Re: [PATCH] org.el: Fix percent substitutions in `org-open-file'

[Ihor Radchenko <yantar92@gmail.com>]

Max Nikulin <manikulin@gmail.com> writes:

> It's pity that this issue has not fix yet. I have tried to implement 
> another helper function. It is hardly usable outside of `org-open-file' 
> (perhaps it is still suitable to make mailcap commands), but separate 
> function makes the code testable. I hope, the attached patch fixes the 
> problems with multiple regexp groups and with percent characters in 
> replacement string. Notice that "\%", not "%%" is used to escape percent 
> in mailcap, anyway neither variant was supported before.
> From 2f2850dcdc0cba8cfc6c0e21fc893c4e664d575c Mon Sep 17 00:00:00 2001
> From: Max Nikulin <manikulin@gmail.com>
> Date: Sat, 27 Aug 2022 23:51:24 +0700
> Subject: [PATCH] org.el: Fix percent substitutions in `org-open-file'

Thanks! LGTM, except one comment.

> +(defun org--open-file-format-command
> +    (mailcap-command file link match-data)
> +  "Format MAILCAP-COMMAND to launch viewer for FILE.
> +
> ...
> +For example, to specify particular location withing a PDF file,
> +`org-file-apps' list may have the following entries (order is important):
> +
> +    ;; Page and search string,
> +    ;; e.g. <file:///usr/share/doc/bash/bashref.pdf::34::order of redirections>.
> +    (\"\\\\.pdf::\\\\([0-9]+\\\\)::\\\\(.+\\\\)\\\\\\='\"
> +        . \"okular --page %1 --find %2 %s\")
> +    ;; Internal anchor and search string,
> +    ;; e.g. <file:///usr/share/doc/bash/bashref.pdf::Redirections::allocate a file>.
> +    (\"\\\\.pdf::\\\\(.+\\\\)::\\\\(.+\\\\)\\\\\\='\"
> +        . \"okular --find %2 file://%s\\\\\\\\#%1\")
> +    ;; Page number, e.g. <file:///usr/share/doc/bash/bashref.pdf::34>.
> +    (\"\\\\.pdf::\\\\([0-9]+\\\\)\\\\\\='\" . \"okular --page %1 %s\")
> +    ;; Internal reference, e.g. <file:///usr/share/doc/bash/bashref.pdf::Redirections>.
> +    (\"\\\\.pdf::\\\\(.+\\\\)\\\\\\='\" . \"okular file://%s\\\\\\\\#%1\")
> +    ;; No location within the file, optionally followed by \"::\",
> +    ;; e.g. <file:///usr/share/doc/bash/bashref.pdf>.
> +    (\"\\\\.pdf\\\\(?:::\\\\)?\\\\\\='\" . \"okular %s\")

This is a nice set of examples, but it probably does not belong to this
docstring. I'd rather see this in `org-file-apps' docstring or even in
the manual.

-- 
Ihor Radchenko,
Org mode contributor,
Learn more about Org mode at https://orgmode.org/.
Support Org development at https://liberapay.com/org-mode,
or support my work at https://liberapay.com/yantar92