Yes, I tried it both ways:

irb(main):002:0> require 'oci8'
LoadError: no such file to load -- oci8lib_18
  from C:/Ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in 
`gem_original_require'
  from C:/Ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in 
`require'
  from C:/Ruby/lib/ruby/site_ruby/1.8/oci8.rb:25
  from C:/Ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in 
`gem_original_require'
  from C:/Ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in 
`require'
  from (irb):2
  from :0
irb(main):003:0> foo = 'oci8'
=> "oci8"
irb(main):004:0> require foo
LoadError: no such file to load -- oci8lib_18
  from C:/Ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in 
`gem_original_require'
  from C:/Ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in 
`require'
  from C:/Ruby/lib/ruby/site_ruby/1.8/oci8.rb:25
  from C:/Ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in 
`gem_original_require'
  from C:/Ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in 
`require'
  from (irb):4
  from :0
irb(main):005:0>
-- 
Posted via http://www.ruby-forum.com/.