<?php
//当前页面 http://localhost/ceshi/url.php?id=365

//获取域名或主机地址
echo $_SERVER['HTTP_HOST']; //localhost
echo "<br>";

//获取当前页面url
echo $_SERVER['PHP_SELF']; //   /ceshi/url.php,如果url为url.php/index/index,则输出/ceshi/url.php/index/index
echo "<br>";

//获取当前页面参数
echo $_SERVER["QUERY_STRING"];//id=365
echo "<br>";

//获取端口
echo $_SERVER["SERVER_PORT"];//80
echo "<br>";

//完成的url
$url =  'http://'.$_SERVER['HTTP_HOST'].$_SERVER['PHP_SELF'].'?'.$_SERVER["QUERY_STRING"];
echo $url;
echo "<br>";

echo "<pre>";
print_r(pathinfo($url));  //返回文件路径的信息 

/结果 Array

(

    [dirname] => http://localhost//ceshi

    [basename] => url.php?id=365

    [extension] => php?id=365

    [filename] => url

)/

print_r(parse_url($url)); //解析 URL,返回其组成部分 

/结果Array

(

    [scheme] => http

    [host] => localhost

    [path] => //ceshi/url.php

    [query] => id=365

)

/

print_r(basename($url)); // 返回路径中的文件名部分  结果url.php?id=365

echo "<br>";

print_r(dirname($url)); //返回路径中的目录部分 结果 http://localhost/ceshi