if err != nil {
		return -1, "dup", err
	}
	syscall.CloseOnExec(newfd)
	return newfd, "", nil
}

// Fchdir wraps syscall.Fchdir.
func (fd *FD) Fchdir() error {
	if err := fd.incref(); err != nil {
		return err
	}
	defer fd.decref()
	return syscall.Fchdir(fd.Sysfd)
}

// ReadDirent wraps syscall.ReadDirent.
// We treat this like an ordinary system call rather than a call

// duplicate file descriptors.
func dupCloseOnExecOld(fd int) (int, string, error) {
	return -1, "dup", syscall.ENOSYS
}

// Fchdir wraps syscall.Fchdir.
func (fd *FD) Fchdir() error {
	if err := fd.incref(); err != nil {
		return err
	}
	defer fd.decref()
	return syscall.Chdir(fd.Path)
}

// ReadDir wraps syscall.ReadDir.
// We treat this like an ordinary system call rather than a call

//sys	Close(fd int) (err error)
//sys	Dup(fd int) (nfd int, err error)
//sys	Dup2(from int, to int) (err error)
//sys	dup3(from int, to int, flags int) (err error)
//sys	Fchdir(fd int) (err error)
//sys	Fchflags(fd int, flags int) (err error)
//sys	Fchmod(fd int, mode uint32) (err error)
//sys	Fchown(fd int, uid int, gid int) (err error)
//sys	Flock(fd int, how int) (err error)
//sys	Fpathconf(fd int, name int) (val int, err error)

		r0, _, e = Syscall(SYS_UNMOUNT, uintptr(unsafe.Pointer(namep)), oldptr, 0)
	}

	if int32(r0) == -1 {
		err = e
	}
	return
}

func Fchdir(fd int) (err error) {
	path, err := Fd2path(fd)

	if err != nil {
		return
	}

	return Chdir(path)
}

type Timespec struct {
	Sec  int32
	Nsec int32
}

type Timeval struct {
	Sec  int32
	Usec int32
}

//sys	Chdir(path string) (err error)
//sys	Chflags(path string, flags int) (err error)
//sys	Chmod(path string, mode uint32) (err error)
//sys	Chown(path string, uid int, gid int) (err error)
//sys	Chroot(path string) (err error)
//sys	Close(fd int) (err error)
//sys	Dup(fd int) (nfd int, err error)
//sys	Dup2(from int, to int) (err error)
//sys	Fchdir(fd int) (err error)

	}
	return nil
}

// Chdir changes the current working directory to the file,
// which must be a directory.
// If there is an error, it will be of type [*PathError].
func (f *File) Chdir() error {
	if err := f.checkValid("chdir"); err != nil {
		return err
	}
	if e := f.pfd.Fchdir(); e != nil {
		return f.wrapErr("chdir", e)
	}
	return nil
}

	return windows.SetFileInformationByHandle(fd.Sysfd, windows.FileBasicInfo, unsafe.Pointer(&du), uint32(unsafe.Sizeof(du)))
}

// Fchdir wraps syscall.Fchdir.
func (fd *FD) Fchdir() error {
	if err := fd.incref(); err != nil {
		return err
	}
	defer fd.decref()
	return syscall.Fchdir(fd.Sysfd)
}

// GetFileType wraps syscall.GetFileType.
func (fd *FD) GetFileType() (uint32, error) {

//sys	Chdir(path string) (err error)
//sys	Chflags(path string, flags int) (err error)
//sys	Chmod(path string, mode uint32) (err error)
//sys	Chown(path string, uid int, gid int) (err error)
//sys	Chroot(path string) (err error)
//sys	Close(fd int) (err error)
//sys	Dup(fd int) (nfd int, err error)
//sys	Dup2(from int, to int) (err error)
//sys	Fchdir(fd int) (err error)

//sys	Chdir(path string) (err error)
//sys	Chflags(path string, flags int) (err error)
//sys	Chmod(path string, mode uint32) (err error)
//sys	Chown(path string, uid int, gid int) (err error)
//sys	Chroot(path string) (err error)
//sys	Close(fd int) (err error)
//sys	Dup(fd int) (nfd int, err error)
//sys	Dup2(from int, to int) (err error)
//sys	Fchdir(fd int) (err error)

		r0, _, e = Syscall(SYS_UNMOUNT, uintptr(unsafe.Pointer(namep)), oldptr, 0)
	}

	if int32(r0) == -1 {
		err = e
	}
	return
}

func Fchdir(fd int) (err error) {
	path, err := Fd2path(fd)

	if err != nil {
		return
	}

	return Chdir(path)
}

type Timespec struct {
	Sec  int32
	Nsec int32
}

type Timeval struct {
	Sec  int32
	Usec int32
}