Add function to sort lines by length.

configs/init-functions.el

@@ -137,5 +137,19 @@ If PROJECT is not specified, assume current project root."
   (interactive)
   (insert (file-name-nondirectory (buffer-file-name))))
 
+(defun sort-lines-by-length (reverse beg end)
+  "Sort lines by length."
+  (interactive "P\nr")
+  (save-excursion
+    (save-restriction
+      (narrow-to-region beg end)
+      (goto-char (point-min))
+      (let ;; To make `end-of-line' and etc. to ignore fields.
+          ((inhibit-field-text-motion t))
+        (sort-subr reverse 'forward-line 'end-of-line nil nil
+                   (lambda (l1 l2)
+                     (apply #'< (mapcar (lambda (range) (- (cdr range) (car range)))
+                                        (list l1 l2)))))))))
+
 (provide 'init-functions)
 ;;; init-functions.el ends here.