args

Learn CLI arguments with the args package.

The args package

args is Dart's package for parsing command-line arguments. It is imported with import 'package:args/args.dart';. The ArgParser class defines options; the parse method parses arguments.

Example: final parser = ArgParser()..addOption('name'); final results = parser.parse(['--name=Ayşe']);. Here the --name option is defined and the --name=Ayşe argument is parsed. results['name'] yields 'Ayşe'. This is the standard way to handle user input in CLI tools.

Defining options with ArgParser

ArgParser adds three kinds of options: addOption (text option), addFlag (boolean flag), addMultiOption (list). Each option can have an abbreviation (abbr) and a help text (help).

Example: final parser = ArgParser()..addOption('name', abbr: 'n');. Here the --name option is added with the -n abbreviation. After parsing you read results['name']. With results.wasParsed('name') you check whether the option was given.

Exercise Parse a name with args

Add import 'package:args/args.dart';. In main create a parser with final parser = ArgParser()..addOption('name');. Parse with final results = parser.parse(['--name=Ayşe']);. Print with print('Hello, ${results['name']}!').

Show example solution

import 'package:args/args.dart';

void main() {
  final parser = ArgParser()..addOption('name');
  final results = parser.parse(['--name=Ayşe']);
  print('Hello, ${results["name"]}!');
}

Test yourself

What does the args package do?
- Makes HTTP requests
- Parses CLI arguments
- Manages databases
- Manipulates DOM
Show answer

Manages databases — the args package parses command-line arguments.

Creating an ArgParser

final parser = ____();

Show answer

final parser = ArgParser();

Match the args parts

args

CLI package
ArgParser

Parser
addOption

Adds an option
parse

Parses

Next lesson: ArgParser

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