PHP获取抓取页面获得跳转后的URL

Question

抓取页面：
http://weixin.sogou.com/weixin?type=2&ie=utf8&query=%E9%98%85%E5%85%B5
内的链接；
但是中间要经过一个步骤，搜狗做了跳转。
例如：http://weixin.sogou.com/websearch/art.jsp?sg=xaXJ7lM8QYSJRqlJNRlxrvDoJgDV2b9Zxfx-iaQmaX_UirnuTv72IQqdCLHJDQgxWL_uhruEJYG2c6h9OnyfCRAOWDr5NK5VIxHygXj6kQt1_yad5qrt7y0qfcahXotg&url=p0OVDH8R4SHyUySb8E88hkJm8GF_McJfBfynRTbN8wjzZ2W8jb8vEr6lWqp4GHrvXY6RLCSg2kSnSF3CFbPwOVLvkvBrfA0sFw2Qjse-dg7W8CcSjpcM6mceCbS6yAyT3u7-YRC86qRYy-5x5In7jJFmExjqCxhpkyjFvwP6PuGcQ64lGQ2ZDMuqxplQrsbk
跳转之后才是微信的真正URL：http://mp.weixin.qq.com/s?__biz=MjM5ODEzNzk2Mw==&mid=209558006&idx=2&sn=8f839662eef543180656253625474837&3rd=MzA3MDU4NTYzMw==&scene=6#rd

请教：如何抓取（获得）到微信的这个URL？

Answer 1

 $url = 'http://www.baidu.com';

$ch = curl_init(); 
curl_setopt($ch, CURLOPT_URL, $url); 
curl_setopt($ch, CURLOPT_VERBOSE, true); 
curl_setopt($ch, CURLOPT_HEADER, true);
curl_setopt($ch, CURLOPT_NOBODY, true);
curl_setopt($ch, CURLOPT_CUSTOMREQUEST, 'GET');
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true); 
curl_setopt($ch, CURLOPT_TIMEOUT, 20); 
curl_setopt($ch, CURLOPT_AUTOREFERER, true); 
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true); 
$ret = curl_exec($ch); 
$info = curl_getinfo($ch); 
curl_close($ch);

这个吧