NOHUP_PERM
nh_fd = open(nout, O_WRONLY | O_CREAT, NOHUP_PERM);
nh_fd = open(nout, O_WRONLY | O_CREAT, NOHUP_PERM);
if ((fd = open(nout, flags, NOHUP_PERM)) < 0) {
(fd = open(nout, flags, NOHUP_PERM)) < 0) {