man(1) Manual page archive

     INIT(8)                                                   INIT(8)

          init, rc  -  process control initialization


          Init is invoked as the last step of the boot procedure (see
          boot(8)). Generally its role is to create a process for each
          typewriter on which a user may log in.

          When init first is executed the console typewriter
          /dev/console. is opened for reading and writing and the
          shell is invoked immediately.  This feature is used to bring
          up a single-user system.  If the shell terminates, init
          comes up multi-user and the process described below is

          When init comes up multiuser, it invokes a shell, with input
          taken from the file /etc/rc. This command file performs
          housekeeping like removing temporary files, mounting file
          systems, and starting daemons.

          Then init reads the file /etc/ttys and forks several times
          to create a process for each typewriter specified in the
          file.  Each of these processes opens the appropriate type-
          writer for reading and writing.  These channels thus receive
          file descriptors 0, 1 and 2, the standard input, output and
          error files.  Opening the typewriter will usually involve a
          delay, since the open is not completed until someone is
          dialed up and carrier established on the channel.  Then
          /etc/getty is called with argument as specified by the last
          character of the ttys file line.  Getty reads the user's
          name and invokes login(1) to log in the user and execute the

          Ultimately the shell will terminate because of an end-of-
          file either typed explicitly or generated as a result of
          hanging up.  The main path of init, which has been waiting
          for such an event, wakes up and removes the appropriate
          entry from the file utmp, which records current users, and
          makes an entry in /usr/adm/wtmp, which maintains a history
          of logins and logouts.  Then the appropriate typewriter is
          reopened and getty is reinvoked.

          Init catches the hangup signal SIGHUP and interprets it to
          mean that the system should be brought from multi user to
          single user.  Use `kill -1 1' to send the hangup signal.

     INIT(8)                                                   INIT(8)

          /dev/tty?, /etc/utmp, /usr/adm/wtmp, /etc/ttys, /etc/rc

          login(1), kill(1), sh(1), ttys(5), getty(8)