ree_gems.rb

#!/usr/bin/env ruby
BASE='/opt/ruby-enterprise-1.8.6-20080624'
# The command to run for your vanila Ruby 'gem' command
OLD_GEM='gem'
# The command to run for REE's 'gem' command
NEW_GEM="#{BASE}/bin/ruby #{BASE}/bin/gem"

output=`#{OLD_GEM} list`
new_list=`#{NEW_GEM} list`
output.each do |line|
  # Skip lines that don't look like a gem version
  matches=line.match(/([A-Z].+) \(([0-9\., ]+)\)/i)
  if matches then
    gem_name=matches[1]
    versions=matches[2]
    versions.split(', ').each do |ver|
      cmd="#{NEW_GEM} install #{gem_name} -v #{ver} --no-rdoc --no-ri --backtrace" 
      # See if this gem is already installed
      if new_list =~ /#{gem_name} \(.*#{ver}.*\)/i then
        puts "#{gem_name} #{ver} is already installed. Skipping" 
      else
        puts cmd
        system(cmd)
      end
    end
  end
end