inet_ntop - PHP code example

PHP Functions - Inet_Ntop() and Str_StartWith()

A php function is a set of instructions that can be used to carry out an action during runtime. The information is stored in variables and transferred to the functions during call using the argument. A comma is used to separate the arguments. PHP function allows for reusability of code, and it helps in simplifying the application. It reduces the amount of code and increases the speed of execution.

The inet_ntop() function converts an IP address structure into a string representation. It is similar to the inet_ntoa() function, but it does not require the Windows Sockets DLL to be loaded.

This function is compatible with IPv4, IPv6, and DHCP. The af argument specifies the family of the address; it can be AF_INET, AF_INET6, or AF_INET6. The src argument points to a buffer that holds the address, which should be in network byte order. The dst argument points to a buffer where the resulting text string is stored; it must not be NULL. The pStringBufSize parameter specifies the size of this buffer, which must be large enough to store the string representation of the IP address.

The PHP 8.0 release introduces a new function, str_starts_with(). This function returns a bool to indicate whether the first string in a list of strings starts with the second string. This feature is useful for creating a list of commands that need to be executed in a specific order. It also supports the use of a trailing comma in the list of parameters, which is helpful to improve the readability.

inet_ntop example

if (!$ipv6) {
            return false;
        }

        // Convert IPv6 to packed format and back so we can check if there is a IPv4 representation of the IP         $packedIp = inet_pton($ipv6);
        if (!$packedIp) {
            return false;
        }

        $convertedIp = inet_ntop($packedIp);
        if (!$convertedIp) {
            return false;
        }
        $convertedIp = explode(':', $convertedIp);
        $ipv4 = array_pop($convertedIp);

        // Additionally filter IPv4 representation of the IP         if (filter_var($ipv4, \FILTER_VALIDATE_IP, \FILTER_FLAG_IPV4)) {
            return $this->validateIpv4($ipv4);
        }

public static function anonymize(string $ip): string
    {
        $wrappedIPv6 = false;
        if (str_starts_with($ip, '[') && str_ends_with($ip, ']')) {
            $wrappedIPv6 = true;
            $ip = substr($ip, 1, -1);
        }

        $packedAddress = inet_pton($ip);
        if (4 === \strlen($packedAddress)) {
            $mask = '255.255.255.0';
        } elseif ($ip === inet_ntop($packedAddress & inet_pton('::ffff:ffff:ffff'))) {
            $mask = '::ffff:ffff:ff00';
        } elseif ($ip === inet_ntop($packedAddress & inet_pton('::ffff:ffff'))) {
            $mask = '::ffff:ff00';
        } else {
            $mask = 'ffff:ffff:ffff:ffff:0000:0000:0000:0000';
        }
        $ip = inet_ntop($packedAddress & inet_pton($mask));

        if ($wrappedIPv6) {
            $ip = '['.$ip.']';
        }

break;

            case 'ipv6':
                $option = FILTER_FLAG_IPV6;
                break;

            default:
                $option = 0;
        }

        return filter_var($ip, FILTER_VALIDATE_IP, $option) !== false
            || (! ctype_print($ip) && filter_var(inet_ntop($ip), FILTER_VALIDATE_IP, $option) !== false);
    }

    /** * Checks a string to ensure it is (loosely) a URL. * * Warning: this rule will pass basic strings like * "banana"; use valid_url_strict for a stricter rule. */
    public function valid_url(?string $str = null): bool
    {
        if (empty($str)) {

        if ( false !== $percent ) {
            $ip_addr = substr( $ip_addr, 0, $percent );
        }

        // No invalid characters should be left.         if ( preg_match( '/[^0-9a-f:]/i', $ip_addr ) ) {
            return '::';
        }

        // Partially anonymize the IP by reducing it to the corresponding network ID.         if ( function_exists( 'inet_pton' ) && function_exists( 'inet_ntop' ) ) {
            $ip_addr = inet_ntop( inet_pton( $ip_addr ) & inet_pton( $netmask ) );
            if ( false === $ip_addr ) {
                return '::';
            }
        } elseif ( ! $ipv6_fallback ) {
            return '::';
        }
    } elseif ( $is_ipv4 ) {
        // Strip any port and partially anonymize the IP.         $last_octet_position = strrpos( $ip_addr, '.' );
        $ip_addr             = substr( $ip_addr, 0, $last_octet_position ) . '.0';
    } else {