115 lines
2.7 KiB
Groff
115 lines
2.7 KiB
Groff
.\" @(#)shutdown.8 1.1 94/10/31 SMI; from UCB 4.3
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.\" Copyright (c) 1980 Regents of the University of California.
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.\" All rights reserved. The Berkeley software License Agreement
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.\" specifies the terms and conditions for redistribution.
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.\"
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.TH SHUTDOWN 8 "1 July 1990"
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.SH NAME
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shutdown \- close down the system at a given time
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.SH SYNOPSIS
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.B /usr/etc/shutdown
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[
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.B \-fhknr
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]
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.I time
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[
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.I warning-message
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\&.\|.\|.
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]
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.SH DESCRIPTION
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.IX "shutdown command" "" "\fLshutdown\fP \(em shut down multiuser operation"
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.LP
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.B shutdown
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provides an automated procedure to notify users when the
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system is to be shut down.
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.I time
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specifies when
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.B shutdown
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will bring the system down; it may be the word
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.B now
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(indicating an immediate shutdown),
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or it may specify a future time in one of two formats:
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.BI + number
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and
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.IB hour : min.
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The first form brings the system down in
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.I number
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minutes, and the second brings the system down
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at the time of day indicated in 24-hour notation.
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.LP
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At intervals that get closer as the apocalypse approaches,
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warning messages are displayed at terminals of all logged-in users,
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and of users who have remote mounts on that machine.
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Five minutes before shutdown,
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or immediately if shutdown is in less than 5 minutes,
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logins are disabled by creating
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.B /etc/nologin
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and writing a message there.
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If this file exists when a user attempts to log in,
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.BR login (1)
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prints its contents and exits. The file is removed just before
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.B shutdown
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exits.
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.LP
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At shutdown time a message is written to the system log daemon,
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.BR syslogd (8),
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containing the time of shutdown,
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the instigator of the shutdown, and the reason.
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Then a terminate signal is sent to
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.BR init ,
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which brings the system down to single-user mode.
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.LP
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The time of the shutdown and the warning message are placed in
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.BR /etc/nologin ,
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which should be used to inform the users as to when the system
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will be back up, and why it is going down (or anything else).
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.SH OPTIONS
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.LP
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As an alternative to the above procedure, these options can be
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specified:
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.TP
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.B \-f
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Shut the system down in the manner of
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.B fasthalt
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(see
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.BR fastboot (8)),
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so that when the system is rebooted,
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the file systems are not checked.
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.TP
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.B \-h
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Execute
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.BR halt (8).
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.TP
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.B \-k
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Simulate shutdown of the system. Do not actually shut down the system.
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.TP
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.B \-n
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Prevent the normal
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.BR sync (2)
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before stopping.
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.TP
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.B \-r
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Execute
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.BR reboot (8).
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.SH FILES
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.PD 0
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.TP 20
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.B /etc/nologin
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tells login not to let anyone log in
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.TP
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.B /etc/xtab
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list of remote hosts that have mounted this host
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.PD
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.SH "SEE ALSO"
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.BR login (1),
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.BR sync (2),
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.BR fastboot (8),
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.BR halt (8),
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.BR reboot (8),
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.BR syslogd (8)
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.SH BUGS
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.LP
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Only allows you to bring the system down between
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\*(lqnow\*(rq and 23:59 if
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you use the absolute time for shutdown.
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