John David

John David

1565931321

Build a Command-Line Application with Node.js

Originally published by Chidume Nnamdi at https://blog.bitsrc.io

Since the advent of Nodejs, command-line tools have been built using the JavaScript programming language, the most popular and widely used language in the world. There are many popular CLI tools built using JS:

These are popular CLI tools we have in npmjs.org. NPM is the world most popular Node package manager. You reading this, you must have worked with Nodejs, and there is no way you haven’t used the popular npm command with its helluva pile of sub-commands:

  • publish
  • init
  • cache clean
  • etc

Short intro

You see, Nodejs made us be able to write command-line tools in our fav language: JS. Without Nodejs, we will just write a cmd0line in C/C++ and compile to executable. We know the popular commands we use in cmd/bash:

  • ls
  • touch
  • mkdir
  • cd
  • etc

These are executable files(.exe, .app, in Linux systems there is no file extension) in our system path, written in C/C++ and compiled to executable format. If we run the ls command to list files and folders in our current directory:

$ ls'autorun.inf/' 'System Information/'

The ls file is forked and run, the results it returns is displayed on the cmd/bash/sh.

we can create our our program and run it in cmd-line:

// hello.cpp

#include <iostream>;int main() {

 cout >> “Hello world”;

 return 0;

}

On compilation, we will have the executable file hello.exe. On execution in he cmd-line, it will display “Hello world” in the cmd:

$ hello

Hello world

You see, this is a CLI tool written in C/C++ but with Nodejs we can write the same in JavaScript, can you imagine that? A language we knew from the beginning of our programming journey that it was a browser-based language, can now be used to create CLI utilities that can be done in C/C++.

So, in this post, we will see how to write a CLI tool in JS.

Project Setup

First, you need to download the Nodejs program and install it. Open your browser and navigate to https://nodejs.org and there on the main page you can download the version of Node.js that corresponds to your platform.

Next, we have to initialize a Node project:

mkdir node-cli

cd node-cli

npm init -y

This app will mimic our hello.cpp program it will just output “Hello world” in the terminal.

We create an index.js file

touch index.js

Open it and pour in the below contents:

// index.js

console.log(“Hello world”);

If we run node . in our terminal, we will see the contents display:

$ node .

Hello world

We added . to the node command because the entry point is the index.js so Node will know to run the index.js file which is the default file for any Node project. If we create a file like hello.js, to run it we must specify its name in the node command: node hello or node hello.js.

I know, a Hello world program isn’t ideal to demonstrate a concept but this isn’t about the example it is about how to make a shell-command line program in Nodejs.

Making our project a Shell-Cmd

Our program is called with the node command, we want it to be called like a regular shell command like how the Angular CLI is called: ng.

It is very easy to achieve. First we add #!/usr/bin/env node to the index.js file:

// index.js

#!/usr/bin/env nodeconsole.log(“Hello world”);

This makes it possible to execute this project without the node command. See it has already been added in the command #!/usr/bin/env node.

Next, we need to update our package.json file:

// package.json

{

 name: “node-cli”,

 // …

 bin: “./index.js”

 // …

}

See we added a bin property with the value pointed to the index.js file. The bin prop specifies command names for a node project, but as we have a single file the name property will be used as the shell command name.

Now our app is not globally available like we cannot run node-cli in our shell to run the project. But we don’t want the CLI name to be node-cli, we want it to be hello, so we can run it like this: hello. To do that we will change the name property in the package.json to hello.

// package.json

{

 name: “hello”,

 // …

 bin: “./index.js”

 // …

}

Making our project globally available

To make our project available globally we would create a symlink using the npm link command.

We run:

npm link

yarn link

in our project. This command creates a symbolic link between the project directory and executable command.

In Windows, you will see hello.cmd created in ~/Admin/AppData/LocalRoaming/npm, the hello.cmd is the file that will be run when we type hello in cmd/bash/sh in any directory.

To test it, make sure you are not in the project directory. Open cmd/bash/sh and type hello:

$ helloHello world

Boom!!! our Node app works globally in our machine!

Publishing our project to NPM

To be able for users to install our node project and use it globally in the machine, we have to push it to NPM.

Before pushing our project, we need to bet or ignore some files or folders, node_modules is the main folder that is usually ignored because when the dependencies in the node_modules will be installed when the users pull in our project.

Since we have not installed any dependencies so we have no node_modules folder, but if to say we have it. To ignore it is easy just create .npmignore file and add the node_modules folder in it.

// .npmignore

node_modules/

We can then push our project to NPM:

npm publish

yarn publish+ hello@0.0.1

Users can install our hello project globally:

npm i hello -g

The user can run the hello command in the shell like this:

$ helloHello world

Adding commands to our project

A node project can have many commands. Our hello project has one shell command hello, we can add many commands to it.

We can add commands like:

  • sayName: says my name “Nnamdi Chidume” and my details like age, career.
  • tip: gives a tip of the day.
  • today: prints today’s date.

To do that we will edit our package.json

// package.json

{

 name: “hello”,

 // …

 bin: “./index.js”

 // …

}|

 |

 v// package.json

{

 name: “hello”,

 // …

 bin: {

 “hello”: “./index.js”,

 “sayName”: “./sayName.js”,

 “tip”: “./tip.js”,

 “today”: “./today.js”

 }

 // …

}

The bin property is now an object that holds the command and its corresponding file to call.

Now, let’s create the files:

touch sayName.js

touch tip.js

touch today.js

Then, we flesh them out.

#!/usr/bin/env node

// sayName.jsconsole.log(“Im Chidume Nnamdi\n”)

console.log(“I am a Software Developer”)#!/usr/bin/env node

// tip.jsconsole.log(“Never give up”)

console.log(“There is light at the end of the tunnel”)

#!/usr/bin/env node

// today.jsconsole.log("Today’s date is " + Date.now().toLocaleString())

Now our node-cli project folder would look like this:

node-cli

 index.js

 sayName.js

 tip.js

 today.js

 package.json

 .npmignore

Run the npm link to create symlinks for our new commands. You can also publish the new updates to NPM to add the new commands.

After done with that, our users can use our commands as shell commands:

$ hello

Hello world

$ sayName

I’m Chidume Nnamdi

I am a Software Developer

$ tip

Never give up

There is light at the end of the tunnel

$ today

Today’s date is Fri 02/07/2019

Conclusion

See we demonstrated how to create a command-line tool in JS using Nodejs. It is very easy, just a couple of tweaks you have your CLI.

I know I didn’t demonstrate with a real-world example, I only explained and demoed how to configure to get your CLI. With the knowledge, create your real-world example and make it a CLI with the tweaks you learned here.

If you have any question regarding this or anything I should add, correct or remove, feel free to comment, email or DM me.

Thanks !!!

Thanks for reading

If you liked this post, share it with all of your programming buddies!

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Further reading about Node.js

The Complete Node.js Developer Course (3rd Edition)

Angular & NodeJS - The MEAN Stack Guide

NodeJS - The Complete Guide (incl. MVC, REST APIs, GraphQL)

Best 50 Nodejs interview questions from Beginners to Advanced in 2019

Node.js 12: The future of server-side JavaScript

An Introduction to Node.js Design Patterns

Basic Server Side Rendering with Vue.js and Express

Fullstack Vue App with MongoDB, Express.js and Node.js

How to create a full stack React/Express/MongoDB app using Docker

Creating your first npm package

Top 10 npm Security Best Practices

How to publish a React Native component to NPM


#node-js #npm #web-development

What is GEEK

Buddha Community

Build a Command-Line Application with Node.js

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Hire Dedicated Node.js Developers - Hire Node.js Developers

If you look at the backend technology used by today’s most popular apps there is one thing you would find common among them and that is the use of NodeJS Framework. Yes, the NodeJS framework is that effective and successful.

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Aria Barnes

Aria Barnes

1622719015

Why use Node.js for Web Development? Benefits and Examples of Apps

Front-end web development has been overwhelmed by JavaScript highlights for quite a long time. Google, Facebook, Wikipedia, and most of all online pages use JS for customer side activities. As of late, it additionally made a shift to cross-platform mobile development as a main technology in React Native, Nativescript, Apache Cordova, and other crossover devices. 

Throughout the most recent couple of years, Node.js moved to backend development as well. Designers need to utilize a similar tech stack for the whole web project without learning another language for server-side development. Node.js is a device that adjusts JS usefulness and syntax to the backend. 

What is Node.js? 

Node.js isn’t a language, or library, or system. It’s a runtime situation: commonly JavaScript needs a program to work, however Node.js makes appropriate settings for JS to run outside of the program. It’s based on a JavaScript V8 motor that can run in Chrome, different programs, or independently. 

The extent of V8 is to change JS program situated code into machine code — so JS turns into a broadly useful language and can be perceived by servers. This is one of the advantages of utilizing Node.js in web application development: it expands the usefulness of JavaScript, permitting designers to coordinate the language with APIs, different languages, and outside libraries.

What Are the Advantages of Node.js Web Application Development? 

Of late, organizations have been effectively changing from their backend tech stacks to Node.js. LinkedIn picked Node.js over Ruby on Rails since it took care of expanding responsibility better and decreased the quantity of servers by multiple times. PayPal and Netflix did something comparative, just they had a goal to change their design to microservices. We should investigate the motivations to pick Node.JS for web application development and when we are planning to hire node js developers. 

Amazing Tech Stack for Web Development 

The principal thing that makes Node.js a go-to environment for web development is its JavaScript legacy. It’s the most well known language right now with a great many free devices and a functioning local area. Node.js, because of its association with JS, immediately rose in ubiquity — presently it has in excess of 368 million downloads and a great many free tools in the bundle module. 

Alongside prevalence, Node.js additionally acquired the fundamental JS benefits: 

  • quick execution and information preparing; 
  • exceptionally reusable code; 
  • the code is not difficult to learn, compose, read, and keep up; 
  • tremendous asset library, a huge number of free aides, and a functioning local area. 

