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

typedef unsigned char byte;

const int name_max = 16;

typedef struct _pet
{ char name[name_max], type[name_max];
  int SSN;
  short int length, weight, birth_year;
  char sex;
  byte birth_month, birth_date;
  byte num_legs, num_eyes, num_fins; } pet;

pet * new_pet(const char * NM, const char * TY, int S, int L, int W, int BY, int BM, int BD,
              char SX, int NL, int NE, int NF)
{ pet * p = (pet *)malloc(sizeof(pet));
  strncpy(p->name, NM, name_max);
  strncpy(p->type, TY, name_max);
  p->SSN = S;
  p->length = L;
  p->weight = W;
  p->birth_year = BY;
  p->birth_month = BM;
  p->birth_date = BD;
  p->sex = SX;
  p->num_legs = NL;
  p->num_eyes = NE;
  p->num_fins = NF;
  return p; }

void set_pet_name(pet * p, const char * nm)
{ strncpy(p->name, nm, name_max); }

void print_pet(const pet * p)
{ printf("%.16s the %.16s, SSN %09d, sex %c, born %d-%d-%d\n",
         p->name, p->type, p->SSN, p->sex, p->birth_year, p->birth_month, p->birth_date);
  printf("  %d inches long, %d ounces, %d legs, %d eyes, %d fins.\n\n",
         p->length, p->weight, p->num_legs, p->num_eyes, p->num_fins); }

int main()
{ pet * array[20];
  int i;
  printf("sizeof(pet) is %d\n", sizeof(pet));
  array[0] = new_pet("Tom",     "cat",      635287163,  28,    9*16, 2004, 11,  3, 'M', 4, 2, 0);
  array[1] = new_pet("Stumpy",  "dog",       32283673,  24,   12*16, 2003,  7,  4, 'M', 3, 2, 0);
  array[2] = new_pet("Goldie",  "goldfish", 733283721,   2,       1, 2011, 12, 14, 'F', 0, 2, 5);
  array[3] = new_pet("Orangey", "goldfish", 273381721,   2,       2, 2012,  3, 28, 'M', 0, 2, 5);
  array[4] = new_pet("Millie",  "dog",      131231912,  45,   67*16, 2006, 10, 10, 'F', 4, 2, 0);
  array[5] = new_pet("Fluffy",  "elephant", 936253176, 110, 2023*16, 1997,  6, 13, 'F', 4, 2, 0);
  array[6] = new_pet("Cordelia","poodle",    43244365,  28,     160, 2009,  9, 23, 'F', 4, 1, 0);
  array[7] = new_pet("Jimbo",   "snake",    236283931, 175,   41*16, 2007,  9, 25, 'M', 0, 2, 0);
  array[8] = new_pet("Polly",   "parrot",   538901046,  10,      40, 1975,  5, 31, 'F', 2, 2, 0);
  array[9] = new_pet("Pugh",    "conch",    065172614,  12,      52, 1999,  4, 17, 'M', 0, 0, 0);
  array[10]= new_pet("Hammy",   "hamster",  185782394,   4,       4, 2010, 12, 15, 'F', 4, 2, 0);
  array[11]= NULL;

  printf("Cordelia is at address %d\n", array[6]);
  printf("Jimbo is at address    %d\n", array[7]);
  printf("the difference is %d\n", (int)array[7] - (int)array[6]);

  set_pet_name(array[6], "Princess Cordelia Persephone Fluffiness Ponyweather Penelope Cutiepie Chorlmondeley-Featherstonehaugh III");

  for (i = 0; array[i] != NULL; i += 1)
    print_pet(array[i]);

  for (i = 0; array[i] != NULL; i += 1)
    free(array[i]); }