I am hoping to figure out how to do a query search that will comment out a line instead of query replace. That is, do an interactive query search, and if I say yes, comment out the line the match is on.
Does this command exist? If not, how would I write it? I'm new to elisp, and don't know how to program my own functions.
(defun my-comment-matching-line ()
(interactive "*")
(call-interactively 'search-forward)
(beginning-of-line)
;; don't comment the region maybe
(push-mark)
(comment-line 1))
Should comment-line not be available, here from a recent newcomment.el:
(defun comment-line (n)
"Comment or uncomment current line and leave point after it.
With positive prefix, apply to N lines including current one.
With negative prefix, apply to -N lines above. Also, further
consecutive invocations of this command will inherit the negative
argument.
If region is active, comment lines in active region instead.
Unlike `comment-dwim', this always comments whole lines."
(interactive "p")
(if (use-region-p)
(comment-or-uncomment-region
(save-excursion
(goto-char (region-beginning))
(line-beginning-position))
(save-excursion
(goto-char (region-end))
(line-end-position)))
(when (and (eq last-command 'comment-line-backward)
(natnump n))
(setq n (- n)))
(let ((range
(list (line-beginning-position)
(goto-char (line-end-position n)))))
(comment-or-uncomment-region
(apply #'min range)
(apply #'max range)))
(forward-line 1)
(back-to-indentation)
(unless (natnump n) (setq this-command 'comment-line-backward))))
"Symbol's function definition is void: comment-line"
– Jaime Arturo Gomez Jan 19 '16 at 15:37
query-replace-regexp. Replace the line by the line prefixed with a comment start. – Drew Jan 07 '16 at 22:42