Simple Password Generator

genpass.clj

#!/usr/bin/env bb

(require '[clojure.tools.cli :refer [parse-opts]])

(def generator (java.security.SecureRandom.))

(defn gen-pass [alphabet length]
  (let [bound (count alphabet)
        idxs  (repeatedly length #(.nextInt generator bound))]
    (apply str (map alphabet idxs))))

(def symbols {:uppercase "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
              :lowercase "abcedfghijklmnopqrstuvwxyz"
              :numerical "0123456789"
              :special   "!@#$%^&*"})

(def default-length 16)

(let [parsed (-> *command-line-args*
                 (parse-opts [["-u" "--uppercase"]
                              ["-l" "--lowercase"]
                              ["-n" "--numerical"]
                              ["-s" "--special"]
                              ["-x" "--extras EXTRAS"]]))
      options (parsed :options)
      flags  (or (keys options) (keys symbols))
      length (edn/read-string (first (:arguments parsed)))
      length (if (integer? length) length default-length)
      alphabet (->> flags (select-keys symbols) vals
                    (apply str (options :extras)) vec)]
  (print (gen-pass alphabet length)))