gnome-font-viewer --version (return code: 0)
GNOME Font Viewer 3.16.2
gnome-font-viewer --help (return code: 0)
Usage:
gnome-font-viewer [OPTION...]
Help Options:
-h, --help Show help options
--help-all Show all help options
--help-gapplication Show GApplication options
--help-gtk Show GTK+ Options
Application Options:
--version Show the application's version
--display=DISPLAY X display to use