Interface CacheFs

Returns true if the path exists, false otherwise.

For detailed information, see the documentation of the asynchronous version of this API: exists.

fs.exists() is deprecated, but fs.existsSync() is not. The callback parameter to fs.exists() accepts parameters that are inconsistent with other Node.js callbacks. fs.existsSync() does not use a callback.

import { existsSync } from 'node:fs';

if (existsSync('/etc/passwd'))
  console.log('The path exists.');
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Since

v0.1.21

Asynchronously reads the entire contents of a file.

If no encoding is specified (using options.encoding), the data is returned as a Buffer object. Otherwise, the data will be a string.

If options is a string, then it specifies the encoding.

When the path is a directory, the behavior of fsPromises.readFile() is platform-specific. On macOS, Linux, and Windows, the promise will be rejected with an error. On FreeBSD, a representation of the directory's contents will be returned.

An example of reading a package.json file located in the same directory of the running code:

import { readFile } from 'node:fs/promises';
try {
  const filePath = new URL('./package.json', import.meta.url);
  const contents = await readFile(filePath, { encoding: 'utf8' });
  console.log(contents);
} catch (err) {
  console.error(err.message);
}
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It is possible to abort an ongoing readFile using an AbortSignal. If a request is aborted the promise returned is rejected with an AbortError:

import { readFile } from 'node:fs/promises';

try {
  const controller = new AbortController();
  const { signal } = controller;
  const promise = readFile(fileName, { signal });

  // Abort the request before the promise settles.
  controller.abort();

  await promise;
} catch (err) {
  // When a request is aborted - err is an AbortError
  console.error(err);
}
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Aborting an ongoing request does not abort individual operating system requests but rather the internal buffering fs.readFile performs.

Any specified FileHandle has to support reading.

Since

v10.0.0

Asynchronously reads the entire contents of a file.

Asynchronously reads the entire contents of a file.

Returns the contents of the path.

For detailed information, see the documentation of the asynchronous version of this API: readFile.

If the encoding option is specified then this function returns a string. Otherwise it returns a buffer.

Similar to readFile, when the path is a directory, the behavior of fs.readFileSync() is platform-specific.

import { readFileSync } from 'node:fs';

// macOS, Linux, and Windows
readFileSync('<directory>');
// => [Error: EISDIR: illegal operation on a directory, read <directory>]

//  FreeBSD
readFileSync('<directory>'); // => <data>
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Since

v0.1.8

Synchronously reads the entire contents of a file.

Synchronously reads the entire contents of a file.