Ruby and ri(1) ruby information

[Roger]

>
> I recently would up with a book on Ruby and got curious about it.
> I discovered I have Ruby installed.  This was a fresh install of
> xubuntu 13.04, so I assume it came with the distro.
>
> Following the book (The Ruby Programming Language, O'Reilly) in the
> first few pages it talks about things that come with.  Including the
> ri command, and it gives examples.  None of them work -- they all say
> "Nothing known about x"
>
> Is there something I have done wrong?  Is there something I can do to
> put it right?  Or is this time to file a bug?
>
I have been learning Ruby and Rails this year and as far as I can grasp 
at this time ri and rdoc are documentation facilities for ruby gems.
Don't quote me though
Roger