Đóng gói & thư viện

stack.h - opaque (chỉ lộ interface)

#ifndef STACK_H
#define STACK_H

typedef struct Stack Stack;   /* kieu CHUA HOAN CHINH (incomplete) */

Stack *stack_create(void);          /* tao moi; tra NULL neu het bo nho */
void   stack_push(Stack *s, int x);
int    stack_pop(Stack *s);         /* yeu cau stack khong rong */
int    stack_empty(const Stack *s);
void   stack_destroy(Stack *s);     /* giai phong (nhan NULL an toan) */

#endif

stack.c - định nghĩa struct được giấu ở đây

#include <stdlib.h>
#include "stack.h"

struct Stack {              /* CHI file nay biet bo cuc */
    int *data;
    int len, cap;
};

Stack *stack_create(void) {
    Stack *s = malloc(sizeof *s);
    if (!s) return NULL;
    s->data = NULL; s->len = s->cap = 0;
    return s;
}

void stack_destroy(Stack *s) {
    if (!s) return;          /* free(NULL) an toan, nhung kiem tra cho ro */
    free(s->data);
    free(s);
}
/* push / pop / empty: thao tac s->... ben trong .c */

main.c - dùng thư viện stack

#include "stack.h"      /* chi can interface */

int main(void) {
    Stack *s = stack_create();
    if (!s) return 1;          /* luon kiem tra */
    stack_push(s, 1);
    stack_push(s, 2);
    int top = stack_pop(s);    /* 2 */
    stack_destroy(s);          /* nguoi tao chiu trach nhiem giai phong */

    /* s->len;  sizeof(Stack);  Stack x;  -> LOI: kieu chua hoan chinh */
    return 0;
}

cấu trúc thư mục

myproject/
├── include/          # header CONG KHAI (API) -> nguoi ngoai #include
│   └── stack.h
├── src/              # implementation (.c) + header noi bo neu can
│   └── stack.c
├── tests/            # unit test
│   └── test_stack.c
├── CMakeLists.txt    # build (xem khoa Toolchain)
└── README.md         # gioi thieu, cach build & dung