al_get_path_component - Allegro 5 API

       Return  the  i’th directory component of a path, counting from zero.  If the index is negative then count
       from the right, i.e. -1 refers to the last path component.  It is an error to pass an index which is  out
       of bounds.

       al_get_path_component - Allegro 5 API

al_get_path_num_components(3alleg5), al_get_path_tail(3alleg5)

Allegro reference manual                                                          al_get_path_component(3alleg5)

              #include <allegro5/allegro.h>

              const char *al_get_path_component(const ALLEGRO_PATH *path, int i)