Determining when a file has finished copying

[Larry Bates]

writeson wrote:
> Hi all,
> 
> I'm writing some code that monitors a directory for the appearance of
> files from a workflow. When those files appear I write a command file
> to a device that tells the device how to process the file. The
> appearance of the command file triggers the device to grab the
> original file. My problem is I don't want to write the command file to
> the device until the original file from the workflow has been copied
> completely. Since these files are large, my program has a good chance
> of scanning the directory while they are mid-copy, so I need to
> determine which files are finished being copied and which are still
> mid-copy.
> 
> I haven't seen anything on Google talking about this, and I don't see
> an obvious way of doing this using the os.stat() method on the
> filepath. Anyone have any ideas about how I might accomplish this?
> 
> Thanks in advance!
> Doug

The best way to do this is to have the program that copies the files copy them 
to a temporarily named file and rename it when it is completed.  That way you 
know when it is done by scanning for files with a specific mask.

If that is not possible you might be able to use pyinotify 
(http://pyinotify.sourceforge.net/) to watch for WRITE_CLOSE events on the 
directory and then process the files.

-Larry