#include <iostream>
#include <winsock2.h>
#include <windows.h>


#define InternetAddr "127.0.0.1"
#define iPort 6000

#pragma comment(lib, "ws2_32.lib")

#pragma pack(push, 1)
struct Person
{
  char name[20];
  int age;
};
#pragma pack(pop)


  void main()
  {
    Person person;

    memset(&person, 0x00, sizeof(person));

    WSADATA wsa;
    WSAStartup(MAKEWORD(2, 2), &wsa);

    SOCKET fdServer = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);

    struct sockaddr_in server;
    server.sin_family = AF_INET;
    server.sin_addr.s_addr = inet_addr(InternetAddr);
    server.sin_port = htons(iPort);

    int ret = bind(fdServer, (sockaddr*)&server, sizeof(server));
    ret = listen(fdServer, 4);


    SOCKET AcceptSocket;
    fd_set fdread;
    timeval tv;
    int nSize;

    while (1)
    {

      FD_ZERO(&fdread);//初始化fd_set
      FD_SET(fdServer, &fdread);//分配套接字句柄到相应的fd_set


      tv.tv_sec = 0;//这里我们打算让select等待两秒后返回，避免被锁死，也避免马上返回
      tv.tv_usec = 0;

      select(0, &fdread, NULL, NULL, &tv);

      static int num = 0;
      nSize = sizeof(server);
      if (FD_ISSET(fdServer, &fdread))//如果套接字句柄还在fd_set里，说明客户端已经有connect的请求发过来了，马上可以accept成功
      {
        num++;
        AcceptSocket = accept(fdServer, (sockaddr*)&server, &nSize);


        char Buf[] = "back to client";

        char sendBuf[100] = { 0 };

        sprintf(sendBuf, "[%d] %s", num, Buf);
        
        send(AcceptSocket, sendBuf, strlen(sendBuf) + 1, 0);

        char* buffer = new char(sizeof(Person));
    
    //    ret = recv(AcceptSocket,(char*) &person, sizeof(Person), 0);
        ret = recv(AcceptSocket, buffer, sizeof(Person), 0);
        
        memcpy(&person, buffer, sizeof(Person));

        person.age = ntohl(person.age);

        printf("num=%d name:%s, age:%d\n",num, person.name, person.age);

    //    printf("%s\n", buffer);

        
      }

      else//还没有客户端的connect请求，我们可以去做别的事，避免像没有用select方式的阻塞套接字程序被锁死的情况，如果没用select,当程序运行到accept的时候客户端恰好没有connect请求，那么程序就会被锁死，做不了任何事情
      {
        //do something
      //  ::MessageBox(NULL, "waiting", "recv", MB_ICONINFORMATION);//别的事做完后，继续去检查是否有客户端连接请求
      
        //printf("nothing....\n");
        //Sleep(2000);
      }
    }

    char buffer[128];
    ZeroMemory(buffer, 128);

    ret = recv(AcceptSocket, buffer, 128, 0);//这里同样可以用select，用法和上面一样

  //  ::MessageBox(NULL, buffer, "recv", MB_ICONINFORMATION);

  //  printf("%s", buffer);

    closesocket(AcceptSocket);
    WSACleanup();

    return;

  }

#include <Winsock2.h>
#include <stdio.h>

#pragma comment (lib, "ws2_32.lib")

#pragma pack(push, 1)
struct Person
{
  char  name[20];
  int    age;
};
#pragma pack(pop)

void main()
{
  Person person;
  memset(&person, 0x00, sizeof(Person));
  char* sn = "Jame";
  memcpy(person.name, sn, strlen(sn));
  person.age = 14;

  WORD wVersionRequested;
  WSADATA wsaData;
  int err;

  wVersionRequested = MAKEWORD(1, 1);

  err = WSAStartup(wVersionRequested, &wsaData);
  if (err != 0) {
    return;
  }


  if (LOBYTE(wsaData.wVersion) != 1 ||
    HIBYTE(wsaData.wVersion) != 1) {
    WSACleanup();
    return;
  }


  SOCKET sockClient = socket(AF_INET, SOCK_STREAM, 0);

  SOCKADDR_IN addrSrv;
  addrSrv.sin_addr.S_un.S_addr = inet_addr("127.0.0.1");
  addrSrv.sin_family = AF_INET;
  addrSrv.sin_port = htons(6000);
  connect(sockClient, (SOCKADDR*)&addrSrv, sizeof(SOCKADDR));

  

  char* str = new char(sizeof(Person));

  person.age = htonl(person.age);

  memcpy(str, &person, sizeof(Person));

  // send(sockClient,(const char*) &person, sizeof(Person), 0);

  send(sockClient, str, sizeof(Person), 0);

  printf("name:%s, age:%d\n", person.name, ntohl(person.age));

  char recvBuf[100];
  recv(sockClient, recvBuf, 100, 0);
  printf("%s\n", recvBuf);

  closesocket(sockClient);
  WSACleanup();

  getchar();
}