博主分享了一段初学者的Linux C语言编程经验，利用内核提供的链表接口实现了一个简单的航班查询程序。尽管作者自谦为新人，但通过实践内核链表操作展示了学习过程。
之所以把这个代码称为一个程序而不叫一个项目，是因为鄙人还是个还没入行的新人，不敢妄自菲薄，只因一时兴起上来感慨吐槽一番，如果有什么不对的地方，请各位大牛高台贵手，如果能提点一番，小弟感激不尽
废话不多，拿到题目就开干。
刚学完内核链表，就拿它来开刀。内核给你写好封装一些链表操作的接口函数，拿来用多爽，不用自己写。这个写好的东西在哪呢，在内核目录的include/linux/下。
#include
#include
#include
#include "kernel_list.h"
struct flight
{
char flight_id[15]; //航班号 //航班号
char flight_place[15]; //航班起飞站->终点站 //买票者的名字
char flight_time[15]; //起飞时间 //买到的票的座位号
int flight_seat; //航班总座位数 //票的张数
float price; //机票价格 //花费的金额
int remain; //剩余座位数
char st[15]; //座位标志
struct list_head mylist;
};
// 内核链表的初始化
struct flight * list_init()
{
struct flight *head=malloc(sizeof(struct flight));
INIT_LIST_HEAD(&(head->mylist));
return head;
}
//判断链表是否为空
int kernellist_empty(struct flight *head)
{
return list_empty(&(head->mylist));
}
// 创建新的节点
struct flight * new_node(char *flight_id,char *flight_place,char *flight_time,int flight_seat,float price)
{
struct flight *new=malloc(sizeof(struct flight));
strcpy(new->flight_id,flight_id);
strcpy(new->flight_place,flight_place);
strcpy(new->flight_time,flight_time);
new->flight_seat=flight_seat;
new->remain=flight_seat;
new->price=price;
bzero(new->st,15);
INIT_LIST_HEAD(&(new->mylist));
return new;
}
// 添加新的节点到内核链表中 添加到head的前面
int kernellist_add(struct flight *new,struct flight *head)
{
list_add_tail(&(new->mylist), &(head->mylist));
return 0;
}
//添加到head的后面
int kernellist_add_tail(struct flight *new,struct flight *head)
{
list_add(&(new->mylist), &(head->mylist));
return 0;
}
//删除一个节点
int kernellist_del(struct flight *del)
{
list_del(&(del->mylist));
return 0;
}
// 打印航班信息
int show(struct flight *head)
{
if(kernellist_empty(head))
{
printf("no any flight exist!\n");
return 1;
}
printf("----------------------------------------------------------\n");
printf("flight_id flight_place flight_time flight_seat price\n");
struct flight *pos;
list_for_each_entry(pos,&(head->mylist),mylist) //该宏函数实际是个for循环
//for (pos = list_entry((head)->next, typeof(*pos), member); &pos->member != (head); pos = list_entry(pos->member.next, typeof(*pos), member))
{
printf("%-16s%-16s%-16s%-13d%.2f\n",pos->flight_id,pos->flight_place,pos->flight_time,pos->flight_seat,pos->price);
}
printf("----------------------------------------------------------\n");
return 0;
}
//打印卖票信息
int show_ticket(struct flight *head)
{
int i;
if(kernellist_empty(head))
{
printf("no bodey buy ticket!\n");
return 0;
}
printf("----------------------------------------------------------\n");
printf("flight_id name num price ticketnum\n");
struct flight *pos;
list_for_each_entry(pos,&(head->mylist),mylist) //该宏函数实际是个for循环
//for (pos = list_entry((head)->next, typeof(*pos), member); &pos->member != (head); pos = list_entry(pos->member.next, typeof(*pos), member))
{
printf("%-16s%-16s%-16d%-8.2f",pos->flight_id,pos->flight_place,
pos->flight_seat,pos->price);
for(i=0;i<15;i++)
{
if(pos->flight_time[i] == 1)
printf("%d ",i+1);
}
printf("\n");
}
printf("----------------------------------------------------------\n");
return 0;
}
//翻转航班信息
int reversal(struct flight *head)
{
