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