代码：
请多开几个客户端进行测试。
//server
#define _WINSOCK_DEPRECATED_NO_WARNINGS
#define _CRT_SECURE_NO_WARNINGS
#include <winsock2.h>
#include <stdio.h>
#include <vector>
#include<ws2tcpip.h>//定义socklen_t
using namespace std;
#pragma comment(lib, "WS2_32") // 链接到WS2_32.lib
#define SERVER_IP "127.0.0.1"// 默认服务器端IP地址
#define SERVER_PORT 8888// 服务器端口号
class server
{
public:
server();
void init();
void process();
private:
int listener;//监听套接字
sockaddr_in serverAddr;//IPV4的地址方式
vector <int> socksArr;//存放创建的套接字
};
int main()
{
server ser;
ser.process();
return 0;
}
server::server()
{
listener = 0;
serverAddr.sin_family = PF_INET;
serverAddr.sin_port = SERVER_PORT;
serverAddr.sin_addr.s_addr = inet_addr(SERVER_IP);//将字符串类型转换uint32_t
}
//初始化函数，创建监听套接字，绑定端口，并进行监听
void server::init()
{
WSADATA wsaData;
WSAStartup(MAKEWORD(2, 2), &wsaData);
listener = socket(AF_INET, SOCK_STREAM, 0);//采用ipv4,TCP传输
if (listener == -1) { printf("Error at socket(): %ld\n", WSAGetLastError()); perror("listener failed"); exit(1); }
else printf("Server is running......\n");
if (bind(listener, (sockaddr *)&serverAddr, sizeof(serverAddr)) < 0)
{
perror("bind error");
exit(1);
}
listen(listener, 5);//listener这个套接字监听申请的链接，最大等待连接队列为5,等待accept()
socksArr.push_back(listener);//将监听套接字加入套接字数组，数组内首个套接字就是服务器的套接字
}
void server::process()
{
int mount = 0;
fd_set fds,fds_copy;
FD_ZERO(&fds);//将fds清零
init();
//下面就是不断的检查申请的连接队列
printf("Server is waiting......\n");
while (1)
{
mount = socksArr.size();
//每次循环更新一次fds数组
for (int i = 0; i<mount; ++i)
{
FD_SET(socksArr[i], &fds);
}
struct timeval timeout = { 1,0 };//每个Select等待三秒
switch (select(0, &fds, NULL, NULL, &timeout))
{
case -1: //select error
{
perror("select\n");
printf("Error at socket(): %ld\n", WSAGetLastError());
printf("%d\n", mount);
Sleep(1000);
break;
}
case 0: //等待时间内无客户端申请连接
{
break;
}
default:
{
//将数组中的每一个套接字都和剩余的套接字进行比较，从而得到当前的任务
for (int i = 0; i < mount; ++i)
{
//首个套接字就是服务器的套接字，当期存在并收到客户端连接请求，进行连接并更新套接字数组（将连接的客户端套接字加进数组中）
if (i == 0 && FD_ISSET(socksArr[i], &fds))
{
struct sockaddr_in client_addr;
int clntSz = sizeof(struct sockaddr_in);
//返回一个用户的套接字
int clientfd = accept(listener, (struct sockaddr*)&client_addr, &clntSz);
//添加用户，服务器上显示消息，并通知用户连接成功
socksArr.push_back(clientfd);
printf("connect sucessfully\n");
char ID[1024];
sprintf(ID, "You ID is: %d and ", clientfd);
char buf[30] = "welcome joint the chatroom! \n";
strcat(ID, buf);
send(clientfd, ID, sizeof(ID) - 1, 0);//减去最后一个'/0'
}
if (i != 0 && FD_ISSET(socksArr[i], &fds))
{
char buf[1024];
memset(buf, '\0', sizeof(buf));
int size = recv(socksArr[i], buf, sizeof(buf) - 1, 0);
//检测是否断线
if (size == 0 || size == -1)
{
printf("client %d leave\n", socksArr[i]);
closesocket(socksArr[i]);//关闭这个套接字
