RC0(1M)                                                   RC0(1M)



     NAME
          rc0 - run commands performed to stop the operating system

     SYNOPSIS
          /etc/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 three system states that require this procedure.
          They are state 0 (the system halt state), state 5 (the
          firmware state), and state 6 (the reboot state).  Whenever a
          change to one of these states occurs, the /etc/rc0 procedure
          is run.  The entry in /etc/inittab might read:

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

          Some of the actions performed by /etc/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 commands in
          /etc/rc0 and files in /etc/shutdown.d and /etc/rc0.d
          determines how the system is shut down.

          The recommended sequence for /etc/rc0 is:

          Stop System Services and Daemons.

               Various system services (such as 3BNET Local Area
               Network or LP Spooler) are gracefully terminated.

               When new services are added that should be terminated
               when the system 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 /etc/rc0 and processes 0 and 1, which



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     RC0(1M)                                                   RC0(1M)



               are special to the operating system.

          Unmount All File Systems

               Only the root file system (/) remains 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 nothing to do.  It should not be
          possible to get the system's attention.  The only thing that
          can be done is to turn off the power or possibly get the
          attention of a firmware monitor.  The command can be used
          only by the super-user.

     FILES
          The execution by /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).

     ORIGIN
          AT&T V.3





























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