// Verify file exists fs.stat(filePath, (err, stats) => 'application/octet-stream'; const fileSize = stats.size;
function resolveSafeFile(requestedName) // Prevent path‑traversal (../) attacks const safeName = path.basename(requestedName); const absolutePath = path.join(FILE_ROOT, safeName); if (!absolutePath.startsWith(FILE_ROOT)) throw new Error('Invalid file path'); return absolutePath; DOWNLOAD FILE - Transpile Girl Rescue Operation...
/* Button */ .download-btn display: inline-flex; align-items: center; gap: .5rem; padding: .75rem 1.5rem; font-size: 1rem; font-weight: 600; color: #fff; background: #0069d9; border: none; border-radius: .4rem; cursor: pointer; transition: background .2s; // Verify file exists fs
.hidden display: none; script.js
| Part | What it does | Files/Code | |------|--------------|------------| | | A nice button that the user clicks to start the download. | index.html , style.css | | Client‑side logic | Handles the click, shows a spinner, and reports errors. | script.js | | Server‑side endpoint | Streams the requested file with correct MIME type, proper caching headers, and range‑request support. | server.js (Node + Express) | | Security & best‑practice checklist | Prevents path‑traversal, enforces authentication, logs activity, etc. | – | 1️⃣ UI – a single “DOWNLOAD FILE” button index.html | server
// --------------------------------------------------------------- // 3️⃣ Helper – safely resolve a file inside a designated folder // --------------------------------------------------------------- const FILE_ROOT = path.resolve(__dirname, 'files'); // <--- put your .zip/.pdf/.docx here
// --------------------------------------------------------------- // 1️⃣ Boilerplate – bring in the required modules // --------------------------------------------------------------- const express = require('express'); const path = require('path'); const fs = require('fs'); const mime = require('mime-types'); // npm i mime-types const app = express(); const PORT = process.env.PORT || 3000;
