客户端服务端跨平台移植，并添加线程

客户端代码：

#ifdef _WIN32
	#define WIN32_LEAN_AND_MEAN
	#define _WINSOCK_DEPRECATED_NO_WARNINGS
	#include <WinSock2.h>
	#include <windows.h>
	#pragma comment(lib,"ws2_32.lib")
#else
	#include <unistd.h>  //uni std
	#include <arpa/inet.h>
	#include <string.h>
	#include <stdint.h>

#define SOCKET int
#define INVALID_SOCKET  (SOCKET)(~0)
#define SOCKET_ERROR            (-1)
#endif

#include <iostream>
#include <thread>	//C++标准线程库

bool g_bRun = true;
using namespace std;

#pragma region 结构体定义
enum CMD {
	CMD_LOGIN,
	CMD_LOGOUT,
	CMD_ERROR,
	CMD_LOGIN_RESULT,
	CMD_LOGOUT_RESULT,
	CMD_NEW_USER_JOIN
};

struct DataHeader {
	short dataLength;
	short cmd;
};

struct Login : public DataHeader {//DataPackage
	Login() {
		dataLength = sizeof(Login);
		cmd = CMD_LOGIN;
	}
	char userName[32];
	char PassWord[32];
};

struct LoginResult : public DataHeader {
	LoginResult() {
		dataLength = sizeof(LoginResult);
		cmd = CMD_LOGIN_RESULT;
		result = 0;
	}

	int result;
};

struct Logout : public DataHeader {
	Logout() {
		dataLength = sizeof(Logout);
		cmd = CMD_LOGOUT;
	}

	char userName[32];
};

struct LogoutResult : public DataHeader {
	LogoutResult() {
		dataLength = sizeof(LogoutResult);
		cmd = CMD_LOGOUT_RESULT;
		result = 0;
	}

	int result;
};

struct NewUserJoin : public DataHeader {
	NewUserJoin() {
		dataLength = sizeof(NewUserJoin);
		cmd = CMD_NEW_USER_JOIN;
		sock = 0;
	}

	int sock;
};

struct DataPackage {
	int age;
	char name[32];
};

#pragma endregion

int processor(SOCKET _cSock) {
	//缓冲区
	char szRecv[4096] = {};
	// 5 接收客户端数据
	int nLen = recv(_cSock, szRecv, sizeof(DataHeader), 0);
	DataHeader* header = (DataHeader*)szRecv;
	if (nLen <= 0) {
		cout << "与服务器断开连接，任务结束..." << endl;
		return -1;
	}
	switch (header->cmd) {
	case CMD_LOGIN_RESULT: {
		recv(_cSock, szRecv + sizeof(DataHeader), header->dataLength - sizeof(DataHeader), 0);
		LoginResult* login = (LoginResult*)szRecv;
		cout << "收到服务端消息：CMD_LOGIN_RESULT, 数据长度：" << login->dataLength << endl;
		break;
	}
	case CMD_LOGOUT_RESULT: {
		recv(_cSock, szRecv + sizeof(DataHeader), header->dataLength - sizeof(DataHeader), 0);
		LogoutResult* logout = (LogoutResult*)szRecv;
		cout << "收到服务端消息：CMD_LOGOUT_RESULT, 数据长度：" << logout->dataLength << endl;
		break;
	}
	case CMD_NEW_USER_JOIN: {
		recv(_cSock, szRecv + sizeof(DataHeader), header->dataLength - sizeof(DataHeader), 0);
		NewUserJoin* userJoin = (NewUserJoin*)szRecv;
		cout << "收到服务端消息：CMD_LOGOUT_RESULT, 数据长度：" << userJoin->dataLength << endl;
		break;
	}
	}
	return 0;
}

void cmdThread(SOCKET sock) {
	while (true) {
		char cmdBuf[256] = {};
		cin >> cmdBuf;
		/*cout << cmdBuf << endl;*/
		if (0 == strcmp(cmdBuf, "exit")) {
			cout << "退出cmdThread线程" << endl;
			g_bRun = false;
			break;
		}
		else if (0 == strcmp(cmdBuf, "login")) {
			Login login;
			strcpy(login.userName, "lyd");
			strcpy(login.PassWord, "lydmm");
			send(sock, (const char*)&login, sizeof(Login), 0);
		}
		else if (0 == strcmp(cmdBuf, "logout")) {
			Logout logout;
			strcpy(logout.userName, "lyd");
			send(sock, (const char*)&logout, sizeof(Logout), 0);
		}
		else {
			cout << "不支持的命令..." << endl;
		}
	}
}

int main() {
#ifdef _WIN32
	//启动Windows socket 2.x环境
	WORD ver = MAKEWORD(2, 2);
	WSADATA dat;
	WSAStartup(ver, &dat);
#endif // _WIN32
	// 用Socket API 建立一个简易的TCP服务端

	// 1 建立一个socket
	SOCKET _sock = socket(AF_INET, SOCK_STREAM, 0);
	if (INVALID_SOCKET == _sock) {
		cout << "建立Socket失败..." << endl;
	}
	else {
		cout << "建立Socket成功..." << endl;
	}
	// 2 连接服务器 connect
	sockaddr_in _sin = {};
	_sin.sin_family = AF_INET;
	_sin.sin_port = htons(4567);
#ifdef _WIN32
	/*_sin.sin_addr.S_un.S_addr = inet_addr("192.168.88.130");*/
	_sin.sin_addr.S_un.S_addr = inet_addr("127.0.0.1");
#else
	_sin.sin_addr.s_addr = inet_addr("192.168.88.130");
#endif
	//_sin.sin_addr.S_un.S_addr = inet_addr("127.0.0.1");
	int  ret = connect(_sock, (sockaddr*)&_sin, sizeof(sockaddr_in));
	if (SOCKET_ERROR == ret) {
		cout << "连接服务器失败..." << endl;
	}
	else {
		cout << "连接服务器成功..." << endl;
	}
	// 启动线程
	thread t1(cmdThread, _sock);
	t1.detach();
	while (g_bRun) {

		fd_set fdReads;
		FD_ZERO(&fdReads);
		FD_SET(_sock, &fdReads);
		timeval t = { 1,0 };
		int ret = select(_sock + 1, &fdReads, 0, 0, &t);
		if (ret < 0) {
			cout << "select任务结束" << endl;
			break;
		}

		if (FD_ISSET(_sock, &fdReads)) {
			FD_CLR(_sock, &fdReads);
			if (-1 == processor(_sock)) {
				cout << "select任务结束2..." << endl;
				break;
			}
		}
		//线程thread

		//cout << "空闲时间处理其他业务 ..." << endl;
		//仅仅适用于Windows
		// Sleep(1000);
	}
#ifdef _WIN32
	// 7 关闭套接字closesocket
	closesocket(_sock);
	// 8 清除windows socket环境
	WSACleanup();
#else
	close(_sock);
#endif // _WIN32

	cout << "客户端已退出,任务结束..." << endl;
	//保留界面
	getchar();
	return 0;
}

服务端代码：

#ifdef _WIN32
	#define WIN32_LEAN_AND_MEAN
	#define _WINSOCK_DEPRECATED_NO_WARNINGS
	#include <WinSock2.h>
	#include <windows.h>
	#pragma comment(lib,"ws2_32.lib")
#else
	#include <unistd.h>  //uni std
	#include <arpa/inet.h>
	#include <string.h>
	#include <stdint.h>
	#define SOCKET int
	#define INVALID_SOCKET  (SOCKET)(~0)
	#define SOCKET_ERROR            (-1)
#endif

#include <iostream>
#include <vector>
#include <thread>	//C++标准线程库

using namespace std;

#pragma region 结构体定义

enum CMD {
	CMD_LOGIN,
	CMD_LOGOUT,
	CMD_ERROR,
	CMD_LOGIN_RESULT,
	CMD_LOGOUT_RESULT,
	CMD_NEW_USER_JOIN
};

struct DataHeader {
	short dataLength;
	short cmd;
};

struct Login : public DataHeader {//DataPackage
	Login() {
		dataLength = sizeof(Login);
		cmd = CMD_LOGIN;
	}
	char userName[32];
	char PassWord[32];
};

struct LoginResult : public DataHeader {
	LoginResult() {
		dataLength = sizeof(LoginResult);
		cmd = CMD_LOGIN_RESULT;
		result = 0;
	}

	int result;
};

struct Logout : public DataHeader {
	Logout() {
		dataLength = sizeof(Logout);
		cmd = CMD_LOGOUT;
	}

	char userName[32];
};

struct LogoutResult : public DataHeader {
	LogoutResult() {
		dataLength = sizeof(LogoutResult);
		cmd = CMD_LOGOUT_RESULT;
		result = 0;
	}

	int result;
};

struct NewUserJoin : public DataHeader {
	NewUserJoin() {
		dataLength = sizeof(NewUserJoin);
		cmd = CMD_NEW_USER_JOIN;
		sock = 0;
	}

	int sock;
};

struct DataPackage {
	int age;
	char name[32];
};

#pragma endregion

using namespace std;

vector<SOCKET> g_clients;

int processor(SOCKET _cSock) {
	//缓冲区
	char szRecv[4096] = {};
	// 5 接收客户端数据
	int nLen = (int)recv(_cSock, szRecv, sizeof(DataHeader), 0);
	DataHeader* header = (DataHeader*)szRecv;
	if (nLen <= 0) {
		cout << "客户端< socket = " << _cSock << " >已退出，任务结束..." << endl;
		return -1;
	}
	switch (header->cmd) {
	case CMD_LOGIN: {
		recv(_cSock, szRecv + sizeof(DataHeader), header->dataLength - sizeof(DataHeader), 0);
		Login* login = (Login*)szRecv;
		cout << "收到客户端<Socket = " << _cSock << ">请求：CMD_LOGIN, 数据长度：" << login->dataLength << " ,userName =  " << login->userName << " PassWord = " << login->PassWord << endl;
		//忽略判断用户密码是否正确
		LoginResult ret;
		send(_cSock, (char*)&ret, sizeof(LoginResult), 0);
		break;
	}
	case CMD_LOGOUT: {
		recv(_cSock, szRecv + sizeof(DataHeader), header->dataLength - sizeof(DataHeader), 0);
		Logout* logout = (Logout*)szRecv;
		cout << "收到客户端<Socket = " << _cSock << ">请求：CMD_LOGOUT, 数据长度：" << logout->dataLength << " ,userName =  " << logout->userName << endl;
		//忽略判断用户密码是否正确
		LogoutResult ret;
		send(_cSock, (char*)&ret, sizeof(ret), 0);
		break;
	}
	default: {
		DataHeader header = { 0,CMD_ERROR };
		send(_cSock, (char*)&header, sizeof(header), 0);
	}
	}
	return 0;
}

