getopt and getsubopt C

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



int
main (int argc, char **argv)
{

enum
{
   T, TH, D, BUTT
};

const char *other_options[]=
{
   [T] = "t",
   [TH] = "u",
   [D] = "cc",
   [BUTT] = NULL
};


  int aflag = 0;
  int bflag = 0;
  char *cvalue = NULL;
  int index;
  int c;

  opterr = 0;

  /* for subopts within opts */
   char *subopts;
   char *value;
 /* required arguments use : after them
    optional arguments :: after them */
  static char string_options[]=
  "ab::c:df::e:";
  static struct option long_options[]=
  { /* required_argument 1 { : }
       optional_argument 2 { ::} */
    {"alpha",0,0,'a'},
    {"beta",0,0,'b'},
    {"charlie",1,0,'c'},
    {"delta",0,0,'d'},
    {"echo",1,0,'e'},
    {"foxtrot",0,0,'f'},
    {0,0,0,0} // required at end
  };
  while ((c = getopt_long_only (argc, argv,
    string_options,long_options,
    &index)) != -1)
  {
    switch (c)
      {
      case 'a':
        aflag = 1;
        printf("alpha %s: aflag=%d\n",
    optarg,aflag);
        break;
      case 'b':
        bflag = 1;
        printf("beta %s: bflag=%d\n",
    optarg,bflag);
        break;
      case 'c':
    if(optarg == NULL)
       printf("argument is required\n");
        cvalue = optarg;
    printf("\ncvalue= %s\noptarg= %s\n",
        cvalue,optarg);
        break;
     case 'd':
     printf("delta\n");
    break;
      case '?':
        if (optopt == 'c')
          fprintf (stderr, "Option -%c "
    "requires an argument.\n", optopt);
        else if (isprint (optopt))
          fprintf (stderr, "Unknown option"
    "  `-%c'.\n", optopt);
        else
          fprintf (stderr,
                   "Unknown option "
        "character `\\x%x'.\n",
                   optopt);
           break;
      case 'e':
         subopts=optarg;
          while(*subopts != '\0')
          {
        switch(getsubopt(&subopts,
                   (char **)other_options,
                  &value))
           {  //cli ./programName -e t=value

            case T:
                 if(value == NULL)
                printf("value in"
            " subopt not "
            "present\n");
            else
            printf("subopt value\n"
                " = %s\n",value);
            break;
        default:
        printf("unknown < %s >\n",
            value);
        exit(1);
        break;
       } //end switch subopt
            break;
    }//end while subopt
        case 'f':
            printf("foxtrot\n");
        break;
      default:
           abort ();
       break;
      } // end 1st switch
  } // 1st while
  printf ("aflag = %d, bflag = %d, cvalue = %s\n",
          aflag, bflag, cvalue);

  for (index = optind; index < argc; index++)
    printf ("Non-option argument %s\n",
             argv[index]);

return 0;
}