taglinefilesource code
OPOST1786drivers/char/tty_io.ctty_std_termios.c_oflag = OPOST | ONLCR;
OPOST228drivers/char/tty_ioctl.cif (tty->termios->c_oflag & OPOST)
OPOST264drivers/char/tty_ioctl.ctermios->c_oflag |= OPOST | ONLCR;
OPOST143include/linux/tty.h#define O_OPOST(tty)  _O_FLAG((tty),OPOST)