files_in_gem

# File lib/rubygems/commands/contents_command.rb, line 94
  def files_in_gem(spec)
    gem_path  = spec.full_gem_path
    extra     = "/{#{spec.require_paths.join ','}}" if options[:lib_only]
    glob      = "#{gem_path}#{extra}/**/*"
    prefix_re = /#{Regexp.escape(gem_path)}\//

    Dir[glob].map do |file|
      [gem_path, file.sub(prefix_re, "")]
    end
  end