php获取当前域名的方法示例

$domain = $_SERVER['HTTP_HOST'];
echo $domain;

$protocol = isset($_SERVER['HTTPS']) && $_SERVER['HTTPS'] === 'on' ? 'https://' : 'http://';
$domain = $_SERVER['HTTP_HOST'];
$current_url = $protocol . $domain;
echo $current_url;

<?
//获取当前的域名:
echo $_SERVER['SERVER_NAME'];
//获取来源网址,即点击来到本页的上页网址
echo $_SERVER["HTTP_REFERER"];
$_SERVER['REQUEST_URI'];//获取当前域名的后缀
$_SERVER['HTTP_HOST'];//获取当前域名
dirname(__FILE__);//获取当前文件的物理路径
dirname(__FILE__)."/../";//获取当前文件的上一级物理路径
?>

<?php
//获取域名或主机地址
echo $_SERVER['HTTP_HOST']."<br />";
//获取网页地址
echo $_SERVER['PHP_SELF']."<br />";
//获取网址参数
echo $_SERVER["QUERY_STRING"]."<br />";
//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'];
//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);
?>