sulogin

SULOGIN(8)                    System Administration                   SULOGIN(8)



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
       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.

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

REPORTING BUGS
       For bug reports, use the issue tracker at
       https://github.com/karelzak/util-linux/issues.

AVAILABILITY
       The sulogin command is part of the util-linux package which can be
       downloaded from Linux Kernel Archive
       <https://www.kernel.org/pub/linux/utils/util-linux/>.



util-linux 2.37.2                  2021-06-02                         SULOGIN(8)