This installs the core Plack modules that are required to build web applications quickly and easily (see Listing 4 below).

以上步骤就是快速方便地构建Web应用程序所需的核心Plack模块（参见下方 清单4）。

In Listing 6, for example, we are using Plack::App::Directory to get a directory listing and to serve it's content as static files.

例如，在 清单6 中，我们使用Plack::App::Directory来列出目录，并将其内容用作静态文件。