Example of hardcoded iteration limit of positional parameters to single digit values in bash source code

subst.c

/* Return the word list that corresponds to `$*'. */
WORD_LIST *
list_rest_of_args ()
{
  register WORD_LIST *list, *args;
  int i;

  /* Break out of the loop as soon as one of the dollar variables is null. */
  for (i = 1, list = (WORD_LIST *)NULL; i < 10 && dollar_vars[i]; i++)
    list = make_word_list (make_bare_word (dollar_vars[i]), list);

  for (args = rest_of_args; args; args = args->next)
    list = make_word_list (make_bare_word (args->word->word), list);

  return (REVERSE_LIST (list, WORD_LIST *));
}