How do you make git diff use gitx --diff on OS X

Question

Gitx has a great diff viewer, how do I make git automatically pipe git diff whatever into gitx?

I\'ve tried to set git config diff.external to a shell scrip

Answer 1

like sigjuice is saying up there. Only that noobs (like i am now) need to know how to "connect" git to use it. Here is what I did

echo 'opendiff $2 $5' > ~/opendiff-git.sh
chmod a+x ~/opendiff-git.sh
git config --global diff.external ~/opendiff-git.sh 

and now all "git diff whatever" should open FileMerge.app ...