C++ 后台运行cmd

#include 
int APIENTRY _tWinMain(HINSTANCE hInstance,
                     HINSTANCE hPrevInstance,
                     LPTSTR    lpCmdLine,
                     int       nCmdShow)
{
	// #include   
	std::string command = "ping 127.0.0.1";
	SECURITY_ATTRIBUTES sa = {sizeof(SECURITY_ATTRIBUTES), NULL, TRUE};
    HANDLE hRead, hWrite;
    if (!CreatePipe(&hRead, &hWrite, &sa, 0))
    {
        return 0;
    }
 
    STARTUPINFOA si = {sizeof(STARTUPINFO)};
    GetStartupInfoA(&si);
    si.dwFlags = STARTF_USESHOWWINDOW | STARTF_USESTDHANDLES;
    si.wShowWindow = SW_HIDE;
    si.hStdError = hWrite;
    si.hStdOutput = hWrite;
 
    PROCESS_INFORMATION pi;
	if (!CreateProcessA(NULL, (char*)command.c_str(), NULL, NULL, TRUE, NULL, NULL, NULL, &si, &pi))
    {
        return 0;
    }
    CloseHandle(hWrite);

	std::string strRet;
    char buff[10] = {0};
    DWORD dwRead = 0;
    while (ReadFile(hRead, buff, 1, &dwRead, NULL))
    {
        strRet.append(buff, dwRead);
		if(buff[0] == '\r') {
			MessageBoxA(0,strRet.c_str(),0,0);
			strRet= "";
		}
    }
    CloseHandle(hRead);
	return 0;
}