Vim: Save read only

Today, after a long time editing the Apache configuration file (/etc/httpd/httpd.conf), I realized that I was logged in as a normal user and couldn’t save the file (E212: Can't open file for writing).

A common solution is to save a copy in any directory and then replace the original file with the copy using sudo mv. But I knew there was a simpler way because this had happened several times in the past.

I had forgotten the command, but I managed to find it and I will leave it documented here for future reference.

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

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

Why does it work?

From the :help file of vim and man tee, we have:

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

In other words, we send the buffer as if it were a pipe to the input of sudo tee %, which writes this buffer to the current file, but as a superuser.

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

(Session added in March 2024)

The previous tip 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 to write and read files that require 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