xref: /netbsd-src/sbin/shutdown/shutdown.8 (revision aaf4ece63a859a04e37cf3a7229b5fab0157cc06)
1.\"	$NetBSD: shutdown.8,v 1.26 2003/08/07 10:04:39 agc Exp $
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30.\"     @(#)shutdown.8	8.2 (Berkeley) 4/27/95
31.\"
32.Dd October 18, 2002
33.Dt SHUTDOWN 8
34.Os
35.Sh NAME
36.Nm shutdown
37.Nd close down the system at a given time
38.Sh SYNOPSIS
39.Nm
40.Op Fl b Ar bootstr
41.Op Fl Ddfhknpr
42.Ar time
43.Op Ar message ... | Ar -
44.Sh DESCRIPTION
45.Nm
46provides an automated shutdown procedure for super-users
47to nicely notify users when the system is shutting down,
48saving them from system administrators, hackers, and gurus, who
49would otherwise not bother with such niceties.
50.Pp
51Available friendlinesses:
52.Bl -tag -width bootstr
53.It Fl b Ar bootstr
54The given
55.Ar bootstr
56is passed to
57.Xr reboot 8
58for the benefit of those systems that can pass boot arguments to the
59firmware.
60Currently, this only affects sun3 and sparc machines.
61.It Fl d
62.Nm
63will pass the
64.Fl d
65flag to
66.Xr reboot 8
67or
68.Xr halt 8 .
69If neither the
70.Fl h
71or
72.Fl r
73flags are specified, then
74.Fl d
75also implies
76.Fl r .
77.It Fl f
78.Nm
79arranges, in the manner of
80.Xr fastboot 8 ,
81for the file systems
82.Em not to be
83checked on reboot.
84.It Fl h
85The system is halted at the specified
86.Ar time
87when
88.Nm
89execs
90.Xr halt 8 .
91.It Fl k
92Kick everybody off.
93The
94.Fl k
95option
96does not actually halt the system, but leaves the
97system multi-user with logins disabled (for all but super-user).
98.It Fl n
99Prevent the normal
100.Xr sync 2
101before stopping.
102.It Fl p
103The system is powered down at the specified
104.Ar time
105when
106.Nm
107execs
108.Xr halt 8 .
109If the powerdown fails, or the system does not support software powerdown,
110the system will simply halt.
111.It Fl r
112The system is rebooted at the specified
113.Ar time
114when
115.Nm
116execs
117.Xr reboot 8 .
118.It Fl D
119Prevents
120.Nm
121from detaching from the tty with
122.Xr fork 2 Ns /
123.Xr exit 3 .
124.It Ar time
125.Ar Time
126is the time at which
127.Nm
128will bring the system down and
129may be the word
130.Ar now
131or a future time in one of two formats:
132.Ar +number ,
133or
134.Ar [[[[[cc]yy]mm]dd]hh]mm ,
135where the century, year, month, day, and hour may be defaulted
136to the current system values.
137The first form brings the system down
138.Ar number
139minutes from the current time; the second brings the system down at the
140absolute time specified.
141If the century is not specified, it defaults to 1900 for years between 69
142and 99, or 2000 for years between 0 and 68.
143A leading zero in the
144.Dq yy
145value is
146.Em not
147optional.
148.It Ar message ...
149Any other arguments comprise the warning message that is broadcast
150to users currently logged into the system.
151.It Ar -
152If
153.Ar -
154is supplied as the only argument after the time, the warning message is read
155from the standard input.
156.El
157.Pp
158At intervals, becoming more frequent as apocalypse approaches
159and starting at ten hours before shutdown, warning messages are displayed
160on the terminals of all users logged in.
161Five minutes before shutdown, or immediately if shutdown is in less
162than 5 minutes, logins are disabled by creating
163.Pa /etc/nologin
164and copying the warning message there.
165If this file exists when a user attempts to log in,
166.Xr login 1
167prints its contents and exits.
168The file is removed just before
169.Nm
170exits.
171.Pp
172At shutdown time a message is written in the system log, containing the
173time of shutdown, who initiated the shutdown and the reason.
174Next a message is printed announcing the start of the system shutdown hooks.
175Then the shutdown hooks in
176.Pa /etc/rc.shutdown
177are run.
178And a message is printed indicating that they have completed.
179After a short delay a terminate
180signal is then sent to
181.Xr init 8
182to bring the system down to single-user state (depending on above options).
183The time of the shutdown and the warning message are placed in
184.Pa /etc/nologin
185and should be used to inform the users about when the system will
186be back up and why it is going down (or anything else).
187.Sh FILES
188.Bl -tag -width /etc/rc.shutdown -compact
189.It Pa /etc/nologin
190tells
191.Xr login 1
192not to let anyone log in
193.It Pa /fastboot
194tells
195.Xr rc 8
196not to run fsck when rebooting
197.It Pa /etc/rc.shutdown
198System shutdown commands
199.El
200.Sh SEE ALSO
201.Xr login 1 ,
202.Xr wall 1 ,
203.Xr fastboot 8 ,
204.Xr halt 8 ,
205.Xr reboot 8
206.Sh BACKWARD COMPATIBILITY
207The hours and minutes in the second time format may be separated by
208a colon (``:'') for backward compatibility.
209.Sh HISTORY
210The
211.Nm
212command appeared in
213.Bx 4.0 .
214