php获取当前域名、主机、URL、端口、参数、网址、路径、代理等

        //获取域名或主机地址
    echo $_SERVER['HTTP_HOST']."";
    //获取网页地址
    echo $_SERVER['PHP_SELF']."";
    //获取网址参数
    echo $_SERVER["QUERY_STRING"]."";
    //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'];
    //包含端口号的完整url
    echo 'http://'.$_SERVER['SERVER_NAME'].':'.$_SERVER["SERVER_PORT"].$_SERVER["REQUEST_URI"];
    //只取路径
    $url='http://'.$_SERVER['SERVER_NAME'].$_SERVER["REQUEST_URI"];
    echo dirname($url);
    ?>

php, URL