(BSD System Compatibility)

shutdown(1Mbsd)

shutdown -- (BSD) close down the system at a given time

Synopsis

   /usr/ucb/shutdown [-fhknr] time [warning-message . . . ]

Description

shutdown provides an automated procedure to notify users when the system is to be shut down. time specifies when shutdown will bring the system down; it may be the word now (indicating an immediate shutdown), or it may specify a future time in one of two formats: +number and hour:min. The first form brings the system down in number minutes, and the second brings the system down at the time of day indicated in 24-hour notation.

At intervals that get closer as the apocalypse approaches, warning messages are displayed at terminals of all logged-in users, and of users who have remote mounts on that machine.

At shutdown time a message is written to the system log daemon, syslogd(1M), containing the time of shutdown, the instigator of the shutdown, and the reason. Then a terminate signal is sent to init, which brings the system down to init state 1.

Command options

As an alternative to the above procedure, these options can be specified:

-f: Arrange, in the manner of fastboot(1Mbsd), that when the system is rebooted, the file systems will not be checked.
-h: Execute halt(1Mbsd).
-k: Simulate shutdown of the system. Do not actually shut down the system.
-n: Prevent the normal sync(2) before stopping.
-r: Execute reboot(1Mbsd).

Files

/etc/xtab: list of remote hosts that have mounted this host

References

fastboot(1Mbsd), halt(1Mbsd), reboot(1Mbsd), sync(2), syslogd(1M)

Notices

Only allows you to bring the system down between now and 23:59 if you use the absolute time for shutdown.