What are some methods to check if an external link is still functioning using PHP?

When working with external links in PHP, it is important to ensure that the links are still functioning to provide a seamless user experience. One way to check if an external link is still functioning is by using the PHP function `get_headers()`, which retrieves the headers sent by the server in response to a HTTP request. By checking the response code in the headers, we can determine if the link is still valid.

function checkLinkStatus($url) {
    $headers = @get_headers($url);
    
    if($headers && strpos($headers[0], '200')) {
        return true; // link is functioning
    } else {
        return false; // link is not functioning
    }
}

// Example usage
$link = 'http://www.example.com';
if(checkLinkStatus($link)) {
    echo 'Link is functioning.';
} else {
    echo 'Link is not functioning.';
}