title: how to use a common function an all controller in zend framework
body: <p>I have declared a function </p>
  
  <pre><code>public function findexts($filename) {
      $filename = strtolower($filename);
      $exts = split("[/\\.]", $filename);
      $n = count($exts) - 1;
      $exts = $exts[$n];
      return $exts;
  }
  </code></pre>
  
  <p>i want to use this function in all my controller . how to declare that function and where to declare this function (i mean in which file ) without repeating code?</p>