php获取当前页面的完整url

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/test.php?id=1

//获取域名或主机地址

echo $_SERVER['HTTP_HOST']."<br>";  #localhost

//获取网页地址
echo $_SERVER['PHP_SELF']."<br>"; #/blog/test.php

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

//获取用户代理
echo $_SERVER['HTTP_REFERER']."<br>"; 

//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/test.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/test.php?id=5

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