title: Peek data in Serial port windows
body: <p>How to know the data bytes availability at serail port in windows?
  I mean, I just want to check whether serail port empty or not?</p>
  
  <p>NOTE:
  there was function in Linux "ioctl(fd,FIONREAD,&amp;availableBytes)", I need to implement similar functionality in windows.</p>
  
  <p>~ Johnnie</p>