Fedora 9: mutt/alpine: problem viewing attachments; xdg?

[Michael Hannon]

Greetings.  One of my "customers" is having a problem viewing
attachments with command-line mail clients, alpine and mutt, on a system
running Fedora 9, i386.

The attachment type of most interest is PDF.  He's been getting error
messages to the effect that the attachment is an unrecognized MIME type,
and that a given attachment could not be found.  (Note that the
different error messages probably arise under different conditions,
after either his own environment or the system environment has changed
slightly.)

In fact, PDF should be recognized:

    # grep pdf /etc/mime.types
    application/pdf                 pdf

    # grep pdf /etc/mailcap
    application/pdf; /usr/bin/xdg-open %s

I've been able to work around the problem by modifying /etc/mailcap to
explicitly invoke a PDF viewer, as:

    # grep pdf /etc/mailcap
    application/pdf; /usr/bin/xpdf %s

I presume I could also use evince instead of xpdf.

The xdg-open man page states:

    xdg-open opens a file or URL in the user's preferred application.
    If a URL is provided the URL will be opened in the user's
    preferred web browser. If a file is provided the file will be
    opened in the preferred application for files of that type.
    xdg-open supports file, ftp, http and https URLs.

When I try to use xdg-open, it ALWAYS tries to open a browser (firefox),
apparently because it's always being "fed" a URL, even for local files
(as "file://foo.bar").  I'm not sure about this.

Also I have yet to figure out how to tell xdg-open what my "preferred
application" is.  Where does it get that information?

If you can shed any light on any of this, please let me know.

Thanks.

-- Mike