Write file with sudo in vim

Sometimes a file owned by root is opened in vim by a non-root user. If the user tries to :w the changes, vim will refuse. One way around this is to use the write command in a special way:

:w !sudo tee >/dev/null %

Explanation:

• :w - the write command. When called with :w !cmd, cmd is executed with the contents of the current file passed to stdin. In this case, write is not acually writing the file, it's passing it to tee which does the actual writing
• !sudo tee - execute the tee command with sudo
  • tee outputs stdin to stdout and writes it to the file given as an argument
• >/dev/null - don't show the stdout output of tee
• % - vim expands this to the current file name or relative path. This is the filename argument to the tee command

A nice helper function mapped to the command :W!:

" save files using sudo with :W!
function! WriteSudo(bang)
  if a:bang != 1
    echo "Use :W! to save with sudo"
    return
  endif
  silent write !sudo tee >/dev/null %
  silent edit!
  redraw!
  echo @% . " written with sudo"
endfunction
command -bang W :execute "call WriteSudo(<bang>0)"

Why this is better than all the other proposed ways:

• Some people recommend using cmap (in some capacity) but this is frustrating as it adds delay when typing :w, replaces the text in the : line while typing, then visually prints the expanded command to be run.

• If the user tries to use :W without the bang, it tells the user to run :W! instead. This forces the user to think about it and avoids mistyping :W instead of :w

• The file is automatically reloaded from disk (avoiding "File has been changed outside vim" errors)

• The file/path is outputted to vim and the user is informed that the file was written with sudo. No other proposed method does this (to my knowledge)

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