Generic Linked List

typedef struct list {

void *data;

struct list *next;

} List;

int main(void)

{

List *list1, *list2, *list3, *list4;

char c[] = { 'a', 'b', 'c', 'd' };

int i[] = { 1, 2, 3, 4 };

char *str[] = { "hello1", "hello2", "hello3", "hello4" };

list1 = list2 = list3 = list4 = NULL;

insert(&list1, &c[0], sizeof(char));

insert(&list1, &c[1], sizeof(char));

insert(&list1, &c[2], sizeof(char));

insert(&list1, &c[3], sizeof(char));

insert(&list2, &i[0], sizeof(int));

insert(&list2, &i[1], sizeof(int));

insert(&list2, &i[2], sizeof(int));

insert(&list2, &i[3], sizeof(int));

insert(&list3, str[0], strlen(str[0])+1);

insert(&list3, str[1], strlen(str[0])+1);

insert(&list3, str[2], strlen(str[0])+1);

insert(&list3, str[3], strlen(str[0])+1);

insert(&list4, &chk[0], sizeof chk[0]);

insert(&list4, &chk[1], sizeof chk[1]);

insert(&list4, &chk[2], sizeof chk[2]);

printf("Printing characters:");

print(list1, printchar);

printf(" : done\n\n");

printf("Printing integers:");

print(list2, printint);

printf(" : done\n\n");

printf("Printing strings:");

print(list3, printstr);

printf(" : done\n\n");

printf("Printing composite:");

print(list4, printcomp);

printf(" : done\n");

return 0;

}

void insert(List **p, void *data, unsigned int n)

{

    List *temp;

    int i;

     /* Error check is ignored */

    temp = malloc(sizeof(List));

     temp->data = malloc(n);

     for (i = 0; i < n; i++)

        *(char *)(temp->data + i) = *(char *)(data + i);

     temp->next = *p;

     *p = temp;

}

void print(List *p, void (*f)(void *))

{

     while (p)

     {

           (*f)(p->data);

         p = p->next;

       }

}

void printstr(void *str)

{

printf(" \"%s\"", (char *)str);

}

void printint(void *n)

{

printf(" %d", *(int *)n);

}

void printchar(void *c)

{

printf(" %c", *(char *)c);

}