On 04/07/2011 07:43 PM, Tony Yarusso wrote:

> Depending on your use case, you might also be interested in a tool
> called incron, which lets you kick off tasks when files under a
> particular path change.

incron is viable, but even better would be lsyncd[1] that kicks off a 
rsync command when new files are added to the watched directory. I'm 
building a simple dropbox clone this way for fun. I only have one way 
syncing (and a public directory that a vhost points to) at the moment as 
I devise the best way to get two way without a loop[2]. My plan to get 
out of the loop is, on the client side, hardlink the directory to a new 
directory (hardlinks are to avoid the extra download cost), rsync from 
server to client's new directory, rsync from new directory to the 
dropbox folder - assuming small files, this will be within the 20second 
watch window. Additional resource[3].

Cheers,
Jeremy

[1]: http://code.google.com/p/lsyncd/
[2]: http://code.google.com/p/lsyncd/issues/detail?id=48&can=1
[3]: http://fak3r.com/geek/howto-build-your-own-open-source-dropbox-clone/