SULOGIN(8) System Administration SULOGIN(8)

# [NAME](#NAME)

sulogin - single-user login

# [SYNOPSIS](#SYNOPSIS)

**sulogin** \[options] \[*tty*]

# [DESCRIPTION](#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](#OPTIONS)

**-e**, **--force**

If the default method of obtaining the root password from the system via [**getpwnam**(3)](/man/os/util-linux/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 and exit.

# [ENVIRONMENT](#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](#AUTHORS)

**sulogin** was written by Miquel van Smoorenburg for sysvinit and later ported to util-linux by Dave Reisner and Karel Zak.

# [REPORTING BUGS](#REPORTING_BUGS)

For bug reports, use the *issue tracker* <https://github.com/util-linux/util-linux/issues>.

# [AVAILABILITY](#AVAILABILITY)

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/>.

2026-09-25 util-linux 2.42.4

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Document: sulogin(8) from util-linux 2.42.4-r0 (Chainguard OS)