title: What's the magic of "-" (a dash) in command-line parameters?
body: <p>Examples:</p>
  
  <ul>
  <li><p>Create an ISO image and burn it directly to a CD.</p>
  
  <p><code>mkisofs -V Photos -r /home/vivek/photos | cdrecord -v dev=/dev/dvdrw -</code>  </p></li>
  <li><p>Change to the previous directory.</p>
  
  <p><code>cd -</code></p></li>
  <li><p>Listen on port 12345 and untar data sent to it.</p>
  
  <p><code>nc -l -p 12345 | tar xvzf -</code></p></li>
  </ul>
  
  <p>What is the purpose of the dash and how do I use it?</p>