Has DNS

@return bool True/false.
554101
public function has_dns() {
		if (\is_null($this->dns)) {
			if (! $this->is_fqdn()) {
				$this->dns = false;
			}
			elseif ($this->is_ip()) {
				$this->dns = $this->is_ip(false);
			}
			else {
				$this->dns = !! \filter_var(
					\gethostbyname("{$this->host}."),
					\FILTER_VALIDATE_IP,
					\FILTER_FLAG_NO_PRIV_RANGE | \FILTER_FLAG_NO_RES_RANGE
				);
			}
		}

		return $this->dns;
	}
916855
public function isReserved() : bool
   {

      if ( $this->states[ 'RESERVED' ] ) { return true; }

      if ( ! $this->hasTLD() ) { return false; }

      return $this->_tld->isReserved();

   }
1260465
public function hasConfig() {
		if ($this->_configSupplied !== null) {
			return true;
		}
		
		if ($this instanceof LocatorAwareInterface && $this->hasLocator()
			&& $this->getLocator()->has($this->getConfigServiceId())) {
			return true;
		}
		
		return false;
	}
522907
public function has($id) {
		if (! $this->connectionCheckStatus) {
			$this->addServer();
		}
		
		return $this->getClient()->get($this->prepareId($id)) !== false;
	}
1259258
public function query()
    {
        // Query every server using it's domain name.
        for ($i = 0; $i < $this->numservers; $i++) {
            $result = $this->querySingleServer($this->server[$i]);
            if ($this->debug) {
                echo "server: {$this->server[$i]}\n";
                echo "result: $result\n";
            }

            if ($result) {
                return $result;
            }
        }
        return false;
    }
66073
public function isPubliclyRoutable(): bool
    {
        try {
            $ip = IpUtilsFactory::getAddress($this->host);

            if ($ip->isPrivate()) {
                return false;
            }

            if ($ip->isLoopback()) {
                return false;
            }

            if ($ip instanceof IPv4 && $this->isIpv4InUnroutableRange($ip)) {
                return false;
            }

            return true;
        } catch (\UnexpectedValueException $unexpectedValueException) {
            return true;
        }
    }
799889
public function has($name)
    {
        if (isset($this->cookies[$name]) || isset($_COOKIE[$name])) {
            return true;
        }

        return false;
    }
1202120
protected function getDnsRecord($domain)
    {
        if (filter_var($domain, FILTER_VALIDATE_URL) === false) {
            $this->eye->logger()->debug('DNS URL not valid', $domain);
            return false;
        }

        try {
            $dns = $this->pollDns($this->parseUrl($domain));
        } catch (Exception $e) {
            $this->eye->logger()->debug('DNS lookup failed', ['domain' => $domain,
                                                              'exception' => $e->getMessage()]);
            return false;
        }

        return $this->stripTtlFromDns($dns);
    }
1306145
public function isDomain($host)
	{
	    $dnsResult = false;
	    //$this->_vhost :  Host.TLD
	    //idn_to_ascii
	    $dnsResult = @dns_get_record( \Idna::encode( $host ), DNS_ANY );
	    if ( $dnsResult )
	    {
	        ModuleVisitorLog::writeLog( __METHOD__ , __LINE__ , ': True' );
	        return true;
	    }
	    ModuleVisitorLog::writeLog( __METHOD__ , __LINE__ , ': False' );
	    return false;
	}
539349
public function isEmail($checkDNS = true)
    {
        $isValid = filter_var($this->returnValue, FILTER_VALIDATE_EMAIL) !== false;
        if ($isValid && $checkDNS) {
            $domain  = substr(strrchr($this->returnValue, "@"), 1);
            // domain not found in DNS
            $isValid = checkdnsrr($domain, "MX") && checkdnsrr($domain, "A");
        }
        return $isValid;
    }
1359093
public function isPrivate(): bool
    {
        if ($this->isLoopback()) {
            return true;
        }

        $filtered = filter_var(
            $this->address,
            FILTER_VALIDATE_IP,
            FILTER_FLAG_NO_PRIV_RANGE | FILTER_FLAG_NO_RES_RANGE
        );

        return $filtered === false;
    }
595852
public function requiresHttps(): bool
    {
        if ($this->requiresHttps) {
            return true;
        }

        $this->requiresHttps = $this->routingAnnotations()->requiresHttps();
        return $this->requiresHttps;
    }
407617
public function list_dynamicdns()
    {
        if (!$this->is_loggedin) {
            return false;
        }

        $response = $this->exec_curl('/api/s/' . $this->site . '/list/dynamicdns');

        return $this->process_response($response);
    }
890238
public static function isSSL() : bool {
		if (isset($_SERVER['HTTP_X_FORWARDED_PROTO']) && strtolower($_SERVER['HTTP_X_FORWARDED_PROTO']) == 'https') {
			return true;
		} else if (!empty($_SERVER['HTTPS']) && $_SERVER['HTTPS'] != 'off') {
			return true;
		} else {
			return false;
		}
	}
1002209
public function has($path) {
        $mapping = $this->mapper->get($path);

        if (!$mapping) {
            return false;
        }

        return $this->client->has($mapping['fid']);
    }
1340852
protected function _is_conn()
	{
		if ( ! is_resource($this->_conn_id))
		{
			if ($this->_debug == true)
			{
				throw new \InvalidArgumentException('Invalid connection');
			}
			return false;
		}
		return true;
	}
1186767
public function has($alias)
    {
        $alias = $this->normalizeNamespace($alias);

        if (isset($this->byAlias[$alias]) || isset($this->byEntity[$alias])) {
            return true;
        }

        return false;
    }