git-diff-两个分支的同一个文件的差异

git diff master:app/Article.php feature/hello:app/Article.php
就是比较 master和feature/hello两个分支的app/Aritcle.php的差异

如果当前就在feature/hello分支上，这样也可以查到master和feature/hello两个分支的同一个文件的差异：
git diff master app/Article.php