file.cljs

(defn exec-chan
  "spawns a child process for cmd with args. routes stdout, stderr, and
  the exit code to a channel. returns the channel immediately."
  [cmd args & [{:keys [chan]}]]
  (let [c (or chan (a/chan)), p (spawn cmd args)]
    (.on (.-stdout p) "data"  #(put! c [:out  (str %)]))
    (.on (.-stderr p) "data"  #(put! c [:err  (str %)]))
    (.on p            "close" #(a/close! c))
    c))

(defn exec [[cmd & args] & [{:keys [timeout chan] :or {timeout 2000}}]]
  (let [c (exec-chan cmd (clj->js args))
        out-chan (or chan (a/chan))]
    (go
      (loop []
        (let [v (alt!
                  (a/timeout timeout) ::timeout
                  c ([v] v))]
          (when (not= v ::timeout)
            (>! out-chan v)
            (recur))))
      (a/close! out-chan)))
  out-chan)

(defn test-fn []
  (go
    (let [result (<! (a/into [] (exec ["./test.sh" "-d" "3"])))]
      (println result))))