PHP determines whether the visitor is a search engine crawler

We can use HTTP_USER_AGENT to determine whether it is a spider. Search engine spiders have their own unique signs, some of which are listed below.

function is_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 php code below comes with more spider logos

function isCrawler() {
 echo $agent= strtolower($_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;
 }
}
if (isCrawler()){
 echo "Hello Spider! ";
}
else{
 echo "You are not a spider spirit! ";
}

php