/* From: http://www.gnu.org/software/libc/manual/html_node/Getopt.html */
/* Should also look at getopt_long for gnu style long string option specifier*/

#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
     
int main (int argc, char **argv)
{
  
  int aflag = 0;
  
  int bflag = 0;

  int dvalue = 0;
  
  double fvalue = 0.0;

  char *cvalue = NULL;
  
  int index;
  
  int c;
  
  opterr = 0;
  
  while ((c = getopt (argc, argv, "abc:d:f:")) != -1)
    switch (c)
      {
	     
      case 'a':
	     
	aflag = 1;
	     
	break;
	     
      case 'b':
	     
	bflag = 1;
	     
	break;
	     
      case 'c':
	     
	cvalue = optarg;
	     
	break;

      case 'd':
	     
	dvalue = atoi(optarg);
	     
	break;

      case 'f':
	     
	fvalue = atof(optarg);
	     
	break;
	     
      case '?':
	     
	if (isprint (optopt))
	  fprintf (stderr, "Unknown option `-%c'.\n", optopt);
	     
	else
	  fprintf (stderr,
		   "Unknown option character `\\x%x'.\n", optopt);
	     
	return 1;
	     
      default:

	if (isprint (optopt))
	  fprintf (stderr, "Unknown option `-%c'.\n", optopt);
	     
	else
	  fprintf (stderr,
		   "Unknown option character `\\x%x'.\n", optopt);

	break;
	/* abort (); */
	     
      }
  
     
  printf ("aflag = %d, bflag = %d, cvalue = %s dvalue = %d fvalue=%lf\n",
               aflag, bflag, cvalue, dvalue, fvalue);
  
  for (index = optind; index < argc; index++)
    printf ("Non-option argument %s\n", argv[index]);
  
  return 0;
  
}