app.js

const express = require('express');
const os = require('os');

const app = express();

app.get('/', (req, res) => {
  res.send('Hello, Express.js!');
});

app.get('/about', (req, res) => {
  res.send('About page');
});

app.get('/users/:userId', (req, res) => {
  const userId = req.params.userId;
  res.send(`User ID: ${userId}`);
});

const PORT = process.env.PORT || 3000;

// Get local IP address
const networkInterfaces = os.networkInterfaces();
let localIpAddress = '';

Object.keys(networkInterfaces).forEach(interfaceName => {
  networkInterfaces[interfaceName].forEach(network => {
    if (network.family === 'IPv4' && !network.internal) {
      localIpAddress = network.address;
    }
  });
});

// If no local IP address found, fallback to localhost
if (!localIpAddress) {
  localIpAddress = 'localhost';
}

app.listen(PORT, localIpAddress, () => {
  console.log(`Server is running on http://${localIpAddress}:${PORT}`);
});