al_ftell - Allegro 5 API

       Returns the current position in the given file, or -1 on error.  errno is set to indicate the error.

       On some platforms this function may not support large files.

       al_ftell - Allegro 5 API

al_fseek(3alleg5), al_get_errno(3alleg5)

Allegro reference manual                                                                       al_ftell(3alleg5)

              #include <allegro5/allegro.h>

              int64_t al_ftell(ALLEGRO_FILE *f)