方法定义：

/**
* @title Check if Apache's mod_rewrite is installed.
*
* @author Pierre-Henry Soria * @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;
}