Vim: Save a read-only file

Today, after a good while editing the Apache configuration file (/etc/httpd/httpd.conf), I realized I was logged in as a normal user and could not save the file (E212: Can't open file for writing).

A common workaround is to save a copy into some directory and then replace the original file with the copy using sudo mv. But I knew there was a simpler way, since this has happened several times before.

I had forgotten the command, but I managed to find it and I am writing it down here for future reference.

Just call sudo tee straight from vim: :w !sudo tee %

Vim will warn you (W12) that the file has been modified and must be reloaded. Press L to reload.

Why does it work?

From vim’s :help file and man tee, we have:

• :w[rite] {file} ⇒ Writes the whole buffer to {file}.
• !{cmd} ⇒ Runs {cmd} with the shell.
• tee [FILE] ⇒ Reads from standard input and writes to FILE (or stdout).
• % ⇒ A reference to the current file

In other words, we pipe the buffer into the input of sudo tee %, which writes that buffer to the current file, but as the super user.

Some alternatives I found on commandlinefu:

• :%!sudo tee %
• :w !sudo tee > /dev/null %
• command W :execute ':silent w !sudo tee % > /dev/null' | :edit!
• :w !pfexec tee %

Neovim

(Section added in March 2024)

The tip above does not work in Neovim (see https://github.com/neovim/neovim/issues/1716).

Fortunately there are plugins that solve this problem. I use Suda: https://github.com/lambdalisue/suda.vim.

It adds the commands :SudaWrite and :SudaRead for writing and reading files that need elevated permissions.

Links

• http://www.commandlinefu.com/commands/view/1204/save-a-file-you-edited-in-vim-without-the-needed-permissions
• https://github.com/neovim/neovim/issues/1716