threads / discuss / 26068

Can `add --patch` display the diff in my difftool instead of just printing it on the command line?

Subject: Can `add --patch` display the diff in my difftool instead of just printing it on the command line?

## tl;dr

3 messages between Dec 14, 2010 and Dec 14, 2010.

replies: 2people: 2as markdown or json

Dun Peal· Dec 14, 2010, 21:17 UTC · lore

Hi.

I'd like to display the diff of each modified working copy file, and have the option of staging (or reversing) each patch after it is displayed. This is exactly the same thing `add --patch` does, except I want the diff to be displayed in my difftool (happens to be vimdiff) rather than just being printed.

Thanks, D.

Jeff King· Dec 14, 2010, 21:38 UTC · re: Dun Peal · lore

Re: Can `add --patch` display the diff in my difftool instead of just printing it on the command line?

On Tue, Dec 14, 2010 at 03:17:09PM -0600, Dun Peal wrote:

Show 5 quoted lines

> I'd like to display the diff of each modified working copy file, and
> have the option of staging (or reversing) each patch after it is
> displayed. This is exactly the same thing `add --patch` does, except I
> want the diff to be displayed in my difftool (happens to be vimdiff)
> rather than just being printed.

You can't do this with "git add -p" now, but I suspect the patch would be relatively straightforward. See patch_update_file in git-add--interactive.perl. You just need to replace:

  for (@{$head->{DISPLAY}}) {
    print;
  }

with code to dump the diff in @{$head->{TEXT}} either to stdin of your display program or to a tempfile that your program operates on. Conditional on having some config option to specify your program, of course.

Or did you want something more integrated with vimdiff? If you want to primarily see the diff in vim and then have mappings set up to stage or revert changes, that is pretty straightforward to do. Just have vim dump the relevant hunk to "git apply --cached" or "git apply -R". I would be surprised if the vim integration packages didn't have something like this already.

-Peff

Dun Peal· Dec 14, 2010, 22:22 UTC · re: Jeff King · lore

Re: Can `add --patch` display the diff in my difftool instead of just printing it on the command line?

On Tue, Dec 14, 2010 at 3:38 PM, Jeff King <peff@peff.net> wrote:

Show 12 quoted lines

> You can't do this with "git add -p" now, but I suspect the patch would
> be relatively straightforward. See patch_update_file in
> git-add--interactive.perl. You just need to replace:
>
>  for (@{$head->{DISPLAY}}) {
>    print;
>  }
>
> with code to dump the diff in @{$head->{TEXT}} either to stdin of your
> display program or to a tempfile that your program operates on.
> Conditional on having some config option to specify your program, of
> course.

That's exactly what I want, thanks. Seems like there should be a flag / config that tells `add --interactive` to render the diffs through a difftool. I know several Git users who always use their difftools for large, complex patches, which are exactly the kind of patches you'd manage with --interactive / --patch. Hope one of you Git bigwigs takes the time to add that feature :-)

.D