如可获取url中非本地域名,就是?to=后面的字串中的域名http://127.0.0.1/wwwww/yuancheng.php?to=http://auction1.paipai.com/2A8B5E1F00000000002A3B1A07E07BC4http://127.0.0.1/wwwww/yuancheng.php?to=http://www.baidu.com/2A8B5E1http://127.0.0.1/wwwww/yuancheng.php?to=http://bbbs.sougou.com/2A8B5E111111111111111http://127.0.0.1/wwwww/yuancheng.php?to=http://sougou.com/2A8B5E11主要是取来做一个判断