c++ string vs. c string

Hello guys

I have a dns reply parser, which is written in c code.. The reply is in binary, so parsing data is a little different as normally.. I wonder if would it be easier/better to use c++ string instead of char and char pointers for processing data?

Im used to char *p = sth; sth++; etc..

Heres the example of a function so you get a better idea what I'm doing..

Code:

---

int decodehostname(char *buf, char *packet, unsigned int len, unsigned int pos) {
        unsigned int label;
        int bufpos = 0, r = 0;

restart:
        while(pos < len) {
                label = packet[pos++];

                if (label & 0xC0) {
                        if (pos >= len) return 0;
                        label = ((label & 0x3F) << 8) | packet[pos++];

                        if (r == 0) r = pos;
                        pos = label;

                        goto restart;
                }
                //printf("  bufpos: %d pos: %d label: %d\n  len: %d\n", bufpos, pos, label, len);
                if (label == 0)
                        break;

                //check
                if (bufpos + label + 1 >= 128) return 0;
                if (pos + label > len) return 0;

                memcpy(buf + bufpos, packet + pos, label);
                pos += label;
                bufpos += label;
                buf[bufpos++] = '.';
        }
        if (bufpos) bufpos--;
        buf[bufpos] = 0;

        return (r ? r : pos);
}

---

Thanks for help again

Code:

---

int decodehostname(string &buf, string &packet, unsigned int len, unsigned int pos) {
      unsigned int label;
      int bufpos = 0, r = 0;

      while(pos < len) {
            label = packet[pos++];

            if (label & 0xC0) {
                  if (pos >= len) return 0;
                  label = ((label & 0x3F) << 8) | packet[pos++];

                  if (r == 0) r = pos;
                  pos = label;

                  continue;
            }
            //printf("  bufpos: %d pos: %d label: %d\n  len: %d\n", bufpos, pos, label, len);
            if (label == 0)
                  break;

            //check
            if (bufpos + label + 1 >= 128) return 0;
            if (pos + label > len) return 0;

            string part = packet.substr(pos, label);
            buf.replace(bufpos, part.length() ,part );
            pos += label;
            bufpos += label;
            buf[bufpos++] = '.';
      }
      if (bufpos) bufpos--;
      buf[bufpos] = 0;

      return (r ? r : pos);
}

---

It's usually easier to use the C++ string class than C strings. They can do everything C arrays can, and if you need a C string you can use the .c_str() member function (which returns a const char *; if you need a modifiable C string then you need to use one).