FD_CLR(socksArr[i], &fds);//在列表中删除
socksArr.erase(socksArr.begin() + i);//在套接字数组中删除
}
//若是没有掉线
else
{
printf("clint %d says: %s \n", socksArr[i], buf);
//将此客户端说的话发送给每一个客户端
char client[1024];
sprintf(client, "client %d:", socksArr[i]);
strcat(client, buf);
for (int j = 1; j < mount; j++)
{
send(socksArr[j], client, sizeof(client) - 1, 0);
}
}
}
}
break;
}
}
}
}
//Client
#define _WINSOCK_DEPRECATED_NO_WARNINGS
#include<conio.h>
#include <iostream>
#include <thread>
#include <winsock2.h>
#include <stdio.h>
#include<ws2tcpip.h>//定义socklen_t
#pragma comment(lib, "WS2_32") // 链接到WS2_32.lib
using namespace std;
#define SERVER_IP "127.0.0.1"// 默认服务器端IP地址
#define SERVER_PORT 8888// 服务器端口号
class client
{
public:
client();
void init();
void process();
private:
int user; //客户端套接字（句柄）
int writing;
sockaddr_in serverAddr;
void sendata();
};
int main()
{
client user;
user.process();
return 0;
}
client::client()
{
user = 0;
writing = 0;
serverAddr.sin_family = PF_INET;
serverAddr.sin_port = SERVER_PORT;
serverAddr.sin_addr.s_addr = inet_addr(SERVER_IP);//将字符串类型转换uint32_t
}
void client::init()
{
WSADATA wsaData;
WSAStartup(MAKEWORD(2, 2), &wsaData);
user = socket(AF_INET, SOCK_STREAM, 0);//采用ipv4,TCP传输，成功时返回非负数socket描述符
if (user <= 0)
{
perror("establish client faild");
printf("Error at socket(): %ld\n", WSAGetLastError());
exit(1);
};
printf("establish succesfully\n");//创建成功，阻塞式的等待服务器连接
if (connect(user, (const sockaddr *)&serverAddr, sizeof(serverAddr)) < 0)
{
perror("connect to server faild");
printf("Error at socket(): %ld\n", WSAGetLastError());
exit(1);
}
printf("connect IP:%s Port:%d succesfully\n", SERVER_IP, SERVER_PORT);//创建成功
}
void client::process()
{
char recvbuf[1024];
fd_set fdread, fedwrite;
FD_ZERO(&fdread);//将fdread清零
FD_ZERO(&fedwrite);//将fedwrite清零
init();
while (1)
{
FD_SET(user, &fdread);
if (writing == 0)
FD_SET(user, &fedwrite);
struct timeval timeout = { 1,0 };//每个Select等待三秒
switch (select(0, &fdread, &fedwrite, NULL, &timeout))
{
case -1:
{
printf("Error at socket(): %ld\n", WSAGetLastError());
break;
}
case 0:
break;
default:
{
if (FD_ISSET(user, &fdread))//有待读事件
{
int size = recv(user, recvbuf, sizeof(recvbuf) - 1, 0);
if (size > 0)
{
printf("server : %s\n", recvbuf);
memset(recvbuf, '\0', sizeof(recvbuf));
}
else if (size == 0)
{
printf("server is closed\n");
exit(1);
}
}
if (FD_ISSET(user, &fedwrite))
{
FD_ZERO(&fedwrite);//将fedwrite清零
writing = 1;//表示正在写入
thread sendtask(bind(&client::sendata, this));
sendtask.detach();//将子线程和主进程分离且互相不影响
}
break;
}
}
}
}
void client::sendata()
{
char sendbuf[1024];
char middle[1024];
cin.getline(sendbuf, 1024);//读取一行
send(user, sendbuf, sizeof(sendbuf) - 1, 0);
writing = 0;
}