shutdown - graciously close the system down
shutdown [-hrRmk] [-x code] [time-specification [message]]
Shutdown is a program which allows a system operator to close down the
system in an nice way. Shutdown informs the users why and when the system
is going down. This warning is issued 10 minutes before shutdown time
and every minute in the last 5 minutes. At this time (5 minutes),
shutdown creates a file /etc/nologin to prevent new users from logging
Shutdown keeps a logfile of shutdowns. Every shutdown is registered in
/usr/adm/wtmp, if this file exists, and by syslog(3) (level auth.notice).
After these actions, a call is done to reboot(2) which actually brings
the system down.
Time-specification may be something like 15:00, 15.00, +15, or now for a
shutdown at 3pm (twice), 15 minutes from now, or immediately.
The message may be used to describe why the system is going down, it may
also be typed on standard input with the -m option.
-h This flag prevents the system from rebooting after the shutdown.
The system can now be powered off. This is the default.
-r This flag indicates that the system should reboot after shutting
-R Reboot the system by resetting it. Normally the kernel will try to
return to the Boot Monitor. With -R the system will receive a
Halt the system and let the Monitor execute the given code as if
typed at the monitor prompt. You can for instance use -x 'boot hd0'
as a very fast way to reboot "from the top."
-m Allows the operator to type a shutdown message on standard input,
that will be added to the messages displayed on all terminals.
-k This option gives the possibility of terminating an already started
shutdown. This is only possible if shutdown time has not yet
-C Check if the system crashed. This option is not used at shutdown
time, but at reboot time. It tells if the file systems should be
checked by testing if the last entry in the wtmp file is a shutdown
entry. (A crude replacement for a file system clean flag.)
reboot(2), syslog(3), halt(8), boot(8).
Edvard Tuinder (firstname.lastname@example.org.NL)