O_NOCTTY
if ((fd = open(_PATH_TTY, O_RDONLY | O_NOCTTY)) >= 0) {
fd = open(_PATH_TTY, O_RDWR | O_NOCTTY);
fd = open(_PATH_TTY, O_RDWR | O_NOCTTY);
if ((fd = open(_PATH_TTY, O_RDWR | O_NOCTTY)) >= 0) {
#ifndef O_NOCTTY
master = posix_openpt(O_RDWR|O_NOCTTY);
#ifndef O_NOCTTY
t = open(line, O_RDWR|O_NOCTTY);