shutdown(8)
- NetBSD Manual Pages
SHUTDOWN(8) NetBSD System Manager's Manual SHUTDOWN(8)
NAME
shutdown -- close down the system at a given time
SYNOPSIS
shutdown [-b bootstr] [-Ddfhknpr] time [message ... | -]
DESCRIPTION
shutdown 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:
-b bootstr
The given bootstr is passed to reboot(8) for the benefit of
those systems that can pass boot arguments to the firmware.
Currently, this only affects sun3 and sparc machines.
-d shutdown will pass the -d flag to reboot(8) or halt(8). If nei-
ther the -h or -r flags are specified, then -d also implies -r.
-f shutdown arranges, in the manner of fastboot(8), for the file
systems not to be checked on reboot.
-h The system is halted at the specified time when shutdown execs
halt(8).
-k Kick everybody off. The -k option does not actually halt the
system, but leaves the system multi-user with logins disabled
(for all but super-user).
-n Prevent the normal sync(2) before stopping.
-p The system is powered down at the specified time when shutdown
execs halt(8). If the powerdown fails, or the system does not
support software powerdown, the system will simply halt.
-r The system is rebooted at the specified time when shutdown execs
reboot(8).
-D Prevents shutdown from detaching from the tty with fork(2)/
exit(3).
time Time is the time at which shutdown will bring the system down
and may be the word now or a future time in one of two formats:
+number, or [[[[[cc]yy]mm]dd]hh]mm, where the century, year,
month, day, and hour may be defaulted to the current system val-
ues. The first form brings the system down number minutes from
the current time; the second brings the system down at the abso-
lute time specified. If the century is not specified, it
defaults to 1900 for years between 69 and 99, or 2000 for years
between 0 and 68. A leading zero in the ``yy'' value is not
optional.
message ...
Any other arguments comprise the warning message that is broad-
cast to users currently logged into the system.
- If - is supplied as the only argument after the time, the warn-
ing message is read from the standard input.
At intervals, becoming more frequent as apocalypse approaches and start-
ing at ten hours before shutdown, warning messages are displayed on the
terminals of all users logged in. Five minutes before shutdown, or imme-
diately if shutdown is in less than 5 minutes, logins are disabled by
creating /etc/nologin and copying the warning message there. If this
file exists when a user attempts to log in, login(1) prints its contents
and exits. The file is removed just before shutdown exits.
At shutdown time a message is written in the system log, containing the
time of shutdown, who initiated the shutdown and the reason. Next a mes-
sage is printed announcing the start of the system shutdown hooks. Then
the shutdown hooks in /etc/rc.shutdown are run. And a message is printed
indicating that they have completed. After a short delay a terminate
signal is then sent to init(8) to bring the system down to single-user
state (depending on above options). The time of the shutdown and the
warning message are placed in /etc/nologin and should be used to inform
the users about when the system will be back up and why it is going down
(or anything else).
FILES
/etc/nologin tells login(1) not to let anyone log in
/fastboot tells rc(8) not to run fsck when rebooting
/etc/rc.shutdown System shutdown commands
SEE ALSO
login(1), wall(1), fastboot(8), halt(8), reboot(8)
BACKWARD COMPATIBILITY
The hours and minutes in the second time format may be separated by a
colon (``:'') for backward compatibility.
HISTORY
The shutdown command appeared in 4.0BSD.
NetBSD 4.0 October 18, 2002 NetBSD 4.0
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