PHP中获取当前页面的完整URL

echo $_SERVER['HTTP_HOST']."<br>"; #localhost//获取网页地址

echo $_SERVER['PHP_SELF']."<br>"; #/blog/testurl.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/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