Flutter & Dart: Get File Name and Extension from Path/URL

This article shows you how to retrieve the name and extension of a file from a file path or a web URL in Dart (and Flutter as well).

In order to get the job done, we need the dart:io library and the path package (this one is published by the Dart team).Advertisements

Install the latest version of the path package by executing the following command:

flutter pub add path

Then run:

flutter pub get

No special permission is required.

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The path package provides 3 useful functions that can help us get the filename or extension with ease:

• basename(): Returns the file name with extension
• extension(): Returns the file extension
• basenameWithoutExtension(): Returns the file name without extension

Example

The code:

// main.dart
import 'dart:io';
import 'package:path/path.dart';

void main() {
  // File Path
  const examplePath = '/my-secret/some-path/abcxyz/my-book.pdf';

  final File _file = File(examplePath);
  final _filename = basename(_file.path);
  final _extension = extension(_file.path);
  final _nameWithoutExtension = basenameWithoutExtension(_file.path);
  print('Filename: $_filename');
  print('Filename without extension: $_nameWithoutExtension');
  print('Extension: $_extension');
}

Output:Advertisements

Filename: my-book.pdf
Filename without extension: my-book
Extension: .pdf

You can get the same result with a file from the internet with its URL instead of a local path:

import 'dart:io';
import 'package:path/path.dart';

void main() {
  // File URL from the internet
  const exampleUrl = 'https://www.kindacode.com/some-directory/my-photo.jpg';
  final File _file = File(exampleUrl);
  final _filename = basename(_file.path);
  final _nameWithoutExtension = basenameWithoutExtension(_file.path);
  final _extenion = extension(_file.path);
  print('Filename: $_filename');
  print('Filename without extension: $_nameWithoutExtension');
  print('Extension: $_extenion');
}

Output:

Filename: my-photo.jpg
Filename without extension: my-photo
Extension: .jpg

Conclusion

You’ve learned how to retrieve the name and extension of a file from a path or web URL. Continue learning more about Flutter and Dart by taking a look at the following articles:

• Flutter StreamBuilder examples
• Dart: Extract a substring from a given string (advanced)
• Working with Cupertino Date Picker in Flutter
• Flutter and Firestore Database: CRUD example
• Remove duplicate items from a list in Dart
• Working with dynamic Checkboxes in Flutter

You can also check out our Flutter topic page or Dart topic page for the latest tutorials and examples.