From: John Joyce <dangerwillrobinsondanger@...>
Date: 2007-03-23T20:21:24+09:00
Subject: Re: How do I properly spawn an external process on OS X from Ruby?

It might be worth your time to check out Automator actions or  
AppleScript more before creating daemons.
If you use the AppleScript method there is definitely a way to send a  
file to an app and then take the result and send it to a Ruby file.  
You don't necessarily have to leave the Ruby process running, but you  
can. Depends what you want to do.
The trouble might be, OS X applications must have AppleScript enabled  
in them. Not everything in the app will be available to you, but  
passing a file should be painless and easy. Depends on the app though.