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
secondsSpecify 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
Copyright (C) 1998-2006 Miquel van Smoorenburg. Copyright (C) 2012 Karel Zak <kzakredhat.com> This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |