linux 内核链表

#ifndef CHAIN_H
#define CHAIN_H
#include "../apue.h"
//指针域
struct list_head
{
    struct list_head *pre;
    struct list_head *next;
};

//节点
struct node
{
    struct in_addr addr;//数据域
    struct list_head list;
};

#endif

1 #include <stdio.h>
  2
  3 struct node
  4 {
  5 int date;
  6 int age;
  7 };
  8
  9 int main()
 10 {
 11     struct node model;
 12     struct node *pnode;
 13     pnode =&model;
 14     pnode->date=3;
 15     pnode->age=20;
 16
 17 #if 1
 18     printf("%d\n", ((struct node *)((unsigned long )(&(pnode->age)) -((unsigned long)&(((struct node *)0)->age))))->age);
 19
 20 #endif
 21
 22 }

#include "./chain.h"
#include "../apue.h"
//初始化节点
void init_node(struct node **phead, int size, struct in_addr addr)
{
    *phead=malloc(size);
    (*phead)->addr=addr;
    (*phead)->list.pre =&(*phead)->list;
    (*phead)->list.next=&(*phead)->list;
}
//向链表出入数据
void insert_head_chain(struct list_head *pre, struct list_head *next, struct list_head *pnew)
{
    pnew->next=next;
    pnew->pre=pre;
    pre->next=pnew;
    next->pre=pnew;
}
void insert_chain(struct list_head *phead, struct list_head *pnew)
{
      //insert_head_chain(phead, pnew, phead->next);
      insert_head_chain(phead->pre, phead, pnew);
}
//创建链表,并向链表中插入数据
void add_chain(struct node *phead, struct in_addr user_addr)
{
    int i=0;
    struct node *pnew=NULL;
  // for(i=0; i<num; i++)
  // {
        init_node(&pnew, sizeof(struct node), user_addr);
        insert_chain(&phead->list, &pnew->list);
  // }
}
#define list_entry(mem_addr, type, member) ((type *)(((unsigned long)mem_addr)-((unsigned long)&( ((type *)0)->member))))
//遍历链表
void show_chain(struct list_head *phead)
{
    struct node *p=NULL;
    struct list_head *index=NULL;
    for(index=phead->next; index!=phead; index=index->next)
    {
       p=list_entry(index, struct node, list);
       printf("%d->", p->addr);
    }
    printf("在线好友\n");
    return ;
}
//搜索好友
//struct in_addr select_chain(struct list_head *phead, struct in_addr user_addr)
in_addr_t  select_chain(struct list_head *phead, struct in_addr user_addr)
{
    struct node *p=NULL;
    struct list_head *index=NULL;
    for(index=phead->next; index!=phead; index=index->next)
    {
       p=list_entry(index, struct node, list);
       if(p->addr.s_addr==user_addr.s_addr)
       {
           return user_addr.s_addr;
       }
    }
    return 0;
}
//修改链接
void del_list(struct list_head *del)
{
    del->pre->next=del->next;
    del->next->pre=del->pre;
}

//处理下线好友
int delete_chain(struct list_head *phead, struct in_addr user_addr)
{
    struct node *p=NULL;
    struct list_head *index=NULL;
    for(index=phead->next; index!=phead; index=index->next)
    {
       p=list_entry(index, struct node, list);
       if(p->addr.s_addr==user_addr.s_addr)
       {
            del_list(index);
            free(p);
            return 1;
       }
    }
    return 0;
}