It often happens to forget to use sudo when editing configuration files with vim. You write your modifications and when you want to save, you get the annoying error: “E45: ‘readonly’ option is set (add ! to override)”.
The following oneliner will ask for your password and save the modifications to the edited file:
After you type :w !sudo tee % you are asked to press enter to continue and O, to overwrite. You will still remain in the read only mode, you can only exit vim with :q! (don’t worry, your modifications have already been added)
$ vim /etc/passwd
[:w !sudo tee %]
- :w saves the file
- !sudo calls the sudo command
- tee redirects vim’s output
- % the current file