O_NOCTTY
(oflag & ~(O_ACCMODE | O_NOCTTY)) != 0) {
{ O_NOCTTY, "O_NOCTTY" },
fd = open("/dev/tty", O_RDWR | O_NOCTTY);
if ((fd = open(_PATH_TTY, O_RDONLY | O_NOCTTY)) >= 0) {
if ((fd = open(_PATH_TTY, O_RDWR | O_NOCTTY)) >= 0) {
#ifndef O_NOCTTY
fd = open(_PATH_TTY, O_RDWR | O_NOCTTY);
fd = open(_PATH_TTY, O_RDWR | O_NOCTTY);