79

Sometimes I start editing configuration files in /etc using Vim, but forget to use sudo to start Vim. The inevitable result then is that after finishing my edits I encounter the dreaded notice that I don't have the permission to save the file.

Mostly the edits are small enough that I just exit Vim and do the whole thing again as root. I could of course save to a location I can write to and then copy as root, but that is also somewhat annoying.

But I'm sure there is an easier way to become root or use sudo from inside Vim, without having to discard the changes. If the method would not rely on sudo being set up for the user that would be even better.

Improve this question
2

5 Answers 5

Reset to default
57

sudo cannot change the effective user of an existing process, it always creates a new process that has the elevated privileges and the original shell is unaffected. This is a fundamental of UNIX design. I most often just save the file to /tmp as a workaround. If you really want to save it directly you might try using a feature of Vim where it can pipe a file to another process. Try saving with this command:

:w !sudo dd of=%

Tested and works. Vim will then ask you to reload the file, but it's unnecessary: you can just press o to avoid reloading and losing your undo history. You can even save this to a Vim command/function or even bind it to a key for easy access, but I'll leave that as an exercise to the reader.

Improve this answer
8
  • You should wrap the % in quotes in case the filename contains a space.
    – intuited
    Apr 10, 2011 at 16:37
  • Also: this will not reset the 'modified' setting; you can do that manually with set nomodified.
    – intuited
    Apr 10, 2011 at 16:44
  • 2
    Actually, if you really want to be careful, you should do exec 'w !sudo dd of=' . shellescape(expand('%')) in case the filename contains quotes, backslashes, dollar-signs, etc.
    – intuited
    Apr 10, 2011 at 16:53
  • How is that different to the Commandlinefu -command by plaes?
    – user2362
    Apr 10, 2011 at 23:49
  • 1
    @hhh Using tee as @plaes suggests will send the entire file to your terminal screen as well as write it out to the filesystem which may not be very desirable, especially when editing a large file over a slow terminal/network connection.
    – penguin359
    Apr 11, 2011 at 0:09
41

Saving the file as root:

:w !sudo tee %
Improve this answer
0
14

Call sudoedit to edit files as root.

Think of the inconvenience when calling vim directly as a warning that you're being too casual in doing something potentially dangerous.

Improve this answer
8

You can put this in your .vimrc

cmap w!! %!sudo tee > /dev/null %

You trigger it by doing :w!! - it will push the file through sudo tee to the current filename (%).

From a now-deleted post at https://stackoverflow.com/questions/95072/what-are-your-favorite-vim-tricks; see also: https://stackoverflow.com/questions/1218390/what-is-your-most-productive-shortcut-with-vim

Improve this answer
1
  • And if you've got moreutils installed, just use !sudo sponge % instead.
    – towo
    Nov 26, 2016 at 17:59
3

This also works well:

:w !sudo sh -c "cat > %"

This is inspired by the comment of @Nathan Long in this answer.

NOTICE:

" must be used instead of ' because we want % to be expanded before passing to shell.

Improve this answer

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .