git/git-diff-script

#!/bin/sh
rev=($(git-rev-parse --revs-only "$@"))
flags=($(git-rev-parse --no-revs "$@"))
case "${#rev[*]}" in
0)
	git-diff-files -M -p "$@";;
1)
	git-diff-cache -M -p "$@";;
2)
	begin=$(echo "${rev[1]}" | tr -d '^')
	end="${rev[0]}"
	git-diff-tree -M -p $flags $begin $end;;
*)
	echo "I don't understand"
	exit 1;;
esac