In addition, it’s a piece of a well known MEAN tech stack (the blend of MongoDB, Express.js, Angular, and Node.js — four tools that handle all vital parts of web application development). 

Designers Can Utilize JavaScript for the Whole Undertaking 

This is perhaps the most clear advantage of Node.js web application development. JavaScript is an unquestionable requirement for web development. Regardless of whether you construct a multi-page or single-page application, you need to know JS well. On the off chance that you are now OK with JavaScript, learning Node.js won’t be an issue. Grammar, fundamental usefulness, primary standards — every one of these things are comparable. 

In the event that you have JS designers in your group, it will be simpler for them to learn JS-based Node than a totally new dialect. What’s more, the front-end and back-end codebase will be basically the same, simple to peruse, and keep up — in light of the fact that they are both JS-based. 

A Quick Environment for Microservice Development 

There’s another motivation behind why Node.js got famous so rapidly. The environment suits well the idea of microservice development (spilling stone monument usefulness into handfuls or many more modest administrations). 

Microservices need to speak with one another rapidly — and Node.js is probably the quickest device in information handling. Among the fundamental Node.js benefits for programming development are its non-obstructing algorithms.

Node.js measures a few demands all at once without trusting that the first will be concluded. Many microservices can send messages to one another, and they will be gotten and addressed all the while. 

Versatile Web Application Development 

Node.js was worked in view of adaptability — its name really says it. The environment permits numerous hubs to run all the while and speak with one another. Here’s the reason Node.js adaptability is better than other web backend development arrangements. 

Node.js has a module that is liable for load adjusting for each running CPU center. This is one of numerous Node.js module benefits: you can run various hubs all at once, and the environment will naturally adjust the responsibility. 

Node.js permits even apportioning: you can part your application into various situations. You show various forms of the application to different clients, in light of their age, interests, area, language, and so on. This builds personalization and diminishes responsibility. Hub accomplishes this with kid measures — tasks that rapidly speak with one another and share a similar root. 

What’s more, Node’s non-hindering solicitation handling framework adds to fast, letting applications measure a great many solicitations. 

Control Stream Highlights

Numerous designers consider nonconcurrent to be one of the two impediments and benefits of Node.js web application development. In Node, at whatever point the capacity is executed, the code consequently sends a callback. As the quantity of capacities develops, so does the number of callbacks — and you end up in a circumstance known as the callback damnation. 

In any case, Node.js offers an exit plan. You can utilize systems that will plan capacities and sort through callbacks. Systems will associate comparable capacities consequently — so you can track down an essential component via search or in an envelope. At that point, there’s no compelling reason to look through callbacks.

 

Final Words

So, these are some of the top benefits of Nodejs in web application development. This is how Nodejs is contributing a lot to the field of web application development. 

I hope now you are totally aware of the whole process of how Nodejs is really important for your web project. If you are looking to hire a node js development company in India then I would suggest that you take a little consultancy too whenever you call. 

Good Luck!

Original Source

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Vincent Lab

Vincent Lab

1605178380

How to Create a Command Line (CLI) Tool in Node.js

In this video I will show you how to turn a Node.js application into a command line tool application.

#command line #node.js #cli #command line interface #template generator #node.js cli

sophia tondon

sophia tondon

1625114985

Top 10 NodeJs app Development Companies- ValueCoders

Node.js is a prominent tech trend in the space of web and mobile application development. It has been proven very efficient and useful for a variety of application development. Thus, all business owners are eager to leverage this technology for creating their applications.

Are you striving to develop an application using Node.js? But can’t decide which company to hire for NodeJS app development? Well! Don’t stress over it, as the following list of NodeJS app development companies is going to help you find the best partner.

Let’s take a glance at top NodeJS application development companies to hire developers in 2021 for developing a mind-blowing application solution.

Before enlisting companies, I would like to say that every company has a foundation on which they thrive. Their end goals, qualities, and excellence define their competence. Thus, I prepared this list by considering a number of aspects. While making this list, I have considered the following aspects:

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  • Offered services
  • Year of experience (Average 8+ years)
  • Credibility & Excellence
  • Served clients and more

I believe this list will help you out in choosing the best NodeJS service provider company. So, now let’s explore the top NodeJS developer companies to choose from in 2021.

#1. JSGuru

JSGuru is a top-rated NodeJS app development company with an innovative team of dedicated NodeJS developers engaged in catering best-class UI/UX design, software products, and AWS professional services.

It is a team of one of the most talented developers to hire for all types of innovative solution development, including social media, dating, enterprise, and business-oriented solutions. The company has worked for years with a number of startups and launched a variety of products by collaborating with big-name corporations like T-systems.

If you want to hire NodeJS developers to secure an outstanding application, I would definitely suggest them. They serve in the area of eLearning, FinTech, eCommerce, Telecommunications, Mobile Device Management, and more.

  • Ratings: 4.9/5.0

  • Founded: 2006

  • Headquarters: Banja Luka, Bosnia, and Herzegovina

  • Price: Starting from $50/hour

Visit Website - https://www.valuecoders.com/blog/technology-and-apps/top-node-js-app-development-companies

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