Low-level web programming in Racket and a wiki in 500 lines(matt.might.net)

  ; extract the URI from the request:
  (define uri (request-uri req))
  
  ; extract the resource from the URI:
  (define resource 
    (map path/param-path (url-path uri)))
  
  ; find the file location:
  (define file (string-append
                document-root
                "/" 
                (string-join resource "/")))