4.3BSD - /usr/man/cat8/shutdown.0

SHUTDOWN(8)                                                        SHUTDOWN(8)


NAME
       shutdown - close down the system at a given time

SYNOPSIS
       /etc/shutdown [ -k ] [ -r ] [ -h ] [ -f ] [ -n ] time [ warning-message
       ... ]

DESCRIPTION
       Shutdown provides an automated shutdown procedure  which  a  super-user
       can use to notify users nicely when the system is shutting down, saving
       them from system administrators, hackers, and gurus, who  would  other‐
       wise not bother with niceties.

       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 and hour:min.  The first form
       brings the system down in number minutes and the second brings the sys‐
       tem down at the time of day indicated (as a 24-hour clock).

       At  intervals which get closer together as apocalypse approaches, warn‐
       ing messages are displayed at the terminals of all users on the system.
       Five  minutes  before  shutdown,  or immediately if shutdown is in less
       than 5 minutes, logins are disabled by creating /etc/nologin and  writ‐
       ing  a  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 ran shutdown and the reason.   Then  a  terminate
       signal  is  sent to init to bring the system down to single-user state.
       Alternatively, if -r, -h, or -k  was  used,  then  shutdown  will  exec
       reboot(8),  halt(8),  or avoid shutting the system down (respectively).
       (If it isn’t obvious, -k is to make people think the  system  is  going
       down!)

       With  the  -f  option, shutdown arranges, in the manner of fastboot(8),
       that when the system is rebooted the file systems will not be  checked.
       The -n option prevents the normal sync(2) before stopping.

       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 sys‐
       tem will be back up and why it is going down (or anything else).

FILES
       /etc/nologin   tells login not to let anyone log in

SEE ALSO
       login(1), reboot(8), fastboot(8)

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


4th Berkeley Distribution        May 26, 1986                      SHUTDOWN(8)