C语言双向循环链表api（源自gluster源码）

2019-07-21 07:44发布

C语言双向循环链表api（源自gluster源码），基本的操作如增加、删除和遍历等。#include <stdio.h>
#include <stdlib.h>
#include <string.h>/*定义表头*/
struct list_head {
struct list_head *next;
struct list_head *prev;
};/*表头初始化*/
#define INIT_LIST_HEAD(head) do {
      (head)->next = (head)->prev = head;
} while (0)/*增加*/
static inline void
list_add (struct list_head *new, struct list_head *head)
{
new->prev = head;
new->next = head->next; new->prev->next = new;
new->next->prev = new;
}/*删除*/
static inline void
list_del (struct list_head *old)
{
old->prev->next = old->next;
old->next->prev = old->prev; old->next = (void *)0xbabebabe;
old->prev = (void *)0xcafecafe;
}/*判断链表是否为空*/
static inline int
list_empty (struct list_head *head)
{
return (head->next == head);
}#define list_entry(ptr, type, member)
((type *)((char *)(ptr)-(unsigned long)(&((type *)0)->member)))#define list_for_each(pos, head)
for (pos = (head)->next; pos != (head); pos = pos->next)/*遍历，关于list_for_each_entry，百度*/
#define list_for_each_entry(pos, head, member)
for (pos = list_entry((head)->next, typeof(*pos), member);
      &pos->member != (head);
      pos = list_entry(pos->member.next, typeof(*pos), member))/*例：先定义一个结构体*/
typedef struct student
{
int num;       //学号
int score;    //分数
char name[20];
struct list_head student_list;
}STU;STU *head=NULL;int main(void)
{
STU *new=NULL; new = (STU *)malloc(sizeof(STU));
bzero(new, sizeof(STU));
new->num = 8;
new->score = 8;
strcpy(new->name, "8888");
/*链表初始化*/
if(head == NULL)
{
      // head = (STU *)malloc(sizeof(STU));
      // bzero(head, sizeof(STU));
      head = new;
      INIT_LIST_HEAD(&head->student_list);
}
else
{
      list_add(&new->student_list, &head->student_list);
} if(list_empty(&head->student_list))
{
      printf("list only head ");
      printf("head->num:%d, score:%d, name:%s ", head->num, head->score, head->name);
}
/*将新成员插入链表*/
int i;
for(i=0;i<5;i++)
{
      new = (STU *)malloc(sizeof(STU));
      bzero(new, sizeof(STU));
      new->num = i;
      new->score = i+1;
      strcpy(new->name, "2233");
      list_add(&new->student_list, &head->student_list);
}
/*删除指定的成员*/
STU *pos=NULL;
list_for_each_entry(pos, &head->student_list, student_list)
{
      if(pos->num == 2){
         list_del(&pos->student_list);
         free(pos);
         pos = NULL;
         break;
         // printf("num:%d, score:%d, name:%s ", pos->num, pos->score, pos->name);
      }
}
/*遍历链表*/
list_for_each_entry(pos, &head->student_list, student_list)
{
      printf("num:%d, score:%d, name:%s ", pos->num, pos->score, pos->name);
}
return 0;
}示例输出：list only head
head->num:8, score:8, name:8888
num:4, score:5, name:2233
num:3, score:4, name:2233
num:1, score:2, name:2233
num:0, score:1, name:2233
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