检查外部文件是否在国家/地区php中被阻止

I'd like to know whether it's a way in php to check whether external file is blocked or not in certain countries.

I need to replace Google map for Bing map in China but functions like get_headers() or file_get_contents() don't do what I need.

In China you can use specific google maps url

  www.google.cn/maps/

and api access

  <script src="http://maps.google.cn/maps/api/js?key=API_KEY" type="text/javascript">