测试网址: http://localhost/chuhe/testurl.php?id=xxoo&name=fuck

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>"; #/chuhe/testurl.php

获取网址参数

echo $_SERVER["QUERY_STRING"]."<br>"; #id=xxoo&name=fuck

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/chuhe/testurl.php?id=xxoo&name=fuck

包含端口号的完整url

echo 'http://'.$_SERVER['SERVER_NAME'].':'.$_SERVER["SERVER_PORT"].$_SERVER["REQUEST_URI"]; 
http://localhost:80/chuhe/testurl hp?id=xxoo&name=fuck

只取路径

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