Re: Bug: can not start a w32 GUI program from Emacs

[Lennart Borgman (gmail)]

Mathias Dahl wrote:
> >     (w32-shell-execute "open" ".")
> >
> > just gives "ShellExecute failed: No application is associated with the
> > specified file for this operation".
>
> If you thought the above to work, in the same way that "start ." works
> from cmd.exe I think you simply missed that "." is "magic" only inside
> cmd.exe. So it's natural that ShellExecute does not recognize it. I
> guess if you put the correct data in Windows registry, it might be
> possible to open a "." file though...


Maybe it is more about file name expansion? For example

   (expand-file-name ".")

works in Emacs. And directory-files (which depends on a basic w32 API) 
returns also "." in the list of files.


> I have something similar for dired that I use a lot:
>
>   (defun w32-dired-open-explorer ()
>     "Open a file in dired mode by explorer.exe as you double click it."
>     (interactive)
>     (let ((file-name (dired-get-file-for-visit)))
>       (if (file-exists-p file-name)
>           (w32-shell-execute "open" (concat "\"" (slash-to-backslash
> file-name) "\"") nil 1))))

Seems useful, but maybe it is better to use convert-standard-filename 
and expand-file-name here?

> While on the subject of w32-shell-execute I have found that it is
> often much easier to use than struggling with `call-process' et al,
> when you just want to "start" something. Of course when you want to
> control output and input, then it's another story.

I believe that w32-shell-execute can start only programs by file 
association, or am I missing something? call-process can also wait (even 
for a gui app I believe).

As I pointed out in another message there is perhaps a problem with 
w32proc in that it binds stdin etc for gui applications. I believe that 
exe-files on w32 that are marked as gui do not have consoles. But I am 
not at all sure that this is a problem. Anyway I patched away that in my 
patched version now to see if any problems shows up.