struct list_head *pos;
pos = head->mylist.next;
while(pos->next != &(head->mylist))
list_move_tail(head->mylist.prev,pos);
return 0;
}
//航班信息排序
int flight_sort(struct flight *head)
{
int choose;
struct list_head *posi;
struct list_head *posj;
struct list_head *temp;
while(1)
{
printf( "====================================================================\n"
"[1]flight_id [2]flight_time [3]price [4]reversal [5]show [0]quit\n"
"====================================================================\n");
if(scanf("%d",&choose) != 1 || getchar()!='\n') //判断是否正确输入
{
choose=6;
while(getchar() != '\n');
}
switch(choose)
{
case 0:
return 0;
break;
case 1:
list_for_each(posi,&(head->mylist))
//for (posi = head->mylist.next; posi != &(head->mylist);posi = posi->next)
{
for (posj = posi->next; posj != &(head->mylist);posj = posj->next)
{
if(strcmp(list_entry(posi,struct flight,mylist)->flight_id,list_entry(posj,struct flight,mylist)->flight_id)==1)
{
temp = posi->prev;
list_move(posi,posj);
list_move(posj,temp);
temp=posi;
posi = posj;
posj = temp;
}
}
}
break;
case 2:
list_for_each(posi,&(head->mylist))
//for (posi = head->mylist.next; posi != &(head->mylist);posi = posi->next)
{
for (posj = posi->next; posj != &(head->mylist);posj = posj->next)
{
if(strcmp(list_entry(posi,struct flight,mylist)->flight_time,list_entry(posj,struct flight,mylist)->flight_time)==1)
{
temp = posi->prev;
list_move(posi,posj);
list_move(posj,temp);
temp=posi;
posi = posj;
posj = temp;
}
}
}
break;
case 3:
list_for_each(posi,&(head->mylist))
//for (posi = head->mylist.next; posi != &(head->mylist);posi = posi->next)
{
for (posj = posi->next; posj != &(head->mylist);posj = posj->next)
{
if(list_entry(posi,struct flight,mylist)->price>list_entry(posj,struct flight,mylist)->price)
{
temp = posi->prev;
list_move(posi,posj);
list_move(posj,temp);
temp=posi;
posi = posj;
posj = temp;
}
}
}
break;
case 4:
reversal(head);
show(head);
break;
case 5:
show(head);
break;
default:
printf("invalid input !!\n"); //输入错误
break;
}
}
}
//买票
int flight_buy(struct flight *head,struct flight *masg)
{
int i;
int count = 0;
char str[15]; //存放买票的航班号
char name[15]; //存放买票的名字
char seat[15];
memset(seat,2,15); //临时存放座位号 由于后面使用strcpy 所以不能用0
struct flight *pos;
int ticket; //买票的张数
struct flight *mynewnode;
struct flight *n;
show(head);
while(1)
{
printf("enter flight id you want buy or quit to back primary menu\n");
gets(str);
if(strcmp(str, "quit") == 0)
break;
list_for_each_entry(pos,&(head->mylist),mylist)
{
if(strcmp(str,pos->flight_id) == 0) //查找航班号
{
printf("enter how many you want buy\n");
// scanf("%d",&ticket);
// getchar();
lable1: if(scanf("%d",&ticket) != 1 || getchar()!='\n') //判断是否正确输入
{
while(getchar() != '\n');
printf("invalid intput! try again\n");
goto lable1;
}
if(ticket<=0) //输入的票数小于等于0
{
printf("invalid intput! try again\n");
goto lable1;
}
printf("%s flight have %d tickets!\n",pos->flight_id,pos->remain);
if(ticket > pos->remain) //余票不足
{
printf("no have more tickets!\n");
}
else
{
printf("please enter you name!\n");
gets(name);
printf("you tiickets numbel is:\n");
for(i=0;i<15;i++) //分配座位号
