uint32_t GetHex(void) {
    #define MAXIN 4096 /* MAXIN is the maximum number of input characters */
      static char input[MAXIN]; /* declared as static so it's not on the stack */
      char last;
      uint32_t result;
      fgets(input,MAXIN,stdin); /* fgets as scanf() can't handle blank lines */
      /* First of all check if it was a blank line, i.e. just a '\n' input...*/
      if ('\n' == input[0]) return(INERR);  /* ...which is invalid input too */
      /* Now sscanf() can be used to parse a hex # but we still need to detect
         extraneous input _after_ a valid hex #. has been parsed, hence the %c
         that should have '\n' assigned to it. So, if a valid hex # is parsed
         _and_ there was at least one more character - which there should be -
         then sscanf() will return 2 - the number of successfully parsed items */
      if ((sscanf(input,"%8x%c",&result,&last) < 2)) return(INERR);
      /* Now check to make sure the last character input was a '\n', if not... */
      if ('\n' != last) return(INERR);      /* ...then return an input error value */
      /* If we get to this point it has to be a valid hex # so just return it. */
      return(result);
    }