如何通过PHP中的代理ip和端口获取url内容？

Question

我希望通过代理获取某些网址的内容。我从http://letushide.com/filter/http,all,all/list_of_free_HTTP_proxy_servers

获取了代理ip和端口

但我正在使用以下代码并返回空白页面。

$url = "http://google.co.in";
$agent = "Mozilla/5.0 (X11; U; Linux i686; en-US) 
        AppleWebKit/532.4 (KHTML, like Gecko) 
        Chrome/4.0.233.0 Safari/532.4";

$referer = "http://www.google.com/";
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_HTTPPROXYTUNNEL, 1);
curl_setopt($ch, CURLOPT_PROXY, '190.122.XXX.XXX:8080');
curl_setopt($ch, CURLOPT_REFERER, $referer);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);
curl_setopt($ch, CURLOPT_MAXREDIRS, 2);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 10);
curl_setopt($ch, CURLOPT_USERAGENT, $agent);
$data = curl_exec($ch);
curl_close($ch);
echo $data;