core.clj

(defn check-user
  "Checks the nickname of the user.  This functions as a basic authorization check for commands like \"!join\"."
  [nick f]
  (if (= nick "defn")
    f
    nil))

(def bot-fnmap
     {:on-message
      (fn [{:keys [nick channel message irc]}]
        (let [[cmd & more] (.split message " ")]
          (condp = cmd
            "!join" (check-user nick (join-chan irc (first more)))
            #".*" (send-message irc #"defn-bot" (str nick " wtf are you talking about?")))))
      :on-quit (fn [{:keys [nick reason irc]}]
                 (send-message irc "#defn-bot" (str nick " quit.  His reason was: " reason)))
      :on-part (fn [{:keys [nick reason channel irc]}]
                 (send-message irc channel (str nick " parted. Reason: " reason)))})

(def bot
     (connect
      (create-irc
       {:name "defn-bot",
        :server "irc.freenode.net",
        :username "defn-bot",
        :port 6667,
        :realname "defn-bot"
        :fnmap bot-fnmap})
      :channels ["#defn-bot"]))