# Directory class

A reference to a directory (or folder) on the file system.

A Directory instance is an object holding a path on which operations can be performed. The path to the directory can be absolute or relative. You can get the parent directory using the getter parent, a property inherited from FileSystemEntity.

In addition to being used as an instance to access the file system, Directory has a number of static properties, such as systemTemp, which gets the system's temporary directory, and the getter and setter current, which you can use to access or change the current directory.

Create a new Directory object with a pathname to access the specified directory on the file system from your program.

    var myDir = new Directory('myDir');

Most methods in this class occur in synchronous and asynchronous pairs, for example, create and createSync. Unless you have a specific reason for using the synchronous version of a method, prefer the asynchronous version to avoid blocking your program.

## Create a directory

The following code sample creates a directory using the create method. By setting the `recursive` parameter to true, you can create the named directory and all its necessary parent directories, if they do not already exist.

    import 'dart:io';

    void main() {
      // Creates dir/ and dir/subdir/.
      new Directory('dir/subdir').create(recursive: true)
        // The created directory is returned as a Future.
        .then((Directory directory) {
          print(directory.path);
      });
    }

## List a directory

Use the list or listSync methods to get the files and directories contained by a directory. Set `recursive` to true to recursively list all subdirectories. Set `followLinks` to true to follow symbolic links. The list method returns a Stream that provides FileSystemEntity objects. Use the listen callback function to process each object as it become available.

    import 'dart:io';

    void main() {
      // Get the system temp directory.
      var systemTempDir = Directory.systemTemp;

      // List directory contents, recursing into sub-directories,
      // but not following symbolic links.
      systemTempDir.list(recursive: true, followLinks: false)
        .listen((FileSystemEntity entity) {
          print(entity.path);
        });
    }

## The use of Futures

I/O operations can block a program for some period of time while it waits for the operation to complete. To avoid this, all methods involving I/O have an asynchronous variant which returns a Future. This future completes when the I/O operation finishes. While the I/O operation is in progress, the Dart program is not blocked, and can perform other operations.

For example, the exists method, which determines whether the directory exists, returns a boolean value using a Future. Use `then` to register a callback function, which is called when the value is ready.

    import 'dart:io';

    main() {
      final myDir = new Directory('dir');
      myDir.exists().then((isThere) {
        isThere ? print('exists') : print('non-existent');
      });
    }

In addition to exists, the stat, rename, and other methods, return Futures.

## Other resources

- Dart by Example provides additional task-oriented code samples that show how to use various API from the Directory class and the related File class.

- I/O for Command-Line Apps a section from A Tour of the Dart Libraries covers files and directories.

- Write Command-Line Apps, a tutorial about writing command-line apps, includes information about files and directories.

Implements
  - FileSystemEntity

## Constructors

Directory(String path)
  Creates a Directory object. [...]
  factory
Directory.fromRawPath(Uint8List path)
  factory
Directory.fromUri(Uri uri)
  Create a Directory object from a URI. [...]
  factory

## Properties

absolute → Directory
  Returns a Directory instance whose path is the absolute path to this. [...]
  read-only
path → String
  Gets the path of this directory.
  read-only
uri → Uri
  Returns a Uri representing the directory's location. [...]
  read-only
hashCode → int
  The hash code for this object. [...]
  read-only, inherited
isAbsolute → bool
  Returns a bool indicating whether this object's path is absolute. [...]
  read-only, inherited
parent → Directory
  The directory containing this.
  read-only, inherited
runtimeType → Type
  A representation of the runtime type of the object.
  read-only, inherited

## Methods

create({bool recursive: false }) → Future<Directory>
  Creates the directory with this name. [...]
createSync({bool recursive: false }) → void
  Synchronously creates the directory with this name. [...]
createTemp([String prefix ]) → Future<Directory>
  Creates a temporary directory in this directory. Additional random characters are appended to `prefix` to produce a unique directory name. If `prefix` is missing or null, the empty string is used for `prefix`. [...]
createTempSync([String prefix ]) → Directory
  Synchronously creates a temporary directory in this directory. Additional random characters are appended to `prefix` to produce a unique directory name. If `prefix` is missing or null, the empty string is used for `prefix`. [...]
list({bool recursive: false, bool followLinks: true }) → Stream<FileSystemEntity>
  Lists the sub-directories and files of this Directory. Optionally recurses into sub-directories. [...]
listSync({bool recursive: false, bool followLinks: true }) → List<FileSystemEntity>
  Lists the sub-directories and files of this Directory. Optionally recurses into sub-directories. [...]
rename(String newPath) → Future<Directory>
  Renames this directory. Returns a `Future<Directory>` that completes with a Directory instance for the renamed directory. [...]
renameSync(String newPath) → Directory
  Synchronously renames this directory. Returns a Directory instance for the renamed directory. [...]
resolveSymbolicLinks() → Future<String>
  Resolves the path of a file system object relative to the current working directory. [...]
resolveSymbolicLinksSync() → String
  Resolves the path of a file system object relative to the current working directory. [...]
toString() → String
  Returns a human readable string for this Directory instance.
delete({bool recursive: false }) → Future<FileSystemEntity>
  Deletes this FileSystemEntity. [...]
  inherited
deleteSync({bool recursive: false }) → void
  Synchronously deletes this FileSystemEntity. [...]
  inherited
exists() → Future<bool>
  Checks whether the file system entity with this path exists. Returns a `Future<bool>` that completes with the result. [...]
  inherited
existsSync() → bool
  Synchronously checks whether the file system entity with this path exists. [...]
  inherited
noSuchMethod(Invocation invocation) → dynamic
  Invoked when a non-existent method or property is accessed. [...]
  inherited
stat() → Future<FileStat>
  Calls the operating system's stat() function on the path of this FileSystemEntity. [...]
  inherited
statSync() → FileStat
  Synchronously calls the operating system's stat() function on the path of this FileSystemEntity. [...]
  inherited
watch({int events: FileSystemEvent.all, bool recursive: false }) → Stream<FileSystemEvent>
  Start watching the FileSystemEntity for changes. [...]
  inherited

## Operators

operator ==(dynamic other) → bool
  The equality operator. [...]
  inherited

## Static Properties

current ↔ Directory
  Creates a directory object pointing to the current working directory.
  read / write
systemTemp → Directory
  Gets the system temp directory. [...]
  read-only