    # File lib/chef/knife/cookbook_delete.rb, line 37
          def run
            confirm("Files that are common to multiple cookbooks are shared, so purging the files may disable other cookbooks. Are you sure you want to purge files instead of just deleting the cookbook") if config[:purge]
            @cookbook_name, @version = name_args
            if @cookbook_name && @version
              delete_explicit_version
            elsif @cookbook_name && config[:all]
              delete_all_versions
            elsif @cookbook_name && @version.nil?
              delete_without_explicit_version
            elsif @cookbook_name.nil?
              show_usage
              ui.fatal("You must provide the name of the cookbook to delete")
              exit(1)
            end
          end