Re: dired-view-command-alist

[Juri Linkov <juri@jurta.org>]

Richard Stallman <rms@gnu.org> writes:
> The plan is to replace that with a better implementation that already
> exists.

The plan to replace that with Gnus mailcap functions has
several problems:

1. Moving MIME-related files out of Gnus and eliminating the
dependencies is a too drastic change.

Maybe at least now we could put code that uses Gnus functions
in dired.el and call it conditionally when `mailcap' and `mm-decode'
are available?

2. Mailcap may contain different commands for viewing a file.
Before running one of them, dired should ask the user which command to run.
Even if there is only one command, dired should ask for confirmation
and allow the user to edit that command.

A user interface for that already exists in `dired-guess-default' in
dired-x.el.  But there is one difference: dired uses ? and *
to substitute file names in shell commands, while mailcap uses %s.
Using %s instead of special markers ? and * in Dired shell commands
might solve the problem of their ambiguity where the same symbol
is used for the list of Dired file names or shell wildcards.

3. Usually a list of commands in mailcap is incomplete.
Dired should provide an option to extend it.  A good starting point
is `dired-guess-shell-alist-default' in dired-x.

-- 
Juri Linkov
http://www.jurta.org/emacs/