{
if(pos->st[i] != 1)
{
pos->st[i]=1;
count++;
seat[i]=1;
printf("%d\t",i+1);
}
if(count>=ticket)
{
count=0;
break;
}
}
printf("\n");
if(kernellist_empty(masg)) //买票链表为空
{
mynewnode = new_node(str,name,seat,ticket,ticket*pos->price);
kernellist_add(mynewnode,masg);
}
else
{
list_for_each_entry(n,&(masg->mylist),mylist) //查找是否有相同的票
{
if(strcmp(name,n->flight_place) == 0 && strcmp(str,n->flight_id) == 0) //有相同的票则票数量添加
{
n->flight_seat+=ticket;
n->price+=ticket*pos->price;
for(i=0;i<15;i++)
{
if(seat[i] == 1)
n->flight_time[i]=1;
}
break;
}
if(n->mylist.next==&(masg->mylist)) //没有则建立一个新的结构体存放
{
mynewnode = new_node(str,name,seat,ticket,ticket*pos->price);
kernellist_add(mynewnode,masg);
break;
}
}
}
printf("succeed buy tickets!\n");
pos->remain -= ticket; //余票减少
}
break;
}
if(pos->mylist.next==&(head->mylist)) //没有查找到航班号
printf("no such flight exist!\n");
}
memset(seat,2,15); //清空座位号
}
}
//退票
int unticket(struct flight *p,struct flight *masg)
{
int i;
int ticketnum; //退票数量
int count=0;
char str[15]; //名字
char strid[15]; //航班号
struct flight *pos;
struct flight *pos1;
while(1)
{
printf("please enter you name or quit to back!\n");
gets(str);
if(strcmp(str, "quit") == 0)
break;
printf("flight_id name num price\n");
list_for_each_entry(pos,&(masg->mylist),mylist)// 双向链表没有遍历完
{
if(strcmp(str,pos->flight_place) == 0)
{
printf("%-16s%-16s%-16d%.2f\n",pos->flight_id,pos->flight_place,pos->flight_seat,pos->price);
// if(pos->flight_seat > 1)
// {
// pos->flight_seat -= 1;
// }
// else
// kernellist_del(pos);
// break;
count++;
}
// if(pos->mylist.next==&(masg->mylist))
// printf("no such ticket exist!\n");
}
if(count==0) //你没有买票
printf("no such ticket exist!\n");
else if(count > 1) //你买了两种以上
{
printf("please enter you want flight id unticket!\n");
gets(strid);
list_for_each_entry(pos,&(masg->mylist),mylist)
{
if(strcmp(str,pos->flight_place) == 0 && strcmp(strid,pos->flight_id) == 0)
{
printf("you have ticket numbel is \n");
// printf("flight_id name num price\n");
// printf("%-16s%-16s%-16d%.2f\n",pos->flight_id,pos->flight_place,pos->flight_seat,pos->price);
for(i=0;i<15;i++)
{
if(pos->flight_time[i] == 1)
printf("%d\t",i+1);
}
printf("\n");
printf("how many you want unticket!\n");
lable: if(scanf("%d",&ticketnum) != 1 || getchar()!='\n') //判断是否正确输入
{
while(getchar() != '\n');
printf("invalid intput! try again\n");
goto lable;
}
if(pos->flight_seat < ticketnum || ticketnum <= 0)
{
printf("invalid intput! try again\n");
goto lable;
}
else if(pos->flight_seat == ticketnum) //全退
{
kernellist_del(pos);
list_for_each_entry(pos1,&(p->mylist),mylist)
{
if(strcmp(strid, pos1->flight_id)==0)
{
pos1->remain += ticketnum;
break;
}
}
printf("unticket successful!\n");
}
else // 退ticketnum张
{
pos->flight_seat -= ticketnum; //你拥有的票减少ticketnum张
list_for_each_entry(pos1,&(p->mylist),mylist)
{
if(strcmp(strid, pos1->flight_id)==0)
{
pos1->remain += ticketnum; //剩余的票数增加
break;
}
}
pos->price -= pos1->price*ticketnum; //你付的总价减少
for(i=0;i<15;i++)
{
if(pos->flight_time[i] == 1) //座位号回收 默认从小开始回收
{
pos->flight_time[i]=2;
ticketnum--;
}
if(ticketnum == 0)
break;
