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}`); });