Dart Directory
last modified April 4, 2025
The Directory class in Dart provides operations for working with
file system directories. It's part of Dart's dart:io library.
Directory supports creating, listing, deleting, and checking directory properties. It works synchronously and asynchronously for file operations.
Basic Definition
Directory represents a directory in the file system. It provides
methods to manipulate directories and their contents.
Key features include path manipulation, file listing, creation, deletion, and existence checking. Directory operations can be synchronous or async.
Creating a Directory
This example demonstrates how to create a new directory.
import 'dart:io';
void main() async {
var dir = Directory('new_directory');
try {
await dir.create();
print('Directory created: ${dir.path}');
} catch (e) {
print('Error creating directory: $e');
}
}
We create a Directory object and call create() to make the directory. The async/await pattern is used for asynchronous file operations.
$ dart main.dart Directory created: new_directory
Listing Directory Contents
This example shows how to list files and subdirectories in a directory.
import 'dart:io';
void main() async {
var dir = Directory('.'); // Current directory
try {
var contents = await dir.list().toList();
print('Contents of ${dir.path}:');
for (var entity in contents) {
print(entity.path);
}
} catch (e) {
print('Error listing directory: $e');
}
}
The list() method returns a stream of directory entries. We convert it to a list and print each entry's path. This shows all files and subdirectories.
$ dart main.dart Contents of .: ./main.dart ./new_directory ./pubspec.yaml
Checking Directory Existence
This example demonstrates how to check if a directory exists.
import 'dart:io';
void main() async {
var dir = Directory('test_dir');
if (await dir.exists()) {
print('Directory exists');
} else {
print('Directory does not exist');
await dir.create();
print('Created directory');
}
}
The exists() method checks if the directory exists. If not, we create it. This pattern is useful for ensuring directories exist before operations.
$ dart main.dart Directory does not exist Created directory
Deleting a Directory
This example shows how to delete a directory and its contents.
import 'dart:io';
void main() async {
var dir = Directory('temp_dir');
// Create some test content
await dir.create();
await File('${dir.path}/test.txt').create();
try {
await dir.delete(recursive: true);
print('Directory deleted successfully');
} catch (e) {
print('Error deleting directory: $e');
}
}
The delete() method removes the directory. The recursive parameter allows deleting non-empty directories. Without it, deletion fails if not empty.
$ dart main.dart Directory deleted successfully
Getting Directory Properties
This example demonstrates accessing directory properties and metadata.
import 'dart:io';
void main() async {
var dir = Directory('.'); // Current directory
try {
var stat = await dir.stat();
print('Directory: ${dir.path}');
print('Type: ${stat.type}');
print('Size: ${stat.size} bytes');
print('Modified: ${stat.modified}');
print('Accessed: ${stat.accessed}');
} catch (e) {
print('Error getting directory stats: $e');
}
}
The stat() method returns a FileStat object with directory metadata. This includes size, modification time, and file type information.
$ dart main.dart Directory: . Type: directory Size: 4096 bytes Modified: 2025-04-04 14:30:22.000 Accessed: 2025-04-04 14:35:10.000
Best Practices
- Async operations: Prefer async methods for better performance
- Error handling: Always handle potential IO exceptions
- Path handling: Use path.join() for cross-platform paths
- Resource cleanup: Close streams when done with directory listings
Source
This tutorial covered Dart's Directory class with practical examples showing common directory operations like creation, listing, and deletion.
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