#include <stdio.h>
#define LIST_HEAD_INIT(name) { &(name), &(name) }
#define list_for_each_entry(obj, head, list) for (obj = (typeof(*obj) *)((char *)((&head)->next) - (char *) &((typeof(*obj) *)0)->list); &obj->list != (&head); obj = (typeof(*(obj)) *)((char *)((obj)->list.next) - (char *) &((typeof(*(obj)) *)0)->list))
struct list_head {
struct list_head *next, *prev;
};
struct student {
// 通过相对偏移量可以计算所在结构体首地址
struct list_head list;
int age;
};
struct list_head students = LIST_HEAD_INIT(students);
void list_add(struct list_head *new, struct list_head *head) {
struct list_head* prev = head;
struct list_head* next = head->next;
next->prev = new;
new->next = next;
new->prev = prev;
prev->next = new;
}
void list_del(struct list_head *entry) {
struct list_head* prev = entry->prev;
struct list_head* next = entry->next;
next->prev = prev;
prev->next = next;
}
void add_student(struct student* s) {
// 把list插入到students后面
list_add(&s->list, &students);
}
void del_student(struct student* s) {
list_del(&s->list);
}
void print_all_students_age() {
struct student* s;
list_for_each_entry(s, students, list) {
printf(" %d", s->age);
}
printf("\n");
}
int main() {
struct student s1 = {.age = 16};
struct student s2 = {.age = 17};
struct student s3 = {.age = 18};
add_student(&s1);
add_student(&s2);
add_student(&s3);
print_all_students_age();
del_student(&s2);
print_all_students_age();
return 0;
}
![](https://img2023.cnblogs.com/blog/1230454/202312/1230454-20231212221250426-1399845716.png)