TCP sending and receiving information (C++)

Table of contents

1. Introduction

2. Receive data

3. Send data

---

 

1. Introduction

One of the differences between tcp and udp is that tcp is connected and udp is connectionless. The code for sending and receiving data in udp can run independently. Before sending data in tcp, you must ensure that the party receiving the data is open, otherwise the connection cannot be established.

2. Receive data

tcpRecv.h

#pragma once
#include<iostream>
#include<winsock.h>
#pragma comment(lib,"ws2_32.lib")
using namespace std;

class tcpRecv
{
public:
	tcpRecv();
	~tcpRecv();
	void initialization();
	void recvData();
public:
	//定义发送缓冲区和接受缓冲区
	char send_buf[100];
	char recv_buf[100];
	//定义服务端套接字，接受请求套接字
	SOCKET s_server;
	SOCKET s_accept;
	//服务端地址客户端地址
	SOCKADDR_IN server_addr;
	SOCKADDR_IN accept_addr;
};

 tcpRecv.cpp

#include "tcpRecv.h"

tcpRecv::tcpRecv()
{
	initialization();
	//填充服务端信息
	server_addr.sin_family = AF_INET;
	server_addr.sin_addr.S_un.S_addr = htonl(INADDR_ANY);
	server_addr.sin_port = htons(14555);
	//创建套接字
	s_server = socket(AF_INET, SOCK_STREAM, 0);
	if (bind(s_server, (SOCKADDR *)&server_addr, sizeof(SOCKADDR)) == SOCKET_ERROR) {
		cout << "套接字绑定失败！" << endl;
		WSACleanup();
	}
	else {
		cout << "套接字绑定成功！" << endl;
	}
	//设置套接字为监听状态
	if (listen(s_server, SOMAXCONN) < 0) {
		cout << "设置监听状态失败！" << endl;
		WSACleanup();
	}
	else {
		cout << "设置监听状态成功！" << endl;
	}
	cout << "服务端正在监听连接，请稍候...." << endl;
	//接受连接请求
	int len = sizeof(SOCKADDR);
	s_accept = accept(s_server, (SOCKADDR *)&accept_addr, &len);
	if (s_accept == SOCKET_ERROR) {
		cout << "连接失败！" << endl;
		WSACleanup();
	}
	cout << "连接建立，准备接受数据" << endl;
}


tcpRecv::~tcpRecv()
{
	//关闭套接字
	closesocket(s_server);
	closesocket(s_accept);
	//释放DLL资源
	WSACleanup();
}


void tcpRecv::initialization() {
	//初始化套接字库
	WORD w_req = MAKEWORD(2, 2);//版本号
	WSADATA wsadata;
	int err;
	err = WSAStartup(w_req, &wsadata);
	if (err != 0) {
		cout << "初始化套接字库失败！" << endl;
	}
	else {
		cout << "初始化套接字库成功！" << endl;
	}
	//检测版本号
	if (LOBYTE(wsadata.wVersion) != 2 || HIBYTE(wsadata.wHighVersion) != 2) {
		cout << "套接字库版本号不符！" << endl;
		WSACleanup();
	}
	else {
		cout << "套接字库版本正确！" << endl;
	}
	//填充服务端地址信息

}

void tcpRecv::recvData() {
	//接收数据
	int recv_len = recv(s_accept, recv_buf, 100, 0);
	if (recv_len < 0) {
		cout << "接受失败！" << endl;
	}
	else {
		cout << "接收信息为:" << recv_buf << endl;
	}
}

 main.cpp

#include "tcpRecv.h"

int main() {
	tcpRecv tcp;
	while (1) {
		tcp.recvData();
	}
	return 0;
}

3. Send data

tcpSend.h

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

class tcpSend
{
public:
	tcpSend();
	~tcpSend();
	void initialization();
	void sendData(std::string&data);
public:
	//定义服务端套接字，接受请求套接字
	SOCKET s_server;
	//服务端地址客户端地址
	SOCKADDR_IN server_addr;
};

 tcpSend.cpp

#include "tcpSend.h"

tcpSend::tcpSend()
{
	initialization();
	//填充服务端信息
	server_addr.sin_family = AF_INET;
	server_addr.sin_addr.S_un.S_addr = inet_addr("127.0.0.1");
	server_addr.sin_port = htons(14555);
	//创建套接字
	s_server = socket(AF_INET, SOCK_STREAM, 0);
	if (connect(s_server, (SOCKADDR *)&server_addr, sizeof(SOCKADDR)) == SOCKET_ERROR) {
		cout << "服务器连接失败！" << endl;
		WSACleanup();
	}
	else {
		cout << "服务器连接成功！" << endl;
	}
}


tcpSend::~tcpSend()
{
	//关闭套接字
	closesocket(s_server);
	//释放DLL资源
	WSACleanup();
}

void tcpSend::initialization() {
	//初始化套接字库
	WORD w_req = MAKEWORD(2, 2);//版本号
	WSADATA wsadata;
	int err;
	err = WSAStartup(w_req, &wsadata);
	if (err != 0) {
		cout << "初始化套接字库失败！" << endl;
	}
	else {
		cout << "初始化套接字库成功！" << endl;
	}
	//检测版本号
	if (LOBYTE(wsadata.wVersion) != 2 || HIBYTE(wsadata.wHighVersion) != 2) {
		cout << "套接字库版本号不符！" << endl;
		WSACleanup();
	}
	else {
		cout << "套接字库版本正确！" << endl;
	}
	//填充服务端地址信息

}

void tcpSend::sendData(std::string&data) {
	int send_len = send(s_server, data.c_str(), sizeof(data), 0);
	if (send_len < 0) {
		cout << "发送失败！" << endl;
	}
	else {
		std::cout << "send data：" << data.c_str() << std::endl;
	}

}

 main.cpp

#include "tcpSend.h"

int main() {
	tcpSend tcp;
	for (int i = 0; i < 100; i++) {
		std::string s = "test " + std::to_string(i);
		tcp.sendData(s);
		Sleep(1000);
	}
	return 0;
}