How to Switch Users Using su Command in Linux

How to Switch Users Using su Command in Linux

Hey there! 👋 Welcome to this beginner-friendly Linux tutorial from ProgramGuru.org.

In this lesson, we’ll learn how to use the su command in Linux to switch between users on your system. Whether you're managing multiple users or need to perform tasks with elevated privileges, the su command is an essential tool to know.

🔍 What is the su Command?

su stands for “substitute user” or “switch user.” It allows you to temporarily log in as another user without fully logging out or switching terminals.

By default, running su without a username will attempt to switch to the root user.

📌 Syntax

su [options] [username]

👤 Example 1: Switch to the root user

su

You’ll be prompted to enter the root password.

Password: 
# (Now you’re operating as root!)

👤 Example 2: Switch to another user

su john

Password: 
$ (Now you're logged in as user 'john')

💡 Tip: Confirm the Current User

whoami

john

🔐 What if you get an authentication error?

Make sure the target user has a password set and that you typed it correctly. The root user must also have permission to switch to that account.

⚠️ Important Security Note

• Using su gives you full control of the target user’s environment.
• Be very cautious when switching to root, as this gives you access to modify or delete critical system files.
• Always log out of the root session when done. Just type exit.

👋 Exiting the su session

exit

$ (Back to your original user)

✅ Recap

Let’s quickly review what we’ve learned:

• Use su to switch to another user.
• Use su username to switch to a specific user.
• Type exit to return to your original session.

And that’s it! 🎉 You now know how to use the su command like a pro.

Stay tuned to ProgramGuru.org for more hands-on Linux tutorials. Happy terminal-ing! 🖥️🐧