bug#4987: 23.1; shell-command: optionally include working dir in prompt

[Juri Linkov]

> > At http://namazu.org/~tsuchiya/elisp/shell-command.el is an emacs
> > library that "enables tab-completion for `shell-command'".
> >
> > I noticed recently that Emacs does this internally now.  Yay!  But one
> > thing shell-command.el did that Emacs 23 doesn't appear to do, is to
> > include the working directory in the shell-command and
> > dired-do-shell-command prompts.  It'd be neat if Emacs did that, too.
>
> shell-command.el relies on defadvices to implement this.  I think a clean
> implementation should be designed to work more like minibuf-eldef.el.

On second thought, there is no need to over-complicate this feature.
So we could add a new defcustom to define the prompt format and to
use it in `read-shell-command' to modify the prompt.

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