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How to Create a Command-Line Password Generator with Node.js And Deploy it to npmjs

Are you tired of coming up with weak passwords that are easy to guess? Do you struggle to come up with secure passwords that meet all the requirements? If so, why not create your own password generator using Node.js and yargs?

In this tutorial, we'll show you how to create a command-line password generator that allows users to generate strong passwords of any length and including any combination of symbols, numbers, and capital letters. Not only is this a useful tool to have in your arsenal, but it's also a fun project to work on.



npm install -g muath-ye/password-generator

Simple Usage



Advanced Usage

passgen -c -l 18


Step 1: Setting up the Project

The first step is to create a new Node.js project. Open up your terminal and create a new directory for your project:

mkdir password-generator
cd password-generator

Next, initialize a new Node.js project and install the necessary dependencies:

npm init -y
npm install yargs crypto

We'll be using the yargs module to parse command-line arguments and the crypto module to generate random passwords.

Step 2: Writing the Code

Now that we've set up our project and installed the necessary dependencies, it's time to write some code. Open up your favorite text editor and create a new file called index.js. This is where we'll write our password generator code.

First, let's require the necessary modules at the top of our file:

const crypto = require('crypto');
const yargs = require('yargs');

Next, let's define our generatePassword function. This function will take an options object as its argument, which will include the length of the password as well as options for including symbols, numbers, and capital letters.

const generatePassword = ({ length = 12, symbols = false, numbers = false, uppercase = false, complex = false }) => {
  let characters = 'abcdefghijklmnopqrstuvwxyz';
  if (symbols || complex) {
    characters += '!@#$%^&*()_+-=';
  if (numbers || complex) {
    characters += '0123456789';
  if (uppercase || complex) {
  const buffer = crypto.randomBytes(length);
  const password = Array.from(buffer)
    .map(byte => characters[byte % characters.length])
  return password;

This function generates a password of the specified length, including symbols, numbers, and/or capital letters if the corresponding options are set to true. The crypto.randomBytes method is used to generate a buffer of random bytes, which are then mapped to characters in the characters string using the modulus operator.

Now, let's define our yargs options. We'll add options for length, symbols, numbers, uppercase and complex, each with a default value of false.

const argv = yargs
  .option('length', {
    alias: 'l',
    description: 'Length of the password',
    type: 'number',
    default: 12
  .option('symbols', {
    alias: 's',
    description: 'Include symbols',
    type: 'boolean',
    default: false
  .option('numbers', {
    alias: 'n',
    description: 'Include numbers',
    type: 'boolean',
    default: false
  .option('uppercase', {
    alias: 'u',
    description: 'Include uppercase letters',
    type: 'boolean',
    default: false
  .option('complex', {
    alias: 'c',
    description: 'Include uppercase, symbols and numbers letters',
    type: 'boolean',
    default: false
  .alias('help', 'h')

The .help() method adds a --help option to your tool, which can be used to display a help message. The .alias('help', 'h') method adds a -h alias for the --help option.

Lastly, let's call our generatePassword function with the options passed in by the user and print the resulting password to the console.

  length: argv.length,
  symbols: argv.symbols,
  numbers: argv.numbers,
  uppercase: argv.uppercase

Step 3: Testing the Tool

Now that we've written our code, let's test our tool to make sure it's working as expected. In your terminal, run the following command:

node index.js

This should generate a random password of 12 characters, consisting only of lowercase letters.

To generate a password with specific options, pass the corresponding flags to the node index.js command. For example, to generate a password with a length of 20 characters, including symbols and numbers but not uppercase letters, run the following command:

node index.js --length 20 --symbols --numbers

Or you can pass the option aliases:

node index.js -l 20 -s -n

This should generate a random password of 20 characters, including symbols and numbers but not uppercase letters.

And that's it! You've now created your own command-line password generator using Node.js and yargs. This tool is a useful addition to your security arsenal, and it's also a fun project to work on. Now you can generate strong passwords quickly and easily, without having to come up with them yourself.

We hope you found this tutorial helpful and informative. Remember to always use strong passwords and keep them safe. Happy coding!

Step 4: Deploy the tool to packages

To publish your package on the NPM registry, you need to have an account. If you don't have an account, visit the NPM sign up page to create yours.

Update the package.json File

Open your package.json file and add a bin property to specify the location of your command-line script.

  "name": "@muath-ye/password-generator",
  "version": "1.0.0",
  "description": "Generates a strong password",
  "bin": {
    "passgen": "./index.js"
  "preferGlobal": true,
  "author": "Muath Alsowadi",
  "repository": "muath-ye/passgen",
  "license": "MIT",
  "dependencies": {
    "yargs": "^17.1.1",
    "crypto": "^1.0.1"

This tells Node.js where to find the script that will be executed when the user types the command passgen.

Install npm Globally

To make your package available globally, you need to have npm installed globally on your machine. If you don't have it installed, you can download and install it from the official website


Run npm link to create a symbolic link between your package and the global node_modules directory on your system.

npm link

Then you can your tool before publishing it to npmjs.



Run npm unlink to remove the created symbolic link.

npm unlink

If you want to remove your package entirely from your system, you can run the following commands:

npm uninstall -g muath-ye/password-generator

Publish Your Package

Run the following command to publish your package to the npm registry:

npm login

The command npm login will prompt you to enter your npm username and password. If you don't have an account, you can create one on the website

You will be asked for one-time password An image

npm publish --access public

The command npm publish --access public will publish your package to the npm registry and make it available for anyone to download and use.

Install Your Package

To install your package globally, run the following command:

npm install -g password-generator

This will install your package globally and make it available as a command-line tool.

Try Your Package

To use your package, open up your terminal and type the following command:

passgent --help

This should display the help message for your password generator tool, indicating that your package was installed and is working correctly.

Congratulations! You have successfully created a command-line password generator with Node.js and yargs, and deployed it as a global package to the npm registry.

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