SHUTDOWN(8) | System Manager's Manual | SHUTDOWN(8) |
shutdown
—
shutdown |
[-Ddfhknprvxz ] [-b
bootstr] time
[message ... | -] |
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-d
shutdown
will pass the -d
flag to reboot(8) or
halt(8) to request a kernel
core dump. If neither 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
-k
-k
option does not
actually halt the system, but leaves the system multi-user with logins
disabled (for all but super-user).-n
-p
-r
-v
-v
to reboot(8) or
halt(8).-x
-x
to
reboot(8) or
halt(8).-z
-z
to
reboot(8) or
halt(8).-D
shutdown
from detaching from the tty with
fork(2)/
exit(3).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 are two digit decimal values, which may be defaulted
to the current system values. The two digit (decimal, even with a leading
zero) minute field is required in this form. The first form brings the
system down number minutes from the current time;
the second brings the system down at the absolute time specified. If the
century is not specified, but the year is, the century defaults to 2000
(cc==20, the 21st century) for years between 20 and 99, or 2100 for years
between 0 and 19. A leading zero in the “yy” value (as with
all the others) is not optional.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 message 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, shutdown
runs
halt(8) or
reboot(8), or sends a
terminate signal to init(8) to
bring the system down to single-user mode, depending on the choice of
options.
The time of the shutdown and the warning message are placed in /etc/nologin and should be used to tell the users why the system is going down, when it will be back up, and to share any other pertinent information.
shutdown
command was originally written by Ian
Johnstone for UNSW's modified Version 6 AT&T
UNIX, modified, and then incorporated in
4.1BSD.
July 1, 2022 | NetBSD 10.1 |