SULOGIN(8) System Administration SULOGIN(8)NAMEsulogin - Single-user login
SYNOPSISsulogin [options] [tty]
DESCRIPTIONsulogin 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):
sulogin will be connected to the current terminal, or to the optional
tty device that can be specified on the command line (typically
After the user exits the single-user shell or presses control-D at the
prompt, the system will continue to boot.
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 they are damaged or nonex‐
istent, sulogin will start a root shell without asking for a
Only use the -e option if you are sure the console is physically
protected against unauthorized access.
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.
Display help text and exit.
Display version information and exit.
ENVIRONMENT VARIABLESsulogin 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.
AUTHORsulogin 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 ⟨ftp://ftp.kernel.org/pub/linux/utils/util-
util-linux Jul 2012 SULOGIN(8)