al_identify_bitmap - Allegro 5 API

       This works exactly as al_identify_bitmap_f(3alleg5) but you specify the filename of the file for which to
       detect  the  type and not a file handle.  The extension, if any, of the passed filename is not taken into
       account - only the file contents.

       al_identify_bitmap - Allegro 5 API

al_init_image_addon(3alleg5), al_identify_bitmap_f(3alleg5), al_register_bitmap_identifier(3alleg5)

Allegro reference manual                                                             al_identify_bitmap(3alleg5)

       5.1.12

              #include <allegro5/allegro.h>

              char const *al_identify_bitmap(char const *filename)