/**
     * @title Check if Apache's mod_rewrite is installed.
     *
     * @author Pierre-Henry Soria <ph7software@gmail.com>
     * @copyright (c) 2013, Pierre-Henry Soria. All Rights Reserved.
     * @return boolean
     */
function isRewriteMod()
{
     if (function_exists('apache_get_modules'))
     {
     $aMods = apache_get_modules();
     $bIsRewrite = in_array('mod_rewrite', $aMods);
     }
     else
     {
     $bIsRewrite = (strtolower(getenv('HTTP_MOD_REWRITE')) == 'on');
     }
     return $bIsRewrite;
}

if (!isRewriteMod()) exit('Please install Apache mod_rewrite module.');