A detailed explanation of Linux commands su

Su allows a user to temporarily become another user. It executes a command with a true and valid user ID, group ID, and an additional group of given user, usually an interactive shell.

Su[option] ... [USER [ARG] ...]

If user is not specified, the default is root, and if user has a password and is not a superuser, prompts for a password.

By default, SU does not change the current directory, and the home and shell are changed according to user, and user and logname are set if they are not superuser. By default, the shell is not a login shell.

Additional args can be passed to the shell as parameters;

Options:

-C COMMAND,--Command=command

Pass command to Shell

-F,--Fast

-,-L,--Login

Make Theshell a login shell

-m,-p,--preserve-environment

-sshell,--Shell=shell

Run the shell, not from user ' spasswd entry,

Exit value

125:SU itself failed to run

126: If Subshell is found but cannot be invoked

127: Subshell not found

Otherwise, it's Subshell's exit status.