Start a section on "Tools to handle buffers and modes"

README.org

@@ -1449,6 +1449,45 @@ on run
 end run
 #+end_src
 
+* Tools to handle buffers and modes
+:PROPERTIES:
+:CUSTOM_ID: sec:buffer-mode-tools
+:END:
+
+#+caption[Tools to handle buffers and modes]:
+#+caption: Tools to handl buffers and modes.
+#+name: lst:buffer-mode-tools
+#+begin_src emacs-lisp -n :results silent
+(defun set-all-buffers-with-modes (minor-mode value modes)
+  "Set MINOR-MODE to VALUE for all buffers with a mode derived from MODES."
+  (dolist (buffer (buffer-list))
+    (with-current-buffer buffer
+      (when (and (derived-mode-p modes) (buffer-file-name))
+        (funcall minor-mode value)))))
+
+(defun enable-ro-all-org-mode-buffers ()
+  "Enable `buffer-read-only' of all `org-mode' buffers."
+  (interactive)
+  (set-all-buffers-with-modes #'read-only-mode +1 '(org-mode))
+  (message "Enabled `buffer-read-only' of all `org-mode' buffers."))
+
+(defun disable-ro-all-org-mode-buffers ()
+  "Disable `buffer-read-only' of all `org-mode' buffers."
+  (interactive)
+  (set-all-buffers-with-modes #'read-only-mode -1 '(org-mode))
+  (message "Disabled `buffer-read-only' of all `org-mode' buffers."))
+
+(defun active-major-modes ()
+  "Return a list of active major modes found by iterating over all buffers."
+  (let (result)
+    (dolist (buffer (buffer-list))
+      (with-current-buffer buffer
+        (let ((mode major-mode))
+          (push mode result))))
+    (cl-sort (cl-remove-duplicates result) #'string-lessp)))
+#+end_src
+
+
 * Completion
 :PROPERTIES:
 :CUSTOM_ID: sec:completion