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

void check(Object? error) {
  if (error != null) {
    throw error;
  }
}

void main() async {
  // The easiest way to create a temporary file in Dart is by
  // using the `File.createTemp` method. It creates a file and
  // opens it for reading and writing. We provide an empty string
  // as the first argument, so it will create the file in the
  // default temporary directory for our OS.
  var file = await File.createTemp('sample');
  check(file == null);

  // Display the name of the temporary file. On
  // Unix-based OSes the directory will likely be `/tmp`.
  // The file name starts with the prefix given as the
  // argument to `File.createTemp` and the rest
  // is chosen automatically to ensure that concurrent
  // calls will always create different file names.
  print('Temp file name: ${file.path}');

  // Clean up the file after we're done. The OS is
  // likely to clean up temporary files by itself after
  // some time, but it's good practice to do this
  // explicitly.
  await file.delete();

  // We can write some data to the file.
  await file.writeAsBytes([1, 2, 3, 4]);

  // If we intend to create many temporary files, we may
  // prefer to create a temporary *directory*.
  // `Directory.systemTemp` provides the system temp directory,
  // and we can create a new directory inside it.
  var tempDir = await Directory.systemTemp.createTemp('sampledir');
  print('Temp dir name: ${tempDir.path}');

  // Clean up the directory after we're done.
  await tempDir.delete(recursive: true);

  // Now we can synthesize temporary file names by
  // prefixing them with our temporary directory.
  var tempFilePath = path.join(tempDir.path, 'file1');
  await File(tempFilePath).writeAsBytes([1, 2]);
}