Domain Validation in php

DomainValidation.php

    function checkDomain(string $url, string $remark = 'Domain Offline/invalid', int $timeout = 10): mixed
    {
        // Parse the URL to extract the host, port, and scheme
        $parsedUrl = parse_url($url);
        $host = $parsedUrl['host'] ?? $url;
        $port = $parsedUrl['port'] ?? -1; // Use -1 if port is not specified
        $scheme = $parsedUrl['scheme'] ?? 'http'; // Default to HTTP if scheme is not specified

        // Check if the input is an IP address
        $isIp = filter_var($host, FILTER_VALIDATE_IP);

        if ($isIp) {
            // If it's an IP address, skip DNS resolution
            $ips = [$host];
        } else {
            // Check if the domain has a valid DNS A record
            $dnsRecords = dns_get_record($host, DNS_A);
            if (empty($dnsRecords)) {
                return $remark;
            }

            $ips = array_column($dnsRecords, 'ip');
        }

        // Use the default port if it's not specified in the URL
        if ($port === -1) {
            $port = $scheme === 'https' ? 443 : 80;
        }

        // Try to establish a connection
        $fp = fsockopen($isIp ? $host : $ips[0], $port, $errno, $errstr, $timeout);
        if ($fp) {
            fclose($fp);
            return $url;
        }

        return $remark;
    }