LINUX_IN_CLOEXEC
fd_set_exclose(l, fd, (flags & LINUX_IN_CLOEXEC) != 0);
#define LINUX_IN_ALL_FLAGS (LINUX_IN_CLOEXEC|LINUX_IN_NONBLOCK)
RS(fd = syscall(LINUX_SYS_inotify_init1, LINUX_IN_CLOEXEC));