How to Switch User in Linux: Simple Commands Explained

To switch user in Linux, use the su command followed by the username, or use sudo -i -u username for switching with elevated privileges. These commands let you operate as another user without logging out.

Syntax

The basic syntax to switch user in Linux is:

• su [username] - Switches to the specified user account.
• sudo -i -u [username] - Switches to the specified user with root privileges if allowed.

If no username is given, su switches to the root user by default.

bash

su [username]
sudo -i -u [username]

Example

This example shows switching from the current user to user alice using su and then back to the original user.

bash

su alice
whoami
exit
whoami

Output

alice
originaluser

Common Pitfalls

Common mistakes when switching users include:

• Not having the target user's password when using su.
• Trying su without root privileges or sudo rights.
• Confusing su and sudo usage.

Remember, su requires the target user's password, while sudo uses your own password if you have permission.

bash

Wrong:
su alice
# Fails if you don't know alice's password

Right:
sudo -i -u alice
# Uses your password if you have sudo rights

Quick Reference

Command	Description
su	Switch to root user or specified user with their password
su - username	Switch to specified user with login environment
sudo -i -u username	Switch to specified user using sudo privileges
exit	Return to previous user session

Key Takeaways

Use su username to switch user by entering their password.

Use sudo -i -u username to switch user with your sudo rights.

su switches user environment; sudo runs commands with elevated rights.

Always use exit to return to your original user session.

Not knowing the target user's password will block su but not sudo if permitted.