一个浏览器检查类

//原作者：epsilon7
//SonyMusic([e-mail])
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) {　
$this->MAJORVER = substr($this->VERSION,0,$j);　
$this->MINORVER = substr($this->VERSION,$j+1,strlen($this->VERSION));　
}　
else {　
$this->MAJORVER = $this->VERSION;　
}
}
}

//测试程序开始
$test=new browserdetector;
echo $test->UA."
";
echo $test->BROWSER."
";
echo $test->PLATFORM."
";
echo $test->VERSION."
";
echo $test->MAJORVER."
";
echo $test->MINORVER."
";
?>