PHP 获取当前 URL

';
echo $_SERVER['HTTP_HOST']."
";
echo '获取网页地址:
';
echo $_SERVER['PHP_SELF']."
";
echo '获取网址参数:
';
echo $_SERVER["QUERY_STRING"]."
";
echo '获取完整的url:
';
echo 'http://'.$_SERVER['HTTP_HOST'].$_SERVER['REQUEST_URI']."
";
echo 'http://'.$_SERVER['HTTP_HOST'].$_SERVER['PHP_SELF'].'?'.$_SERVER['QUERY_STRING']."
";
echo '包含端口号的完整url:
';
echo 'http://'.$_SERVER['SERVER_NAME'].':'.$_SERVER["SERVER_PORT"].$_SERVER["REQUEST_URI"]."
";
$url='http://'.$_SERVER['SERVER_NAME'].$_SERVER["REQUEST_URI"]."
";
echo dirname($url);
?>