А можно ли как-нибудь без chmod +x? Все это по NFS примаунчено, поэтому так не получится.
В гноме из гуевого файл браузера двойным щелчком запускаются PDF-ки, значит эти ассоциации уже где-то есть. Возможно есть какая-то прога (может даже gnome-specific), такая чтоб:
$ dpkg -S `which see`
mime-support: /usr/bin/see
apt-cache show mime-support
Description: MIME files 'mime.types' & 'mailcap', and support programs
As these files can be used by all MIME compliant programs, they
have been moved into their own package that others can depend upon.
.
Other packages add themselves as viewers/editors/composers/etc by
using the provided "update-mime" program.
.
In addition, the commands "see", "edit", "compose", and "print"
will display, alter, create, and print (respectively) any file using
a program determined from the entries in the mime.types and mailcap
files.
man see
RUN-MAILCAP(1) Run Mailcap Programs RUN-MAILCAP(1)
NAME
run-mailcap, see, edit, compose, print - execute programs via entries
in the mailcap file
SYNOPSIS
run-mailcap --action=<action> [--debug=<value>] [<mime-type>:[<encod‐
ing>:]]<filename> [...]
The see, edit, compose and print versions are just aliases that default
to the view, edit, compose, and print actions (respectively).
You can make this your default pager and/or editor by adding the fol‐
lowing to your shell startup: