title: chgrp : Operation not permitted?
body: <p>I have this simple line of code:</p>
  
  <pre><code>      mkdir($path_to_rpi, 0755);
        chgrp($path_to_rpi, 'sambashare');
  </code></pre>
  
  <p>Directory is created as <strong>www-data</strong> and group is the same. <strong>www-data</strong> owns the directory and yet the chgrp fails?!?</p>
  
  <p>What am I missing here?</p>