al_fwrite - Allegro 5 API

       Write `size' bytes from the buffer pointed to by `ptr' into the given file.

       Returns the number of bytes actually written.  If an error occurs, the return value is a short byte count
       (or zero).

       al_fwrite - Allegro 5 API

al_fputc(3alleg5),        al_fputs(3alleg5),        al_fwrite16be(3alleg5),       al_fwrite16le(3alleg5),
       al_fwrite32be(3alleg5), al_fwrite32le(3alleg5)

Allegro reference manual                                                                      al_fwrite(3alleg5)

              #include <allegro5/allegro.h>

              size_t al_fwrite(ALLEGRO_FILE *f, const void *ptr, size_t size)