Re: Refer to the directory of the currently being loaded elisp script from within the Emacs lisp file itself.

["Óscar Fuentes" <ofv@wanadoo.es>]

Hongyi Zhao <hongyi.zhao@gmail.com> writes:

> On Thu, Jun 10, 2021 at 11:40 PM Óscar Fuentes <ofv@wanadoo.es> wrote:
>>
>> Hongyi Zhao <hongyi.zhao@gmail.com> writes:
>>
>> >> BTW, the correct method for concatenating a directory and a file name is
>> >>
>> >> (load-file
>> >>   (concat
>> >>     (file-name-as-directory (file-name-directory load-file-name))
>> >>     "auth.el.gpg"))
>> >
>> > I tried you above code, it still doesn't work with the following info:
>> >
>> > file-name-as-directory: Wrong type argument: stringp, nil [2 times]
>> > Mark set
>>
>> load-file-name is defined while the file is being loaded, after that it
>> is nil. So if you tried with `C-x C-e' or some other interactive command
>> it wont work.
>>
>> Once the code above is in the correct file, save it, start Emacs and
>> report back what happens.
>
> See my current usage on
> <https://github.com/hongyi-zhao/screen2latex.el/blob/bd820184a29158c14de1afaf564f9e2898dd88ac/screen2latex.el#L45>
> according to the instructions here.
>
> After I start Emacs and tried with `M-x screenlatex RET', I will see
> the following info in *Messages* buffer:
>
> expand-file-name: Wrong type argument: stringp, nil

As explained previously, load-file-name is only defined when the file is
being loaded, otherwise it is nil.

You can put the directory name on a variable at load time and use that
variable on your command:

(setq my-directory (file-name-directory load-file-name)

(defun screen2latex ()
...
  (load-file (expand-file-name "auth.el.gpg" my-directory))