* `write(daten)`: Schreibt `daten` (`str` oder `bytes`) in die Datei.
* `read(anzahl)`: Liest `anzahl` (`int`) bytes/Zeichen aus der Datei.
* `seek(versatz)`: Geht zur Position `versatz` (`int`) in der Datei.
    * Z. B. würde `await myfile.seek(0)` zum Anfang der Datei gehen.
    * Das ist besonders dann nützlich, wenn Sie `await myfile.read()` einmal ausführen und dann diese Inhalte erneut auslesen müssen.

* `write(data)`: Записать данные `data` (`str` или `bytes`) в файл.
* `read(size)`: Прочитать количество `size` (`int`) байт/символов из файла.
* `seek(offset)`: Перейти к байту на позиции `offset` (`int`) в файле.
    * Наример, `await myfile.seek(0)` перейдет к началу файла.
    * Это особенно удобно, если вы один раз выполнили команду `await myfile.read()`, а затем вам нужно прочитать содержимое файла еще раз.

* `write(data)`: Writes `data` (`str` or `bytes`) to the file.
* `read(size)`: Reads `size` (`int`) bytes/characters of the file.
* `seek(offset)`: Goes to the byte position `offset` (`int`) in the file.
    * E.g., `await myfile.seek(0)` would go to the start of the file.
    * This is especially useful if you run `await myfile.read()` once and then need to read the contents again.
* `close()`: Closes the file.

	runtime.SetFinalizer(file, nil)
	return err
}

// seek sets the offset for the next Read or Write on file to offset, interpreted
// according to whence: 0 means relative to the origin of the file, 1 means
// relative to the current offset, and 2 means relative to the end.
// It returns the new offset and an error, if any.
func (f *File) seek(offset int64, whence int) (ret int64, err error) {

	// exist on disk for until Close is called (at the end of the process).
	Get(ActionID) (Entry, error)

	// Put adds an item to the cache.
	//
	// The seeker is only used to seek to the beginning. After a call to Put,
	// the seek position is not guaranteed to be in any particular state.
	//
	// As a special case, if the ReadSeeker is of type noVerifyReadSeeker,
	// the verification from GODEBUG=goverifycache=1 is skipped.
	//

func Getdirentries(fd int, buf []byte, basep *uintptr) (n int, err error) {
	n, err = Getdents(fd, buf)
	if err != nil || basep == nil {
		return
	}

	var off int64
	off, err = Seek(fd, 0, 1 /* SEEK_CUR */)
	if err != nil {
		*basep = ^uintptr(0)
		return
	}
	*basep = uintptr(off)
	if unsafe.Sizeof(*basep) == 8 {
		return
	}
	if off>>32 != 0 {

type Section struct {
	SectionHeader

	// Embed ReaderAt for ReadAt method.
	// Do not embed SectionReader directly
	// to avoid having Read and Seek.
	// If a client wants Read and Seek it must use
	// Open() to avoid fighting over the seek offset
	// with other clients.
	//
	// ReaderAt may be nil if the section is not easily available
	// in a random-access form. For example, a compressed section

	// Compute output ID.
	h := sha256.New()
	if _, err := file.Seek(0, 0); err != nil {
		return OutputID{}, 0, err
	}
	size, err := io.Copy(h, file)
	if err != nil {
		return OutputID{}, 0, err
	}
	var out OutputID
	h.Sum(out[:0])

	if _, err := file.Seek(0, 0); err != nil {
		return OutputID{}, 0, err
	}

	if !c.can[cmdPut] {

func Getdirentries(fd int, buf []byte, basep *uintptr) (n int, err error) {
	n, err = Getdents(fd, buf)
	if err != nil || basep == nil {
		return
	}

	var off int64
	off, err = Seek(fd, 0, 1 /* SEEK_CUR */)
	if err != nil {
		*basep = ^uintptr(0)
		return
	}
	*basep = uintptr(off)
	if unsafe.Sizeof(*basep) == 8 {
		return
	}
	if off>>32 != 0 {

		}

		go func() {
			defer close(errc)
			defer conn.Close()

			f, err := os.Open(newton)
			if err != nil {
				errc <- err
				return
			}
			defer f.Close()
			if _, err := f.Seek(seekTo, io.SeekStart); err != nil {
				errc <- err
				return
			}

			expectSendfile(t, conn, func() {
				_, err = io.CopyN(conn, f, sendSize)
			})
			if err != nil {
				errc <- err