Provided by: flightgear_2019.1.1+dfsg-2_amd64 

NAME
js_demo - Joystick demo application for FlightGear
SYNOPSIS
js_demo
DESCRIPTION
js_demo is a FlightGear utility that shows detected joysticks and provides a way to monitor them as their axes are moved or their buttons are pressed.
EXIT STATUS
js_demo always exits with 0.
SEE ALSO
fgfs(1), the FlightGear wiki "Input device" page ⟨http://wiki.flightgear.org/Input_device⟩