title: PHP missing mb_strpos function?
body: <p>I get this error:</p>
  
  <pre><code>PHP Fatal error:  Call to undefined function mb_strpos() in /my/file.php
  </code></pre>
  
  <p>Which is odd because <a href="http://us.php.net/manual/en/function.mb-strpos.php" rel="noreferrer"><code>mb_strpos()</code></a> was introduced in PHP 4, and I'm running PHP 5.3.3</p>
  
  <pre><code>$ php -v
  PHP 5.3.3 (cli) (built: Feb 22 2012 19:38:14) 
  Copyright (c) 1997-2010 The PHP Group
  Zend Engine v2.3.0, Copyright (c) 1998-2010 Zend Technologies
  </code></pre>
  
  <p>Anybody else run into something like this and know how to fix it? I searched and I can't figure it out.</p>
  
  <p>PS. I'm running centOS 5.</p>