Print message if file is not written on :update

Question

When I do :update, I'd like to print a message if the buffer was not written (because it wasn't changed).

I get a message upon save, but would like a message if save didn't occur, also.

Answer 1

Here is an improved version to support as many of write/update features as possible. Even if it'd be of a lesser use for this case, it's a good habit to be more precise while creating new commands.

Also try never define a mapping as a prefix of another one (<leader>w vs. <leader>wq), as this may lead to surprising delays.

command! -bar -bang -range=% -nargs=* -complete=file Update
    \   if &modified
    \ |     execute printf('%s %d,%dwrite%s %s', <q-mods>, <line1>, <line2>,
    \           <q-bang>, <q-args>)
    \ | else
    \ |     echo 'Buffer is not modified'
    \ | endif

nnoremap <leader>w :Update<CR>
nnoremap <leader>q :Update<Bar>quit<CR>

Answer 2

With help from this answer, I came up with:

function! s:UpdateVerbose()
    if ! getbufinfo(bufnr())[0].changed
        echomsg "Save unnecessary: buffer is unchanged"
    else
        write
    endif
endfunction
com! UpdateVerbose call s:UpdateVerbose()

" <leader>w to update file (only if it has changed) - a lot faster than :w<Enter>:
nnoremap <Leader>w  :UpdateVerbose<CR>
nnoremap <Leader>wq :UpdateVerbose<CR>:q<CR>