Re: executable-find in files.el

["Eli Zaretskii" <eliz@gnu.org>]

> Cc: emacs-devel@gnu.org
> From: Stefan Monnier <monnier@iro.umontreal.ca>
> Date: Wed, 11 May 2005 19:16:46 -0400
> 
> > Yes.  But since you obviously didn't read my identical comment posted
> > in response to your suggestion to do what you just did in this version
> > of executable-find (or perhaps you read it, but disregarded it), I
> > posted the same comment again.
> 
> Hmm... I replied to it in
> http://lists.gnu.org/archive/html/emacs-devel/2005-05/msg00381.html but
> haven't seen any answer.

That's not the comment I meant.  I meant what I said here:

  http://lists.gnu.org/archive/html/emacs-devel/2005-05/msg00379.html

which got no responses.

> Fine, but as long as noone changes call-process to do something meaningful
> when requested to execute a file which is only available via
> a file-name-handler, I think we should stick to 1 because I think it's more
> important to match the behavior of call-process (as I wrote in the comment).

I think we don't know what is more important.  Software is funny: it
can use the infrastructure in ways that are unimaginable when the
infrastructure was written.  That is why infrastructure needs to be
consistent.  I'm sure I'm not saying anything you didn't already know.

> But, really, this is all academic anyway since I don't know of anyone who
> has funny file-name-handled directories on her exec-path.

That's not the only difference between openp and file-executable-p.
Please compare check_executable and openp, and you will see that:

  . on Windows, check_executable uses stat to verify executability
  . on Posix systems, check_executable uses euidaccess if it's available
  . by contrast, openp always uses access

These are subtle differences, but they are real.