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.
Only use the -e option if you are sure the console is physically protected against unauthorized access.
-t, --timeout seconds
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.
For bug reports, use the issue tracker at https://github.com/util-linux/util-linux/issues.
The sulogin command is part of the util-linux package which can be downloaded from Linux Kernel Archive https://www.kernel.org/pub/linux/utils/util-linux/.