Working with Sudo and Su Commands in Ubuntu Linux
The sudo and su commands in Ubuntu Linux let you run tasks with administrator rights or switch your entire terminal session to another user. Ubuntu 8.04 LTS and later versions rely heavily on sudo to keep your system safe by granting temporary power for just one task at a time.
Running the sudo command gives you single-command access to install software or change settings without putting your whole system at risk. Typing su switches your identity entirely until you type exit, which can break things if you make a mistake.
Sudo executes a single command as another user, typically root, while su switches your entire session to that user. Use sudo command for specific elevated tasks, and su – to log in as root for an extended session.
Sudo
Ubuntu’s `sudo` command grants administrator powers, letting you run commands that typically require root access without logging out. This control over who can use `sudo` and for what purpose makes system management safer. Effectively, `sudo` lets you wield root power for specific tasks. Rules for user privileges live in the `/etc/sudoers` file, which controls how `sudo` behaves.
The `sudo` command includes safeguards against accidental mistakes. It prompts for confirmation before executing actions, encouraging you to think twice.
sudo apt update
su
The `su` command in Ubuntu lets you switch to another user account, like the main administrator (root). To switch accounts, you need the password for the account you want to use. For example, typing `su -` lets you become the root user for a little while, giving you temporary admin control.
The su command lets you switch to other accounts on the system, but you’ll need to know the account password you’re switching to.
Example:
su -
Another example:
If you want to switch to a user on the system called john, you run the commands below:
Running `su -` switches to another user's account, such as John's, and loads that user's environment settings and home directory path. This command has the same effect as logging into the system directly as the user you're switching to.
su - john
Hopefully, this clarifies the differences between these two commands. Remember, `sudo` lets you run commands as another user without changing your own identity. `su`, on the other hand, allows you to switch to a user and adopt their identity.
Conclusion:
We've covered the main differences between sudo and su. If you spot any errors, please let us know using the form below.
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About the Author
Richard
Tech Writer, IT Professional
Richard, a writer for Geek Rewind, is a tech enthusiast who loves breaking down complex IT topics into simple, easy-to-understand ideas. With years of hands-on experience in system administration and enterprise IT operations, he’s developed a knack for offering practical tips and solutions. Richard aims to make technology more accessible and actionable. He's deeply committed to the Geek Rewind community, always ready to answer questions and engage in discussions.
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