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).
After the user exits 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 via getpw-
nam(3) from the system fails, manually 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 with-
out 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
Print a help message.
-V, --version
Output version.
ENVIRONMENT VARIABLES
sulogin looks for the environment variable SUSHELL or sushell to deter-
mine 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 <ftp://ftp.kernel.org/pub/linux/utils/util-
linux/>.
util-linux Jul 2012 SULOGIN(8)