docs(emacs/custom elisp): generate passwords in Emacs

docs/emacs/custom-elisp.org

@@ -119,3 +119,33 @@ APPEND and COMPARE-FN, see `add-to-list'."
     (dolist (elt elements return)
       (setq return (add-to-list list-var elt append compare-fn)))))
 #+end_src
+
+** Generate and insert random passwords
+#+begin_src emacs-lisp
+(defun my/generate-password (nb-chars)
+  "Generate an alphanumeric password of NB-CHARS."
+  (shell-command-to-string
+   (concat "tr -dc 'A-Za-z0-9!@#$%^&*' < /dev/urandom | head -c "
+           (number-to-string nb-chars))))
+#+end_src
+
+#+begin_src emacs-lisp
+(defun my/copy-generated-password (&optional prefix)
+  (interactive "P")
+  (kill-new
+   (my/generate-password (if prefix
+                             (string-to-number
+                              (completing-read "Amount of characters: " nil))
+                           32))))
+#+end_src
+
+#+begin_src emacs-lisp
+(defun my/insert-generated-password (&optional prefix)
+  (interactive "P")
+  (insert
+   (my/generate-password (if prefix
+                             (string-to-number
+                              (completing-read "Amount of characters: "
+                                               nil))
+                           32))))
+#+end_src