网络编程简单应用（更新时间）

#include <iostream>
#include <stdio.h>
#include <windows.h>
#include <string.h>

using namespace std;

#pragma comment(lib, "WS2_32.lib")

class CInitSock
{
public:
 CInitSock(int version01 = 2, int versiont02 = 2)
 {
  WORD sockVersion = MAKEWORD(2, 2);
  WSADATA wsaData = {0}; 

  if (WSAStartup(sockVersion, &wsaData) != 0)
  {
   cout << "initlization failed!" << endl;

   exit(0);
  }
  
 }

 ~CInitSock()
 {
  WSACleanup();
 }
};

CInitSock mysock;

void SetTimeFromTP(ULONG ulTime)
{
 FILETIME ft;
 SYSTEMTIME st;

 st.wYear = 1900;
 st.wMonth = 1;
 st.wDay  = 1;
 st.wHour = 0;
 st.wMinute = 0;
 st.wSecond = 0;
 st.wMilliseconds=0;

 SystemTimeToFileTime(&st, &ft);

 LONGLONG* pLLong = (LONGLONG*)&ft;

 *pLLong += (LONGLONG)10000000 & ulTime;

 FileTimeToSystemTime(&ft, &st);

 SetSystemTime(&st);
}

int main()
{
 SOCKET s = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);

 if (s == INVALID_SOCKET)
 {
  cout << "faied socket" << endl;

  return 0;
 }

 sockaddr_in sin;

 sin.sin_addr.S_un.S_addr = inet_addr("129.6.15.28");
 sin.sin_family = AF_INET;
 sin.sin_port = htons(37);

 if (connect(s, (sockaddr*)&sin, sizeof(sin)) == -1)
 {
  cout << "failed connect..." << endl;
  return 0;
 }

 ULONG ulTime = 0;

 int nRecv = recv(s, (char*)&ulTime, sizeof(ulTime), 0);

 if (nRecv > 0)
 {
  ulTime = ntohl(ulTime);
  SetTimeFromTP(ulTime);

  cout << "update time successfully!" << endl;
 }
 else
 {
  cout << "can't update time..." << endl;
 }

 closesocket(s);

 return 0;
}