get_path (Gem::Commands::UnpackCommand)

    # File lib/rubygems/commands/unpack_command.rb, line 67
      def get_path(gemname, version_req)
        return gemname if gemname =~ /\.gem$/i
        specs = Gem::SourceIndex.from_installed_gems.search(/\A#{gemname}\z/, version_req)
        selected = specs.sort_by { |s| s.version }.last
        return nil if selected.nil?
        # We expect to find (basename).gem in the 'cache' directory.
        # Furthermore, the name match must be exact (ignoring case).
        if gemname =~ /^#{selected.name}$/i
          filename = selected.full_name + '.gem'
          return File.join(Gem.dir, 'cache', filename)
        else
          return nil
        end
      end