al_ferrmsg - Allegro 5 API

       Return  a  message  string with details about the last error that occurred on the given file handle.  The
       returned string is empty if there was  no  error,  or  if  the  file  interface  does  not  provide  more
       information.

       al_ferrmsg - Allegro 5 API

al_fclearerr(3alleg5), al_ferror(3alleg5)

Allegro reference manual                                                                     al_ferrmsg(3alleg5)

              #include <allegro5/allegro.h>

              const char *al_ferrmsg(ALLEGRO_FILE *f)