title: Git diff cached does nothing
body: <p>Here is where I'm at:</p>
  
  <ol>
  <li>Created a new repo on GitHub</li>
  <li>Initialized (git add .) my working directory locally on my PC</li>
  <li>commited (git commit -m) all changes to stage</li>
  <li>Made another change by adding a new .png file</li>
  <li>Did another git commit -m</li>
  <li>Now I want to see a list of all staged files that will be pushed before I actually push them for the first time (or really at any time) to the remote repo (https//.../../).  So I assumed there'd be 2 commit full of changes to show for</li>
  </ol>
  
  <p>If I tried to <code>commit again (#3)</code>, it shows <code>nothing to commit, working directory clean</code>.  So I must have committed successfully last time I assume is why it's saying this.</p>
  
  <p>When I do a <code>git status</code> I get <code>nothing to commit, working directory clean</code></p>
  
  <p>BUT when I try to type <code>git diff --cached --name-only</code> or <code>git diff --staged</code> in terminal in OS X it did nothing.  I just get the command prompt after running that command again.  </p>
  
  <p>Am I missing something here?  I've searched for stuff on git diff but I must be blind.</p>