// EPLAN9 error, wrapped in *PathError.
func Chown(name string, uid, gid int) error {
	return &PathError{Op: "chown", Path: name, Err: syscall.EPLAN9}
}

// Lchown changes the numeric uid and gid of the named file.
// If the file is a symbolic link, it changes the uid and gid of the link itself.
// If there is an error, it will be of type *PathError.
func Lchown(name string, uid, gid int) error {

	isExistTests = append(isExistTests,
		isExistTest{err: &fs.PathError{Err: syscall.ERROR_FILE_NOT_FOUND}, is: false, isnot: true},
		isExistTest{err: &os.LinkError{Err: syscall.ERROR_FILE_NOT_FOUND}, is: false, isnot: true},
		isExistTest{err: &os.SyscallError{Err: syscall.ERROR_FILE_NOT_FOUND}, is: false, isnot: true},

		isExistTest{err: &fs.PathError{Err: _ERROR_BAD_NETPATH}, is: false, isnot: true},

	)
	isPermissionTests = append(isPermissionTests,
		isPermissionTest{err: &fs.PathError{Err: syscall.EACCES}, want: true},
		isPermissionTest{err: &fs.PathError{Err: syscall.EPERM}, want: true},
		isPermissionTest{err: &fs.PathError{Err: syscall.EEXIST}, want: false},

		isPermissionTest{err: &os.LinkError{Err: syscall.EACCES}, want: true},

type isExistTest struct {
	err   error
	is    bool
	isnot bool
}

var isExistTests = []isExistTest{
	{&fs.PathError{Err: fs.ErrInvalid}, false, false},
	{&fs.PathError{Err: fs.ErrPermission}, false, false},
	{&fs.PathError{Err: fs.ErrExist}, true, false},
	{&fs.PathError{Err: fs.ErrNotExist}, false, true},
	{&fs.PathError{Err: fs.ErrClosed}, false, false},
	{&os.LinkError{Err: fs.ErrInvalid}, false, false},

			fmt.Println(err)
		}
	}

	// Output:
	// file does not exist
}

func ExampleAs() {
	if _, err := os.Open("non-existing"); err != nil {
		var pathError *fs.PathError
		if errors.As(err, &pathError) {
			fmt.Println("Failed at path:", pathError.Path)
		} else {
			fmt.Println(err)
		}
	}

	// Output:
	// Failed at path: non-existing
}

func ExampleUnwrap() {
	err1 := errors.New("error1")

			d.bufp, d.nbuf = 0, nb

			if err != nil {
				if err == io.EOF {
					break
				}
				return names, dirents, infos, &PathError{Op: "readdir", Path: file.name, Err: err}
			}
			if nb < syscall.STATFIXLEN {
				return names, dirents, infos, &PathError{Op: "readdir", Path: file.name, Err: syscall.ErrShortStat}
			}
		}

		// Get a record from the buffer.
		b := d.buf[d.bufp:]

	}
	defer f.Close()

	// Can't make directory named after file.
	err = MkdirAll(fpath, 0777)
	if err == nil {
		t.Fatalf("MkdirAll %q: no error", fpath)
	}
	perr, ok := err.(*PathError)
	if !ok {
		t.Fatalf("MkdirAll %q returned %T, not *PathError", fpath, err)
	}
	if filepath.Clean(perr.Path) != filepath.Clean(fpath) {
		t.Fatalf("MkdirAll %q returned wrong error path: %q not %q", fpath, filepath.Clean(perr.Path), filepath.Clean(fpath))

)

type lockType int8

const (
	readLock = iota + 1
	writeLock
)

func lock(f File, lt lockType) error {
	return &fs.PathError{
		Op:   lt.String(),
		Path: f.Name(),
		Err:  errors.ErrUnsupported,
	}
}

func unlock(f File) error {
	return &fs.PathError{
		Op:   "Unlock",
		Path: f.Name(),
		Err:  errors.ErrUnsupported,
	}

// bits (before umask).
// If there is an error, it will be of type *PathError.
func Mkdir(name string, perm FileMode) error {
	longName := fixLongPath(name)
	e := ignoringEINTR(func() error {
		return syscall.Mkdir(longName, syscallMode(perm))
	})

	if e != nil {
		return &PathError{Op: "mkdir", Path: name, Err: e}
	}

	// mkdir(2) itself won't handle the sticky bit on *BSD and Solaris

	})
	if err != nil {
		return nil, &PathError{Op: "stat", Path: name, Err: err}
	}
	fillFileStatFromSys(&fs, name)
	return &fs, nil
}

// lstatNolog lstats a file with no test logging.
func lstatNolog(name string) (FileInfo, error) {
	var fs fileStat
	err := ignoringEINTR(func() error {
		return syscall.Lstat(name, &fs.sys)
	})
	if err != nil {
		return nil, &PathError{Op: "lstat", Path: name, Err: err}
	}