Provided by: util-linux_2.31.1-0.4ubuntu3.7_amd64 bug


       sulogin - single-user login


       sulogin [options] [tty]


       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.


       -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.


       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.


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


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