// Copyright 2016 The Go Authors. All rights reserved. // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. package os import ( "io/fs" "sort" ) type readdirMode int const ( readdirName readdirMode = iota readdirDirEntry readdirFileInfo ) // Readdir reads the contents of the directory associated with file and // returns a slice of up to n FileInfo values, as would be returned // by Lstat, in directory order. Subsequent calls on the same file will yield // further FileInfos. // // If n > 0, Readdir returns at most n FileInfo structures. In this case, if // Readdir returns an empty slice, it will return a non-nil error // explaining why. At the end of a directory, the error is io.EOF. // // If n <= 0, Readdir returns all the FileInfo from the directory in // a single slice. In this case, if Readdir succeeds (reads all // the way to the end of the directory), it returns the slice and a // nil error. If it encounters an error before the end of the // directory, Readdir returns the FileInfo read until that point // and a non-nil error. // // Most clients are better served by the more efficient ReadDir method. 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 } // Readdirnames reads the contents of the directory associated with file // and returns a slice of up to n names of files in the directory, // in directory order. Subsequent calls on the same file will yield // further names. // // If n > 0, Readdirnames returns at most n names. In this case, if // Readdirnames returns an empty slice, it will return a non-nil error // explaining why. At the end of a directory, the error is io.EOF. // // If n <= 0, Readdirnames returns all the names from the directory in // a single slice. In this case, if Readdirnames succeeds (reads all // the way to the end of the directory), it returns the slice and a // nil error. If it encounters an error before the end of the // directory, Readdirnames returns the names read until that point and // a non-nil error. func (f *File) Readdirnames(n int) (names []string, err error) { if f == nil { return nil, ErrInvalid } names, _, _, err = f.readdir(n, readdirName) if names == nil { // Readdirnames 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. names = []string{} } return names, err } // A DirEntry is an entry read from a directory // (using the ReadDir function or a File's ReadDir method). type DirEntry = fs.DirEntry // ReadDir reads the contents of the directory associated with the file f // and returns a slice of DirEntry values in directory order. // Subsequent calls on the same file will yield later DirEntry records in the directory. // // If n > 0, ReadDir returns at most n DirEntry records. // In this case, if ReadDir returns an empty slice, it will return an error explaining why. // At the end of a directory, the error is io.EOF. // // If n <= 0, ReadDir returns all the DirEntry records remaining in the directory. // When it succeeds, it returns a nil error (not io.EOF). func (f *File) ReadDir(n int) ([]DirEntry, error) { if f == nil { return nil, ErrInvalid } _, dirents, _, err := f.readdir(n, readdirDirEntry) if dirents == nil { // Match Readdir and Readdirnames: don't return nil slices. dirents = []DirEntry{} } return dirents, err } // testingForceReadDirLstat forces ReadDir to call Lstat, for testing that code path. // This can be difficult to provoke on some Unix systems otherwise. var testingForceReadDirLstat bool // ReadDir reads the named directory, // returning all its directory entries sorted by filename. // If an error occurs reading the directory, // ReadDir returns the entries it was able to read before the error, // along with the error. func ReadDir(name string) ([]DirEntry, error) { f, err := Open(name) if err != nil { return nil, err } defer f.Close() dirs, err := f.ReadDir(-1) sort.Slice(dirs, func(i, j int) bool { return dirs[i].Name() < dirs[j].Name() }) return dirs, err }