how to configure xdg-open applications?

[Paul Johnson]

On Thu, Nov 20, 2008 at 1:21 PM, Rex Dieter <rdieter at math.unl.edu> wrote:
> Paul Johnson wrote:
>
>> I want to change the programs that xdg-open points to for things like
>> pdf or dvi.  There are no configure tools I can find on the
>> freedesktop site and the xdg-open man page gives no help at all. In
>> /etc/xdg I don't see settings for evince or such.  "grep -r pdf *" in
>> the /etc/xdg directory returns nothing.
>>
>> Throw me some help, please.
>
> xdg-open uses the default apps as defined by the desktop you're using
> (gnome, kde, etc...).  So, the question becomes, which desktop are you
> using?  Do you need help setting the default .pdf app on desktop foo?
>
> -- Rex
>

Well, I use several different desktops, if you must know.  On all of
them LyX runs and uses xdg-open to grab pdf files, and I had thought
that the freedesktop framework was aiming at having a
desktop-brand-free method of specifying what applications are used.
That is the long term goal, I think.  Googling tells me that many
people have the same desire, but it is not implemented YET because the
freedesktop people are coming along with general standards after the
desktop systems evolved.

But I have something of an answer.  The previous poster points me to
the xdg-mime program. It is used to set the default applications. I've
been testing it and reading its source code.  It is not a general
application chooser.  Rather, it "adjusts most desktops" to use a
program program. If you run it  in your current environment, it tells
you what is specified if it understands what desktop you are previous
running (AFAIK, it is OK for Gnome,KDE, and XFCE, but not for a less
desktopish desktop like an old fashioned window-manager-only setup
like  WindowMaker.  If you use xdg-mime to set a value, it tries to
set values for Gnome, KDE, and XFCE if it finds them in your system.
It can set them either for the whole system or the user account.

Another answer I've found is that Gnome users can hand edit this file:

/usr/share/applications/defaults.list

That is the "gnome" way of doing it system wide, and xdg-mime just
edits that file for you.

If an individual user already has this file,

~/.local/share/applications/defaults.list

then system-wide changes will have no effect, and users have to either
edit their own defaults.list or delete it and let it be re-created by
the desktop environment.  That will copy the system-wide set into the
user's account.

But, then again, this is all stuff I've pieced together in the last 2
hours, so hopefully the program maintainers will step up and tell us
if I have it wrong.


pj



-- 
Paul E. Johnson
Professor, Political Science
1541 Lilac Lane, Room 504
University of Kansas