title: How the @,x,X directives work with Ruby pack()/unpack() method?
body: <p>I just went through the <a href="http://www.ruby-doc.org/core-1.9.3/Array.html#method-i-frozen-3F" rel="nofollow">Ruby Doc</a>. But there is no sufficient code to understand how the below three are used in Real life programming:</p>
  
  <p><code>@</code>,<code>X</code>,<code>x</code>.</p>
  
  <p>can anyone explain it with a simple snippet?</p>
  
  <p>Thanks</p>