syscalltbl__id_at_idx
int id = syscalltbl__id_at_idx(sc->e_machine, i);
int prog_fd, key = syscalltbl__id_at_idx(e_machine, i);
int key = syscalltbl__id_at_idx(e_machine, i);
int syscalltbl__id_at_idx(int e_machine, int idx);