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 November 7, 2022 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. 59In order to use the 60.Nm 61command, the user must have root privileges or be a member of the 62operator group. 63.Pp 64The following options are available: 65.Bl -tag -width indent 66.It Fl c 67The system is power cycled (power turned off and then back on) 68at the specified time. 69If the hardware doesn't support power cycle, the system will be 70rebooted. 71At the present time, only systems with BMC supported by the 72.Xr ipmi 4 73driver that implement this functionality support this flag. 74The amount of time the system is off is dependent on the device 75that implements this feature. 76.It Fl h 77The system is halted at the specified 78.Ar time . 79.It Fl p 80The system is halted and the power is turned off 81(hardware support required, otherwise the system is halted) 82at the specified 83.Ar time . 84.It Fl r 85The system is rebooted at the specified 86.Ar time . 87.It Fl k 88Kick everybody off. 89The 90.Fl k 91option 92does not actually halt the system, but leaves the 93system multi-user with logins disabled (for all but super-user). 94.It Fl o 95If one of the 96.Fl c , 97.Fl h , 98.Fl p 99or 100.Fl r 101options are specified, 102.Nm 103will execute 104.Xr halt 8 105or 106.Xr reboot 8 107instead of sending a signal to 108.Xr init 8 . 109.It Fl n 110If the 111.Fl o 112option is specified, prevent the file system cache from being flushed by passing 113.Fl n 114to 115.Xr halt 8 116or 117.Xr reboot 8 . 118This option should probably not be used. 119.It Ar time 120.Ar Time 121is the time at which 122.Nm 123will bring the system down and 124may be the case-insensitive word 125.Ar now 126(indicating an immediate shutdown) or 127a future time in one of two formats: 128.Ar +number , 129or 130.Ar yymmddhhmm , 131where the year, month, and day may be defaulted 132to the current system values. 133The first form brings the system down in 134.Ar number 135minutes and the second at the absolute time specified. 136.Ar +number 137may be specified in units other than minutes by appending the corresponding 138suffix: 139.Dq Li s , 140.Dq Li sec , 141.Dq Li m , 142.Dq Li min , 143.Dq Li h , 144.Dq Li hour . 145.Pp 146If an absolute time is specified, but not a date, 147and that time today has already passed, 148.Nm 149will assume that the same time tomorrow was meant. 150(If a complete date is specified which has already passed, 151.Nm 152will print an error and exit without shutting the system down.) 153.It Ar warning-message 154Any other arguments comprise the warning message that is broadcast 155to users currently logged into the system. 156.It Fl 157If 158.Sq Fl 159is supplied as an option, the warning message is read from the standard 160input. 161.El 162.Pp 163At intervals, becoming more frequent as apocalypse approaches 164and starting at ten hours before shutdown, warning messages are displayed 165on the terminals of all users logged in. 166Five minutes before 167shutdown, or immediately if shutdown is in less than 5 minutes, 168logins are disabled by creating 169.Pa /var/run/nologin 170and copying the 171warning message there. 172If this file exists when a user attempts to 173log in, 174.Xr login 1 175prints its contents and exits. 176The file is 177removed just before 178.Nm 179exits. 180.Pp 181At shutdown time a message is written to the system log, containing the 182time of shutdown, the person who initiated the shutdown and the reason. 183The corresponding signal is then sent to 184.Xr init 8 185to respectively halt, reboot or bring the system down to single-user state 186(depending on the above options). 187The time of the shutdown and the warning message 188are placed in 189.Pa /var/run/nologin 190and should be used to 191inform the users about when the system will be back up 192and why it is going down (or anything else). 193.Pp 194A scheduled shutdown can be canceled by killing the 195.Nm 196process (a 197.Dv SIGTERM 198should suffice). 199The 200.Pa /var/run/nologin 201file that 202.Nm 203created will be removed automatically. 204.Pp 205When run without options, the 206.Nm 207utility will place the system into single user mode at the 208.Ar time 209specified. 210.Pp 211Calling 212.Dq Nm poweroff 213is equivalent to running: 214.Bd -literal -offset indent 215shutdown -p now 216.Ed 217.Sh FILES 218.Bl -tag -width /var/run/nologin -compact 219.It Pa /var/run/nologin 220tells 221.Xr login 1 222not to let anyone log in 223.El 224.Sh EXAMPLES 225Reboot the system in 30 minutes and display a warning message on the terminals 226of all users currently logged in: 227.Pp 228.Dl # shutdown -r +30 \&"System will reboot\&" 229.Sh COMPATIBILITY 230The hours and minutes in the second time format may be separated by 231a colon (``:'') for backward compatibility. 232.Sh SEE ALSO 233.Xr kill 1 , 234.Xr login 1 , 235.Xr wall 1 , 236.Xr nologin 5 , 237.Xr halt 8 , 238.Xr init 8 , 239.Xr reboot 8 240.Sh HISTORY 241A 242.Nm 243command was originally written by Ian Johnstone for UNSW's modified 244.At "6th Edn" . 245It was modified and then incorporated in 246.Bx 4.1 . 247