gnome-sudoku --version (return code: 0)
gnome-sudoku 3.18.4
gnome-sudoku --help (return code: 0)
Usage:
gnome-sudoku [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:
-v, --version Show release version
-s, --show-possible-values Show the possible values for each cell
--display=DISPLAY X display to use