/* Add current char to buffer (if not out of space) and read next one  */
static int nextc(RN *rn)
/* Add current char to buffer (if not out of space) and read next one  */
static int nextc(RN *rn)
{
    rn->buff[0] = '\0';
    return 0;
  }
  else {
    rn->buff[rn->n++] = rn->c;
    rn->c = l_getc(rn->f);
    return 1;
  }
}