title: How to know if a file is being copied?
body: <p>I am currently trying to check wether the copy of a file  from a directory to another is done.
  I would like to know if the target file is still being copied.</p>
  
  <p>So I would like to get the number of file descriptors openned on this file.
  I use C langage and don't really find a way to resolve that problem.</p>