How do I view 'git diff' output with my preferred diff tool/ viewer?

Question

When I type git diff, I want to view the output with my visual diff tool of choice (SourceGear \"diffmerge\" on Windows). How do I configure git to do this?

Answer 1

I have one addition to this. I like to regularly use a diff app that isn't supported as one of the default tools (e.g. kaleidoscope), via

git difftool -t

I also like to have the default diff just be the regular command line, so setting the GIT_EXTERNAL_DIFF variable isn't an option.

You can use an arbitrary diff app as a one-off with this command:

git difftool --extcmd=/usr/bin/ksdiff

It just passes the 2 files to the command you specify, so you probably don't need a wrapper either.