built-in-module.js

//Built - In Modules - Node has some modules that very smart people created and are included with node. These modules are known as
// built in modules . There are many built - in modules in Node.js. The basic and important built in modules which will be covered in
//this file are OS, HTTPS, FS and PATH

// OS MODULE
const os = require('os');

//Finding our user info
const user = os.userInfo();
console.log(user);
console.log(`Hello How can I help you ${user.username}`);

//Finding out the system uptime
console.log(`The system uptime is ${(os.uptime())/60} minutes`);

//Creating an OS Object
const currentOS = {
    name: os.type(),
    release : os.release(),
    totalMem: os.totalmem(),
    freeMem: os.freemem(),
}
console.log(currentOS);

//PATH MODULE

const path = require('path');

console.log(path.sep); // Will print the URL separator , which is different for different platforms
console.log(path.join(__dirname, '/Hello/')); // It will print the URL with the arguments by cleaning it and using its separator
console.log(path.basename(__dirname));

const absolute = path.resolve(__dirname,__filename , '/variables.js//');
console.log(absolute);

//File System Module (FS ( Sync ))

const {readFileSync, writeFileSync} = require('fs');

const firstTxt = readFileSync('./fileSystemContent/first.text', 'utf8');
console.log(firstTxt);

const randomParagraph = "As she sat watching the world go by, something caught her eye. It wasn't so much its color or shape, but the way it was moving. She squinted to see if she could better understand what it was and where it was going, but it didn't help. As she continued to stare into the distance, she didn't understand why this uneasiness was building inside her body. She felt like she should get up and run. If only she could make out what it was. At that moment, she comprehended what it was and where it was heading, and she knew her life would never be the same. This paragraph has been written by JS using the built in file system module "

writeFileSync('./fileSystemContent/result.txt', randomParagraph, {flag: 'a'});

//HTTPS Module - is used to set up servers and API's
// We will import the https module

const http = require('http');

const server = http.createServer((req, res) => {
    if (req.url === '/') {
        res.end('Welcome to the Home Page');
    }
    else if (req.url === '/about') { // Use else if here
        res.end('Welcome to the about page');
    }
    else {
        res.end(`
            <h1>OOPS..</h1>
            <p>This page hasn't been yet created...</p>
        `);
    }
});

server.listen(5000);