Subject: bug#18132: Time for a smarter dired-guess-shell-alist-default? (dired-x.el)

From: Reuben Thomas <[email-masked]>
Date: Wed, 30 Jul 2014 17:44:13 +0100

On 30 July 2014 17:32, Juri Linkov <[email-masked]> wrote:

> >> run-mailcap is fully supported by shell-command and async-shell-command
> where
> >> the list of available commands can be accessed using M-n in its
> minibuffer.
> >
> > I can't see any mention of run-mailcap in the Emacs source; do you mean
> > simply that it's possible to add it to the list of commands used?
>
> grep -nH mailcap *.el
> ./dired-aux.el:558:(declare-function mailcap-file-default-commands
> "mailcap" (files))
> ./dired-aux.el:562:This function is used to add all related commands
> retrieved by `mailcap'
> ./dired-aux.el:565:  (let ((commands (and (boundp 'files) (require
> 'mailcap nil t)
> ./dired-aux.el:566:                    (mailcap-file-default-commands
> files))))
> ./simple.el:2743:(declare-function mailcap-file-default-commands "mailcap"
> (files))
> ./simple.el:2748:This function is used to add all related commands
> retrieved by `mailcap'
> ./simple.el:2754:        (commands (and filename (require 'mailcap nil t)
> ./simple.el:2755:                       (mailcap-file-default-commands
> (list filename)))))
>

I'm sorry if I've missed something, but I don't see what this has to do
with run-mailcap.

> We could leave the original list intact, and add xdg-open/w32-shell-execute
> to the top of the list, so it would be the first suggestion that the user
> will get after the first M-n.
>

It would be good to discourage customization of
dired-guess-shell-alist-{default,user}, and steer users towards the
non-program-specific mechanisms. It would also be good eventually not to
have to maintain the list, or indeed the dired-guess-shell mechanism at all.

As for your mention of "the first M-n", as far as I can discover, the first
time I press M-n, the default command, which was already mentioned in the
prompt, is simply inserted at point, as if I had typed it. So is "the first
suggestion that the user will get after the first M-n" actually the same
thing as "the default suggestion"? (I hope so!)

> There is a good example how to check its availability in
> `browse-url-can-use-xdg-open' that could be moved
> to a more general file like simple.el.
>

Thanks for the pointer.

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