---
name: "sulogin"
section: "8"
platform: "linux"
package: "util-linux"
version: "2.42.4-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/sulogin"
---

# sulogin(8)

single-user login

## 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)](/getpwnam/3.md) 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

**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.

## REPORTING BUGS

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

## 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/\>.