Add the file errors to prevent using an invalid file path.

src/cipher_analytical_machine/cli.clj

@@ -28,6 +28,7 @@
    ["-l" "--language CODE" "The string will be used to set a default symbols for a cipher."
     :validate [#(contains? language-options %) "Must be a code from the list: en, uk!!!"]]
    ["-C" "--cracking" "Cracking the encrypted message."]
+   ["-O" "--output-file OUTPUT-FILE" "Save the program output to a file."]
    ["-h" "--help"]])
 
 (defn usage [options-summary]
@@ -68,6 +69,12 @@
       (map-has-keys? options [:message, :message-file])
       {:exit-message (error-msg ["You can't use message and message-file options at the same time!!!"])}
 
+      (file/is-file-not-exists? (:message-file options))
+      {:exit-message (error-msg ["Please, check the path to the message file!!!"])}
+
+      (file/is-file-exists? (:output-file options))
+      {:exit-message (error-msg ["Please, choose another file!!! Overwriting was prevented!!!"])}
+
       (and (map-has-keys? options [:cipher, :key])
            (or (contains? options :message)
                (contains? options :message-file))
@@ -129,6 +136,18 @@
       (set-symbols)
       (load-and-set-option :message)))
 
+(defn save-output
+  "Save the output to a file"
+  [output options]
+  (let [file-path (:output-file options)]
+    (file/write-file file-path output)))
+
+(defn show-and-save-output
+  "Print and save the output to a file if needed"
+  [output options]
+  (save-output output options)
+  (println output))
+
 (defn cracking-actions
   [options arguments action-type]
   (let [message (:message options)
@@ -154,11 +173,13 @@
 (defn actions
   [options arguments action-type]
   (let [options (load-all-options options)]
-    (println
+    (->
      (cond
        (contains? #{:encrypt :decrypt} action-type)
        (crypt-actions options arguments action-type)
 
        (= action-type :cracking)
-       (cracking-actions options arguments action-type)))))
+       (cracking-actions options arguments action-type))
+
+     (show-and-save-output options))))
 

src/cipher_analytical_machine/file.clj

@@ -16,3 +16,6 @@
 (defn read-file [file-path]
   (slurp file-path))
 
+(defn write-file [file-path content]
+  (spit file-path content))
+