From: Park Heesob <phasis68@...>
Date: 2008-04-15T22:21:15+09:00
Subject: Re: win32-changenotify and modifying a file

Hi,
----- Original Message ----- 
From: "Tomek Paczkowski" <oinopion@gmail.com>
Newsgroups: comp.lang.ruby
To: "ruby-talk ML" <ruby-talk@ruby-lang.org>
Sent: Tuesday, April 15, 2008 9:45 PM
Subject: win32-changenotify and modifying a file


>    Hey!
> 
> I'm working with win32-changenofity library to listen for any changes in 
> a directory. I'm interested in added, deleted and modified files. That's 
> my code:
> 
> #-------
> filter = ChangeNotify::FILE_NAME | ChangeNotify::DIR_NAME
> abs_path = File.expand_path(dir)
> ChangeNotify.new(abs_path, true, filter) do |cn|
>   cn.wait do |events|
>     events.each do |event|
>       puts(event.action, event.file_name)
>     end
>   end
> end
> #--------
> 
> The problem is when I modify file on disk, it's not reported. When I use 
> additional filters like SIZE or LAST_WRITE I get changes reported few 
> times. Is there some combination which will report file change only once?
> 
> -- 
It's a feature of ChangeNotify.
You could filter duplicate event like this:

filter = ChangeNotify::FILE_NAME | ChangeNotify::DIR_NAME | ChangeNotify::LAST_WRITE
abs_path = File.expand_path(dir)
pre_event = nil
ChangeNotify.new(abs_path, true, filter) do |cn|
   cn.wait do |events|
     events.each do |event| 
       next if [event.action,event.file_name] == pre_event
       pre_event = [event.action,event.file_name]
       puts(event.action, event.file_name)
     end
   end
end


Regards,

Park Heesob