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32 .\" @(#)shutdown.8 8.2 (Berkeley) 4/27/95
40 .Nd "close down the system at a given time"
53 .Op Ar warning-message ...
56 provides an automated shutdown procedure for super-users
57 to nicely notify users when the system is shutting down,
58 saving them from system administrators, hackers, and gurus, who
59 would otherwise not bother with such niceties.
61 The following options are available:
62 .Bl -tag -width indent
64 The system is halted at the specified
67 The system is halted and the power is turned off
68 .Pq hardware support required
72 The system is rebooted at the specified
79 does not actually halt the system, but leaves the
80 system multi-user with logins disabled (for all but super-user).
93 instead of sending signal to
98 is specified, prevent the file system cache from being flushed by passing
104 This option should probably not be used.
109 will bring the system down and
112 (indicating an immediate shutdown) or
113 specify a future time in one of two formats:
117 where the year, month, and day may be defaulted
118 to the current system values. The first form brings the system down in
120 minutes and the second at the absolute time specified.
121 .It Ar warning-message
122 Any other arguments comprise the warning message that is broadcast
123 to users currently logged into the system.
127 is supplied as an option, the warning message is read from the standard
131 At intervals, becoming more frequent as apocalypse approaches
132 and starting at ten hours before shutdown, warning messages are displayed
133 on the terminals of all users logged in. Five minutes before
134 shutdown, or immediately if shutdown is in less than 5 minutes,
135 logins are disabled by creating
138 warning message there. If this file exists when a user attempts to
141 prints its contents and exits. The file is
146 At shutdown time a message is written to the system log, containing the
147 time of shutdown, the person who initiated the shutdown and the reason.
148 Corresponding signal is then sent to
150 to respectively halt, reboot or bring the system down to single-user state
151 (depending on the above options).
152 The time of the shutdown and the warning message
155 and should be used to
156 inform the users about when the system will be back up
157 and why it is going down (or anything else).
159 .Bl -tag -width /var/run/nologin -compact
160 .It Pa /var/run/nologin
161 tells login not to let anyone log in
170 .Sh BACKWARD COMPATIBILITY
171 The hours and minutes in the second time format may be separated by
172 a colon (``:'') for backward compatibility.