al_make_temp_file
ALLEGRO_FILE *al_make_temp_file(const char *template, ALLEGRO_PATH **ret_path)
Make a temporary randomly named file given a filename 'template'.
'template' is a string giving the format of the generated filename and should include one or more capital Xs. The Xs are replaced with random alphanumeric characters. There should be no path separators.
If 'ret_path' is not NULL, the address it points to will be set to point to a new path structure with the name of the temporary file.
Returns the opened ALLEGRO_FILE on success, NULL on failure.