al_get_num_joysticks - Allegro 5 API

       Return  the  number of joysticks currently on the system (or potentially on the system).  This number can
       change after al_reconfigure_joysticks(3alleg5) is called, in order to support hotplugging.

       Returns 0 if there is no joystick driver installed.

       al_get_num_joysticks - Allegro 5 API

al_get_joystick(3alleg5), al_get_joystick_active(3alleg5)

Allegro reference manual                                                           al_get_num_joysticks(3alleg5)

              #include <allegro5/allegro.h>

              int al_get_num_joysticks(void)