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. 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 October 23, 2017 32.Dt SHUTDOWN 8 33.Os 34.Sh NAME 35.Nm shutdown , 36.Nm poweroff 37.Nd "close down the system at a given time" 38.Sh SYNOPSIS 39.Nm 40.Op Fl 41.Oo 42.Fl c | Fl h | Fl p | 43.Fl r | Fl k 44.Oc 45.Oo 46.Fl o 47.Op Fl n 48.Oc 49.Ar time 50.Op Ar warning-message ... 51.Nm poweroff 52.Sh DESCRIPTION 53The 54.Nm 55utility provides an automated shutdown procedure for super-users 56to nicely notify users when the system is shutting down, 57saving them from system administrators, hackers, and gurus, who 58would otherwise not bother with such niceties. 59.Pp 60The following options are available: 61.Bl -tag -width indent 62.It Fl c 63The system is power cycled (power turned off and then back on) 64at the specified time. 65If the hardware doesn't support power cycle, the system will be 66halted. 67At the present time, only systems with BMC supported by the 68.Xr ipmi 4 69driver that implement this functionality support this flag. 70The amount of time the system is off is dependent on the device 71that implements this feature. 72.It Fl h 73The system is halted at the specified 74.Ar time . 75.It Fl p 76The system is halted and the power is turned off 77(hardware support required, otherwise the system is halted) 78at the specified 79.Ar time . 80.It Fl r 81The system is rebooted at the specified 82.Ar time . 83.It Fl k 84Kick everybody off. 85The 86.Fl k 87option 88does not actually halt the system, but leaves the 89system multi-user with logins disabled (for all but super-user). 90.It Fl o 91If one of the 92.Fl c , 93.Fl h , 94.Fl p 95or 96.Fl r 97options are specified, 98.Nm 99will execute 100.Xr halt 8 101or 102.Xr reboot 8 103instead of sending a signal to 104.Xr init 8 . 105.It Fl n 106If the 107.Fl o 108option is specified, prevent the file system cache from being flushed by passing 109.Fl n 110to 111.Xr halt 8 112or 113.Xr reboot 8 . 114This option should probably not be used. 115.It Ar time 116.Ar Time 117is the time at which 118.Nm 119will bring the system down and 120may be the case-insensitive word 121.Ar now 122(indicating an immediate shutdown) or 123a future time in one of two formats: 124.Ar +number , 125or 126.Ar yymmddhhmm , 127where the year, month, and day may be defaulted 128to the current system values. 129The first form brings the system down in 130.Ar number 131minutes and the second at the absolute time specified. 132.Ar +number 133may be specified in units other than minutes by appending the corresponding 134suffix: 135.Dq Li s , 136.Dq Li sec , 137.Dq Li m , 138.Dq Li min . 139.Dq Li h , 140.Dq Li hour . 141.It Ar warning-message 142Any other arguments comprise the warning message that is broadcast 143to users currently logged into the system. 144.It Fl 145If 146.Sq Fl 147is supplied as an option, the warning message is read from the standard 148input. 149.El 150.Pp 151At intervals, becoming more frequent as apocalypse approaches 152and starting at ten hours before shutdown, warning messages are displayed 153on the terminals of all users logged in. 154Five minutes before 155shutdown, or immediately if shutdown is in less than 5 minutes, 156logins are disabled by creating 157.Pa /var/run/nologin 158and copying the 159warning message there. 160If this file exists when a user attempts to 161log in, 162.Xr login 1 163prints its contents and exits. 164The file is 165removed just before 166.Nm 167exits. 168.Pp 169At shutdown time a message is written to the system log, containing the 170time of shutdown, the person who initiated the shutdown and the reason. 171The corresponding signal is then sent to 172.Xr init 8 173to respectively halt, reboot or bring the system down to single-user state 174(depending on the above options). 175The time of the shutdown and the warning message 176are placed in 177.Pa /var/run/nologin 178and should be used to 179inform the users about when the system will be back up 180and why it is going down (or anything else). 181.Pp 182A scheduled shutdown can be canceled by killing the 183.Nm 184process (a 185.Dv SIGTERM 186should suffice). 187The 188.Pa /var/run/nologin 189file that 190.Nm 191created will be removed automatically. 192.Pp 193When run without options, the 194.Nm 195utility will place the system into single user mode at the 196.Ar time 197specified. 198.Pp 199Calling 200.Dq Nm poweroff 201is equivalent to running: 202.Bd -literal -offset indent 203shutdown -p now 204.Ed 205.Sh FILES 206.Bl -tag -width /var/run/nologin -compact 207.It Pa /var/run/nologin 208tells 209.Xr login 1 210not to let anyone log in 211.El 212.Sh EXAMPLES 213Reboot the system in 30 minutes and display a warning message on the terminals 214of all users currently logged in: 215.Pp 216.Dl # shutdown -r +30 \&"System will reboot\&" 217.Sh COMPATIBILITY 218The hours and minutes in the second time format may be separated by 219a colon (``:'') for backward compatibility. 220.Sh SEE ALSO 221.Xr kill 1 , 222.Xr login 1 , 223.Xr wall 1 , 224.Xr nologin 5 , 225.Xr halt 8 , 226.Xr init 8 , 227.Xr reboot 8 228.Sh HISTORY 229A 230.Nm 231command was originally written by Ian Johnstone for UNSW's modified 232.At "6th Edn" . 233It was modified and then incorporated in 234.Bx 4.1 . 235