title: require_once("facebook-sdk/facebook.php") throws a warning "failed to open stream:Permission denied"
body: <p>I'm trying out the tutorials for Facebook developers. However, I can't include the Facebook PHP SDK successfully in my code. As stated, <code>require_once("facebook_sdk/facebook.php");</code> throws the following error:</p>
  
  <pre><code>Warning: require_once(facebook_sdk/facebook.php) [function.require-once]: failed to
  open stream: Permission denied in /opt/lampp/htdocs/awesome/plas.php on line 2
  
  Fatal error: require_once() [function.require]: Failed opening required 'facebook_sdk/facebook.php'
  (include_path='.:/opt/lampp/lib/php') in /opt/lampp/htdocs/awesome/plas.php on line 2
  </code></pre>
  
  <p>I am developing under Lucid Lynx. I tried doing <code>chmod 777 facebook.php</code> but the problem persists. I found <a href="https://stackoverflow.com/questions/1197493/require-once-failed-to-open-stream-permission-denied">this SO question</a> but the resolution arrived at (renaming the file, as it may be conflicting with one of PHP's own) does not work for me. (Come to think of it, how will a file named <em>facebook.php</em> conflict with internal PHP files?!) Even if I switch to plain <code>require</code>, the same warnings are thrown.</p>
  
  <p>Curiously, if I copy the files (<code>facebook.php</code> and <code>base_facebook.php</code>) outside of <code>facebook_sdk</code> and change the <code>require_once</code> line accordingly, the require succeeds. Any thoughts?</p>