SYS_GETDTABLESIZE            = 89  // { int getdtablesize(void); }
	SYS_DUP2                     = 90  // { int dup2(u_int from, u_int to); }
	SYS_FCNTL                    = 92  // { int fcntl(int fd, int cmd, long arg); }
	SYS_SELECT                   = 93  // { int select(int nd, fd_set *in, fd_set *ou, \
	SYS_FSYNC                    = 95  // { int fsync(int fd); }

	return
}

var ioSync int64

func CloseOnExec(fd int) { fcntl(fd, F_SETFD, FD_CLOEXEC) }

func SetNonblock(fd int, nonblocking bool) (err error) {
	flag, err := fcntl(fd, F_GETFL, 0)
	if err != nil {
		return err
	}
	if nonblocking {
		flag |= O_NONBLOCK
	} else {
		flag &= ^O_NONBLOCK
	}
	_, err = fcntl(fd, F_SETFL, flag)
	return err
}

	SYS_GETDTABLESIZE            = 89  // { int getdtablesize(void); }
	SYS_DUP2                     = 90  // { int dup2(u_int from, u_int to); }
	SYS_FCNTL                    = 92  // { int fcntl(int fd, int cmd, long arg); }
	SYS_SELECT                   = 93  // { int select(int nd, fd_set *in, fd_set *ou, \
	SYS_FSYNC                    = 95  // { int fsync(int fd); }

	MOVL	nch+16(FP), DX
	MOVQ	ev+24(FP), R10
	MOVL	nev+32(FP), R8
	MOVQ	ts+40(FP), R9
	MOVL	$SYS_kevent, AX
	SYSCALL
	JCC	2(PC)
	NEGQ	AX
	MOVL	AX, ret+48(FP)
	RET

// func fcntl(fd, cmd, arg int32) (int32, int32)
TEXT runtime·fcntl(SB),NOSPLIT,$0
	MOVL	fd+0(FP), DI	// fd
	MOVL	cmd+4(FP), SI	// cmd
	MOVL	arg+8(FP), DX	// arg
	MOVL	$SYS_fcntl, AX
	SYSCALL
	JCC	noerr

int getcwd(uintptr_t, size_t);
int accept(int, uintptr_t, uintptr_t);
int getdirent(int, uintptr_t, size_t);
int wait4(int, uintptr_t, int, uintptr_t);
int ioctl(int, int, uintptr_t);
int fcntl(uintptr_t, int, uintptr_t);
int fsync_range(int, int, long long, long long);
int acct(uintptr_t);
int chdir(uintptr_t);
int chroot(uintptr_t);
int close(int);
int dup(int);
void exit(int);

}

func Dup3(oldfd, newfd, flags int) error {
	if oldfd == newfd || flags&^O_CLOEXEC != 0 {
		return EINVAL
	}
	how := F_DUP2FD
	if flags&O_CLOEXEC != 0 {
		how = F_DUP2FD_CLOEXEC
	}
	_, err := fcntl(oldfd, how, newfd)
	return err
}

/*
 * Exposed directly
 */
//sys	Access(path string, mode uint32) (err error)
//sys	Adjtime(delta *Timeval, olddelta *Timeval) (err error)
//sys	CapEnter() (err error)

	SYS_GETDTABLESIZE            = 89  // { int getdtablesize(void); }
	SYS_DUP2                     = 90  // { int dup2(u_int from, u_int to); }
	SYS_FCNTL                    = 92  // { int fcntl(int fd, int cmd, long arg); }
	SYS_SELECT                   = 93  // { int select(int nd, fd_set *in, fd_set *ou, \
	SYS_FSYNC                    = 95  // { int fsync(int fd); }

	SYS_SETPGID              = 82  // { int|sys||setpgid(pid_t pid, pid_t pgid); }
	SYS_DUP2                 = 90  // { int|sys||dup2(int from, int to); }
	SYS_FCNTL                = 92  // { int|sys||fcntl(int fd, int cmd, ... void *arg); }
	SYS_FSYNC                = 95  // { int|sys||fsync(int fd); }
	SYS_SETPRIORITY          = 96  // { int|sys||setpriority(int which, id_t who, int prio); }

	SYS_SETPGID              = 82  // { int|sys||setpgid(pid_t pid, pid_t pgid); }
	SYS_DUP2                 = 90  // { int|sys||dup2(int from, int to); }
	SYS_FCNTL                = 92  // { int|sys||fcntl(int fd, int cmd, ... void *arg); }
	SYS_FSYNC                = 95  // { int|sys||fsync(int fd); }
	SYS_SETPRIORITY          = 96  // { int|sys||setpriority(int which, id_t who, int prio); }

func fcntl(fd int, cmd int, arg int) (val int, err error) {
	r0, _, e1 := syscall(abi.FuncPCABI0(libc_fcntl_trampoline), uintptr(fd), uintptr(cmd), uintptr(arg))
	val = int(r0)
	if e1 != 0 {
		err = errnoErr(e1)
	}
	return
}

func libc_fcntl_trampoline()

//go:cgo_import_dynamic libc_fcntl fcntl "libc.so"