PHP 判断是否为标准IP地址

PHP 判断是否为标准IP地址

function is_ipaddress($ip_address = '') {
    /* check for ipv4/v6 */
    if (substr_count($ip_address, ":")) {
        /* compressed dot format */
        if (substr_count($ip_address, "::")) {
            $ip_address = str_replace("::", ":", $ip_address);
            $segments   = explode(":", $ip_address);
        }else{
            $segments = explode(":", $ip_address);

            if (sizeof($segments) != 8) {
                /* should be 8 segments */
                return false;
            }
        }

        $i = 0;
        foreach ($segments as $segment) {
            $i++;

            if ((trim($segment) == "") && ($i == 1)) {
                continue;
            }elseif (!is_numeric("0x" . $segment)) {
                return false;
            }
        }

        return true;
    }else if (strlen($ip_address) <= 15) {
        $octets = explode('.', $ip_address);

        $i = 0;

        if (count($octets) != 4) {
            return false;
        }

        foreach($octets as $octet) {
            if ($i == 0 || $i == 3) {
                if(($octet < 0) || ($octet > 255)) {
                    return false;
                }
            }else{
                if(($octet < 0) || ($octet > 255)) {
                    return false;
                }
            }

            $i++;
        }

        return true;
    }else{
        return false;
    }
}```