O_NDELAY
#ifdef O_NDELAY
blocking_flags |= O_NDELAY;
flags |= O_NDELAY;
fcntl(devtty,F_SETFL,O_NDELAY);
# ifndef O_NDELAY /* assert O_NDELAY */
# ifndef O_NDELAY /* assert O_NDELAY */
# ifdef O_NDELAY
#if defined(F_SETFL) && defined(O_NDELAY)
if (fcntl(fd, F_SETFL, e & ~O_NDELAY) == -1)
#elif defined(F_SETFL) && defined(O_NDELAY)
if (fcntl(el->el_infd, F_SETFL, n|O_NDELAY) < 0)
if ((fd = open(dev, O_RDWR | O_NDELAY)) < 0)
res |= cvtto_bsd_mask(lflags, LINUX_O_NDELAY, O_NDELAY);
res |= cvtto_linux_mask(bflags, O_NDELAY, LINUX_O_NDELAY);
if ((fd = open(dev, O_RDWR | O_NDELAY)) < 0)
db = dbopen(filename, O_RDWR|O_CREAT|O_NDELAY|O_EXLOCK, 0644, DB_HASH,
f->f_file = open(ctty, O_WRONLY | O_NDELAY, 0);