How do I pass command line arguments to a Node.js program?

Question

I have a web server written in Node.js and I would like to launch with a specific folder. I\'m not sure how to access arguments in JavaScript. I\'m running node like this:

Answer 1

No Libs with Flags Formatted into a Simple Object

function getArgs () {
    const args = {};
    process.argv
        .slice(2, process.argv.length)
        .forEach( arg => {
        // long arg
        if (arg.slice(0,2) === '--') {
            const longArg = arg.split('=');
            const longArgFlag = longArg[0].slice(2,longArg[0].length);
            const longArgValue = longArg.length > 1 ? longArg[1] : true;
            args[longArgFlag] = longArgValue;
        }
        // flags
        else if (arg[0] === '-') {
            const flags = arg.slice(1,arg.length).split('');
            flags.forEach(flag => {
            args[flag] = true;
            });
        }
    });
    return args;
}
const args = getArgs();
console.log(args);

Examples

Simple

input

node test.js -D --name=Hello

output

{ D: true, name: 'Hello' }

Real World

input

node config/build.js -lHRs --ip=$HOST --port=$PORT --env=dev

output

{ 
  l: true,
  H: true,
  R: true,
  s: true,
  ip: '127.0.0.1',
  port: '8080',
  env: 'dev'
}