Ihor Radchenko <yanta...@posteo.net> writes:
> Olivier Lischer <olivier.lisc...@liolin.ch> writes:
>
>>> Thanks for the patch, but may you please explain why introducing such
>>> variable is useful?
>>
>> Sure.
>>
>> I configure all my .dotfiles in an Org mode file and tangle the
>> configuration in the right places. The tangled files are all
>> read-only to prevent accidentally editing of the "right" configuration
>> file. With the current tangling mechanism, this results in a "Permission
>> denied" error because the function writes to a read-only file. In a
>> earlier version this use case was possible because the file was
>> recreated before writing to it.
>
> Thanks for the explanation!
>
> I suggest changing your patch, setting the default value of
> `org-babel-tangle-remove-file-before-write' to 'auto.
> This will keep the current behaviour but fall back to delete + write new
> file when the tangle target is read-only.
> That will avoid feature regression.
I changed the path as you proposed.
>From a464592f622ba42732a5449d2c4db51f1975444a Mon Sep 17 00:00:00 2001
From: Olivier Lischer <olivier.lisc...@liolin.ch>
Date: Tue, 23 Jan 2024 21:02:20 +0100
Subject: [PATCH] ob-tangle: Add flag to optionally remove files before writing
* lisp/ob-tangle.el: Add variable
`org-babel-tangle-remove-file-before-write'.
(org-babel-tangle): Remove file before writing when
`org-babel-tangle-remove-file-before-write' is set.
The variable `org-babel-tangle-remove-file-before-write' adds support
for the current and old behaviour of `org-babel-tangle'.
TINYCHANGE
---
etc/ORG-NEWS | 4 ++++
lisp/ob-tangle.el | 14 ++++++++++----
2 files changed, 14 insertions(+), 4 deletions(-)
diff --git a/etc/ORG-NEWS b/etc/ORG-NEWS
index f537486d4..c7c3ee264 100644
--- a/etc/ORG-NEWS
+++ b/etc/ORG-NEWS
@@ -800,6 +800,10 @@ Completion is enabled for links to man pages added using ~org-insert-link~:
=C-c C-l man RET emacscl TAB= to get =emacsclient=. Of course, the ~ol-man~
library should be loaded first.
+*** =ob-tangle.el=: Add flag to optionally remove files before writing
+
+When ~org-babel-tangle-remove-file-before-write~ is set to ~t~ the file is removed before writing.
+
** New functions and changes in function arguments
*** New API functions to store data within ~org-element-cache~
diff --git a/lisp/ob-tangle.el b/lisp/ob-tangle.el
index 72089a9a5..64b7c2cf8 100644
--- a/lisp/ob-tangle.el
+++ b/lisp/ob-tangle.el
@@ -141,7 +141,7 @@ controlled by the :comments header argument."
:version "24.1"
:type 'string)
-(defcustom org-babel-tangle-uncomment-comments nil
+(defcustom org-babel-tangle-uncomment-comments 'auto
"Inhibits automatic commenting and addition of trailing newline
of tangle comments. Use `org-babel-tangle-comment-format-beg'
and `org-babel-tangle-comment-format-end' to customize the format
@@ -166,6 +166,12 @@ read-write permissions for the user, read-only for everyone else."
:package-version '(Org . "9.6")
:type 'integer)
+(defcustom org-babel-tangle-remove-file-before-write nil
+ "Prevents the deletion of an existing file before tangle"
+ :group 'org-babel-tangle
+ :package-version '(Org . "9.7")
+ :type 'boolean)
+
(defun org-babel-find-file-noselect-refresh (file)
"Find file ensuring that the latest changes on disk are
represented in the file."
@@ -313,9 +319,9 @@ matching a regular expression."
(compare-buffer-substrings
nil nil nil
tangle-buf nil nil)))))))
- ;; We do not erase, but overwrite previous file
- ;; to preserve any existing symlinks.
- (write-region nil nil file-name)
+ (when (and (file-exists-p file-name) org-babel-tangle-remove-file-before-write)
+ (delete-file file-name))
+ (write-region nil nil file-name)
(mapc (lambda (mode) (set-file-modes file-name mode)) modes))
(push file-name path-collector))))))
(if (equal arg '(4))
--
2.43.0
