利用匿名管道实现CMD回显

SECURITY_ATTRIBUTES sa;
 HANDLE hRead,hWrite;
  
 sa.nLength = sizeof(SECURITY_ATTRIBUTES); 
 sa.lpSecurityDescriptor = NULL; //使用系统默认的安全描述符 
 sa.bInheritHandle = TRUE; //创建的进程继承句柄

 if (!CreatePipe(&hRead,&hWrite,&sa,0)) //创建匿名管道
 {  
   MessageBox(L"CreatePipe Failed!",L"提示",MB_OK | MB_ICONWARNING);  
   return;
 }

 STARTUPINFO si; 
 PROCESS_INFORMATION pi;

 ZeroMemory(&si,sizeof(STARTUPINFO));
 si.cb = sizeof(STARTUPINFO); 
 GetStartupInfo(&si); 
 si.hStdError = hWrite; 
 si.hStdOutput = hWrite; //新创建进程的标准输出连在写管道一端
 si.wShowWindow = SW_HIDE; //隐藏窗口 
 si.dwFlags = STARTF_USESHOWWINDOW | STARTF_USESTDHANDLES;

 UpdateWindow();
 char cmdline[200]; 
 CString tmp;//,stredit2;
 GetDlgItemText(IDC_EDIT_CMD,stredit2); //获取编辑框中输入的命令行
 tmp.Format(L"%s",stredit2);
 //sprintf(cmdline,"%s",tmp);
 if (!CreateProcess(L"ffmpeg.exe",tmp.GetBuffer(),NULL,NULL,TRUE,NULL,NULL,NULL,&si,&pi)) //创建子进程
 {
   MessageBox(L"CreateProcess Failed!",L"提示",MB_OK | MB_ICONWARNING);  
   return;
 }
 CloseHandle(hWrite); //关闭管道句柄

 char buffer[4096] = {0};
 //CString strOutput;
 DWORD bytesRead;
  
 while (true) 
 {
   if (ReadFile(hRead,buffer,4095,&bytesRead,NULL) == NULL) //读取管道
   break;
  
   strOutput += buffer;
   SetDlgItemText(IDC_EDIT_OUTPUT,strOutput); //显示输出信息到编辑框,并刷新窗口
   UpdateWindow();
   Sleep(100);
 }
 CloseHandle(hRead);