Add Safely Edit The Sudoers File With Vim as a Unix TIL

README.md

@@ -10,7 +10,7 @@ pairing with smart people at Hashrocket.
 
 For a steady stream of TILs, [sign up for my newsletter](https://crafty-builder-6996.ck.page/e169c61186).
 
-_1278 TILs and counting..._
+_1279 TILs and counting..._
 
 ---
 
@@ -1276,6 +1276,7 @@ _1278 TILs and counting..._
 - [Provide A Fallback Value For Unset Parameter](unix/provide-a-fallback-value-for-unset-parameter.md)
 - [Remove A Directory Called `-p`](unix/remove-a-directory-called-dash-p.md)
 - [Repeat Yourself](unix/repeat-yourself.md)
+- [Safely Edit The Sudoers File With Vim](unix/safely-edit-the-sudoers-file-with-vim.md)
 - [Saying Yes](unix/saying-yes.md)
 - [Search Files Specific To A Language](unix/search-files-specific-to-a-language.md)
 - [Search History](unix/search-history.md)

unix/safely-edit-the-sudoers-file-with-vim.md

@@ -0,0 +1,27 @@
+# Safely Edit The Sudoers File With Vim
+
+The sudoers file is a way on Unix systems to administer various levels of
+permissions to different users. It is important to make sure you "know what
+you're doing" when editing this file. Especially so because if you mangle the
+syntax of the file, you could lock out yourself and even the root user from
+doing all kinds of things. Even from being able to update and fix this file.
+
+Fortunately, there is a command—`visudo`—that opens the sudoers file in an
+editor that will perform pre-save checks to ensure the file is valid syntax.
+
+```bash
+$ visudo
+```
+
+This command has `vi` in the name because it used to be that it would default
+to `vi` as the editor. On Ubuntu, at the very least, this has changed and the
+default is now `nano`.
+
+If you'd like to still have `visudo` open to `vi` (or `vim`), you can specify
+that with the `SUDO_EDITOR` env var.
+
+```bash
+$ SUDO_EDITOR=vim visudo
+```
+
+[source](https://manpages.ubuntu.com/manpages/impish/en/man8/visudo.8.html#environment)