javascript实现：
top.location.href   顶级窗口的地址 this.location.href  当前窗口的地址

PHP实现
#测试网址:     http://localhost/blog/testurl.php?id=5
//获取域名或主机地址  echo $_SERVER['HTTP_HOST']."
"; #localhost

//获取网页地址  echo $_SERVER['PHP_SELF']."
"; #/blog/testurl.php

//获取网址参数  echo $_SERVER["QUERY_STRING"]."
"; #id=5

//获取用户代理  echo $_SERVER['HTTP_REFERER']."
"; //获取完整的url echo 'http://'.$_SERVER['HTTP_HOST'].$_SERVER['REQUEST_URI']; echo 'http://'.$_SERVER['HTTP_HOST'].$_SERVER['PHP_SELF'].'?'.$_SERVER['QUERY_STRING']; #http://localhost/blog/testurl.php?id=5

//包含端口号的完整url echo 'http://'.$_SERVER['SERVER_NAME'].':'.$_SERVER["SERVER_PORT"].$_SERVER["REQUEST_URI"]; #http://localhost:80/blog/testurl.php?id=5

//只取路径 $url='http://'.$_SERVER['SERVER_NAME'].$_SERVER["REQUEST_URI"]; echo dirname($url); #http://localhost/blog