检查ipv4地址是否合法

C++版本

bool checkIpV4(const char *address) {

    if(address == nullptr || reinterpret_cast<const char *>(*address) == "" )
        return false;

    unsigned short holdplace = 0;
    unsigned char count = 0, c = 0, p = 0XFF;

    while (c = (unsigned char)*address++) {
        if (c == '.') {
            if (++count > 3 || p == 0XFF)
                return false;
            holdplace = 0;
            p = 0XFF;
            continue;
        }
        c -= '0';
        holdplace *= 10;
        holdplace += c;
        if (holdplace > 0XFF || c > 9)
            return false;
        p = c;
    }
    return holdplace <= 0XFF && p != 0XFF;
}

GO版本

func CheckIPV4Address(address *string) bool {
    if address == nil || *address == "" {
        return false
    }
    for _, val := range *address{
        if val == '.'{
            if Count++; Count > 3 || P  == 0xFF {
                return false
            }
            Holdplace = 0
            P = 0xFF
            continue
        }
        val -= '0'
        Holdplace *= 10
        Holdplace += val
        if Holdplace > 0xFF || val > 9 {
            return false
        }
        P = uint(val)
    }
    return Holdplace <= 0XFF && P != 0XFF
}

func CheckIPV4Addres(address *string) bool {
    if address == nil || *address == "" {
        return false
    }
    buff := strings.Split(*address,".")
    if len(buff) != 4 {
        return false
    }
    for _, val := range buff {
        if address,err := strconv.Atoi(val); err != nil  || address > 0XFF {
            return false
        }
    }
    return true
}