php获取url地址

#测试网址:  

#http://localhost/blog/url.php?id=6  
//1、获取域名或主机地址
echo $_SERVER['HTTP_HOST']."<br>";
#localhost
//2、获取网页地址
echo $_SERVER['PHP_SELF']."<br>";
#/blog/url.php
//3、获取网址参数
echo $_SERVER["QUERY_STRING"]."<br>";
#id=6
//4、获取用户代理，链接/提交当前页的父页面URL
echo $_SERVER['HTTP_REFERER']."<br>";
//5、获取完整的url
echo 'http://'.$_SERVER['HTTP_HOST'].$_SERVER['REQUEST_URI'];
echo 'http://'.$_SERVER['HTTP_HOST'].$_SERVER['PHP_SELF'].'?'.$_SERVER['QUERY_STRING'];
#http://localhost/blog/url.php?id=6
//6、包含端口号的完整url
echo 'http://'.$_SERVER['SERVER_NAME'].':'.$_SERVER["SERVER_PORT"].$_SERVER["REQUEST_URI"];
#http://localhost:80/blog/url.php?id=6

//7、只取路径
$url='http://'.$_SERVER['SERVER_NAME'].$_SERVER["REQUEST_URI"];
echo dirname($url);