C++基于TCP/IP简单的客户端、服务器通信程序实例

本篇文章实现了一个基于TCP 的一个非常简单的客户/服务器通信程序实例。该程序中通讯协议使用的是面向连接的TCP协议SOCK_STREAM, 服务器的ip地址为本地地址即：

127.0.0.1，端口号为自定义的5099（大于1024即可），服务端的功能只要有客户端连接请求，服务端就接受连接，在连接成功后向客户端发送数据，并且接受客户端发送的

数据。客户端在向服务端发出请求后接受并显示服务端的数据，并且给服务端也发送数据。

以下代码是服务端程序代码：

#include <WinSock2.h>
#include <stdio.h>
#include <stdlib.h>
 
#pragma comment(lib, "ws2_32.lib")
 
void main()
{
	WSADATA wsaData;
	int port = 5099;
 
	char buf[] = "Server: hello, I am a server....."; 
 
	if(WSAStartup(MAKEWORD(2, 2), &wsaData) != 0)
	{
		printf("Failed to load Winsock");
		return;
	}
 
	//创建用于监听的套接字
	SOCKET sockSrv = socket(AF_INET, SOCK_STREAM, 0);
 
	SOCKADDR_IN addrSrv;
	addrSrv.sin_family = AF_INET;
	addrSrv.sin_port = htons(port); //1024以上的端口号
	addrSrv.sin_addr.S_un.S_addr = htonl(INADDR_ANY);
 
	int retVal = bind(sockSrv, (LPSOCKADDR)&addrSrv, sizeof(SOCKADDR_IN));
	if(retVal == SOCKET_ERROR){
		printf("Failed bind:%d
", WSAGetLastError());
		return;
	}
 
	if(listen(sockSrv,10) ==SOCKET_ERROR){
		printf("Listen failed:%d", WSAGetLastError());
		return;
	}
 
	SOCKADDR_IN addrClient;
	int len = sizeof(SOCKADDR);
 
	while(1)
	{
		//等待客户请求到来	
		SOCKET sockConn = accept(sockSrv, (SOCKADDR *) &addrClient, &len);
		if(sockConn == SOCKET_ERROR){
			printf("Accept failed:%d", WSAGetLastError());
			break;
		}
 
		printf("Accept client IP:[%s]
", inet_ntoa(addrClient.sin_addr));
 
		//发送数据
		int iSend = send(sockConn, buf, sizeof(buf) , 0);
		if(iSend == SOCKET_ERROR){
			printf("send failed");
			break;
		}
 
 		char recvBuf[100];
 		memset(recvBuf, 0, sizeof(recvBuf));
// 		//接收数据
 		recv(sockConn, recvBuf, sizeof(recvBuf), 0);
 		printf("%s
", recvBuf);
 
		closesocket(sockConn);
	}
 
	closesocket(sockSrv);
	WSACleanup();
	system("pause");
}

接下来是客户端代码：

#include <WinSock2.h>
#include <stdio.h>
 
#pragma comment(lib, "ws2_32.lib")
 
void main()
{
	//加载套接字
	WSADATA wsaData;
	char buff[1024];
	memset(buff, 0, sizeof(buff));
 
	if(WSAStartup(MAKEWORD(2, 2), &wsaData) != 0)
	{
		printf("Failed to load Winsock");
		return;
	}
 
	SOCKADDR_IN addrSrv;
	addrSrv.sin_family = AF_INET;
	addrSrv.sin_port = htons(5099);
	addrSrv.sin_addr.S_un.S_addr = inet_addr("127.0.0.1");
 
	//创建套接字
	SOCKET sockClient = socket(AF_INET, SOCK_STREAM, 0);
	if(SOCKET_ERROR == sockClient){
		printf("Socket() error:%d", WSAGetLastError());
		return;
	}
 
	//向服务器发出连接请求
	if(connect(sockClient, (struct  sockaddr*)&addrSrv, sizeof(addrSrv)) == INVALID_SOCKET){
		printf("Connect failed:%d", WSAGetLastError());
		return;
	}else
	{
		//接收数据
		recv(sockClient, buff, sizeof(buff), 0);
		printf("%s
", buff);
	}
 
	//发送数据
	char buff = "hello, this is a Client....";
	send(sockClient, buff, sizeof(buff), 0);
 
	//关闭套接字
	closesocket(sockClient);
	WSACleanup();
}