/**
 * getopt-experiment.c
 *   A simple toolbox for experimenting with getopt.
 * Samuel A. Rebelsky.
 * <INSERT MIT LICENSE>
 */

// +---------+-------------------------------------------------------
// | Headers |
// +---------+

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

// +---------+-------------------------------------------------------
// | Helpers |
// +---------+

/**
 * Print an array of strings.
 */
void
fprintstrings (FILE *port, char *strings[], int nstrings)
{
  if (0 == nstrings)
    {
      fprintf (port, "[]");
    } // if no strings
  else
    {
      fprintf (port, "[\"%s\"", strings[0]);
      for (int i = 1; i < nstrings; i++)
        {
          fprintf (port, ", \"%s\"", strings[i]);
        } // for
      fprintf (port, "]");
    } // if (nstrings > 0)
} // fprintstrings

/**
 * Print getopt status.
 */
void
status (FILE *port, int opt, char *argv[], int argc)
{
  fprintf (port, "Status\n");
  fprintf (port, "  opt:    '%c' (%d)\n", opt, opt);
  fprintf (port, "  optopt: '%c' (%d)\n", optopt, optopt);
  fprintf (port, "  optind: %d\n", optind);
  fprintf (port, "  optarg: \"%s\"\n", optarg);
  fprintf (port, "  argv: ");
  fprintstrings (port, argv, argc);
  fprintf (port, "\n\n");
} // status

// +------+----------------------------------------------------------
// | Main |
// +------+

int
main (int argc, char *argv[])
{
  int opt = 0;
  while ((opt = getopt (argc, argv, "abc:d:ef?")) != -1) 
    {
      switch (opt) 
        {
          case 'a':
            break;
          case 'b':
            break;
          case 'c':
            break;
          case 'd':
            break;
          case 'e':
            fprintf (stderr, "Flipping opterr.\n");
            opterr = ! opterr;
            break;
          case 'f':
            break;
          default: 
            fprintf (stderr, "Invalid argument: %c\n", optopt);
            fprintf (stderr, "  Usage: %s [-a] [-b] [-c arg] [-d arg] [-e] [-f [arg]] file0 file1 ...\n",
                    argv[0]);
            break;
        } // switch
      status (stderr, opt, argv, argc);
    } // while

  fprintf (stderr, "DONE PROCESSING OPTIONS\n");
  status (stderr, opt, argv, argc);

  fprintf (stderr, "Remaining strings: ");
  fprintstrings (stderr, argv+optind, argc-optind);
  fprintf (stderr, "\n");

  exit (EXIT_SUCCESS);
} // main