You can use this function on a single line. put your cursor on a line, then use this function. (for only org-mode)
(defun strike-through-for-org-mode () (interactive) (beginning-of-line) (save-excursion (if (string-prefix-p "*" (thing-at-point 'line t)) (progn (setq go_char (string-match "[ ]" (thing-at-point 'line t))) (forward-char (+ go_char 1)) (insert "+") (end-of-line) (insert "+") ) (if (string-match "[^ ]" (thing-at-point 'line t)) (progn (setq go_char (string-match "[^ ]" (thing-at-point 'line t))) (forward-char (+ go_char 2)) (insert "+") (end-of-line) (insert "+") ) (message "[-] Not Proper Position!") ) ) ) )
(defun strike-through-for-org-mode-undo () (interactive) (beginning-of-line) (save-excursion (if (string-match "[+]" (thing-at-point 'line t)) (progn (setq go_char (string-match "[+]" (thing-at-point 'line t))) (forward-char go_char) (delete-char 1) (end-of-line) (delete-char -1) ) (message "[-] Not Proper Position!") ) ) )
org-emphasis-alist. This controls what is to be bold, italic, etc. Mine has also this:(:strike-through t).org-emphasis-alistbefore but everything is working except for+keyword ;-/ and I just wrote 2 functions that can do strike-through automatically. Thank you for kind help anyway! :-)