Building a Simple CLI with Chalk, fs-extra, and Inquirer

March 12, 2025 (2w ago)

Command Line Interfaces (CLIs) can be powerful tools for automation, user interaction, and improving productivity. In this tutorial, we’ll build a simple CLI using Node.js with the help of chalk for styling, fs-extra for file operations, and inquirer for user input.

What Are Chalk, fs-extra, and Inquirer?

Chalk

Chalk is a popular library used for styling and coloring terminal output in Node.js. It allows you to easily add colors, background colors, and styles like bold or underline to text displayed in the terminal.

Example usage:

import chalk from 'chalk';
console.log(chalk.green('Success!'));
console.log(chalk.red.bold('Error!'));

fs-extra

fs-extra is an extension of Node.js's built-in fs module, providing additional methods for handling file system operations. It includes functions like outputFile, copy, and remove, which simplify working with files and directories.

Example usage:

import fs from 'fs-extra';
fs.outputFileSync('example.txt', 'Hello, World!');
console.log('File created successfully.');

Inquirer

Inquirer is a library for handling interactive user prompts in the terminal. It allows you to create command-line questionnaires, take user input, and handle multiple types of prompts.

Example usage:

import inquirer from 'inquirer';
 
inquirer.prompt([
  {
    type: 'input',
    name: 'username',
    message: 'What is your name?'
  }
]).then(answers => {
  console.log(`Hello, ${answers.username}!`);
});

Prerequisites

Before we begin, ensure you have the following installed:

Step 1: Initialize a Node.js Project

Create a new directory for your CLI and initialize a new Node.js project:

mkdir my-cli-tool && cd my-cli-tool
npm init -y

This will generate a package.json file.

Step 2: Install Required Dependencies

We need to install the following npm packages:

Run the following command to install them:

npm install chalk fs-extra inquirer

Step 3: Create the CLI Script

Inside your project folder, create a file named index.js and add the following code:

#!/usr/bin/env node
 
import chalk from 'chalk';
import fs from 'fs-extra';
import inquirer from 'inquirer';
 
console.log(chalk.blue('Welcome to My CLI Tool!'));
 
async function main() {
    const answers = await inquirer.prompt([
        {
            type: 'input',
            name: 'filename',
            message: 'Enter the name of the file to create:'
        },
        {
            type: 'input',
            name: 'content',
            message: 'Enter the content for the file:'
        }
    ]);
 
    const { filename, content } = answers;
    const filePath = `./${filename}`;
 
    try {
        await fs.outputFile(filePath, content);
        console.log(chalk.green(`File "${filename}" created successfully!`));
    } catch (error) {
        console.log(chalk.red('Error creating file:', error));
    }
}
 
main();

Step 4: Make the Script Executable

Modify package.json to add a bin field:

"bin": {
  "mycli": "index.js"
}

Also, modify the script to use ES module support by adding this to package.json:

"type": "module"

Now, make the script executable:

chmod +x index.js

Step 5: Link the CLI Globally

To use the CLI as a global command, run:

npm link

This allows you to run the CLI tool with:

mycli

Step 6: Test the CLI

Try running your CLI tool:

mycli

It will prompt you to enter a filename and content, then create a file with the given details.

Conclusion

You’ve now built a simple Node.js CLI tool using chalk for styling, fs-extra for file handling, and inquirer for user input. You can extend this by adding more commands, handling errors better, and improving the user experience.

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