SHUTDOWN(ADM) UNIX System V
Name
shutdown - terminates all processing
Syntax
/etc/shutdown [ -y ] [ -g[hh:]mm ] [ -i[0156sS] ] [ -f"mesg"
] [ -fFILE ] [ su ]
Description
The primary function of shutdown is to terminate all
currently running processes in an orderly and cautious
manner. shutdown goes through the following steps:
1. All users logged on the system are notified to log off
the system by a broadcasted message.
2. /etc/init is called to perform the the actual shutdown.
Only the super-user can execute the shutdown command.
The options are as follows:
-y Runs the command silently. If this option is
not specified, shutdown will prompt for
confirmation to shut down the system.
-g[hh:]mm Specifies the number of hours and minutes
before shutdown (maximum: 72 hours). 60
seconds is the default. (To shut down the
system immediately without a grace period,
use /etc/haltsys or /etc/reboot).
-i[0156sS]Specifies the init level to bring the system
to (see init(M)). By default, the system is
brought to level 0.
-fmesg mesg is a message enclosed in double quotes
("") to be sent to all terminals warning of
the imminent shutdown during the grace
period.
-fFILE Similar to the -fmesg option, but FILE is the
pathname for a file containing the message.
The optional su argument lets the user go single-user,
without completely shutting down the system (this option is
identical to -i1 and is present for backwards compatibility
with XENIX). Broadcast messages, whether default or
defined, are displayed at regular intervals during the grace
period. The closer the shutdown time, the more frequent the
message:
_________________________________________________
| Time left until shutdown Frequency of message|
|________________________________________________|
| Greater than 1 hour Every hour |
| Greater than 15 minutes Every 15 minutes |
| Less than 15 minutes Every minute |
|________________________________________________|
In general, if no options are specified, shutdown behaves as
follows:
1. Prompt for confirmation
2. 60-second grace period
3. Bring the system to init level 0
4. Broadcast default message prior to shutdown.
See Also
wall(ADM), boot(HW)
Diagnostics
The most common error diagnostic that will occur is device
busy. This diagnostic appears when a particular file system
could not be unmounted. See umount(ADM).
Notes
Once shutdown has been invoked, it must be allowed to run to
completion and must not be interrupted by pressing BREAK or
DEL.
shutdown does not work when executed from within a shell
layer.
shutdown locks the hard disk heads.
shutdown was developed at the University of California,
Berkeley, and is used with permission.
(printed 4/27/90) SHUTDOWN(ADM)