I need to check whether some Linux command is available in the user's shell. Here is what I came up with:

(defn sh->out
  [opts & args]
  (-> (apply process/sh opts args)
      :out))

(defn command-available? [command]
  (when-not (= (or nil "")
               (sh->out "command" "-v" command))
    true))

(command-available? "wget") ;; => true

(command-available? "flippetyfloppetyfloop") ;; => nil (punning)

I made a bb hiccup example here with inline JS here: https://github.com/squint-cljs/squint/blob/main/examples/babashka/index.clj

Sharing snippet to parse and compare version numbers in case it's useful to others:

(defn sh-out->json [opts & args]
  (-> (apply process/sh opts args)
      :out
      (json/parse-string true)))

(defn parse-version-num [version-str]
  (->> (string/split version-str #"\.")
       (mapv #(Integer/parseInt %))))

(defn compare-version-nums [num-1 num-2]
  (compare (parse-version-num num-1)
           (parse-version-num num-2)))

(defn az-required-version? [required-num]
  (let [installed-num (-> (sh-out->json "az" "version" "--output" "json")
                          :azure-cli)]
    (when (-> (compare-version-nums installed-num required-num)
              (>= 0))
      true)))

Does a "TUI library" exist for Clojure that works well with Babashka? I don't necessarily need a full-fledged TUI with menus, colors, loading bars, etc. Just something that loops, prompting the user for a selection or freeform input, then does something with that input, prints user feedback, and repeats, sort of like a REPL.