Method inet_aton

Arduino/libraries/Ethernet2/src/Dns.cpp:58–116

int DNSClient::inet_aton(const char* aIPAddrString, IPAddress& aResult)
{
    // See if we've been given a valid IP address
    const char* p =aIPAddrString;
    while (*p &&
           ( (*p == '.') || (*p >= '0') || (*p <= '9') ))
    {
        p++;
    }

    if (*p == '\0')
    {
        // It's looking promising, we haven't found any invalid characters
        p = aIPAddrString;
        int segment =0;
        int segmentValue =0;
        while (*p && (segment < 4))
        {
            if (*p == '.')
            {
                // We've reached the end of a segment
                if (segmentValue > 255)
                {
                    // You can't have IP address segments that don't fit in a byte
                    return 0;
                }
                else
                {
                    aResult[segment] = (byte)segmentValue;
                    segment++;
                    segmentValue = 0;
                }
            }
            else
            {
                // Next digit
                segmentValue = (segmentValue*10)+(*p - '0');
            }
            p++;
        }
        // We've reached the end of address, but there'll still be the last
        // segment to deal with
        if ((segmentValue > 255) || (segment > 3))
        {
            // You can't have IP address segments that don't fit in a byte,
            // or more than four segments
            return 0;
        }
        else
        {
            aResult[segment] = (byte)segmentValue;
            return 1;
        }
    }
    else
    {
        return 0;
    }