php检测useragent版本示例

<?php
define('ie', 1);
define('firefox', 2);
define('chrome', 3);
define('opera', 4);
class useragentdetect
{
    static $version = array();

    static $useragent = '';

    static function getuseragent()
    {
        $header = getallheaders();
        self :: $useragent = $header['user-agent'];
    }
  function finduseragentbykey($ua, $key)
    {
        $len = strlen($key);
        $start = strpos($ua, $key);

        $pos = strpos($ua, ' ', $start + $len + 1);

        return substr($ua, $start + $len, $pos - $len - $start);
    }
    static function detectuseragent()
    {
         self :: getuseragent();

        if (strpos(self :: $useragent, 'msie') != null)
        {
            self :: $version[] = ie;
            self :: $version[] =self:: finduseragentbykey(self :: $useragent, 'msie');
        }
        else if (strpos(self :: $useragent, 'gecko/') != null)
        {

            self :: $version[] = firefox;
            self :: $version[] =self::  finduseragentbykey(self :: $useragent, 'firefox/');
        }
        else if (strpos(self :: $useragent, 'applewebkit/') != null)
        {
            self :: $version[] = chrome;
            self :: $version[] = self:: finduseragentbykey(self :: $useragent, 'chrome/');
        }
        else if (strpos(self :: $useragent, 'presto/') != null)
        {
            self :: $version[] = opera;
            self :: $version[] = self:: finduseragentbykey(self :: $useragent, 'opera/');
        }
        else
        {
        }

        return self :: $version;
    }

    function matchuseragent($ua, $key)
    {
        preg_match("/$key.([^\s]*?)\s/", $ua, $out);

        return $out[1];
    }
}
$ua=useragentdetect::detectuseragent();

print_r($ua);