A simple HTTP client

client.carp

(load "git@github.com:carpentry-org/sockets@master")
(load "git@github.com:carpentry-org/http@master")

(load "https://veitheller.de/git/carpentry/cli@0.0.7")

(defn read-all [sock s]
  (let [read (Socket.read sock)]
    (if (= &read "")
      (Response.parse &s)
      (let [acc (String.concat &[s read])]
        (match (Response.parse &acc)
          (Result.Error msg) (do (IO.errorln &(fmt "Response: '%s'" &acc)) (Result.Error msg))
          (Result.Success r)
            (let [cl (Array.first &(Map.get (Response.headers &r) "Content-Length"))
                  l (Maybe.from (Maybe.apply cl &(fn [s] (Int.from-string &s))) 0)]
              (if (<= l (length (Response.body &r)))
                (Result.Success r)
                (read-all sock acc))))))))

(defn main []
  (let [p (=> (CLI.new @"A simple HTTP client.")
              (CLI.add &(CLI.str "host" "h" "the host to visit" true))
              (CLI.add &(CLI.str "url" "u" "the URL to visit" false @"/"))
              (CLI.add &(CLI.bool "verbose" "v" "whether we should be verbose"))
              (CLI.add &(CLI.str "verb" "e" "the verb to use" false @"GET"))
              (CLI.add &(CLI.str "body" "b" "the body to send" false @""))
              (CLI.add &(CLI.str "cookies" "c" "the cookies to send" false @""))
              (CLI.add &(CLI.str "proto" "r" "the protocol to use" false @"http"))
              (CLI.add &(CLI.int "port" "p" "the port to use" false 80l)))]
    (match (CLI.parse &p)
      (Result.Error err)
        (do
          (IO.errorln &err)
          (CLI.usage &p))
      (Result.Success args)
        (let [host (str &(Map.get &args "host"))
              url (str &(Map.get &args "url"))
              verb (str &(Map.get &args "verb"))
              verbose (CLI.Type.to-bool (Map.get &args "verbose"))
              body (str &(Map.get &args "body"))
              port (to-int (Map.get &args "port"))
              proto (str &(Map.get &args "proto"))
              cookies (str &(Map.get &args "cookies"))
              c (if (/= &cookies "")
                  (Cookie.parse-many &cookies)
                  (Result.Success []))
             ]
          (match (URI.parse &url)
            (Result.Error err) (IO.errorln &err)
            (Result.Success uri)
              (match c
                (Result.Error err) (IO.errorln &err)
                (Result.Success cl)
                  (Socket.with-client-for sock &host &proto port
                    (if (Socket.valid? &sock)
                      (do
                        (let-do [res &(str &(Request.request verb uri cl {@"Host" [host] @"Content-Length" [(str (length &body))]} body))]
                          (when verbose (IO.println &(fmt "Request: %s" res)))
                          (Socket.send &sock res))
                        (match (read-all &sock @"")
                          (Result.Success r)
                            (if verbose
                              (IO.println &(str &r))
                              (IO.println (Response.body &r)))
                          (Result.Error msg) (IO.errorln &msg)))
                      (IO.errorln
                        &(fmt "Couldn’t connect to host %s on port %d." &host port))))))))))