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appendFileSync - node__fs.d.ts - Node documentation
function appendFileSync

Usage in Deno

```typescript import { appendFileSync } from "node:node__fs.d.ts"; ```
appendFileSync(
data: string | Uint8Array,
options?: WriteFileOptions,
): void
Synchronously append data to a file, creating the file if it does not yet exist. `data` can be a string or a `Buffer`. The `mode` option only affects the newly created file. See [open](../.././node__fs.d.ts/~/open) for more details. ```js import { appendFileSync } from 'node:fs'; try { appendFileSync('message.txt', 'data to append'); console.log('The "data to append" was appended to file!'); } catch (err) { // Handle the error } ``` If `options` is a string, then it specifies the encoding: ```js import { appendFileSync } from 'node:fs'; appendFileSync('message.txt', 'data to append', 'utf8'); ``` The `path` may be specified as a numeric file descriptor that has been opened for appending (using `fs.open()` or `fs.openSync()`). The file descriptor will not be closed automatically. ```js import { openSync, closeSync, appendFileSync } from 'node:fs'; let fd; try { fd = openSync('message.txt', 'a'); appendFileSync(fd, 'data to append', 'utf8'); } catch (err) { // Handle the error } finally { if (fd !== undefined) closeSync(fd); } ```

Parameters

filename or file descriptor
data: string | Uint8Array
optional
options: WriteFileOptions

Return Type

void