总结一个使用 php 判断访问者是否为搜索引擎蜘蛛的函数。

/**
 * 判断是否为搜索引擎蜘蛛
 * @return bool
 */
function isCrawler() {
    $agent = isset($_SERVER['HTTP_USER_AGENT']) ? strtolower($_SERVER['HTTP_USER_AGENT']) : '';
    if ($agent) {
        $spiderSite = [
            '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;
            }
        }

    }

    return false;
}