title: How can I perform a diff that ignores all comments?
body: <p>I have a large codebase that was forked from the original project and I'm trying to track down all the differences from the original. A lot of the file edits consist of commented out debugging code and other miscellaneous comments. The GUI diff/merge tool called Meld under Ubuntu can ignore comments, but only single line comments.</p>
  
  <p>Is there any other convenient way of finding only the non-comment diffs, either using a GUI tool or linux command line tools? In case it makes a difference, the code is a mixture of PHP and Javascript, so I'm primarily interested in ignoring <code>//</code>, <code>/* */</code> and <code>#</code>.</p>