SULOGIN(8)     Linux System Administrator's Manual     SULOGIN(8)

NAME
       sulogin -- Single-user login

SYNOPSIS
       sulogin [ -t timeout ] [ tty-device ]

DESCRIPTION
       sulogin  is  invoked  by init(8) when the system goes into
       single user mode (this is done through an entry  in  init-
       tab(5)).  Init  also  tries  to execute sulogin when it is
       passed the -b flag from the bootmonitor (eg, LILO).

       The user is prompted

            Give root password for system maintenance
            (or type Control-D for normal startup):

       sulogin will connected to the current terminal, or to  the
       optional  device that can be specified on the command line
       (typically /dev/console).

       After the user exits the  single-user  shell,  or  presses
       control-d  at  the  prompt,  the system will (continue to)
       boot to the default runlevel.

ENVIRONMENT VARIABLES
       sulogin looks for  the  environment  variable  SUSHELL  or
       sushell  to determine what shell to start. If the environ-
       ment variable is not set, it will try  to  execute  root's
       shell from /etc/passwd. If that fails it will fall back to
       /bin/sh.

       This is very valuable together with the -b flag  to  init.
       To  boot  the  system  into singe user mode, with the root
       file system mounted read/write, using a special "failsafe"
       shell that is statically linked (this example is valid for
       the LILO bootprompt)

       boot: linux -b rw sushell=/sbin/sash

FILES
       sulogin examines the next files to find the root password.
       If they are damaged, or non-existant, it will use fallback
       methods that even go so far as to provide you with a shell
       prompt  without  asking  for the root password if they are
       irrepairably damaged.

       /etc/passwd,
       /etc/shadow (if present)

AUTHOR
       Miquel van Smoorenburg <miquels@cistron.nl>

SEE ALSO
       init(8), inittab(5).

                           15 May 1996                          1