 8 126to bring the system down to single-user state (depending on above 127options). 128The time of the shutdown and the warning message 129are placed in 130.Pa /etc/nologin 131and should be used to 132inform the users about when the system will be back up 133and why it is going down (or anything else). 134.Sh FILES 135.Bl -tag -width /etc/nologin -compact 136.It Pa /etc/nologin 137tells login not to let anyone log in 138.El 139.Sh SEE ALSO 140.Xr login 1 , 141.Xr wall 1 , 142.Xr nologin 5 , 143.Xr halt 8 , 144.Xr reboot 8 145.Sh BACKWARD COMPATIBILITY 146The hours and minutes in the second time format may be separated by 147a colon (``:'') for backward compatibility. 148.Sh HISTORY 149The 150.Nm 151command appeared in 152.Bx 4.0 . 153