How to Create Your Own CLI

Main approaches and tools for building CLI applications:

Python CLI Frameworks:

• Click - Decorator-based, very popular and intuitive
• Typer - Built on Click, adds type hints for better IDE support
• argparse - Built into Python standard library
• rich - For beautiful terminal formatting and progress bars
• textual - For building full terminal user interfaces

JavaScript/TypeScript CLI Frameworks:

• Commander.js - Feature-rich, widely used
• yargs - Powerful argument parsing
• oclif - Professional CLI framework by Heroku
• Inquirer.js - For interactive prompts
• chalk - For colored output

Basic Python CLI Example with Click:

import click

@click.command()
@click.option('--name', prompt='Your name', help='The person to greet')
@click.option('--count', default=1, help='Number of greetings')
def hello(name, count):
    """Simple CLI that greets NAME COUNT times."""
    for _ in range(count):
        click.echo(f'Hello {name}!')

if __name__ == '__main__':
    hello()

Basic TypeScript CLI Example with Commander:

import { Command } from 'commander';

const program = new Command();

program
  .name('mycli')
  .description('CLI description')
  .version('1.0.0');

program
  .command('greet')
  .description('Greet someone')
  .argument('<name>', 'person to greet')
  .option('-c, --count <number>', 'number of times', '1')
  .action((name, options) => {
    for (let i = 0; i < parseInt(options.count); i++) {
      console.log(`Hello ${name}!`);
    }
  });

program.parse();