kqueue is the "low level" interface, but requires that you handle all file system events as they happen, and fast. There is a higher level interface called fsevents (with accompanying daemon fseventsd) which allows you a more calm way to read the file system events.

http://developer.apple.com/mac/library/documentation/Darwin/Conceptual/FSEvents_ProgGuide/Introduction/Introduction.html

I think launchd just happens to have an integration to kqueue or fseventsd, I'm not sure launching a program every time a file changes would be the best thing :-)

-Ross


On Dec 4, 2009, at 11:08 AM, David Leimbach wrote:

d

On Thu, Dec 3, 2009 at 7:55 PM, Gregory Collins <greg@gregorycollins.net> wrote:
Conal Elliott <conal@conal.net> writes:

> I'd like to make some FRPish toys that keep files updated to have
> functional relationships with other files.  hinotify looks like just
> the sort of underlying magic I could use for efficient implementation
> on linux.  Is there any support for mac os x?  Could support be either
> added to hinotify or maybe inotify and a mac-friendly library be
> abstracted into a common Haskell interface?  I'm fine with an
> imperative interface, since I can abstract into a functional library,
> which I guess would be a sort of persistent simplified FRP.

On Mac & BSD you have to use kqueue, and on Windows it's
ReadDirectoryChangesW. A platform-agnostic Haskell library for detecting
filesystem change notifications is something that I would really
appreciate!

launchd does everything on mac os x, like literally everything.  My mother said if I can't say something good about someone or something then don't say anything at all, and in this case, I'm taking her advice on what I think about launchd, however if you click the link below you might get an idea of how that works on Mac OS X.


Dave 

G
--
Gregory Collins <greg@gregorycollins.net>
_______________________________________________
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe

_______________________________________________
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe