Changing Identity

The su command (Switch User) allows you to switch user accounts within the current terminal session. Unlike sudo, which runs a single command as root, su changes your entire shell session.

Switching to a Normal User

If you are root, you can switch to any other user without needing a password:

bash $ su jdoe

Switching to the Root User

To become the root user, use su without a username argument. This requires the root user's password.

bash $ su Password:

You are now the root user (# prompt)

The Recommended Switch (su -)

Using the hyphen (-) option performs a full login, meaning it loads the target user's environment variables, shell settings, and changes the working directory to their home directory. This is essential for administrative work.

bash $ su - jdoe

Full login as jdoe

To exit the switched session and return to your original user, type exit.