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

#define LEN 6 

int scmp( const void *sp1, const void *sp2 )
{
    return( strcmp(*(char **)sp1, *(char **)sp2) );
}

int scmp_lastChar( const void * p1, const void * p2 )
{

  char ** pStr1 = (char **) p1;
  char ** pStr2 = (char **) p2;

  char * str1 = *pStr1;
  char * str2 = *pStr2;

  char l1 = str1[strlen(str1)-1];
  char l2 = str2[strlen(str2)-1];

  if(l1<l2) return -1;
  else if(l1 == l2) return 0;
  else return 1;
}

int main()
{
  int i;
  char * str_arr[LEN]
    = {"apple", "beta", "aardvark", "arrow", "zebra","aligator"};

  /* print unsorted dates */
  printf ("Printing unsorted string ... \n");
  for (i=0;i<LEN;i++) {
    printf("Str %2d: %s\n",i,str_arr[i]);
  }
  printf ("\n");

  /* call qsort */
  qsort(str_arr, LEN, sizeof(char *), scmp_lastChar);

  printf ("Printing sorted dates ... \n");
  for (i=0;i<LEN;i++) {
    printf("Str %2d: %s\n",i,str_arr[i]);
  }
  printf ("\n");

  return 0;
}