SULOGIN
Section: System Administration (8)
Updated: July 2014
Page Index
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.
AVAILABILITY
The sulogin command is part of the util-linux package and is available from
Linux Kernel Archive