The user is prompted
Input and output will be performed with the standard file descriptors unless the optional device name argument is provided.
If the user enters the correct root password, a login session is initiated. When EOF is pressed instead, the system enters multi-user mode.
After the user exits the single-user shell, or presses EOF, the system begins the initialization process required to enter multi-user mode.
This command can only be used if init has been modified to call
/etc/sulogin instead of /bin/sh,
or if the user has set the inittab to support a single user
login.
For example, the line
co:s:respawn:/etc/sulogin /dev/console
should execute the sulogin command in single user mode.
As complete an environment as possible is created. However, various devices may be unmounted or uninitialized and many of the user commands may be unavailable or nonfunctional as a result.