I don't think org-ref is responsible, except that it installs pdf-tools.
When I click on a link like
[[./2019-07-04.pdf]] it opens in acrobat for me.

I don't have anything fancy
org-file-apps is a variable defined in `org.el'.
Its value is
((auto-mode . emacs) ("\\.mm\\'" . default) ("\\.x?html?\\'" . default)
 ("\\.pdf\\'" . default))

which I guess means on osx that it gets opened with "open".

It looks like you can do this

#+BEGIN_SRC emacs-lisp
(setf (cdr (assoc "\\.pdf\\'" org-file-apps)) "evince %s")
#+END_SRC

to make it open in evince.


John

-----------------------------------
Professor John Kitchin
Doherty Hall A207F
Department of Chemical Engineering
Carnegie Mellon University
Pittsburgh, PA 15213
412-268-7803
@johnkitchin
http://kitchingroup.cheme.cmu.edu



On Thu, Jul 4, 2019 at 7:24 AM Joseph Vidal-Rosset <
joseph.vidal.rosset@gmail.com> wrote:

> Dear Colin (cc. John),
>
> Many thanks ! Unfortunately, I have always the same result. Here is the
> message:
>
> Viewing with pdf-view-mode
> pdf-info-encrypted-p: pdf-info-epdfinfo-program is not executable
>
> is org-ref the culprit? I cc. to John Kitchin.
>
> Best wishes,
>
> Jo.
>
> Le jeu. 4 juil. 2019 à 13:00, Colin Baxter <m43cap@yandex.com> a écrit :
> >
> > Dear Joseph,
> > >>>>> Joseph Vidal-Rosset <joseph.vidal.rosset@gmail.com> writes:
> >
> >     > Hi the list, I do not want to use pdf-tools to view pdf in emacs,
> >     > I want only to use an external program (evince) to view pdf
> >     > files. Unfortunately, links to pdf do not work with openwith and
> >     > my emacs open on a pdf. I cannot delete pdft-tools that is a
> >     > dependency of org-ref that I am using. A solution for my setup
> >     > would be welcome.
> >
> > Try this:
> >
> > (add-hook 'org-mode-hook
> >            '(lambda ()
> >             (delete '("\\.pdf\\'" . default) org-file-apps)
> >             (add-to-list 'org-file-apps '("\\.pdf\\'" . "evince %s"))))
> >
> > Best wishes,
> >
> > Colin Baxter
> > www.Colin-Baxter.com
>
>