一个浏览器检查类

<?php
//原作者：epsilon7
//SonyMusic(sonymusic@163.net)
class BrowserDetector {
var $UA = ""; //$HTTP_USER_AGENT的内容
var $BROWSER= "Unknown"; //浏览器类型
var $PLATFORM = "Unknown"; //操作系统
var $VERSION= ""; //浏览器版本号
var $MAJORVER = ""; //浏览器主版本号
var $MINORVER = ""; //浏览器副版本号
/* 构造函数开始 */
function BrowserDetector(){
$this->UA = getenv(HTTP_USER_AGENT);
$preparens = "";
$parens = "";
$i = strpos($this->UA,"(");
if ($i >= 0) {
$preparens = trim(substr($this->UA,0,$i));
$parens = substr($this->UA,$i+1,strlen($this->UA));
$j = strpos($parens,")");
if($j>=0) {
$parens = substr($parens,0,$j);
}
}
else {
$preparens = $this->UA;
}
$browVer = $preparens;
$token = trim(strtok($parens,";"));
while($token) {
if($token=="compatible") {
}
elseif(preg_match("/MSIE/i","$token")) {
$browVer = $token;
}
elseif(preg_match("/Opera/i","$token")) {
$browVer = $token;
}
elseif(preg_match("/X11/i","$token") || preg_match("/SunOS/i","$token") || preg_match ("/Linux/i","$token")) {
$this->PLATFORM = "Unix";
}
elseif(preg_match("/Win/i","$token")) {
$this->PLATFORM = $token;
}
elseif(preg_match("/Mac/i","$token") || preg_match("/PPC/i","$token")) {
$this->PLATFORM = $token;
}
$token = strtok(";");
}
$msieIndex = strpos($browVer,"MSIE");
if($msieIndex >= 0) {
$browVer = substr($browVer,$msieIndex,strlen($browVer));
}
$leftover = "";
if(substr($browVer,0,strlen("Mozilla")) == "Mozilla") {
$this->BROWSER = "Netscape";
$leftover=substr($browVer,strlen("Mozilla")+1,strlen($browVer));
}
elseif(substr($browVer,0,strlen("Lynx")) == "Lynx") {
$this->BROWSER = "Lynx";
$leftover=substr($browVer,strlen("Lynx")+1,strlen($browVer));
}
elseif(substr($browVer,0,strlen("MSIE")) == "MSIE") {
$this->BROWSER = "IE";
$leftover=substr($browVer,strlen("MSIE")+1,strlen($browVer));
}
elseif(substr($browVer,0,strlen("Microsoft Internet Explorer")) == "Microsoft Internet Explorer") {
$this->BROWSER = "IE";
$leftover=substr($browVer,strlen("Microsoft Internet Explorer")+1,strlen($browVer));
}
elseif(substr($browVer,0,strlen("Opera")) == "Opera") {
$this->BROWSER = "Opera";
$leftover=substr($browVer,strlen("Opera")+1,strlen($browVer));
}
$leftover = trim($leftover);
$i=strpos($leftover," ");
if($i > 0) {
$this->VERSION = substr($leftover,0,$i);
}
else {
$this->VERSION = $leftover;
}
$j = strpos($this->VERSION,".");
if($j >= 0) {
$this->MAJORVER