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（只发送一次）。

客户端：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。（只发送一次）

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\n", 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(sockSr
4000
v, (SOCKADDR *) &addrClient, &len);
if(sockConn == SOCKET_ERROR){
printf("Accept failed:%d", WSAGetLastError());
break;
}

printf("Accept client IP:[%s]\n", 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\n", 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\n", 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();
}

这是初始版本，接下来是实现一问一答的聊天模式版本

服务端代码：

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

using namespace std;

#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\n", WSAGetLastError());
return;
}

if (listen(sockSrv, 10) == SOCKET_ERROR) {
printf("Listen failed:%d", WSAGetLastError());
return;
}

SOCKADDR_IN addrClient;
int len = sizeof(SOCKADDR);

//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]\n", inet_ntoa(addrClient.sin_addr));

int iSend = send(sockConn, buf, sizeof(buf), 0);
if (iSend == SOCKET_ERROR) {
printf("send failed");
//break;
}

while (1)
{

char recvBuf[100];
memset(recvBuf, 0, sizeof(recvBuf));
//接收数据
recv(sockConn, recvBuf, sizeof(recvBuf), 0);

cout << "收到的信息： ";
cout << recvBuf << endl;

//发送数据
cout << "请输入发送的信息： " ;
char sendBuf[100];
memset(sendBuf, 0, sizeof(sendBuf));
cin.getline(sendBuf,sizeof(sendBuf));

iSend = send(sockConn, sendBuf, sizeof(sendBuf), 0);
if (iSend == SOCKET_ERROR) {
printf("send failed");
break;
}

if (sendBuf[0] == 'e')    //关闭套接字
{
closesocket(sockConn);
cout << "关闭接受套接字" << endl;
break;
}

}

closesocket(sockSrv);
WSACleanup();
system("pause");
}

以下是客户端：

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

using namespace std;
#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
while(1)
{
//接收数据
recv(sockClient, buff, sizeof(buff), 0);
cout << "收到的信息: ";
cout << buff << endl;

//发送数据
//char buff1[] = "hello, this is a Client....";
cout << "请输入发送的信息: " ;
char sendBuf[100];
memset(sendBuf, 0, sizeof(sendBuf));
cin.getline(sendBuf,sizeof(sendBuf));
cout << "sizeof(sendBuf):" << sizeof(sendBuf) << endl;
send(sockClient, sendBuf, sizeof(sendBuf), 0);

if (sendBuf[0] == 'e')
{
//关闭套接字
closesocket(sockClient);
cout << "关闭client套接字" << endl;
break;
}

}

WSACleanup();
system("puase");
}