How to open and edit a file from within a function
reddit / emacs

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olivuser · 2022-09-15 14:06

Hej fellows,

I tried to find a solution to this question on my own for quite a
while now. I'm rather certain that I am also phrasing my problem the
wrong way, because it is impossible that it is that hard to find.

I want to write a function that opens my org agenda file(s) in
buffer(s), operates on said buffer(s) and then saves them. More
concretely, I want to have `org-sort-entities` sort my
[`todos.org`](https://todos.org) file every time I used org-capture
(using `org-capture-after-finalize-hook`).

I am grateful for both pointers and complete solutions. As I said, for
some reason I can't wrap my head around the way emacs opens files when
it doesn't happen upon my initiative.

Have a good day, fellows :)

**SOLVED:** I was able to solve the problem! Thanks a bunch,
u/MitchellMarquez42 and u/EternalMigrainity!

Now I will say that the pointer provided by u/MitchellMarquez42 helped
me find a solution that is clearer to me on first sight than the other
one. Nonetheless, thank you both - not least because I not know that
`with-current-buffer` and `with-temp-file` can use `find-file` as
input. I had seen both elements - `with-*-*` and `find-file` \- but
would not have come up with the idea to combine the two. This will
make it that much easier to work with files in the future :-\*

**EDIT:** For some reason, it did not work properly when invoked that
way from a hook. I would add a new todo entry via org-capture and the
org-agenda-file would not be sorted.

    DOES NOT WORK
    (defun org-sort-agenda-files-after-capture (file-list)
      (mapcar #'(lambda (file)
              (with-current-buffer (find-file file)
                (mark-whole-buffer)
                (org-sort-entries nil ?p)
                (save-buffer)
                (kill-buffer)))
          file-list))

    (use-package org-capture
      :hook
      (org-capture-after-finalize . (org-sort-agenda-files-after-
capture org-agenda-files)))

Then I decided to try again removing the argument from the function,
hardcoding `org-agenda-files` into the `org-sort-agenda-files-after-
capture` function instead of the `file-list` parameter. It turns out
that it worked. I don't know why. If you happen to know, I'd love to
be enlightened :-)

    DOES WORK
    (defun org-sort-agenda-files-after-capture ()
      (mapcar #'(lambda (file)
              (with-current-buffer (find-file file)
                (mark-whole-buffer)
                (org-sort-entries nil ?p)
                (save-buffer)
                (kill-buffer)))
          org-agenda-files))

    (use-package org-capture
      :hook
      (org-capture-after-finalize . org-sort-agenda-files-after-
capture))

​

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[deleted] · 2022-09-15 15:09

[removed]

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[deleted] · 2022-09-15 15:23

[deleted]

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EternalMigrainity · 2022-09-15 15:24

pointer lol xd

https://pastebin.com/Rc9vV0Fu

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EternalMigrainity · 2022-09-15 15:25

If this is not what you want then try clarifying a bit I don't know
shit about org

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EternalMigrainity · 2022-09-15 15:35

My code sorts entries invisibly, if you want to see everything happen
in front of you then you could just have your org buffers appear via
find-file and then use org-sort-entries and finally save the buffer,
also, you should consider creating a KBD Macro for sorting with org-
sort-entries that you can call from your code, it'll make things much
easier.

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EternalMigrainity · 2022-09-15 15:43

use dolist instead of dotimes sorry lmaOLOOOOO

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MitchellMarquez42 · 2022-09-15 15:57

Emacs opens files with the command `find-file`. This opens the file in
a new buffer, and returns the name of that buffer.

You can use `with-current-buffer` to execute editing commands in said
buffer, and `save-buffer` to save the buffer.

So something like:

```
(with-current-buffer (find-file "/path/to/todos.org")
  (org-sort-entities) ;; I don't know how Agenda works but should be
pretty straightforward
  (save-buffer)
  ;; optional kill-buffer if you want
)
```

The other commenter links a more complete example that opens multiple
files. This is just a basic outline of how I'd approach the problem.