基于UDP的网络聊天室
项目需求:
- 如果有用户登录,其他用户可以收到这个人的登录信息
- 如果有人发送信息,其他用户可以收到这个人的群聊信息
- 如果有人下线,其他用户可以收到这个人的下线信息
- 服务器可以发送系统信息
服务器端代码
cs
#include<myhead.h>
#define SER_PORT 8888
#define SER_IP "192.168.117.74"
#define PRINT_ERR(msg)
do
{
printf("%s,%d,%s\n", __FILE__, __LINE__, __func__);
perror(msg);
exit(-1);
} while (0)
typedef struct
{
char code; //操作码
char name[32];
char txt[128];
} msg_t;
//链表结构体
typedef struct _NODE
{
struct sockaddr_in c_addr;
struct _NODE *next;
} node_t;
void creat_link(node_t **head);
int do_register(int sockfd, msg_t msg, struct sockaddr_in clientaddr, node_t *phead);
int do_group_chat(int sockfd, msg_t msg, struct sockaddr_in clientaddr, node_t *phead);
int quit_group_chat(int sockfd, msg_t msg, struct sockaddr_in clientaddr, node_t *phead);
int main(int argc, const char *argv[])
{
//创建套接字
int sockfd;
if ((sockfd = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
{
PRINT_ERR("socket error");
}
//创建服务器网络信息结构体
struct sockaddr_in serviceaddr;
memset(&serviceaddr, 0, sizeof(serviceaddr));
serviceaddr.sin_family = AF_INET;
serviceaddr.sin_addr.s_addr = inet_addr(argv[1]);
serviceaddr.sin_port = htons(atoi(argv[2]));
socklen_t serviceaddr_len = sizeof(serviceaddr);
//将服务器网络信息结构体与套接字绑定
if (bind(sockfd, (struct sockaddr *)&serviceaddr, serviceaddr_len) == -1)
{
PRINT_ERR("bind error");
}
//创建客户端网络信息结构体
struct sockaddr_in clientaddr;
memset(&clientaddr, 0, sizeof(clientaddr));
socklen_t clientaddr_len = sizeof(clientaddr);
msg_t msg;
//创建父子进程
pid_t pid;
pid = fork();
if (pid == -1)
{
PRINT_ERR("fork error");
}
else if (pid == 0)
{
//子进程
//接受数据并处理
//定义链表头节点
node_t *phead = NULL;
creat_link(&phead);
phead->next = NULL;
while (1)
{
memset(&msg, 0, sizeof(msg));
memset(&clientaddr, 0, sizeof(clientaddr));
if ((recvfrom(sockfd, &msg, sizeof(msg), 0, (struct sockaddr *)&clientaddr, &clientaddr_len)) == -1)
{
PRINT_ERR("recvfrom error");
}
printf("%8s : [%s]\n", msg.name, msg.txt);
switch (msg.code)
{
case 'L':
do_register(sockfd, msg, clientaddr, phead);
break;
case 'C':
do_group_chat(sockfd, msg, clientaddr, phead);
break;
case 'Q':
quit_group_chat(sockfd, msg, clientaddr, phead);
break;
}
}
}
else if (pid > 0)
{
//父进程
//发系统消息
msg.code='C';
strcpy(msg.name,"server");
while(1)
{
fgets(msg.txt,128,stdin);
msg.txt[strlen(msg.txt)-1]='\0';
if(sendto(sockfd,&msg,sizeof(msg_t),0,(struct sockaddr *)&serviceaddr,serviceaddr_len)==-1)
{
PRINT_ERR("sendto error");
}
}
}
close(sockfd);
return 0;
}
//创建链表头节点函数
void creat_link(node_t **head)
{
*head = (node_t *)malloc(sizeof(node_t));
}
//登录操作
int do_register(int sockfd, msg_t msg, struct sockaddr_in clientaddr, node_t *phead)
{
//遍历链表将登录信息发送给所以人
node_t *p = phead;
while (p->next != NULL)
{
p = p->next;
if (sendto(sockfd, &msg, sizeof(msg_t), 0, (struct sockaddr *)&(p->c_addr), sizeof(p->c_addr)) == -1)
{
PRINT_ERR("recvfrom error");
}
}
//将登录的客户端信息插入保存在链表
//头插
//定义一个新的指针保存客户端信息
node_t *newp = NULL;
creat_link(&newp);
newp->c_addr = clientaddr;
newp->next = phead->next;
phead->next = newp;
return 0;
}
int do_group_chat(int sockfd, msg_t msg, struct sockaddr_in clientaddr, node_t *phead)
{
//遍历链表,将消息发给除自己之外的所有人
node_t *p = phead;
while (p->next != NULL)
{
p = p->next;
//判断链表客户端信息是否是自己
//是自己就不发送
if (memcmp(&(p->c_addr), &clientaddr, sizeof(clientaddr)))
{
if (sendto(sockfd, &msg, sizeof(msg_t), 0, (struct sockaddr *)&(p->c_addr), sizeof(p->c_addr)) == -1)
{
PRINT_ERR("recvfrom error");
}
}
}
return 0;
}
//退出群聊操作
int quit_group_chat(int sockfd, msg_t msg, struct sockaddr_in clientaddr, node_t *phead)
{
node_t *p = phead;
while (p->next != NULL)
{
//判断链表客户端信息是否是自己
//是自己就不发送并且将自己的客户端信息在链表内删除
if (memcmp(&(p->next->c_addr), &clientaddr, sizeof(clientaddr)))
{
p = p->next;
if (sendto(sockfd, &msg, sizeof(msg_t), 0, (struct sockaddr *)&(p->c_addr), sizeof(p->c_addr)) == -1)
{
PRINT_ERR("recvfrom error");
}
}
else
{
node_t *pnew;
pnew = p->next;
p->next = pnew->next;
pnew->next = NULL;
free(pnew);
pnew = NULL;
}
}
return 0;
}
客户端代码
cs
#include<myhead.h>
#define SER_PORT 8888
#define SER_IP "192.168.117.74"
#define PRINT_ERR(msg)
do
{
printf("%s,%d,%s\n", __FILE__, __LINE__, __func__);
perror(msg);
exit(-1);
} while (0)
typedef struct
{
char code; //操作码
char name[32];
char txt[128];
} msg_t;
int main(int argc, const char *argv[])
{
//创建套接字
int sockfd;
if ((sockfd = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
{
PRINT_ERR("socket error");
}
//创建服务器网络信息结构体
struct sockaddr_in serviceaddr;
memset(&serviceaddr, 0, sizeof(serviceaddr));
serviceaddr.sin_family = AF_INET;
serviceaddr.sin_addr.s_addr = inet_addr(argv[1]);
serviceaddr.sin_port = htons(atoi(argv[2]));
socklen_t serviceaddr_len = sizeof(serviceaddr);
//给服务器发送登录数据包
msg_t msg;
memset(&msg, 0, sizeof(msg_t));
msg.code = 'L';
printf("请输入用户名:");
fgets(msg.name, 32, stdin);
msg.name[strlen(msg.name) - 1] = '\0';
strcpy(msg.txt, "加入群聊");
if (sendto(sockfd, &msg, sizeof(msg_t), 0, (struct sockaddr *)&serviceaddr, serviceaddr_len) == -1)
{
PRINT_ERR("sendto error");
}
//创建父子进程
pid_t pid;
pid = fork();
if (pid == -1)
{
PRINT_ERR("fork error");
}
else if (pid == 0)
{
//子进程
//接受数据并处理
while (1)
{
//每次循环前将msg置零
memset(&msg, 0, sizeof(msg));
//接受服务器发过来的信息并打印到终端上
if (recvfrom(sockfd, &msg, sizeof(msg_t), 0, NULL, NULL) == -1)
{
PRINT_ERR("recvfrom error");
}
printf("%8s:[%s]\n", msg.name, msg.txt);
}
}
else if (pid > 0)
{
//父进程
//发送消息
while (1)
{
//memset会把name清除
msg.code = 'C';
fgets(msg.txt, 128, stdin);
msg.txt[strlen(msg.txt) - 1] = '\0';
if (strcmp(msg.txt, "quit") == 0)
{
msg.code = 'Q';
strcpy(msg.txt, "退出群聊");
}
if (sendto(sockfd, &msg, sizeof(msg_t), 0, (struct sockaddr *)&serviceaddr, serviceaddr_len) == -1)
{
PRINT_ERR("sendto error");
}
if (strcmp(msg.txt, "退出群聊") == 0)
{
break;
}
}
kill(pid,SIGKILL);
wait(NULL);
close(sockfd);
}
return 0;
}