以下是网学网为您推荐的PHP-php中取得URL的根域名的代码，希望本篇文章对您学习有所帮助。

复制代码 代码如下:
<?php
/**
* 取得根域名
*
* @author lonely
* @create 2011-3-11
* @version 0.1
* @lastupdate lonely
* @package Sl
*/
class Sl_RootDomain{
private static $self;
private $domain=null;
private $host=null;
private $state_domain;
private $top_domain;
/**
* 取得域名分析实例
* Enter description here ...
*/
public static function instace(){
if(!self::$self)
self::$self=new self();
return self::$self;
}
private function __construct(){
$this->state_domain=array(
''al'',''dz'',''af'',''ar'',''ae'',''aw'',''om'',''az'',''eg'',''et'',''ie'',''ee'',''ad'',''ao'',''ai'',''ag'',''at'',''au'',''mo'',''bb'',''pg'',''bs'',''pk'',''py'',''ps'',''bh'',''pa'',''br'',''by'',''bm'',''bg'',''mp'',''bj'',''be'',''is'',''pr'',''ba'',''pl'',''bo'',''bz'',''bw'',''bt'',''bf'',''bi'',''bv'',''kp'',''gq'',''dk'',''de'',''tl'',''tp'',''tg'',''dm'',''do'',''ru'',''ec'',''er'',''fr'',''fo'',''pf'',''gf'',''tf'',''va'',''ph'',''fj'',''fi'',''cv'',''fk'',''gm'',''cg'',''cd'',''co'',''cr'',''gg'',''gd'',''gl'',''ge'',''cu'',''gp'',''gu'',''gy'',''kz'',''ht'',''kr'',''nl'',''an'',''hm'',''hn'',''ki'',''dj'',''kg'',''gn'',''gw'',''ca'',''gh'',''ga'',''kh'',''cz'',''zw'',''cm'',''qa'',''ky'',''km'',''ci'',''kw'',''cc'',''hr'',''ke'',''ck'',''lv'',''ls'',''la'',''lb'',''lt'',''lr'',''ly'',''li'',''re'',''lu'',''rw'',''ro'',''mg'',''im'',''mv'',''mt'',''mw'',''my'',''ml'',''mk'',''mh'',''mq'',''yt'',''mu'',''mr'',''us'',''um'',''as'',''vi'',''mn'',''ms'',''bd'',''pe'',''fm'',''mm'',''md'',''ma'',''mc'',''mz'',''mx'',''nr'',''np'',''ni'',''ne'',''ng'',''nu'',''no'',''nf'',''na'',''za'',''aq'',''gs'',''eu'',''pw'',''pn'',''pt'',''jp'',''se'',''ch'',''sv'',''ws'',''yu'',''sl'',''sn'',''cy'',''sc'',''sa'',''cx'',''st'',''sh'',''kn'',''lc'',''sm'',''pm'',''vc'',''lk'',''sk'',''si'',''sj'',''sz'',''sd'',''sr'',''sb'',''so'',''tj'',''tw'',''th'',''tz'',''to'',''tc'',''tt'',''tn'',''tv'',''tr'',''tm'',''tk'',''wf'',''vu'',''gt'',''ve'',''bn'',''ug'',''ua'',''uy'',''uz'',''es'',''eh'',''gr'',''hk'',''sg'',''nc'',''nz'',''hu'',''sy'',''jm'',''am'',''ac'',''ye'',''iq'',''ir'',''il'',''it'',''in'',''id'',''uk'',''vg'',''io'',''jo'',''vn'',''zm'',''je'',''td'',''gi'',''cl'',''cf'',''cn'',''yr''
);
$this->top_domain=array(''com'',''arpa'',''edu'',''gov'',''int'',''mil'',''net'',''org'',''biz'',''info'',''pro'',''name'',''museum'',''coop'',''aero'',''xxx'',''idv'',''me'',''mobi'');
$this->url= SERVER[''HTTP_HOST''];
}
/**
* 设置URL
* Enter description here ...
* @param string $url
*/
public function setUrl($url=null){
$url=$url?$url:$this->url;
if(empty($url))return $this;
if(!preg_match("/^http::/is", $url))
$url="http://".$url;
$url=parse_url(strtolower($url));
$urlarr=explode(".", $url[''host'']);
$count=count($urlarr);
if ($count<=2){
$this->domain=array_pop($url);
}else if ($count>2){
$last=array_pop($urlarr);
$last_1=array_pop($urlarr);
if(in_array($last, $this->top_domain)){
$this->domain=$last_1.''.''.$last;
$this->host=implode(''.'', $urlarr);