Building CLI Tools with Node.js: From Simple Scripts to Complex Applications

Building CLI Tools with Node.js

Create powerful command-line tools for automation and productivity.

Project Setup

mkdir my-cli && cd my-cli
npm init -y
npm install commander inquirer chalk ora

// package.json
{
    "name": "my-cli",
    "bin": {
        "mycli": "./bin/index.js"
    }
}

Basic CLI Structure

#!/usr/bin/env node
// bin/index.js

const { program } = require('commander');
const chalk = require('chalk');

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

program
    .command('greet <name>')
    .description('Greet someone')
    .option('-l, --loud', 'Say it loudly')
    .action((name, options) => {
        const greeting = `Hello, ${name}!`;
        console.log(options.loud ? chalk.bold.green(greeting.toUpperCase()) : greeting);
    });

program.parse();

Interactive Prompts

const inquirer = require('inquirer');

async function setup() {
    const answers = await inquirer.prompt([
        {
            type: 'input',
            name: 'projectName',
            message: 'Project name:',
            default: 'my-project'
        },
        {
            type: 'list',
            name: 'template',
            message: 'Choose a template:',
            choices: ['React', 'Vue', 'Angular']
        },
        {
            type: 'confirm',
            name: 'typescript',
            message: 'Use TypeScript?',
            default: true
        }
    ]);

    return answers;
}

Progress Indicators

const ora = require('ora');

async function downloadFiles() {
    const spinner = ora('Downloading files...').start();

    try {
        await download();
        spinner.succeed('Download complete!');
    } catch (error) {
        spinner.fail('Download failed');
        process.exit(1);
    }
}

Publishing to npm

npm login
npm publish

CLI tools are excellent for automating repetitive tasks and improving developer workflows.