title: Unable to diff files in two separate branches in Git
body: <p>I have FileA in branchA and FileB in branchB.</p>
  <p>The problem is that I can access only one file at time.
  I would like to be able to compare the files by FileMerge or meld, since they are the only diffTools whichI have found for Mac.</p>
  <p><strong>How can you diff by meld/FileMerge the two files</strong>?</p>
  <hr />
  <p>[Solved]: <strong>1st developed Problem:</strong> FileMerge does not allow standard input</p>
  <blockquote>
  <p>Masi: You can use <a href="http://kerneltrap.org/index.php?q=mailarchive/git/2007/3/29/242485/thread" rel="noreferrer">opendiff to allow FileMerge</a> to have files from standard input. So the next problem is to find how to make git's diff tool to use opendiff.</p>
  </blockquote>
  <hr />
  <p><strong>2nd developed Problem:</strong> to make Git's diff tool to use opendiff in Mac</p>