基于TCP&socket的CS通信（C++）

服务端

1. socket() 创建套接字
2. bind() 将套接字绑定在本机地址和端口
3. listen() 监听，并等待客户端接入
4. accept() 接受客户端请求
5. recv()/send() 通信
6. close() 关闭套接字

客户端

1. socket() 创建套接字
2. connect() 向服务器端发送连接请求
3. recv()/send() 通信
4. close() 关闭套接字

服务端：

#include<iostream>
using namespace std;
#include<winsock2.h>
#pragma comment(lib,"ws2_32.lib")
#include<windows.h>
#include<string>


int main(){
	//1.确定协议版本
	WSADATA wsaData;
	WSAStartup(MAKEWORD(2, 2), &wsaData);
	if (HIBYTE(wsaData.wVersion) != 2 || LOBYTE(wsaData.wVersion) != 2){
		cout << "确定版本协议失败: " << GetLastError() << endl;
		return -1;
	}
	cout << "确定版本协议成功！" << endl;

	//2.创建socket
	SOCKET serverSocket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
	if (serverSocket == SOCKET_ERROR){
		cout << "创建socket失败: " << GetLastError() << endl;
		return -1;
	}
	cout << "创建socket成功！" << endl;


	//3.设置服务器地址簇
	SOCKADDR_IN addr = { 0 };
	addr.sin_family = AF_INET;
	addr.sin_addr.S_un.S_addr = inet_addr("10.181.73.111");
	addr.sin_port = htons(9527);

	//4.绑定
	int r = bind(serverSocket, (sockaddr*)&addr, sizeof(addr));
	if (r == -1){
		cout << "绑定失败: " << GetLastError() << endl;
		WSACleanup();
		return -1;
	}
	cout << "绑定成功！" << endl;

	//5.监听
	r = listen(serverSocket, 10);
	if (r == -1){
		cout << "监听失败: " << GetLastError() << endl;
		WSACleanup();
		return -1;
	}
	cout << "监听成功！" << endl;

	//6. 接受连接
	SOCKADDR_IN clientAddr = { 0 };
	int len = sizeof(clientAddr);
	SOCKET clientSocket = accept(serverSocket, (sockaddr*)&clientAddr, &len);
	if (clientSocket == SOCKET_ERROR){
		cout << "客户端连接失败:" << GetLastError() << endl;
		closesocket(serverSocket);
		WSACleanup();
		return -1;
	}
	cout << "客户端连接成功" << endl;

	// 7. 通信
	char buff[1024];
	while (1){
		r = recv(clientSocket, buff, 1023, NULL);
		if (r > 0){
			buff[r] = 0;
			cout << "来自客户端的消息:" << buff << endl;
		}
	}

}

客户端：

#include<iostream>
using namespace std;
#include<winsock2.h>
#pragma comment(lib,"ws2_32.lib")
#include<windows.h>
#include<string>


int main(){
	//1.确定协议版本
	WSADATA wsaData;
	WSAStartup(MAKEWORD(2, 2), &wsaData);
	if (HIBYTE(wsaData.wVersion) != 2 || LOBYTE(wsaData.wVersion) != 2){
		cout << "确定版本协议失败: " << GetLastError() << endl;
		return -1;
	}
	cout << "确定版本协议成功！" << endl;

	//2.创建socket
	SOCKET clientSocket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
	if (clientSocket == SOCKET_ERROR){
		cout << "创建socket失败: " << GetLastError() << endl;
		return -1;
	}
	cout << "创建socket成功！" << endl;


	//3.设置服务器地址簇
	SOCKADDR_IN addr = { 0 };
	addr.sin_family = AF_INET;
	addr.sin_addr.S_un.S_addr = inet_addr("10.181.73.111");
	addr.sin_port = htons(9527);

	//4. 连接
	int r = connect(clientSocket, (sockaddr*)&addr, sizeof(addr));
	if (r == -1){
		cout << "服务器连接失败" << GetLastError() << endl;
		closesocket(clientSocket);
		WSACleanup();
		return -1;
	}
	cout << "服务器连接成功！" << endl;

	// 5. 通信
	char buff[1024];
	while (1){
		cout << "输入你发送的消息:";
		cin >> buff;
		send(clientSocket, buff, strlen(buff), NULL);
		}
	}



int sendToServer(char *m_pDataBuffer,int sendDataLen)
{
    /* 创建一个 socket 用于 tcp 通信 */
    if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0)
    {
		return ERROR;
    }

    /* 连接服务器 */
    if (connect(sockfd, (struct sockaddr *) &ServerAddr, sizeof(ServerAddr)) != 0)
    {
		close(sockfd);
		return ERROR;
    }

	int retLen = writen(sockfd, m_pDataBuffer, sendDataLen);
    if(retLen != sendDataLen)
	{
		SAFE_CLOSE(sockfd);
		return ERROR;
    }

	fd_set readset;
	struct timeval tv_read;
	int ret = 0;

	while(1)
	{
		FD_ZERO(&readset);
		FD_SET(sockfd, &readset);
		tv_read.tv_sec = 1;
		tv_read.tv_usec = 0;
		ret = select(sockfd+1, &readset, NULL, NULL, &tv_read);

		if(ret < 0)
		{
			backret = ERROR;
			goto outExit;
		}
		else if (ret == 0)
		{
			backret = ERROR;
			goto outExit;
		}
		else
		{		
			usleep(200*1000);
			memset(recvBuf, 0, 1024);
			len = HPR_Recv(sockfd, recvBuf, 1024);
			if (len == 0)
			{
				backret = ERROR;
				goto outExit;
			}
			else if (len < 0)
			{
				backret = ERROR;
				goto outExit;
			}
		}		
	}    

outExit:
    close(sockfd);
    return backret;
}