_dr_open_dir
if(_dr_open_dir(cf->dr, dirpath, NULL)) {
int _dr_open_dir(DirReader *dr, const char *pathname, char **errmsg);
if(_dr_open_dir(node->dr, pathname, &errmsg)) {
if(_dr_open_dir(pc->dr, FS_PWD, NULL))
if(_dr_open_dir(pc->dr, dirname, NULL))