NAME

       sulogin - single-user login

SYNOPSIS

       sulogin [options] [tty]

DESCRIPTION

       sulogin is invoked by init when the system goes into single-user mode.

       The user is prompted:

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

       If the root account is locked and --force is specified, no password is required.

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

       When  the  user  exits  from  the  single-user shell, or presses control-D at the prompt, the system will
       continue to boot.

OPTIONS

       -e, --force
              If the default method of obtaining the root password from the system via getpwnam(3)  fails,  then
              examine  /etc/passwd  and  /etc/shadow  to  get  the  password.   If  these  files  are damaged or
              nonexistent, or when root account is locked by '!' or '*'  at  the  begin  of  the  password  then
              sulogin will start a root shell without asking for a password.

              Only  use  the  -e option if you are sure the console is physically protected against unauthorized
              access.

       -p, --login-shell
              Specifying this option causes sulogin to start the shell process as a login shell.

       -t, --timeout seconds
              Specify the maximum amount of time to wait for user input.  By default, sulogin will wait forever.

       -h, --help
              Display help text and exit.

       -V, --version
              Display version information and exit.

ENVIRONMENT VARIABLES

       sulogin looks for the environment variable SUSHELL or sushell to determine what shell to start.   If  the
       environment 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.

AUTHOR

       sulogin was written by Miquel van Smoorenburg for sysvinit and later ported to util-linux by Dave Reisner
       and Karel Zak.

AVAILABILITY

       The sulogin command is part of the util-linux package and is available from Linux Kernel Archive.

util-linux                                          July 2014                                         SULOGIN(8)