How can I keep the cursor position when piping the buffer through an external command?

Question

I sometimes make shortcuts for myself, which run some external command on the current buffer, such as

nnoremap <C-f> :%!clang-format -style=file<C-m>

which formats the buffer with clang's formatter.

However, this makes the cursor jump to the beginning of the file. Is there some way to avoid this? I understand it would be difficult finding the correct line after reformatting, but just the same line number would be good. I assume one could set and use marks in the mapping somehow, but any smarter solution would also be appreciated.

Answer 1

See :h getcurpos()

Basically there is an example:

        This can be used to save and restore the cursor position: >
            let save_cursor = getcurpos()
            MoveTheCursorAround
            call setpos('.', save_cursor)

So you can try it with smth like (untested):

nnoremap <C-f> :let save_cursor=getcurpos() <bar> %!clang-format -style=file <bar> call setpos('.', save_cursor)<CR>

Or make it a function:

nnoremap <C-f> :call Clang_format()<CR>

func! Clang_format()
    let save_cursor = getcurpos()
    exe '%!clang-format -style=file'
    call setpos('.', save_cursor)
endfunc