code: public static int findTab(byte [] utf, int start, int length) {
      for(int i=start; i<(start+length); i++) {
        if (utf[i]==(byte)'\t') {
          return i;
        }
      }
      return -1;      
    }
docs: Find the first occured tab in a UTF-8 encoded string
  @param utf a byte array containing a UTF-8 encoded string
  @param start starting offset
  @param length no. of bytes
  @return position that first tab occures otherwise -1