Re: [O] bug#14605: Problem with export an .org file to .pdf does not open pdf file

[Suvayu Ali]

Hi Achim, Carsten,

On Mon, Sep 02, 2013 at 10:54:13PM +0200, Carsten Dominik wrote:
> 
> On 2.9.2013, at 18:54, Achim Gratz <address@hidden> wrote:
> 
> > Carsten Dominik writes:
> >> OK, we now use xdg-open when available on a Linux system.
> > 
> > The availability of xdg-open has nothing to do with whether or not you
> > are running Emacs on a Linux system.  Indeed, even on a system where it
> > is available, it won't do anything useful if you're running from a
> > console.  While I think it's a good default for someone using a desktop
> > that conforms to XDG standards, there should be a check if in fact Emacs
> > is running on such a desktop.
> 
> thanks for this input.  THis makes it more complicated.  Do you know
> how I would test this?  I do know about the variable window-system,
> but that will also return nil when Emacs is running in an xterm, even
> though xdg-open would be working in this case.

I think there are four cases of running from a console,

1. a true terminal (the one you get with Ctrl+Alt-Fn, or in runlevel 3)
2. a remote console without X forwarding
3. a remote console with X forwarding
4. a virtual terminal (terminal emulator in a graphical desktop)

Now xdg-open will not work for (1-2) (for different reasons), but will
work for (3-4).  I think it is reasonable to expect if someone chooses
"export and open", they are on a graphical desktop and not on (1-2).  As
for (3), I think even in that case most people will choose to just
export, and open in some other way (none of us like X forwarding do we?
;)).

As for desktop conformance, Gnome, KDE, XFCE (and by induction LXDE)
conforms.  I think the key is what happens when it does not: xdg-open
fallsback to its own settings.  Quoting the Archlinux wiki summary:

  Inside a desktop environment (e.g. GNOME, KDE, Xfce, etc.), xdg-open
  simply passes the arguments to that desktop environment's file-opener
  application (gvfs-open, kde-open, or exo-open, respectively), which
  means that the associations are left up to the desktop
  environment. When no desktop environment is detected (for example when
  one runs a standalone window manager, e.g. Openbox), xdg-open will use
  its own configuration files.
  ^^^^^^^^^^^^^^^^^^^^^^^^^^^

Given this fallback, I don't think there is much to worry about.  If it
is there, and the user is on a graphical desktop (3-4), it will work.
If it is absent, we still have mailcap.  Nothing to lose here.

Hope this helps,

-- 
Suvayu

Open source is the future. It sets us free.