}
printf("unticket successful!\n");
}
break;
}
}
}
else if(count==1) //你只买了一种票
{
list_for_each_entry(pos,&(masg->mylist),mylist)
{
if(strcmp(str,pos->flight_place) == 0 )
{
printf("you have ticket numbel is \n");
for(i=0;i<15;i++)
{
if(pos->flight_time[i]==1)
printf("%d\t",i+1);
}
printf("\n");
printf("how many you want unticket!\n");
lable2: if(scanf("%d",&ticketnum) != 1 || getchar()!='\n') //判断是否正确输入
{
while(getchar() != '\n');
printf("invalid intput! try again\n");
goto lable2;
}
if(pos->flight_seat < ticketnum || ticketnum <= 0)
{
printf("invalid intput! try again\n");
goto lable2;
}
else if(pos->flight_seat == ticketnum) //全退
{
kernellist_del(pos);
list_for_each_entry(pos1,&(p->mylist),mylist)
{
if(strcmp(strid, pos1->flight_id)==0)
{
pos1->remain += ticketnum;
break;
}
}
printf("unticket successful!\n");
}
else
{
pos->flight_seat -= ticketnum;
list_for_each_entry(pos1,&(p->mylist),mylist)
{
if(strcmp(strid, pos1->flight_id)==0)
{
pos1->remain += ticketnum;
break;
}
}
pos->price -= pos1->price*ticketnum;
for(i=0;i<15;i++)
{
if(pos->flight_time[i] == 1)
{
pos->flight_time[i]=2;
ticketnum--;
}
if(ticketnum == 0)
break;
}
printf("unticket successful!\n");
}
break;
}
}
}
count = 0;
}
return 0;
}
//管理员执行函数
int admi(struct flight *p, char *password,struct flight *masg)
{
int choose=0;
char str1[15];
char str2[15];
char str3[15];
int seat;
float price;
struct flight *mynewnode;
struct flight *pos;
struct flight *n;
while(1)
{
printf("please enter password!\n");
gets(str1);
if(strcmp(str1,password) != 0)
{
printf("error password!\n");
choose++;
}
else
break;
if(choose == 3)
{
return 1;
}
}
while(1)
{
printf( "************************enter you choice**********************************\n"
"[1]insert [2]remove [3]show [4]clear [5]sort [6]changepassword [0]quit\n"
"**************************************************************************\n");
if(scanf("%d",&choose) != 1 || getchar()!='\n') //判断是否正确输入
{
choose=7;
while(getchar() != '\n');
}
switch(choose)
{
case 0:
return 0;
break;
case 1:
while(1)
{
printf("enter flight id you want add or quit to back primary menu\n");
gets(str1);
if(strcmp(str1, "quit") == 0)
break;
printf("enter the flight place\n");
gets(str2);
printf("enter the flight time\n");
gets(str3);
if(str3[1]==':') //判断时间输入格式，为后面的排序做准备
{
for(seat=4;seat>=0;seat--)
str3[seat+1]=str3[seat];
str3[0]=' ';
}
printf("enter the flight seat\n");
scanf("%d",&seat);
getchar();
printf("enter the flight price\n");
scanf("%f",&price);
getchar();
mynewnode = new_node(str1,str2,str3,seat,price);
printf("you want add the flight who's id next\n"); //插入到哪个航班号的后面
gets(str1);
list_for_each_entry(pos,&(p->mylist),mylist)
{
if(strcmp(str1,pos->flight_id) == 0)
{
kernellist_add_tail(mynewnode,pos);
break;
}
if(pos->mylist.next==&(p->mylist)) //如果没找到默认插到最后一个
{
printf("no such flight exist!\n");
kernellist_add(mynewnode,p);
break;
}
}
}
show(p);
break;
case 2:
while(1)
{
if(kernellist_empty(p)) //如果航班信息为空
{
printf("no any flight exist!\n");
break;
}
printf("enter flight id you want remove or quit to back primary menu\n");
gets(str1);
if(strcmp(str1, "quit") == 0)
