posix_openpt
int posix_openpt(int);
extern int posix_openpt(int);
int mfd = posix_openpt(O_RDWR | O_NOCTTY);
if ((mngr = posix_openpt(O_RDWR | O_NOCTTY)) < 0) {
if ((alt_mngr = posix_openpt(O_RDWR | O_NOCTTY)) < 0) {