A user I support is trying to use the dbm module that's part of Ruby's  
standard library, but it doesn't seem to be installed.  We're running  
RedHat Enterprise Linux 5.3, with Ruby 1.8.5 installed via RPM from  
RedHat's repository.  We also have Ruby Gems configured.  Trying to  
require dbm gives this error:

brodbd@patas:~$ irb
irb(main):001:0> require "dbm"
LoadError: no such file to load -- dbm
	from /opt/ruby-gems/lib/site_ruby/1.8/rubygems/custom_require.rb: 
27:in `gem_original_require'
	from /opt/ruby-gems/lib/site_ruby/1.8/rubygems/custom_require.rb: 
27:in `require'
	from (irb):1
irb(main):002:0>

I can't figure out what additional packages I need to install to make  
dbm available, and I'm hoping someone here can help.

I apologize if this is a dumb question, but I'm not terribly familiar  
with Ruby, and my attempts to find an answer via Google haven't been  
successful.

-- 

David Brodbeck
System Administrator, Linguistics
University of Washington