PHP to determine whether a visitor is a search engine spider

We can judge whether it is a spider by http_user_agent, the spider of search engine has its own unique symbol, the following list takes part. functionIs_crawler () {$userAgent=Strtolower($_server[' Http_user_agent ']); $spiders=Array(        ' Googlebot ',//Google crawler' Baiduspider ',//Baidu Crawler' Yahoo! slurp ',//Yahoo crawler' Yodaobot ',//Youdao crawler' MSNBot '//Bing Crawler//More crawler keywords    ); foreach($spiders  as $spider) {        $spider=Strtolower($spider); if(Strpos($userAgent,$spider) !==false) {            return true; }    }    return false;} The following PHP code comes with more spider logosfunctionIscrawler () {Echo $agent=Strtolower($_server[' Http_user_agent ']); if(!Empty($agent)) {                $spiderSite=Array(                        "Tencenttraveler", "baiduspider+", "Baidugame", "Goog                        Lebot "," MSNBot "," sosospider+ "," Sogou web Spider ",                        "Ia_archiver", "Yahoo! slurp", "Youdaobot",                        "Yahoo slurp", "MSNBot", "Java (Often spam bot)", "Baiduspider", "Voila", "Yandex bot", "BSp                        Ider "," Twiceler "," Sogou spider "," Speedy spider ",                        "Google AdSense", "Heritrix", "Python-urllib",                        "Alexa (IA archiver)", "Ask", "Exabot",             "Custo",           "Outfoxbot/yodaobot", "YaCy", "Surveybot",                        "Legs", "lwp-trivial", "Nutch", "Stackrambler",                        "The Web Archive (IA archiver)", "Perl Tool", "Mj12bot",                        "Netcraft", "Msiecrawler", "WGet tools", "Larbin", "Fish search",                ); foreach($spiderSite  as $val) {                        $str=Strtolower($val); if(Strpos($agent,$str) !==false) {                                return true; }                }        } Else {                return false; }}if(Iscrawler ()) {Echo"Hello Spider-Fine!" ";}Else{     Echo"You're not a Spider-Man!" ";}

PHP to determine whether a visitor is a search engine spider