acdimalev

#!/usr/bin/ruby
require 'rubygems'
installed_gems = Gem::Dependency.new '', Gem::Requirement.default
missing = []
# mind the short-hand, looping over installed gem specs
specs = Gem.source_index.search installed_gems
specs.each do |spec|
  gem = Gem::Dependency.new spec.name, spec.version
  # looping over gem dependencies
  specs = Gem.source_index.search gem