php 判断是否为搜索引擎蜘蛛

/**

*    判断是否为搜索引擎蜘蛛

*

*    @author    Eddy

*    @return    bool

*/

function isCrawler() {

        $agent= strtolower($_SERVER[HTTP_USER_AGENT]); 

        if (!empty($agent)) {                

                $spiderSite= array(

                        "TencentTraveler",

                        "Baiduspider+",

                        "BaiduGame",

                        "Googlebot",

                        "msnbot",

                        "Sosospider+",

                        "Sogou web spider",

                        "ia_archiver",

                        "Yahoo! Slurp",

                        "YoudaoBot",

                        "Yahoo Slurp",

                        "MSNBot",

                        "Java (Often spam bot)",

                        "BaiDuSpider",

                        "Voila",

                        "Yandex bot",

                        "BSpider",

                        "twiceler",

                        "Sogou Spider",

                        "Speedy Spider",

                        "Google AdSense",

                        "Heritrix",

                        "Python-urllib",

                        "Alexa (IA Archiver)",

                        "Ask",

                        "Exabot",

                        "Custo",

                        "OutfoxBot/YodaoBot",

                        "yacy",

                        "SurveyBot",

                        "legs",

                        "lwp-trivial",

                        "Nutch",

                        "StackRambler",

                        "The web archive (IA Archiver)",

                        "Perl tool",

                        "MJ12bot",

                        "Netcraft",

                        "MSIECrawler",

                        "WGet tools",

                        "larbin",

                        "Fish search",

                );  

                foreach($spiderSite as $val) {                       

                        $str = strtolower($val);

                        if (strpos($agent, $str) !== false) {

                                return true;

                        }                       

                }  

        } else {

                return false;

        }

}