shutdown(8) - NetBSD Manual Pages

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SHUTDOWN(8)             NetBSD System Manager's Manual             SHUTDOWN(8)


NAME

     shutdown - close down the system at a given time


SYNOPSIS

     shutdown [-dfhkrn] time [message ... | -]


DESCRIPTION

     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:

     -d    shutdown will pass the -d flag to reboot(8) or halt(8).  If the
           neither the -h or -r flags are specified, then -d also implies -r.

     -f    shutdown arranges, in the manner of fastboot(8),  for the file sys-
           tems not to be checked on reboot.

     -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 sys-
           tem, but leaves the system multi-user with logins disabled (for all
           but super-user).

     -n    Prevent the normal sync(2) before stopping.

     -r    The system is rebooted at the specified time when shutdown execs
           reboot(8).

     time  Time is the time at which 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 may be defaulted to the current system values.  The
           first form brings the system down number minutes from the current
           time; the second brings the system down at the absolute time speci-
           fied.  If the century is not specified, it defaults to 1900 for
           years between 69 and 99, or 2000 for years between 0 and 68.  A
           leading zero in the ``yy'' value is not optional.

     message ...
           Any other arguments comprise the warning message that is broadcast
           to users currently logged into the system.

     -     If - is supplied as the only argument after the time, the warning
           message is read from the standard input.

     At intervals, becoming more frequent as apocalypse approaches and start-
     ing at ten hours before shutdown, warning messages are displayed on the
     terminals of all users logged in.  Five minutes before shutdown, or imme-
     diately 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 any-
     thing else).


FILES

     /etc/nologin  tells login not to let anyone log in
     /fastboot     tells rc(8) not to run fsck when rebooting


SEE ALSO

     login(1),  wall(1),  fastboot(8),  halt(8),  reboot(8)


BACKWARD COMPATIBILITY

     The hours and minutes in the second time format may be separated by a
     colon (``:'') for backward compatibility.


HISTORY

     The shutdown command appeared in 4.0BSD.

4.4BSD                         January 20, 1998                              2