al_path_cstr man page
al_path_cstr — Allegro 5 API
#include <allegro5/allegro.h> const char *al_path_cstr(const ALLEGRO_PATH *path, char delim)
Convert a path to its string representation, i.e. optional drive, followed by directory components separated by 'delim', followed by an optional filename.
To use the current native path separator, use ALLEGRO_NATIVE_PATH_SEP for 'delim'.
The returned pointer is valid only until the path is modified in any way, or until the path is destroyed.