From: stephen.tashiro@...
Date: 2006-03-31T02:33:43+09:00
Subject: Unintentional hype of Ruby irb and ri

Perhaps an inflamatory title - but it answers some simple questions.

Having looked at the Pixaxe book and visited various websites with Ruby
tutorials, I think there is an unintentional hype of certain Ruby
features.  We may blame this on the distributors of software.  For
example, the authors tell us how easy it is to use irb.  On my Redhat
Enterprise Linux machine, ruby puts("Hello World") ran fine.  But irb
was not a command known to bash.   The redhat distribution has the
packages:
ruby-docs-1.8.1-7.EL4.2
ruby-tcltk-1.8.1-7.EL4.2
ruby-1.8.1-7.EL4.2
ruby-mode-1.8.1-7.EL4.2
ruby-devel-1.8.1-7.EL4.2
ruby-libs-1.8.1-7.EL4.2
irb-1.8.1-7.EL4.2
So you might get ruby but not irb.

The authors extol the virtues of ri.  I found that ri File  (or ri
almost anything) gave:
No ri documentation found in:
     /usr/share/ri/1.8/system
     /usr/share/ri/1.8/site
     /root/.rdoc

These problems can be blamed on incompetent packaging or installation
of Ruby, but it seems to me that the authors of Ruby tutorials should
warn their readers about such problems and perhaps give some hints
about how to resolve them.

In Redhat Enterprise Linux 4, I was able to resolve the irb problem
simply by installing the irb-1.8.1-7 package.

At to the ri problem,I found no tutorials that mention rdoc or
configure ri.  Reading the output of
ri -h
I concluded it would suffice to run
rdoc --ri
which creates a director called "doc" in my home directory.    And this
makes ri work for the basic ruby objects.  (Of course a more efficient
way on a mult-user system would be to create this "doc" file in only
one location and direct the ri for each user to it.  It would be nice
to have a simple example of this. )