bash.softwareshinobi.com/docs/Linux-Commands/System/044-the-su-command.md

The su command

In linux, su allows you to run commands with a substitute user and group ID.

When called without arguments, su defaults to running an interactive shell as root.

Example :

$ su

In case that you wanted to switch to a user called devdojo, you could do that by running the following command:

$ su devdojo

The syntax of the su command is :

$ su [options] [-] [<user>[<argument>...]]

Options :

-m, -p         --> do not reset environment variables
-w             --> do not reset specified variables
-g             --> specify the primary group
-G             --> specify a supplemental group
-l             --> make the shell a login shell
-f             --> pass -f to the shell (for csh or tcsh)
-s             --> run <shell> if /etc/shell allows it 
-p             --> create a new pseudo terminal
-h             --> display this help
-v             --> display version