shutdown —
close down the system at a given time
shutdown |
[ -
]
[-dfhknpr
]
time
[warning-message
... ] |
shutdown provides an automated shutdown
procedure for superusers 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. When the
shutdown command is issued without options
the system is placed in single user mode at the indicated time after shutting
down all system services.
The options are as follows:
-
-
-d- When used with
-h,
-p, or
-r causes system to perform a dump.
This option is useful for debugging system dump procedures or capturing
the state of a corrupted or misbehaving system. See
savecore(8) for
information on how to recover this dump.
-
-
-f- Create the file /fastboot so that the
file systems will not be checked by
fsck(8) during the next boot.
(See rc(8)).
-
-
-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 superuser).
-
-
-n- When used with
-h,
-p, or
-r prevents the normal
sync(2) before stopping the
system.
-
-
-p- The system is powered down at the specified
time. The
-p flag is passed on to
halt(8), causing machines
which support automatic power down to do so after halting.
-
-
-rshutdown execs
reboot(8) at the specified
time.-
-
- time
- time is the time at which
shutdown will bring the system down and
may be the word now (indicating an
immediate shutdown) or specify a future time in one of two formats:
+number, or
yymmddhhmm, where the year, month, and
day may be defaulted to the current system values. The first form brings
the system down in number minutes and the
second at the absolute time specified.
-
-
- warning-message
- Any other arguments comprise the warning message that is broadcast to
users currently logged into the system.
-
-
-- If ‘
-’ is supplied as an
option, the warning message is read from the standard input.
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
/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. A terminate signal is
then sent to
init 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).
You can cancel a scheduled shutdown with the
kill(1) command by killing the
shutdown process.
- /etc/nologin
- tells login not to let anyone log in
- /etc/rc.shutdown
- run by rc(8) before the system
is shutdown
- /fastboot
- tells rc(8) not to run
fsck(8) during the next
boot
kill(1),
login(1),
wall(1),
halt(8),
rc.shutdown(8),
reboot(8)
The hours and minutes in the second time format may be separated by a colon
(‘:’) for backward compatibility.
The
shutdown command appeared in
4.0BSD.
![[OpenBSD]](/openbsd.gif){kind=small}