Ruby directory alias get original path

Ruby directory alias get original path

I'm working with a directory that's an alias with Ruby on Mac. This means
that this is a folder that just points to another folder. How can I
determine what the original directory that this alias points to?
So for example, in one of my Jenkins job, there is an alias called
lastStable, which points to the latest stable build folder.

path = /Users/steve/.Jenkins/jobs/MyApp/lastStable
lastStable actually points to a folder called 2013-08-06_10_50_49.
How can I get this info dynamically in Ruby?