Command-line tools can help you with all sorts of tasks. This lesson covers the very basics of setting up a CLI tool in Node.js by creating your project with npm, setting up your bin script, and using CAC to parse a single argument.

 

Create a new project, change the "name" porp's value to "hi", then add a "bin" prop, so next time, when we invoke "hi", it will run the command in "bin".

package.json

{  "name": "hi",  "version": "1.0.0",  "description": "",  "main": "index.js",  "scripts": {    "test": "echo \"Error: no test specified\" && exit 1"  },  "keywords": [],  "author": "",  "license": "ISC",  "bin": "./index.js",  "devDependencies": {    "cac": "6.3.12"  }}

 

Install:

npm i -D cac

 

Create index.js file:

• Make sure you have '

  #!/usr/bin/env node

  ' on the top of the file, then it knows should run in node env.
• Using to build commad, you can define 'option', 'command'
• Last you should always call cli.parse() to run the command

#!/usr/bin/env nodeconst cli = require('cac')();cli.option('--type 
     
      ', 'Provide type, [date|foo]')// name is a required fieldcli.command('
      
       ', 'Provide your name')    .action((name, options) => {        const {type} = options;        if (type === 'date') {            console.log(`Hi ${name}, Today is ${
   new Date().toDateString()}`)        } else if (type === 'foo') {            console.log(`Hi ${name}, you should take a rest!`)        } else {            console.log(`Hi ${name}, Good job!`)        }            })cli.help()// Display version number when `-h` or `--help` appearscli.version('0.0.0')cli.parse()
      
     

 

Run: