C++ 简单TCP实例

简单TCP原理如上篇所示。这里用一个简单的例子来演示流程的实现

Server与Client的区别在于

Server用bind, listen, accept，简称“绑听接”

Client用connect，简称“连”

1. 创建Win32控制台项目，加入SimpleTCPServer.cpp

/*
 *	一问一答式简单TCP短连接,用于演示TCP连接原理
 */

#pragma comment (lib, "ws2_32.lib")
#pragma warning (disable: 4267)

#include <WinSock2.h>
#include <stdio.h>

void main()
{
	//变量声明
	char sBuffer[1024];
	SOCKET socketServer;
	sockaddr_in addrServer;
	SOCKET socketClient;
	sockaddr_in addrClient;
	int addrSize = sizeof(addrClient);
	WSADATA wsaData;
	WORD wVersionRequested;

	//Socket环境初始化
	wVersionRequested = MAKEWORD(2, 2);
	int nRes = WSAStartup(wVersionRequested, &wsaData);
	if(nRes != 0)
	{
		return;
	}

	//创建服务器Socket
	socketServer = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
	if (socketServer == INVALID_SOCKET)
	{
		return;
	}

	//服务器地址配置
	addrServer.sin_family = AF_INET;
	addrServer.sin_addr.s_addr = INADDR_ANY;
	addrServer.sin_port = htons(6000);

	//绑定Socket与地址
	if(bind(socketServer, (sockaddr*)&addrServer, sizeof(addrServer)) == SOCKET_ERROR)
	{
		return;
	}

	//最多监听10个客户端
	if (listen(socketServer, 10) == SOCKET_ERROR) 
	{
		return;
	}
	printf("服务器启动成功!\n");

	//等待客户端请求
	while (true)
	{
		printf("等待客户端接入...\n");
		//接受客户端连接
		socketClient = accept(socketServer, (sockaddr*)&addrClient, &addrSize);
		if (socketClient == INVALID_SOCKET)
		{
			continue;
		}
		printf("客户端连接成功: %s\n", inet_ntoa(addrClient.sin_addr));

		//接收客户端消息
		memset(sBuffer, 0, sizeof(sBuffer));
		nRes = recv(socketClient, sBuffer, sizeof(sBuffer), 0);
		if (nRes == SOCKET_ERROR)
		{
			continue;
		}
		printf("	它说: %s\n", sBuffer);

		//向客户端发送消息
		memset(sBuffer, 0, sizeof(sBuffer));
		sprintf(sBuffer, "连接到服务器");
		nRes = send(socketClient, sBuffer, strlen(sBuffer) + 1, 0);
		if (nRes == SOCKET_ERROR)
		{
			continue;
		}

		//关闭客户端连接
		closesocket(socketClient);
	}

	//关闭服务器连接
	closesocket(socketServer);	
	
	//清除Socket环境
	WSACleanup();
}

2. 创建Win32控制台项目，加入SimpleTCPClient.cpp

/*
 *	一问一答式简单TCP短连接,用于演示TCP连接原理
 */

#pragma comment (lib, "ws2_32.lib")
#pragma warning (disable: 4267)

#include <WinSock2.h>
#include <stdio.h>

void main()
{
	//变量声明
	char sBuffer[1024];
	SOCKET socketServer;
	sockaddr_in addrServer;
	WSADATA wsaData;
	WORD wVersionRequested;

	//Socket环境初始化
	wVersionRequested = MAKEWORD(2, 2);
	int nRes = WSAStartup(wVersionRequested, &wsaData);
	if(nRes != 0)
	{
		return;
	}

	//创建服务器Socket
	socketServer = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
	if (socketServer == INVALID_SOCKET)
	{
		WSACleanup();
		return;
	}

	//服务器地址配置
	addrServer.sin_family = AF_INET;
	addrServer.sin_addr.s_addr = inet_addr("127.0.0.1");
	addrServer.sin_port = htons(6000);


	//连接服务器Socket与地址
	if(connect(socketServer, (sockaddr*)&addrServer, sizeof(addrServer)) == SOCKET_ERROR)
	{
		closesocket(socketServer);
		WSACleanup();
		return;
	}

	//向服务端发送消息
	memset(sBuffer, 0, sizeof(sBuffer));
	sprintf(sBuffer, "你好!");
	nRes = send(socketServer, sBuffer, strlen(sBuffer) + 1, 0);
	if (nRes == SOCKET_ERROR)
	{
		closesocket(socketServer);
		WSACleanup();
		return;
	}

	//接收服务端消息
	memset(sBuffer, 0, sizeof(sBuffer));
	nRes = recv(socketServer, sBuffer, sizeof(sBuffer), 0);
	if (nRes == SOCKET_ERROR)
	{
		closesocket(socketServer);
		WSACleanup();
		return;
	}
	printf("%s%s\n", sBuffer, inet_ntoa(addrServer.sin_addr));

	//关闭客户端连接
	closesocket(socketServer);	
	
	//清除Socket环境
	WSACleanup();

	system("pause");
}

分别编译、运行Server和Client。