On Sat, Oct 06, 2018 at 11:51:45AM +0200, Kamil Jońca wrote:
> Teemu Likonen <tlikonen@iki.fi> writes:
> 
> > Kamil Jońca [2018-10-06 11:02:54+02] wrote:
> >
> >> For some time emacs view pdf files with its internal viewer. But I
> >> want to keep old behavior - open them with xpdf/evince How can I do
> >> it?
> >
> > You can use mailcap-user-mime-data variable to override the (generated)
> > defaults in mailcap-mime-data:
> >
> >     (setq mailcap-user-mime-data
> >           '(((type . "application/pdf")
> >              (viewer . "evince %s"))))
> 
> It does not work. Still pdf is open by internal viewer :(
> KJ

Is this from org-mode? If yes, this snippet works for me:

     (setq org-file-apps
          (cons
           '("\\.pdf\\(?:::\\([0-9]*\\)\\)\\'" . "xpdf %s %1")
           (assoc-delete-all "\\.pdf\\'" org-file-apps)))

Otherwise you might want to have a look at doc-view-mode: I think
this is the one responsible for displaying the pdfs whithin Emacs.

Cheers
-- tomás