C++ socket实例 发送消息

//server端：******************************************************************************
#include "stdafx.h"




#include <winsock2.h>
#include <iostream>
#define PORT_SERVER 6656
#define NUM_CLIENTS 10
using namespace std;
#pragma comment(lib,"ws2_32.lib")
void main(){
std::cout << "Start up tcp server." << std::endl;


WSADATA wsaData;
WORD sockVersion = MAKEWORD(2, 0);
if (0 != WSAStartup(sockVersion, &wsaData))
{
  std::cout << "Failed to retrive socket version." << std::endl;
  return ;
} 
SOCKET sock_sev;
sock_sev = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
if (INVALID_SOCKET == sock_sev)
{
  std::cout << "Invalid socket." << std::endl;
  WSACleanup();
  return ;
} 


sockaddr_in addr_sev;
addr_sev.sin_family = AF_INET;
addr_sev.sin_port = htons(PORT_SERVER);
addr_sev.sin_addr.s_addr = INADDR_ANY;
if (SOCKET_ERROR == bind(sock_sev, (sockaddr *)&addr_sev, sizeof(addr_sev)))
{
  std::cout << "Failed to bind." << std::endl;
  WSACleanup();
  return ;
}
if (SOCKET_ERROR == listen(sock_sev, NUM_CLIENTS))
{
  std::cout << "Failed to listen." << std::endl;
  WSACleanup();
  return ;
}


SOCKET clientSocket;//用来和客户端通信的套接字  
struct sockaddr_in clientAddress;//用来和客户端通信的套接字地址  
memset(&clientAddress,0,sizeof(clientAddress));//初始化存放客户端信息的内存  
int addrlen = sizeof(clientAddress);  
       
//接受连接  
if((clientSocket=accept(sock_sev,(sockaddr*)&clientAddress,&addrlen))==INVALID_SOCKET){  
cout<<"接受客户端连接失败！";  
Sleep(3000);  
exit(-1);  
}  


char buf[1024];
cout << "服务端说：";
gets_s(buf);
if(send(clientSocket,buf,strlen(buf),0)==SOCKET_ERROR){  
cout<<"发送数据失败！"<<endl;  
Sleep(3000);  
exit(-1);
}  


system("pause");

}

//client端：*******************************************************************************

#include "stdafx.h"




#include <winsock2.h>
#include <iostream>
#include <stdio.h>
using namespace std;
#define PORT_SERVER 6656
#pragma comment(lib,"ws2_32.lib")


void main()
{
cout << "Start up tcp client." << endl;


WSADATA wsaData;
WORD sockVersion = MAKEWORD(2, 0);
if (0 != WSAStartup(sockVersion, &wsaData))
{
   cout << "Failed to retrive socket version." << endl;
   return ;
}


SOCKET sock_client;
sock_client = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
if (INVALID_SOCKET == sock_client)
{
   cout << "Invalid socket." << endl;
   WSACleanup();
   return ;
}
sockaddr_in addr_sev;
addr_sev.sin_family = AF_INET;
addr_sev.sin_port = htons(PORT_SERVER);
addr_sev.sin_addr.s_addr = inet_addr("127.0.0.1");
if (SOCKET_ERROR == connect(sock_client, (sockaddr *)&addr_sev, sizeof(addr_sev)))
{
   std::cout << "Failed to connect." << std::endl;
   WSACleanup();
   return ;
} 
char buf[512];
int recv_size = 0;
recv_size = recv(sock_client, buf, 512, 0);
if (512 > recv_size)
{
   buf[recv_size] = '\0';
   std::cout << "receive data is :" << buf << std::endl;
   memset(buf, 0, sizeof(buf));
}
else
{
   std::cout << "receive data is overflow" << std::endl;
}
closesocket(sock_client);
WSACleanup();
system("pause");
}