MFC实现多个客户端连接服务器。tcp协议

服务器接收多个客户端链接，可以把客户端标识保存在map中

map<SOCKET, ClientInfo>

因为调用accept返回的SOCKET其实就是int

服务器端：（迭代的面向连接的服务器实现daytime功能）

#include <stdio.h>

#include <sys/socket.h>

#include <unistd.h>

#include <sys/types.h>

#include <netinet/in.h>

#include <stdlib.h>

#include <time.h>

#define SERVER_PORT 20000 // define the defualt connect port id

#define LENGTH_OF_LISTEN_QUEUE 10 //服务器监听队列请求数目

#define BUFFER_SIZE 255

//#define WELCOME_MESSAGE "welcome to connect the server. "

int main(int argc, char **argv)

{

int servfd,clifd//server socket client socket

struct sockaddr_in servaddr,cliaddr

if ((servfd = socket(AF_INET,SOCK_STREAM,0)) <0)

{

printf("create socket error!\n")//错误判断

exit(1)

}

bzero(&servaddr,sizeof(servaddr))//bzero ()置字节字符串s的前n个字节为零

servaddr.sin_family = AF_INET//socket 域 tcp/ip 协议族

servaddr.sin_port = htons(SERVER_PORT)//host -network order

servaddr.sin_addr.s_addr = htons(INADDR_ANY)//host -network order

if (bind(servfd,(struct sockaddr*)&servaddr,sizeof(servaddr))<0)//命名套接字，将其与IP地址及端口绑定

{

printf("bind to port %d failure!\n",SERVER_PORT)

exit(1)

}

if (listen(servfd,LENGTH_OF_LISTEN_QUEUE) <0)// 监听socket队列

{

printf("call listen failure!\n")

exit(1)

}

while (1)

{

char buf[BUFFER_SIZE]

long timestamp//时间戳应答报文(timestamp reply) 时间戳请求报文(timestamp request:) 时间戳请求报文

socklen_t length = sizeof(cliaddr)

clifd = accept(servfd,(struct sockaddr*)&cliaddr,&length)//接受请求，返回一个新套接字描述符

if (clifd <0)

{

printf("error comes when call accept!\n")

break

}

//strcpy(buf,WELCOME_MESSAGE)

//inet_ntop(INET_ADDRSTRLEN,cliaddr.sin_addr,buf,BUFFER_SIZE)

printf("from client,IP:%s,Port:%d\n",inet_ntoa(cliaddr.sin_addr),ntohs(cliaddr.sin_port))

timestamp = time(NULL)//当前时间

//strcat(buf,"timestamp in server:")

strcat(buf,ctime(&timestamp))//strcat把src所指字符串添加到buf结尾处 .ctime把日期和时间转换为字符串

send(clifd,buf,BUFFER_SIZE,0)

close(clifd)

}//exit

close(servfd)

return 0

}

客户端：

#include <stdio.h>

#include <sys/socket.h>

#include <unistd.h>

#include <sys/types.h>

#include <netinet/in.h>

#include <stdlib.h>

#define SERVER_PORT 20000

//#define CLIENT_PORT ((20001+rand())%65536) // define the defualt client port as a random port

#define BUFFER_SIZE 255

//#define REUQEST_MESSAGE "welcome to connect the server.\n"

void usage(char *name)

{

printf("usage: %s IpAddr\n",name)

}

int main(int argc, char **argv)

{

int servfd,clifd,length = 0

struct sockaddr_in servaddr,cliaddr

socklen_t socklen = sizeof(servaddr)

char buf[BUFFER_SIZE]

if (argc <2)

{

usage(argv[0])

exit(1)

}

if ((clifd = socket(AF_INET,SOCK_STREAM,0)) <0)

{

printf("create socket error!\n")

exit(1)

}

//srand(time(NULL))//初始化随机数发生器

bzero(&cliaddr,sizeof(cliaddr))

cliaddr.sin_family = AF_INET

cliaddr.sin_port = htons(CLIENT_PORT)

cliaddr.sin_addr.s_addr = htons(INADDR_ANY)

bzero(&servaddr,sizeof(servaddr))

servaddr.sin_family = AF_INET

inet_aton(argv[1],&servaddr.sin_addr)

servaddr.sin_port = htons(SERVER_PORT)

//servaddr.sin_addr.s_addr = htons(INADDR_ANY)

if (bind(clifd,(struct sockaddr*)&cliaddr,sizeof(cliaddr))<0)

{

printf("bind to port %d failure!\n",CLIENT_PORT)

exit(1)

}

if (connect(clifd,(struct sockaddr*)&servaddr, socklen) <0)

{

printf("can't connect to %s!\n",argv[1])

exit(1)

}

length = recv(clifd,buf,BUFFER_SIZE,0)

if (length <0)

{

printf("error comes when recieve data from server %s!",argv[1])

exit(1)

}

printf("from server %s :\n\t%s ",argv[1],buf)

close(clifd)

return 0

}

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