til/git/use-external-diff-tool-like-difftastic.md

Use External Diff Tool Like Difftastic

Assuming we already have a tool like difft (difftastic) available on our machine, we can use it as a diff viewer for the various git commands that display a diff.

This requires a manual override which involve two pieces — an inline configuration of diff.external specifying the binary of the external differ and the --ext-diff flag which tells these commands to use the external diff binary.

Here is what git show looks like with difft:

$ git -c diff.external=difft show --ext-diff

Without the --ext-diff flag, it will fallback to the default differ despite diff.external being set.

See man git-diff and friends for the --ext-diff flag. See man git-config for diff.external.