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
nor
-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.-
-
is supplied as the only argument after the
time, the warning message is read from the standard input.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.
:
’) for backward compatibility.
shutdown
command was originally written by Ian
Johnstone for UNSW's modified Version 6 AT&T
UNIX, modified, and then incorporated in
4.1BSD.
February 14, 2023 | NetBSD 10.99 |