What is the purpose of filtering search engines in PHP code and what potential issues can arise if not done correctly?

Filtering search engines in PHP code helps prevent unwanted bots and crawlers from accessing your website, which can help improve security and reduce server load. If not done correctly, search engine bots may be blocked from indexing your site, leading to decreased visibility in search engine results. 

// Filter search engine bots by user agent
if (strpos($_SERVER['HTTP_USER_AGENT'], 'Googlebot') !== false || strpos($_SERVER['HTTP_USER_AGENT'], 'bingbot') !== false) {
    // Allow search engine bots to access the site
} else {
    // Block access for other user agents
    header('HTTP/1.1 403 Forbidden');
    exit();
}

Keywords

filtering search engines PHP code potential issues incorrect filtering

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