Linux内核之旅 链表实现

#include "stdio.h"
#include "stdlib.h"

struct list_head{
    struct list_head *prev;
    struct list_head *next;
};

struct task{
    int member;
    struct list_head list;
};

#define list_entry(ptr,member,type) 
((type*)((char *)ptr-(unsigned long)&(((type*)0)->member)))

#define Init_list(list) {&list,&list}

 static  void list_add(struct list_head* ptr,struct list_head* n){
    ptr->next=n->next;
    n->next->prev=ptr;
    n->next=ptr;
    ptr->prev=n;
}

#define for_each(list_)
for(pos=list_.next;pos!=&list_;pos=pos->next)
{printf("%d ",list_entry(pos,list,struct task)->member);}
printf("
");


void main(){
    struct task* tmp;
    int i;
    struct list_head mylist=Init_list(mylist),*pos;

    for( i=0;i<5;i++){
        tmp=(struct task*)malloc(sizeof(struct task));
        scanf("%d",&(tmp->member));
        list_add(&(tmp->list),&mylist);
    }
    
    for_each(mylist);

}