break;
list_for_each_entry(pos,&(p->mylist),mylist)// 双向链表没有遍历完
{
if(strcmp(str1,pos->flight_id) == 0)
{
kernellist_del(pos);
break;
}
if(pos->mylist.next==&(p->mylist))
printf("no such flight exist!\n");
}
if(show(p)) //如果航班信息为空打印信息并退出
break;
}
break;
case 3:
while(1)
{
printf( "---------------------------\n"
"please enter you want print\n"
"[1] print flight message\n"
"[2] print ticket message\n"
"[0] quit\n"
"---------------------------\n");
if(scanf("%d",&seat) != 1 || getchar()!='\n') //判断是否正确输入
{
seat=3;
while(getchar() != '\n');
}
if(seat == 1)
{
show(p);
}
else if(seat == 2)
{
show_ticket(masg);
}
else if(seat == 0)
break;
else
printf("invalid input !!\n");
}
break;
case 4:
list_for_each_entry_safe(pos,n,&(p->mylist),mylist) //安全删除条目
{
kernellist_del(pos);
free(pos);
}
break;
case 5:
flight_sort(p);
break;
case 6:
printf("please enter new password!\n");
gets(str1);
printf("please enter new password again!\n");
gets(str2);
if(strcmp(str1,str2) != 0)
printf( "twice enter different!\n"
"change fail!\n");
else
{
strcpy(password,str1);
printf("change succeed!\n");
}
break;
default:
printf("invalid input !!\n"); //输入错误
break;
}
}
return 0;
}
//用户执行函数
int user(struct flight *p,struct flight *masg)
{
int choose;
while(1)
{
printf( "************************enter you choice************************\n"
"[1]buyticket [2]unticket [3]show [4]sort [0]quit\n"
"****************************************************************\n");
if(scanf("%d",&choose) != 1 || getchar()!='\n') //判断是否正确输入
{
choose=5;
while(getchar() != '\n');
}
switch(choose)
{
case 0:
return 0;
break;
case 1:
flight_buy(p,masg);
break;
case 2:
unticket(p,masg);
break;
case 3:
show(p);
break;
case 4:
flight_sort(p);
break;
default:
printf("invalid input !!\n"); //输入错误
break;
}
}
return 0;
}
int main(int argc,char *argv[])
{
int choose;
struct flight *p=list_init();
struct flight *masg=list_init();
char password[15] = "123";
struct flight *mynewnode;
// char st[15]={0};
mynewnode = new_node("A001","gz->jy"," 8:30",6,260);
kernellist_add(mynewnode,p);
mynewnode = new_node("A002","gz->cs","10:30",8,160);
kernellist_add(mynewnode,p);
mynewnode = new_node("A003","gz->hz","12:30",6,185);
kernellist_add(mynewnode,p);
mynewnode = new_node("A004","gz->sz"," 9:50",4,230);
kernellist_add(mynewnode,p);
mynewnode = new_node("A005","gz->hn","22:30",12,175);
kernellist_add(mynewnode,p);
while(1)
{
printf(" Welcome to Flights System\n");
printf( "************************enter you choice************************\n"
"[1]administrator [2]user [0]end\n"
"****************************************************************\n");
//scanf("%d",&choose);
if(scanf("%d",&choose) != 1 || getchar()!='\n') //判断是否正确输入
{
choose=3;
while(getchar() != '\n');
}
switch(choose)
{
case 0:
return 0; //程序结束
break;
case 1:
admi(p, password,masg);
break;
case 2:
user(p,masg);
break;
default:
printf("invalid input !!\n"); //输入错误
break;
}
}
return 0;
}
#ifndef __DLIST_H
#define __DLIST_H
/* This file is from Linux Kernel (include/linux/list.h)
* and modified by simply removing hardware prefetching of list items.
