title: How do I synchronize in both directions?
body: <p>I want to use rsync to <strong>synchronize</strong> two directories in both directions.</p>
  
  <p>I refer to synchronization in classical sense
  (<strong>not</strong> how it is meant in rsync manuals):<br>
  I want to update the directories <strong>in both directions</strong>,
  depending on which of them is <strong>newer</strong>.</p>
  
  <p>Can this be done by rsync <em>(preferable in a Linux-way)</em>?<br>
  If not, what other solutions exist?</p>