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open - fs - Node documentation
function open

Usage in Deno

import { open } from "node:fs";
open(
path: PathLike,
flags: OpenMode | undefined,
mode:
Mode
| undefined
| null
,
callback: (
err: ErrnoException | null,
fd: number,
) => void,
): void

Asynchronous file open. See the POSIX open(2) documentation for more details.

mode sets the file mode (permission and sticky bits), but only if the file was created. On Windows, only the write permission can be manipulated; see chmod.

The callback gets two arguments (err, fd).

Some characters (< > : " / \ | ? *) are reserved under Windows as documented by Naming Files, Paths, and Namespaces. Under NTFS, if the filename contains a colon, Node.js will open a file system stream, as described by this MSDN page.

Functions based on fs.open() exhibit this behavior as well:fs.writeFile(), fs.readFile(), etc.

Parameters

path: PathLike
optional
flags: OpenMode | undefined = 'r'

See support of file system flags``.

optional
mode:
Mode
| undefined
| null
 = 0o666
callback: (
err: ErrnoException | null,
fd: number,
) => void

Return Type

void
open(
path: PathLike,
flags: OpenMode | undefined,
callback: (
err: ErrnoException | null,
fd: number,
) => void,
): void

Asynchronous open(2) - open and possibly create a file. If the file is created, its mode will be 0o666.

Parameters

path: PathLike

A path to a file. If a URL is provided, it must use the file: protocol.

optional
flags: OpenMode | undefined = 'r'

See support of file system flags``.

callback: (
err: ErrnoException | null,
fd: number,
) => void

Return Type

void
open(
path: PathLike,
callback: (
err: ErrnoException | null,
fd: number,
) => void,
): void

Asynchronous open(2) - open and possibly create a file. If the file is created, its mode will be 0o666.

Parameters

path: PathLike

A path to a file. If a URL is provided, it must use the file: protocol.

callback: (
err: ErrnoException | null,
fd: number,
) => void

Return Type

void