Node.js File System (fs Module)

const fs = require("node:fs");

// Callback style
fs.readFile("data.txt", "utf8", (err, data) => {
  if (err) {
    console.error("ফাইল পড়তে সমস্যা:", err);
    return;
  }
  console.log("ফাইলের content:", data);
});

const fs = require("node:fs").promises;

async function readFile() {
  try {
    const data = await fs.readFile("data.txt", "utf8");
    console.log(data);
  } catch (error) {
    console.error("ত্রুটি:", error.message);
  }
}

readFile();

const fs = require("node:fs").promises;

async function writeFile() {
  // নতুন ফাইল তৈরি / পুরোনো overwrite
  await fs.writeFile("output.txt", "Hello Node.js!", "utf8");
  console.log("ফাইল লেখা হয়েছে!");

  // append — শুধু যোগ করা
  await fs.appendFile("output.txt", "\nনতুন লাইন", "utf8");
}

writeFile();

const fs = require("node:fs").promises;

async function createFolders() {
  // single folder
  await fs.mkdir("uploads");

  // nested folders (recursive)
  await fs.mkdir("uploads/images/2024", { recursive: true });
}

createFolders();

const fs = require("node:fs").promises;

async function deleteFiles() {
  // ফাইল মুছে ফেলা
  await fs.unlink("output.txt");
  console.log("ফাইল মুছে ফেলা হয়েছে");

  // ফোল্ডার মুছে ফেলা (recursive)
  await fs.rm("uploads", { recursive: true, force: true });
  console.log("ফোল্ডার মুছে ফেলা হয়েছে");
}

deleteFiles();

const fs = require("node:fs").promises;

async function fileOperations() {
  // ফাইল আছে কিনা দেখুন
  try {
    await fs.access("data.txt");
    console.log("ফাইল আছে!");
  } catch {
    console.log("ফাইল নেই!");
  }

  // rename
  await fs.rename("old.txt", "new.txt");

  // stat — ফাইলের info
  const stats = await fs.stat("package.json");
  console.log("সাইজ:", stats.size, "bytes");
  console.log("ধরন:", stats.isFile() ? "ফাইল" : "ফোল্ডার");
}

fileOperations();

const fs = require("node:fs").promises;

async function listFiles() {
  const files = await fs.readdir(".");
  console.log("সব ফাইল:", files);

  // nested files
  const allFiles = await fs.readdir(".", {
    recursive: true,
    withFileTypes: true,
  });
  allFiles.forEach((item) => {
    console.log(item.name, item.isDirectory() ? "📁" : "📄");
  });
}

listFiles();