如何通过PHP代码识别访问者是否为搜索引擎爬虫？

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我们可以通过检查HTTP_USER_AGENT来判断是否是爬虫，搜索引擎的爬虫都有自己的独特标识。下面是一个简化的示例：

javascriptfunction is_crawler() { $userAgent=strtolower($SERVER['HTTP_USER_AGENT']); $spiders=array('Goog', 'Baid', 'Sogou'); return in_array($userAgent, $spiders);}

我们可以通过HTTP_USER_AGENT来判断是否是蜘蛛，搜索引擎的蜘蛛都有自己的独特标志，下面列取了一部分。

function is_crawler() { $userAgent = strtolower($_SERVER['HTTP_USER_AGENT']); $spiders = array( 'Googlebot', // Google 爬虫 'Baiduspider', // 百度爬虫 'Yahoo! Slurp', // 雅虎爬虫 'YodaoBot', // 有道爬虫 'msnbot' // Bing爬虫 // 更多爬虫关键字 ); foreach ($spiders as $spider) { $spider = strtolower($spider); if (strpos($userAgent, $spider) !== false) { return true; } } return false; }
下面的php代码附带了更多的蜘蛛标识

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 "你好蜘蛛精！"; } else{ echo "你不是蜘蛛精啊！"; }