title: When is FILE flushed?
body: <p>I have a good old C FILE file descriptor under Windows that is used by an output stream to write data to. My question is simple and yet I could not find the answer:</p>
  
  <p><strong>When is the content flushed to disc assuming I don't call fflush?</strong></p>
  
  <p>The stream constantly receives data and it seems that the content is flushed quite often, but what is the rule for flushing it?</p>