Create first command line application using nodeJs

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In this tutorial i am going to create a very simple command line application using nodeJs, Nodejs provide great flexibility to create command line application, express-geenrator and nodemon are the best CLI example in nodeJs.

I am going to create a custom command line HelloCli application where i’ll run hello [GIVEN_NAME] in terminal and it’ll return message in terminal like this:-
Hello [GIVEN_NAME],
How are you..!!

Ok Lets start the tutorial step by step

Create your application package.json file

package.json

{
  "name": "HelloCLI",
  "version": "10.0.1",
  "description": "First CLI App",
  "dependencies": {},
  "bin": {
    "hello": "hellocli.js"
  }
}

Where 

"bin": {
    "hello": "hellocli.js"
  }

This syntax help node to execute given file like command, So hellocli.js is your custom command file & hello is your custom command you’ll run on terminal

"bin": {
    "COMMAND_NAME": "FILE_NAME"
  }




After that create your CLI file

hellocli.js

#!/usr/bin/env node
console.log("Hello, ",process.argv[2]);
console.log("How are you");

Note: Don’t forget to include #!/usr/bin/env node on the top of the page, this one line tells system that it’s a batch file and act like command.

Now install your command global by running below command.

sudo npm install -g

See below screen shot for output in action.

cli

Thanks 🙂

Published by Rohit