rc0(1M)                                                             rc0(1M)

NAME
     rc0 - run commands performed to stop the operating system

SYNOPSIS
     /sbin/rc0

DESCRIPTION
     This file is executed at each system state change that needs to have
     the system in an inactive state. It is responsible for those actions
     that bring the system to a quiescent state, traditionally called
     "shutdown".

     There are two system states that require this procedure. They are
     state 0 (power off), state 5 (the SASH state), and state 6 (the reboot
     state). Whenever a change to one of these states occurs, the rc0 pro-
     cedure is run. The entry in /etc/inittab might read:

          s0:056:wait:/sbin/rc0 >/dev/console 2>&1 </dev/console

     Some of the actions performed by rc0 are carried out by files in the
     directory /etc/shutdown.d. and files beginning with K in /etc/rc0.d.
     These files are executed in ASCII order (see FILES below for more
     information), terminating some system service. The combination of com-
     mands in rc0 and files in /etc/shutdown.d and /etc/rc0.d determines
     how the system is shut down.

     The recommended sequence for rc0 is:

     -  Stop System Services and Daemons. Various system services (such as
        a Local Area Network or LP Spooler) are gracefully terminated.

        When new services are added that should be terminated when the sys-
        tem is shut down, the appropriate files are installed in
        /etc/shutdown.d and /etc/rc0.d.

     -  Terminate Processes SIGTERM signals are sent to all running
        processes by killall(1M). Processes stop themselves cleanly if sent
        SIGTERM.

     -  Kill Processes SIGKILL signals are sent to all remaining processes;
        no process can resist SIGKILL.

        At this point the only processes left are those associated with rc0
        and processes 0 and 1, which are special to the operating system.

     -  Unmount All File Systems Only /root, proc, /stand, and /dev/fdfs
        remain mounted.

     Depending on which system state the systems end up in (0, 5, or 6),
     the entries in /etc/inittab will direct what happens next. If the
     /etc/inittab has not defined any other actions to be performed as in
     the case of system state 0, then the operating system will have



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rc0(1M)                                                             rc0(1M)

     nothing to do. It should not be possible to get the system's atten-
     tion. The command can be used only by the superuser.

FILES
     The execution by /usr/bin/sh of any files in /etc/shutdown.d occurs in
     ASCII sort-sequence order. See rc2(1M) for more information.

SEE ALSO
     killall(1M), rc2(1M), shutdown(1M).













































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