When to Use su vs sudo: Choosing the Right Linux Privilege Command

1. su command

The su (switch user) command changes the current user identity to another user, typically requiring the root password. After entering the password, the user gains the target account's privileges. Example: su After providing the password, the session runs as the root user.

2. sudo command

The sudo (superuser do) command runs a specific command with root privileges while authenticating with the invoking user's own password. It does not require knowing the root password. Example: sudo apt-get update After entering the password, the user can execute the privileged operation.

3. Comparison

3.1 User identity

su requires the root password and switches the entire session to another user. sudo allows a regular user to perform privileged actions using their own password.

3.2 Permission scope

su grants all permissions of the target user. sudo can be limited via the sudoers file to specific commands or users.

3.3 Security

Because su shares the root password, it poses a security risk. sudo avoids sharing the root password, improving security.

3.4 Logging

sudo records each privileged command and the invoking user, aiding audit trails. su has no built‑in logging.

3.5 Usage

Use su by typing the command and the target user's password. Use sudo by prefixing the desired command with sudo and entering your own password.

4. Suitable scenarios

Use su when you need to work for an extended period as another user.

Use sudo for occasional privileged tasks such as installing software or system updates.

5. Conclusion

Both su and sudo are common Linux commands for changing user identity and executing privileged operations. su requires the root password, while sudo lets regular users perform specific privileged actions with their own password, offering better security and auditability. Choose the command based on your needs and security considerations.