一个简单的TCP通信程序Demo

实现一个最简单的客户端和服务端的通信程序

服务器程序工作

1.初始化 Winsock库

2.创建监听套接字(socket()函数)

3.填写要绑定的本地地址结构(bind()函数)

4.给监听套接字绑定本地IP地址

5.开始监听(listen()函数)

6.循环执行 调用accept()函数接收客户端连接请求,如果accept()函数返回成功.则调用send()函数向客户端发送数据或者调用recv()函数从客户端接收数据

客户端程序工作

1.初始化 Winsock库

2.创建通信套接字(socket()函数)

3.填写要连接的服务器的地址结构

4.与服务器建立连接(connect()函数)

5.调用recv()函数接收服务器数据,send()函数发送数据给服务器

服务器程序代码:

// Server.cpp : Defines the entry point for the console application.
//

#include <iostream>
#include <WinSock2.h>
using namespace std;

#pragma comment(lib, "WS2_32.lib")
//表示链接WS2_32.lib这个库。
#define  PORT 1024

int main()
{
SOCKET sock_server, newsock;
struct sockaddr_in server_addr, client_addr;
char msg[] = { "Hello clinet" };
// 初始化 winsock2.dll[12/27/2017 MagicScaring]
WSADATA wsaData;
WORD wVersionRequested = MAKEWORD(2, 2);        //生成版本号
if (WSAStartup(wVersionRequested, &wsaData) != 0)
{
cout << "加载 winsock.dll失败" << endl;
return 0;
}
// 创建套接字 [12/27/2017 MagicScaring]
if ((sock_server = socket(AF_INET, SOCK_STREAM, 0)) == SOCKET_ERROR)
{
cout << "创建套接字失败! 错误代码:" << WSAGetLastError() << endl;
WSACleanup();                   //注销WinSock动态链接库
return 0;
}
// 填写需要绑定的本地地址 [12/27/2017 MagicScaring]
int addr_len = sizeof(struct sockaddr_in);
memset((void*)&server_addr, 0, sizeof(server_addr));
server_addr.sin_family = AF_INET;
server_addr.sin_port = htons(PORT);
server_addr.sin_addr.s_addr = htonl(INADDR_ANY);

if (bind(sock_server, (struct sockaddr*)&server_addr, addr_len) != 0)
{
cout << "绑定失败!错误代码:" << WSAGetLastError() << endl;
closesocket(sock_server);               //关闭已连接套接字
WSACleanup();                           //注销WinSock动态链接库
return 0;
}

// 开始监听 [12/27/2017 MagicScaring]
if (listen(sock_server, 0) != 0)
{
cout << "listen调用失败!错误代码:" << WSAGetLastError() << endl;
closesocket(sock_server);
WSACleanup();
return 0;
}
else
{
cout << "listening...." << endl;
}
// 循环:接收连接请求并收发数据 [12/27/2017 MagicScaring]
int size;
while (true)
{
if ((newsock = accept(sock_server, (struct sockaddr *)&client_addr, &addr_len)) == INVALID_SOCKET)
{
cout << "accept 函数调用失败! 错误代码:" << WSAGetLastError() << endl;
break;
}
else
{
cout << "成功接收到一个连接请求!" << endl;
size = send(newsock, msg, sizeof(msg), 0);
if (size == SOCKET_ERROR)
{
cout << "发送信息失败! 错误代码:" << WSAGetLastError() << endl;
closesocket(newsock);
continue;
}
else if (size == 0)
{
cout << "对方已关闭连接" << endl;
closesocket(newsock);
continue;
}
else
{
cout << "信息发送成功" << endl;
}
size = recv(newsock, msg, sizeof(msg), 0);
if (size == SOCKET_ERROR)
{
cout << "接收信息失败！ 错误代码：" << WSAGetLastError() << endl;
closesocket(newsock);
WSACleanup();
return 0;
}
else if (size == 0)
{
cout << "对方已关闭连接" << endl;
closesocket(newsock);
WSACleanup();
return 0;
}
else
{
cout << "The message from Client:" << msg << endl;

}
}
}

return 0;
}

客户端程序代码:

// Client.cpp : Defines the entry point for the console application.
//

#include <iostream>
#include <WinSock2.h>
using namespace std;

#pragma comment(lib, "WS2_32.lib")
//表示链接WS2_32.lib这个库。
#define  PORT 1024

int main()
{
SOCKET sock_client;
struct sockaddr_in server_addr;
int addr_len = sizeof(struct sockaddr_in);
char msgbuffer[1000];
memset(msgbuffer, 0, sizeof(msgbuffer));
// 初始化 winsock2.dll[12/27/2017 MagicScaring]
WSADATA wsaData;
WORD wVersionRequested = MAKEWORD(2, 2);        //生成版本号
if (WSAStartup(wVersionRequested, &wsaData) != 0)
{
cout << "加载 winsock.dll失败" << endl;
return 0;
}
// 创建套接字 [12/27/2017 MagicScaring]
if ((sock_client = socket(AF_INET, SOCK_STREAM, 0)) == SOCKET_ERROR)
{
cout << "创建套接字失败! 错误代码:" << WSAGetLastError() << endl;
WSACleanup();                   //注销WinSock动态链接库
return 0;
}
// 填写服务器地址 [12/27/2017 MagicScaring]
char IP[20] = { "192.168.5.38" };
/*char IP[20];
cout << "输入服务器地址:" << endl;
cin >> IP;*/
memset((void*)&server_addr, 0, sizeof(server_addr));
server_addr.sin_family = AF_INET;
server_addr.sin_port = htons(PORT);
server_addr.sin_addr.s_addr = inet_addr(IP);

// 与服务器建立连接 [12/27/2017 MagicScaring]
if (connect(sock_client, (struct sockaddr*)&server_addr, addr_len) == SOCKET_ERROR)
{
cout << "连接失败! 错误代码:" << WSAGetLastError() << endl;
closesocket(sock_client);
WSACleanup();
return 0;
}
while (true)
{
int size;
if ((size = recv(sock_client, msgbuffer, sizeof(msgbuffer), 0)) == SOCKET_ERROR)
{
cout << "接收信息失败！ 错误代码：" << WSAGetLastError() << endl;
closesocket(sock_client);
WSACleanup();
return 0;
}
else if (size == 0)
{
cout << "对方已关闭连接" << endl;
closesocket(sock_client);
WSACleanup();
return 0;
}
else
{
cout << "The message from Server:" << msgbuffer << endl;
}
char send_msg[1000] = { "Hello server" };
if((size = send(sock_client, send_msg, sizeof(send_msg),0)) == SOCKET_ERROR)
{
cout << "发送信息失败! 错误代码:" << WSAGetLastError() << endl;
}
else if (size == 0)
{
cout << "对方已关闭连接" << endl;
}
else
{
cout << "信息发送成功" << endl;
}

}
closesocket(sock_client);
WSACleanup();

return 0;
}

服务器程序运行结果:



客户端程序运行结果: