#include <stdio.h>
#include <assert.h>
#include <stdlib.h>
#include <string.h>
struct Person {
 char *name;
 int age;
 int height;
 int weight;
};
struct Person *Person_create(char *name, int age, int height, int weight)
{
 struct Person *who = malloc(sizeof(struct Person));
 assert(who != NULL);
 who->name = strdup(name);
 who->age = age;
 who->height = height;
 who->weight = weight;
 return who;
}
void Person_destroy(struct Person *who)
{
 assert(who != NULL);
 free(who->name);
 free(who);
}
void Person_print(struct Person *who)
{
 printf("Name: %s\n", who->name);
 printf("\tAge: %d\n", who->age);
 printf("\tHeight: %d\n", who->height);
 printf("\tWeight: %d\n", who->weight);
}
int main(int argc, char *argv[])
{
 // make two people structures
 struct Person *joe = Person_create(
 "Joe Alex", 32, 64, 140);
 struct Person *frank = Person_create(
 struct Person *frank = Person_create(
 "Frank Blank", 20, 72, 180);
 // print them out and where they are in memory
 printf("Joe is at memory location %p:\n", joe);
 Person_print(joe);
 printf("Frank is at memory location %p:\n", frank);
 Person_print(frank);
 // make everyone age 20 years and print them again
 joe->age += 20;
 joe->height -= 2;
 joe->weight += 40;
 Person_print(joe);
 frank->age += 20;
 frank->weight += 20;
 Person_print(frank);
 // destroy them both so we clean up
 Person_destroy(joe);
 Person_destroy(frank);
 return 0;
}