Unix file desciptors

Hi! I’m new on this list, and right now I’m wondering something… Does
somedy know if Ruby streams are Unix File Descriptor’s compatible? I
need to use a file descriptor opened by another process (a daemon
written in C). I’m reading about the IO class, it seems to have a method
that allows creating an IO object using a file descriptor (an integer)
as a parameter. But I see that File has something similar (I guess that
Files is a subcclass of IO). I’m new at Ruby, so I’m not sure about its
internals.
Does somebody know something about this? Thanks.