* Here by copyright, credits attributed to wherever they belong.
* Kulesh Shanmugasundaram (kulesh [squiggly] isis.poly.edu)
*/
/*
* Simple doubly linked list implementation.
*
* Some of the internal functions (“__xxx”) are useful when
* manipulating whole lists rather than single entries, as
* sometimes we already know the next/prev entries and we can
* generate better code by using them directly rather than
* using the generic single-entry routines.
*/
/**
* container_of - cast a member of a structure out to the containing structure
*
* @ptr: the pointer to the member.
* @type: the type of the container struct this is embedded in.
* @member: the name of the member within the struct.
*
*/
#define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
#define container_of(ptr, type, member) ({ \
const typeof( ((type *)0)->member ) *__mptr = (ptr); \
(type *)( (char *)__mptr - offsetof(type,member) );})
/*
* These are non-NULL pointers that will result in page faults
* under normal circumstances, used to verify that nobody uses
* non-initialized list entries.
*/
#define LIST_POISON1 ((void *) 0x00100100)
#define LIST_POISON2 ((void *) 0x00200)
struct list_head {
struct list_head *next, *prev;
};
#define LIST_HEAD_INIT(name) { &(name), &(name) }
#define LIST_HEAD(name) \
struct list_head name = LIST_HEAD_INIT(name)
#define INIT_LIST_HEAD(ptr) do { \
(ptr)->next = (ptr); (ptr)->prev = (ptr); \
} while (0)
/*
* Insert a new entry between two known consecutive entries.
*
* This is only for internal list manipulation where we know
* the prev/next entries already!
*/
static inline void __list_add(struct list_head *new,
struct list_head *prev,
struct list_head *next)
{
next->prev = new;
new->next = next;
new->prev = prev;
prev->next = new;
}
/**
* list_add – add a new entry
* @new: new entry to be added
* @head: list head to add it after
*
* Insert a new entry after the specified head.
* This is good for implementing stacks.
*/
static inline void list_add(struct list_head *new, struct list_head *head)
{
__list_add(new, head, head->next);
}
/**
* list_add_tail – add a new entry
* @new: new entry to be added
* @head: list head to add it before
*
* Insert a new entry before the specified head.
* This is useful for implementing queues.
*/
static inline void list_add_tail(struct list_head *new, struct list_head *head)
{
__list_add(new, head->prev, head);
}
/*
* Delete a list entry by making the prev/next entries
* point to each other.
*
* This is only for internal list manipulation where we know
* the prev/next entries already!
*/
static inline void __list_del(struct list_head *prev, struct list_head *next)
{
next->prev = prev;
prev->next = next;
}
/**
* list_del – deletes entry from list.
* @entry: the element to delete from the list.
* Note: list_empty on entry does not return true after this, the entry is in an undefined state.
*/
static inline void list_del(struct list_head *entry)
{
__list_del(entry->prev, entry->next);
entry->next = (void *) 0;
entry->prev = (void *) 0;
}
/**
* list_del_init – deletes entry from list and reinitialize it.
* @entry: the element to delete from the list.
