注意: 1.使用时包含头文件<List.h>
2.或者<tls.h>
3.如果头文件不存在就将以下代码另存且包含: include "list.h"
4.Linux内核在<linux/list.h>目录下也提供了链表操作函数, 但是接口不太一样, 但是功能更全
以下是源代码及其使用方法:
#ifndef _LIST_H
#define _LIST_H 1/* The definitions of this file are adopted from those which can befound in the Linux kernel headers to enable people familiar withthe latter find their way in these sources as well. *//* Basic type for the double-link list. */
typedef struct list_head
{struct list_head *next;struct list_head *prev;
} list_t;// 定义/创建一个名为name的链表头, 上一项自己, 下一项也指向自己
/* Define a variable with the head and tail of the list. */
#define LIST_HEAD(name) \list_t name = { &(name), &(name) }// 将传入的ptr作为链表头
/* Initialize a new list head. */
#define INIT_LIST_HEAD(ptr) \(ptr)->next = (ptr)->prev = (ptr)/* 紧挨着链表头增加新节点(节点不包含数据)head new(节点) 2
*/
/* Add new element at the head of the list. */
static inline void
list_add (list_t *newp, list_t *head)
{head->next->prev = newp; // 2的上一项是newnewp->next = head->next; // new的下一项是2newp->prev = head; // new的上一项是headhead->next = newp; // head的下一项是new
}/* 添加新元素到链表尾部head 1 2 3 new
*/
/* Add new element at the tail of the list. */
static inline void
list_add_tail (list_t *newp, list_t *head)
{head->prev->next = newp; // 3的下一项是newnewp->next = head; // new的下一项时headnewp->prev = head->prev; // new的上一项时3head->prev = newp; // 头的上一项new
}/* 删除指定元素:(1) 1 elem 2(2) 当链表中只有链表头时, 链表头没有没删除(因为节点不包含数据)head // 自己的上一项是自己// 自己的下一项也是自己
*/
/* Remove element from list. */
static inline void
list_del (list_t *elem)
{elem->next->prev = elem->prev; // 2的上一项是1elem->prev->next = elem->next; // 1的下一项时2
}/* 拼接两个链表:1.如果新增的链表只有一个链表头就不做任何处理(因为链表头不包含数据)2. (head 2) + (add 4 5) ==> (head (5 6) 2 3) // 抛弃链表头add
*/
/* Join two lists. */
static inline void
list_splice (list_t *add, list_t *head)
{/* Do nothing if the list which gets added is empty. */if (add != add->next){add->next->prev = head; // 5的上一项是headadd->prev->next = head->next; // 6的下一项是2head->next->prev = add->prev; // 2的上一项是6head->next = add->next; // head的下一项是5}
}// 根据节点ptr的地址,得到其type结构体的首地址, member是type结构体中的节点变量名
/* Get typed element from list at a given position. */
#define list_entry(ptr, type, member) \((type *) ((char *) (ptr) - (unsigned long) (&((type *) 0)->member)))// 从第一个节点(head的下一项开始, 向后遍历head链表中的所有节点)
/* Iterate forward over the elements of the list. */
#define list_for_each(pos, head) \for (pos = (head)->next; pos != (head); pos = pos->next)// 从第最后一个节点(head的上一项开始, 向前遍历head链表中的所有节点)
/* Iterate forward over the elements of the list. */
#define list_for_each_prev(pos, head) \for (pos = (head)->prev; pos != (head); pos = pos->prev)// 1.从第最后一个节点(head的上一项开始, 向前遍历head链表中的所有节点)
// 2.当遍历过程中需要删除节点时, 用此函数
// 3.如果使用list_for_each_prev, 在删除节点后pos = pos->prev会出错
/* Iterate backwards over the elements list. The list elements can beremoved from the list while doing this. */
#define list_for_each_prev_safe(pos, p, head) \for (pos = (head)->prev, p = pos->prev; \pos != (head); \pos = p, p = pos->prev)#endif /* list.h */