int main() {
#ifdef _WIN32
	//启动Windows socket 2.x环境
	WORD ver = MAKEWORD(2, 2);
	WSADATA dat;
	WSAStartup(ver, &dat);
#endif // _WIN32
	// 用Socket API 建立一个简易的TCP服务端 1 建立一个socket 套接字
	SOCKET _sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
	// 2 bind 绑定用于接受客户端连接的网络接口
	sockaddr_in _sin = {};
	_sin.sin_family = AF_INET;
	_sin.sin_port = htons(4567);// host to net unsigned short
#ifdef _WIN32
	_sin.sin_addr.S_un.S_addr = INADDR_ANY;//inet_addr("127.0.0.1");
#else
	_sin.sin_addr.s_addr = INADDR_ANY;//inet_addr("127.0.0.1");
#endif
	if (bind(_sock, (sockaddr*)&_sin, sizeof(_sin)) == SOCKET_ERROR) {
		//绑定错误
		cout << "绑定网络端口失败..." << endl;
	}
	else {
		cout << "绑定网络端口成功..." << endl;
	}
	//3 listen 监听网络端口
	if (SOCKET_ERROR == listen(_sock, 5)) {
		cout << "监听网络端口失败..." << endl;
	}
	else {
		cout << "监听网络端口成功..." << endl;
	}
	while (true) {
		// 伯克利套接字 BSD socket
		fd_set fdRead; //描述符(Socket) 集合
		fd_set fdWrite;
		fd_set fdExp;
		//清理集合
		FD_ZERO(&fdRead);
		FD_ZERO(&fdWrite);
		FD_ZERO(&fdExp);
		//将描述符(socket)加入集合
		FD_SET(_sock, &fdRead);
		FD_SET(_sock, &fdWrite);
		FD_SET(_sock, &fdExp);
		SOCKET maxSock = _sock;
		for (int n = (int)g_clients.size() - 1; n >= 0; n--) {
			FD_SET(g_clients[n], &fdRead);
			if (maxSock < g_clients[n]) {
				maxSock = g_clients[n];
			}
		}
		//nfds 是一个整数值，是指fd_set集合中所有描述符(socket)的范围，而不是数量
		//既是所有文件描述符最大值+1，在Windows中这个参数可以写0
		timeval t = { 1,0 };
		int  ret = select(maxSock + 1, &fdRead, &fdWrite, &fdExp, &t);
		if (ret < 0) {
			cout << "select任务结束..." << endl;
			break;
		}
		//判断描述符(socket)是否在集合中
		if (FD_ISSET(_sock, &fdRead)) {
			FD_CLR(_sock, &fdRead);
			//4 accept 等待接受客户端连接
			sockaddr_in clientAddr = {};
			int nAddrLen = sizeof(sockaddr_in);
			SOCKET _cSock = INVALID_SOCKET;
#ifdef _WIN32
			_cSock = accept(_sock, (sockaddr*)&clientAddr, &nAddrLen);
#else
			_cSock = accept(_sock, (sockaddr*)&clientAddr, (socklen_t*)&nAddrLen);
#endif // _WIN32
			if (_cSock == INVALID_SOCKET) {
				cout << "接受到无效客户端SOCKET..." << endl;
			}
			else {
				// 新客户端加入，群发
				for (int n = (int)g_clients.size() - 1; n >= 0; n--) {
					NewUserJoin userJoin;
					send(g_clients[n], (const char*)&userJoin, sizeof(NewUserJoin), 0);
				}
				g_clients.push_back(_cSock);
				cout << "新客户端加入：socket = " << (int)_cSock << ", IP = " << inet_ntoa(clientAddr.sin_addr) << endl;
			}
		}
		for (int n = (int)g_clients.size() - 1; n >= 0; n--) {
			if (FD_ISSET(g_clients[n], &fdRead)) {
				if (processor(g_clients[n]) == -1) {
					auto iter = g_clients.begin() + n; //std::vector<SOCKET>::iterator
					if (iter != g_clients.end()) {
						g_clients.erase(iter);
					}
				}
			}
		}
		//cout << "空闲时间处理其他业务 ..." << endl;
	}
#ifdef _WIN32
	for (int n = (int)g_clients.size() - 1; n >= 0; n--) {
		closesocket(g_clients[n]);
	}
	//6 关闭套接字closesocket
	//7 清除windows socket环境
	WSACleanup();
#else
	for (int n = (int)g_clients.size() - 1; n >= 0; n--) {
		close(g_clients[n]);
	}
#endif // _WIN32
	cout << "服务器已退出,任务结束..." << endl;
	//保留界面
	getchar();
	return 0;
}