The command line interface in jockey-gtk for enabling and disabling drivers doesn't really work. It requires an X display to be present, so it can't be used in scripts.
For example, trying to change the display driver with --enable without an X display results in a segfault:
test:~# jockey-gtk --enable xorg:nvidia-180
/var/lib/python-support/python2.6/gtk-2.0/gtk/__init__.py:72: GtkWarning: could not open display
warnings.warn(str(e), _gtk.Warning)
/usr/bin/jockey-gtk:51: Warning: invalid (NULL) pointer instance
self.glade = gtk.glade.XML('/usr/share/jockey/main.glade')
/usr/bin/jockey-gtk:51: Warning: g_signal_connect_data: assertion `G_TYPE_CHECK_INSTANCE (instance)' failed
self.glade = gtk.glade.XML('/usr/share/jockey/main.glade')
/usr/bin/jockey-gtk:51: GtkWarning: gtk_settings_get_for_screen: assertion `GDK_IS_SCREEN (screen)' failed
self.glade = gtk.glade.XML('/usr/share/jockey/main.glade')
/usr/bin/jockey-gtk:51: Warning: g_object_get: assertion `G_IS_OBJECT (object)' failed
self.glade = gtk.glade.XML('/usr/share/jockey/main.glade')
/usr/bin/jockey-gtk:51: GtkWarning: gdk_pango_context_get_for_screen: assertion `GDK_IS_SCREEN (screen)' failed
self.glade = gtk.glade.XML('/usr/share/jockey/main.glade')
/usr/bin/jockey-gtk:51: PangoWarning: pango_context_set_font_description: assertion `context != NULL' failed
self.glade = gtk.glade.XML('/usr/share/jockey/main.glade')
/usr/bin/jockey-gtk:51: PangoWarning: pango_context_set_base_dir: assertion `context != NULL' failed
self.glade = gtk.glade.XML('/usr/share/jockey/main.glade')
/usr/bin/jockey-gtk:51: PangoWarning: pango_context_set_language: assertion `context != NULL' failed
self.glade = gtk.glade.XML('/usr/share/jockey/main.glade')
/usr/bin/jockey-gtk:51: Warning: g_object_unref: assertion `G_IS_OBJECT (object)' failed
self.glade = gtk.glade.XML('/usr/share/jockey/main.glade')
/usr/bin/jockey-gtk:51: GtkWarning: gdk_screen_get_display: assertion `GDK_IS_SCREEN (screen)' failed
self.glade = gtk.glade.XML('/usr/share/jockey/main.glade')
/usr/bin/jockey-gtk:51: GtkWarning: gdk_keymap_get_for_display: assertion `GDK_IS_DISPLAY (display)' failed
self.glade = gtk.glade.XML('/usr/share/jockey/main.glade')
Segmentation fault
Occurs in Ubuntu 9.04 with jockey-common version 0.5-0ubuntu10 and jockey-gtk version 0.5-0ubuntu10.
Jockey recently grew a "jockey-text" frontend, will be uploaded soon.