//
// If fs implements [ReadDirFS], ReadDir calls fs.ReadDir.
// Otherwise ReadDir calls fs.Open and uses ReadDir and Close
// on the returned file.
func ReadDir(fsys FS, name string) ([]DirEntry, error) {
	if fsys, ok := fsys.(ReadDirFS); ok {
		return fsys.ReadDir(name)
	}

	file, err := fsys.Open(name)
	if err != nil {
		return nil, err
	}
	defer file.Close()

	dir, ok := file.(ReadDirFile)
	if !ok {

// along with this program.  If not, see <http://www.gnu.org/licenses/>.

package cmd

// Options for readDir function call
type readDirOpts struct {
	// The maximum number of entries to return
	count int
	// Follow directory symlink
	followDirSymlink bool
}

// Return all the entries at the directory dirPath.
func readDir(dirPath string) (entries []string, err error) {
	return readDirWithOpts(dirPath, readDirOpts{count: -1})
}

	}
	return ^FileMode(0)
}

// Implemented in syscall/syscall_darwin.go.

//go:linkname closedir syscall.closedir
func closedir(dir uintptr) (err error)

//go:linkname readdir_r syscall.readdir_r

				names = append(names, d.Name())
			}
			t.Errorf("ReadDir(%s) = %v, %v, want %v, nil", desc, names, err, []string{"hello.txt", "sub"})
		}
	}

	// Test that ReadDir uses the method when present.
	dirs, err := ReadDir(readDirOnly{testFsys}, ".")
	check("readDirOnly", dirs, err)

	// Test that ReadDir uses Open when the method is not present.
	dirs, err = ReadDir(openOnly{testFsys}, ".")
	check("openOnly", dirs, err)

func isDirEmpty(dirname string, legacy bool) bool {
	if legacy {
		// On filesystems such as btrfs, nfs this is not true, so fallback
		// to performing readdir() instead.
		entries, err := readDirN(dirname, 1)
		if err != nil {
			return false
		}
		return len(entries) == 0
	}
	var stat syscall.Stat_t
	if err := syscall.Stat(dirname, &stat); err != nil {
		return false
	}

// Pipe is a fake call that returns nil.
func (*FakeOS) Pipe() (r *os.File, w *os.File, err error) {
	return nil, nil, nil
}

// ReadDir is a fake call that returns the files under the directory.
func (f *FakeOS) ReadDir(dirname string) ([]os.DirEntry, error) {
	if f.ReadDirFn != nil {
		return f.ReadDirFn(dirname)
	}
	return nil, nil
}

// Glob is a fake call that returns list of virtual files matching a pattern.

	// baseDir is not honored in plan9 and solaris platforms.
	return os.MkdirAll(dirPath, perm)
}

// readDirFn applies the fn() function on each entries at dirPath, doesn't recurse into
// the directory itself, if the dirPath doesn't exist this function doesn't return
// an error.
func readDirFn(dirPath string, filter func(name string, typ os.FileMode) error) error {
	d, err := Open(dirPath)
	if err != nil {

	// Check non existent directory.
	if _, err := readDir("/tmp/non-existent-directory"); err != errFileNotFound {
		t.Fatalf("expected = %s, got: %s", errFileNotFound, err)
	}

	file := path.Join(os.TempDir(), "issue")
	if err := os.WriteFile(file, []byte(""), 0o644); err != nil {
		t.Fatal(err)
	}
	defer os.RemoveAll(file)

	// Check if file is given.
	if _, err := readDir(path.Join(file, "mydir")); err != errFileNotFound {

func (f *File) Readdir(n int) ([]FileInfo, error) {
	if f == nil {
		return nil, ErrInvalid
	}
	_, _, infos, err := f.readdir(n, readdirFileInfo)
	if infos == nil {
		// Readdir has historically always returned a non-nil empty slice, never nil,
		// even on error (except misuse with nil receiver above).
		// Keep it that way to avoid breaking overly sensitive callers.
		infos = []FileInfo{}
	}
	return infos, err
}

// It is used to wrap the Readdir method of http.File so that we can
// remove files and directories that start with a period from its output.
type dotFileHidingFile struct {
	http.File
}

// Readdir is a wrapper around the Readdir method of the embedded File
// that filters out all files that start with a period in their name.
func (f dotFileHidingFile) Readdir(n int) (fis []fs.FileInfo, err error) {