The easiest way to install Clack is to use Quicklisp. After installing Quicklisp, just use:
on your Common Lisp implementation. This command downloads and installs Clack and all dependencies automatically.
To check if everything is installed correctly, run a web server with Clack on your REPL:
(clack:clackup (lambda (env) (declare (ignore env)) '(200 (:content-type "text/plain") ("Hello, Clack!")))) ;-> Hunchentoot server is started. Listening on localhost:5000. #<CLACK.HANDLER:<HANDLER> #x30200A102B3D>
Clack starts a web server on localhost port 5000 by default. Open your web browser and go to http://127.0.0.1:5000/. You should get “Hello, Clack!” message. You may not understand the details of the above code. Don’t worry. I’ll explain it in the next chapter.
To stop the server, use: