| 1 | package fsutil |
| 2 | |
| 3 | import ( |
| 4 | "errors" |
| 5 | "fmt" |
| 6 | "io/fs" |
| 7 | "os" |
| 8 | "path/filepath" |
| 9 | ) |
| 10 | |
| 11 | // DirWritable checks if a directory is writable. If the directory does |
| 12 | // not exist it is created with writable permission. |
| 13 | func DirWritable(dir string) error { |
| 14 | if dir == "" { |
| 15 | return errors.New("directory not specified") |
| 16 | } |
| 17 | |
| 18 | var err error |
| 19 | dir, err = ExpandHome(dir) |
| 20 | if err != nil { |
| 21 | return err |
| 22 | } |
| 23 | |
| 24 | fi, err := os.Stat(dir) |
| 25 | if err != nil { |
| 26 | if errors.Is(err, fs.ErrNotExist) { |
| 27 | // Directory does not exist, so create it. |
| 28 | err = os.Mkdir(dir, 0775) |
| 29 | if err == nil { |
| 30 | return nil |
| 31 | } |
| 32 | } |
| 33 | if errors.Is(err, fs.ErrPermission) { |
| 34 | err = fs.ErrPermission |
| 35 | } |
| 36 | return fmt.Errorf("directory not writable: %s: %w", dir, err) |
| 37 | } |
| 38 | if !fi.IsDir() { |
| 39 | return fmt.Errorf("not a directory: %s", dir) |
| 40 | } |
| 41 | |
| 42 | // Directory exists, check that a file can be written. |
| 43 | file, err := os.CreateTemp(dir, "writetest") |
| 44 | if err != nil { |
| 45 | if errors.Is(err, fs.ErrPermission) { |
| 46 | err = fs.ErrPermission |
| 47 | } |
| 48 | return fmt.Errorf("directory not writable: %s: %w", dir, err) |
| 49 | } |
| 50 | file.Close() |
| 51 | return os.Remove(file.Name()) |
| 52 | } |
| 53 | |
| 54 | // ExpandHome expands the path to include the home directory if the path is |
| 55 | // prefixed with `~`. If it isn't prefixed with `~`, the path is returned |
| 56 | // as-is. |
| 57 | func ExpandHome(path string) (string, error) { |
| 58 | if path == "" { |
| 59 | return path, nil |
| 60 | } |
| 61 | |
| 62 | if path[0] != '~' { |
| 63 | return path, nil |
| 64 | } |
| 65 | |
| 66 | if len(path) > 1 && path[1] != '/' && path[1] != '\\' { |
| 67 | return "", errors.New("cannot expand user-specific home dir") |
| 68 | } |
| 69 | |
| 70 | dir, err := os.UserHomeDir() |
| 71 | if err != nil { |
| 72 | return "", err |
| 73 | } |
| 74 | |
| 75 | return filepath.Join(dir, path[1:]), nil |
| 76 | } |
| 77 | |
| 78 | // FileExists return true if the file exists |
| 79 | func FileExists(filename string) bool { |
| 80 | _, err := os.Lstat(filename) |
| 81 | return !errors.Is(err, os.ErrNotExist) |
| 82 | } |