Dectecting dir changes

[chuck]

I need to write a daemon for Solaris that monitors a directory for
incoming FTP transfers.  Under certain conditions, when the transfer is
complete I need to send an email notification, and do other stuff.
Win32 provides FindFirstChangeNotification(), but as best I can tell
this isn't supported on Solaris.

I am thinking of using the approach suggested here
http://tgolden.sc.sabren.com/python/win32_how_do_i/watch_directory_for_changes.html
which is:

import os, time
path_to_watch = "."
before = dict ([(f, None) for f in os.listdir (path_to_watch)])
while 1:
  time.sleep (10)
  after = dict ([(f, None) for f in os.listdir (path_to_watch)])
  added = [f for f in after if not f in before]
  removed = [f for f in before if not f in after]
  if added: print "Added: ", ", ".join (added)
  if removed: print "Removed: ", ", ".join (removed)
  before = after

My concern with this is that a change may be detected before the ftp
daemon process is done writing the file to disk.  I don't want to take
any action until the file is written and closed.  I know that I could
pole a new file looping to check to see if it's file size is changing
but the timing of such a loop is subject to I/O buffering and is
otherwise not elegant.

Googling shows other solutions using fcntl
(http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/217829) but it
appears that this only works on Linux.

While I'm at it I'm going to throw in a grump about the Python
documentation of fcntl.  The doco indicates to read the source for
fcntl.py to lookup the constants representing the different types of
events/signals that are avaiable.  However fcntl on some platforms
seems to be implemented as a binary leaving no way to look up the
contants for the platform.

Suggestions?