*/
static inline void list_del_init(struct list_head *entry)
{
__list_del(entry->prev, entry->next);
INIT_LIST_HEAD(entry);
}
/**
* list_move – delete from one list and add as another’s head
* @list: the entry to move
* @head: the head that will precede our entry
*/
static inline void list_move(struct list_head *list,
struct list_head *head)
{
__list_del(list->prev, list->next);
list_add(list, head);
}
/**
* list_move_tail – delete from one list and add as another’s tail
* @list: the entry to move
* @head: the head that will follow our entry
*/
static inline void list_move_tail(struct list_head *list,
struct list_head *head)
{
__list_del(list->prev, list->next);
list_add_tail(list, head);
}
/**
* list_empty – tests whether a list is empty
* @head: the list to test.
*/
static inline int list_empty(struct list_head *head)
{
return head->next == head;
}
static inline void __list_splice(struct list_head *list,
struct list_head *head)
{
struct list_head *first = list->next;
struct list_head *last = list->prev;
struct list_head *at = head->next;
first->prev = head;
head->next = first;
last->next = at;
at->prev = last;
}
/**
* list_splice – join two lists
* @list: the new list to add.
* @head: the place to add it in the first list.
*/
static inline void list_splice(struct list_head *list, struct list_head *head)
{
if (!list_empty(list))
__list_splice(list, head);
}
/**
* list_splice_init – join two lists and reinitialise the emptied list.
* @list: the new list to add.
* @head: the place to add it in the first list.
*
* The list at @list is reinitialised
*/
static inline void list_splice_init(struct list_head *list,
struct list_head *head)
{
if (!list_empty(list)) {
__list_splice(list, head);
INIT_LIST_HEAD(list);
}
}
/**
* list_entry – get the struct for this entry
* @ptr: the &struct list_head pointer.
* @type: the type of the struct this is embedded in.
* @member: the name of the list_struct within the struct.
*/
#define list_entry(ptr, type, member) \
((type *)((char *)(ptr)-(unsigned long)(&((type *)0)->member)))
/**
* list_for_each - iterate over a list
* @pos: the &struct list_head to use as a loop counter.
* @head: the head for your list.
*/
#define list_for_each(pos, head) \
for (pos = (head)->next; pos != (head); \
pos = pos->next)
/**
* list_for_each_prev - iterate over a list backwards
* @pos: the &struct list_head to use as a loop counter.
* @head: the head for your list.
*/
#define list_for_each_prev(pos, head) \
for (pos = (head)->prev; pos != (head); \
pos = pos->prev)
/**
* list_for_each_safe - iterate over a list safe against removal of list entry
* @pos: the &struct list_head to use as a loop counter.
* @n: another &struct list_head to use as temporary storage
* @head: the head for your list.
*/
#define list_for_each_safe(pos, n, head) \
for (pos = (head)->next, n = pos->next; pos != (head); \
pos = n, n = pos->next)
/**
* list_for_each_entry - iterate over list of given type
* @pos: the type * to use as a loop counter.
* @head: the head for your list.
* @member: the name of the list_struct within the struct.
*/
#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))
/**
* list_for_each_entry_safe – iterate over list of given type safe against removal of list entry
* @pos: the type * to use as a loop counter.
* @n: another type * to use as temporary storage
* @head: the head for your list.
* @member: the name of the list_struct within the struct.
*/
#define list_for_each_entry_safe(pos, n, head, member) \
for (pos = list_entry((head)->next, typeof(*pos), member), \
n = list_entry(pos->member.next, typeof(*pos), member); \
&pos->member != (head); \
pos = n, n = list_entry(n->member.next, typeof(*n), member))
#endif
在来个Makefile
TARGET=flight_system
SRCS=$(wildcard *.c)
OBJ=$(patsubst %.c, %.o, $(SRCS))
CC=gcc
$(TARGET):$(OBJ)
$(CC) $^ -o $@
%.o:%.c
$(CC) -o $@ -c $<
clean:
rm *.o $(TARGET)
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