getopt() and POSIX

[Elad Lahav <e2lahav@gmail.com>]

Hello,

The configure script attempts to determines whether getopt() is POSIX
compliant by compiling and running the following code:

#include <unistd.h>
#include <stdlib.h>
#include <string.h>

int
main ()
{
  static char program[] = "program";
  static char ab[] = "-ab";
  char *argv[3] = { program, ab, NULL };
  if (getopt (2, argv, "ab:") != 'a')
    return 13;
  if (getopt (2, argv, "ab:") != '?')
    return 14;
  if (optopt != 'b')
    return 15;
  if (optind != 2)
    return 16;
  return 0;
}

This test fails on QNX for the last test point, which has optind set
to 3. However, as far as I can tell, this is what POSIX expects, and 2
is wrong:

https://pubs.opengroup.org/onlinepubs/9699919799/functions/getopt.html

"If the option was the last character in the string pointed to by an
element of argv, then optarg shall contain the next element of argv,
and optind shall be incremented by 2. If the resulting value of optind
is greater than argc, this indicates a missing option-argument, and
getopt() shall return an error indication."

In this case optind is 1 and incremented by 2, the argument is missing
and now optind is greater than argc (2), as expected.

None of this really matters much, except that the compliance failure
leads to an attempt to use rpl_getopt(), which fails due to unresolved
symbols (which is a separate issue).

Thoughts?

--Elad