Yaya kake aiki tare da tsarin fayil a Node?

Question

Accepted Answer

Modalu `fs` na gida ya karanta kuma ya rubuta fayilai da jerin fayilai. Yana ba da sassa uku na API — **promises** (sabunta, an fi so), **callbacks** (asali async), da **sync** (dakewa) — saboda haka kana iya zaɓar daidaita gida ga yanayin.

## Promise API (an ba da shawara)

```js
import { readFile, writeFile, mkdir, readdir } from "fs/promises";

async function work() {
  const data = await readFile("input.txt", "utf8");     // read (utf8 → string)
  await writeFile("output.txt", "Hello");                // write (overwrites)
  await mkdir("new-dir", { recursive: true });           // create dirs (recursive = mkdir -p)
  const files = await readdir("./");                      // list directory contents
}
```

API `fs/promises` yana aiki sosai tare da async/await — zaɓen sabunta don I/O fayil.

## Callback da sync bambantai

```js
import fs from "fs";

fs.readFile("file.txt", "utf8", (err, data) => { ... }); // async callback
const data = fs.readFileSync("file.txt", "utf8");         // SYNC — blocks the event loop!
```

**Gargaɗi:** `*Sync` hanyoyi **dakewa dukkanin sararin aiki** har sai an kammala aiki. Suna da kyau a farawa (lodi saita sau ɗaya kawai) amma ya kamata a gudu dasu a masu sarrafa buɗi — karantsewar dakewa tana dakewa dukkan buɗe-buɗe buɗi.

## Ayyukan gida

```js
await fs.promises.appendFile("log.txt", "new line
"); // append
await fs.promises.unlink("old.txt");                    // delete a file
await fs.promises.rename("a.txt", "b.txt");             // rename/move
const stats = await fs.promises.stat("file.txt");       // metadata (size, mtime)
const exists = fs.existsSync("file.txt");               // check existence
```

## Don manyan fayilai: yi amfani da streams

```js
// ❌ readFile loads the WHOLE file into memory — bad for huge files
const huge = await readFile("10gb.txt"); // could exhaust memory

// ✅ stream it in chunks (constant memory)
fs.createReadStream("10gb.txt").pipe(fs.createWriteStream("copy.txt"));
```

Don manyan fayilai, `readFile` za a loda komai a ajiya a jiya; **streams** saka data a yankuna tare da ajiya mai taba.

## Me ya sa ya zama muhimmi

File I/O shine ƴancin kakakin Node don lodi saita, narkewa, haɗi/saki fayilai, da aikin kayan gida.

Sanin sassa uku na API — kuma mahimmanci, cewa **sync hanyoyi dakewa sararin aiki** (gudu dasu a sarrafa mai sarrafa) da cewa **manyan fayilai suna buƙatar streams** (ba `readFile`) — shine mahimmanci don rubuta code na damre-damre fayil wanda daidai ne kuma aiki mai inganci a ƙarƙashi ƙarƙashi.

API promise tare da async/await shine sikin sifi na sassaucin aiki na yau da gida.