[config]
db.set.user = hello
db.set.pass = secrate

<?php
class IndexController extends Zend_Controller_Action
{

    public function indexAction()
    {
      // Load/Open the file
      $config = new Zend_Config_Ini(
                    APPLICATION_PATH . '/configs/httpd.conf',
                    'config',
                    array('skipExtends'=> true,'allowModifications' => true)
              );
      // Output the value
      echo $config->db->set->user;

      // Change the value
      $config->db->set->user ="change";
      // Write it.
      $writer = new Zend_Config_Writer_Ini(
              array('config'   => $config,
              'filename' => APPLICATION_PATH . '/configs/httpd.conf'));
      $writer->write();

    }
}