.\" Copyright (c) 1988, 1991 The Regents of the University of California.
.\" %sccs.include.redist.man%
.\" @(#)shutdown.8 6.8 (Berkeley) %G%
.Nd "close down the system at a given time"
.Op Ar warning-message ...
provides an automated shutdown procedure for super-users
to nicely notify users when the system is shutting down,
saving them from system administrators, hackers, and gurus, who
would otherwise not bother with such niceties.
Available friendlinesses:
arranges, in the manner of
The system is halted at the specified
does not actually halt the system, but leaves the
system multi-user with logins disabled (for all but super-user).
will bring the system down and
(indicating an immediate shutdown) or
specify a future time in one of two formats:
where the year, month, and day may be defaulted
to the current system values. The first form brings the system down in
minutes and the second at the absolute time specified.
Any other arguments comprise the warning message that is broadcast
to users currently logged into the system.
is supplied as an option, the warning message is read from the standard
At intervals, becoming more frequent as apocalypse approaches
and starting at ten hours before shutdown, warning messages are displayed
on the terminals of all users logged in. Five minutes before
shutdown, or immediately if shutdown is in less than 5 minutes,
logins are disabled by creating
warning message there. If this file exists when a user attempts to
prints its contents and exits. The file is
At shutdown time a message is written in the system log, containing the
time of shutdown, who initiated the shutdown and the reason.
to bring the system down to single-user state (depending on above
The time of the shutdown and the warning message
inform the users about when the system will be back up
and why it is going down (or anything else).
.Bl -tag -width /etc/nologin -compact
tells login not to let anyone log in
not to run fsck when rebooting
.Sh BACKWARD COMPATIBILITY
The hours and minutes in the second time format may be separated by
a colon (``:'') for backward compatibility.