Reading & Writing Files
fs.readFile(), POORI, FILE, ko, MEMORY, mein, LOAD, karta hai, PHIR, CALLBACK, ko, PASS, karta hai — CHHOTI, FILES, ke, liye, IDEAL, hai. BADI, FILES, ke, liye, STREAMS, USE, karna, BEHTAR, hai (MEMORY, EFFICIENT).
fs.writeFile(), EK, FILE, ko, OVERWRITE, karta hai (YA, NAYI, BANATA, hai, AGAR, EXIST, NAHI, karti). fs.appendFile(), EXISTING, CONTENT, ke, ANT, mein, DATA, ADD, karta hai, WITHOUT, OVERWRITE, kiye.
const fs = require("fs/promises");
async function processFile() {
const data = await fs.readFile("input.txt", "utf8");
const processed = data.toUpperCase();
await fs.writeFile("output.txt", processed);
await fs.appendFile("log.txt", "Processing complete\n");
}- readFile() = poori, file, MEMORY, mein, load, karta hai — chhoti, files, ke, liye, IDEAL
- writeFile() = overwrite, appendFile() = existing, content, ke, ANT, mein, ADD
- encoding ("utf8") na, dene, par, Buffer, return, hota hai, string, nahi
fs.writeFile(), THIRD, ARGUMENT, ke, roop, mein, OPTIONS, LETA, hai — flag: "a" (append), "wx" (write, sirf, agar, file, EXIST, nahi, karti — overwrite, se, BACHата, hai). mode, se, FILE, PERMISSIONS, (jaise, 0o644) SET, kiye, ja, sakte, HAIN.
fs.writeFile("log.txt", "entry\n", { flag: "a" }, callback);
// "wx" flag — file, already, exist, karne, PAR, ERROR, throw, karegafs.mkdir(), { recursive: true } OPTION, ke, saath, NESTED, DIRECTORIES, EK, HI, CALL, mein, banaता hai — WARNA, HAR, PARENT, DIRECTORY, ko, MANUALLY, CHECK/CREATE, karna, PADТA hai.