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What is the purpose of visudo?
Visudo locks the sudoers file against multiple simultaneous edits, provides basic sanity checks, and checks for parse errors. If the sudoers file is currently being edited by someone else, or by you in another session, you will receive a message to try again later.
How do you use visudo?
visudo command uses vi as the editor here some tips to use it:
- Switch to root, (su root), then run visudo, (as above).
- Find where it says “root ALL=(ALL) ALL”.
- Type “o” to insert a new line below it.
- Now type what you want to insert, eg “username ALL=(ALL) ALL”.
- Hit esc to exit insert-mode.
- Type “:x” to save and exit.
Why do we use visudo instead of directly editing the ETC sudoers file?
You use visudo mostly to prevent from breaking your system. Visudo runs checks on your changes to make sure you didn’t mess anything up. If you did mess something up, you could completely wreck your ability to fix it or do anything requiring privileges without rebooting into a rescue mode.
Why do we need to use visudo instead of directly modifying the?
If you use a plain editor, mess up the syntax, and save… sudo will (probably) stop working, and, since /etc/sudoers is only modifiable by root, you’re stuck (unless you have another way of gaining root). Additionally it ensures that the edits will be one atomic operation.
Why does visudo not work with sudo command?
As noticed by @EliahKagan (thanks!) in the comment, this will not work for visudo: since you are supposed to call it using sudo, when you do the sudo command will sanitize (read: delete) most environment variables before rising privileges — and it’s a good thing it does.
How to change the default editor in visudo?
Note: this will only work if the file being edited contains the Defaults editor=/path/to/editor line or includes a file that contains it. For example: visudo -f /etc/sudoers.d/my_sudoers_extension will default to Nano.
What should I do if I find an error in visudo?
Upon finding an error, visudo prints a message stating the line number (s) where the error occurred and the user will receive the “What now?” prompt. At the prompt, type e to re-edit the sudoers file, x to exit without saving the changes, or Q to quit and save changes.