* `path` {string|Buffer|URL}

* `callback` {Function}

Tests a user's permissions for the file or directory specified by `path`.

* `path` {string|Buffer|URL}

Synchronous version of [`fs.access()`][]. This throws if any accessibility

checks fail, and does nothing otherwise.

* `file` {string|Buffer|number} filename or file descriptor

* `data` {string|Buffer}

* `options` {Object|string}

* `callback` {Function}

Asynchronously append data to a file, creating the file if it does not yet exist.

* `file` {string|Buffer|number} filename or file descriptor

* `data` {string|Buffer}

* `options` {Object|string}

The synchronous version of [`fs.appendFile()`][]. Returns `undefined`.

Synchronous fsync(2). Returns `undefined`.

* `fd` {integer}

* `callback` {Function}

Asynchronous ftruncate(2). No arguments other than a possible exception are

The last three bytes are null bytes ('\0'), to compensate the over-truncation.

* `fd` {integer}

Synchronous ftruncate(2). Returns `undefined`.

* `path` {string|Buffer|URL}

* `callback` {Function}

Asynchronous mkdir(2). No arguments other than a possible exception are given

* `path` {string|Buffer|URL}

Synchronous mkdir(2). Returns `undefined`.

* `prefix` {string}

* `options` {string|Object}

* `callback` {Function}

Creates a unique temporary directory.

* `prefix` {string}

* `options` {string|Object}

The synchronous version of [`fs.mkdtemp()`][]. Returns the created

folder path.

* `path` {string|Buffer|URL}

* `flags` {string|number}

* `callback` {Function}

Asynchronous file open. See open(2). `flags` can be:

* `'ax+'` - Like `'a+'` but fails if `path` exists.

`mode` sets the file mode (permission and sticky bits), but only if the file was

The callback gets two arguments `(err, fd)`.

* `path` {string|Buffer|URL}

* `flags` {string|number}

Synchronous version of [`fs.open()`][]. Returns an integer representing the file

descriptor.

* `path` {string|Buffer|URL}

* `options` {string|Object}

* `callback` {Function}

Asynchronous readdir(3). Reads the contents of a directory.

* `path` {string|Buffer|URL}

* `options` {string|Object}

Synchronous readdir(3). Returns an array of filenames excluding `'.'` and

`'..'`.

* `path` {string|Buffer|URL|integer} filename or file descriptor

* `options` {Object|string}

* `callback` {Function}

Asynchronously reads the entire contents of a file. Example:

* `path` {string|Buffer|URL|integer} filename or file descriptor

* `options` {Object|string}

Synchronous version of [`fs.readFile()`][]. Returns the contents of the `path`.

* `path` {string|Buffer|URL}

* `options` {string|Object}

* `callback` {Function}

Asynchronous readlink(2). The callback gets two arguments `(err,

* `path` {string|Buffer|URL}

* `options` {string|Object}

Synchronous readlink(2). Returns the symbolic link's string value.

* `path` {string|Buffer|URL}

* `options` {string|Object}

* `callback` {Function}

Asynchronous realpath(3). The `callback` gets two arguments `(err,

* `path` {string|Buffer|URL}

* `options` {string|Object}

Synchronous realpath(3). Returns the resolved path.

* `target` {string|Buffer|URL}

* `path` {string|Buffer|URL}

* `callback` {Function}

Asynchronous symlink(2). No arguments other than a possible exception are given

* `target` {string|Buffer|URL}

* `path` {string|Buffer|URL}

Synchronous symlink(2). Returns `undefined`.

* `path` {string|Buffer}

* `callback` {Function}

Asynchronous truncate(2). No arguments other than a possible exception are

given to the completion callback. A file descriptor can also be passed as the

first argument. In this case, `fs.ftruncate()` is called.

* `path` {string|Buffer}

Synchronous truncate(2). Returns `undefined`. A file descriptor can also be

passed as the first argument. In this case, `fs.ftruncateSync()` is called.

* `filename` {string|Buffer}

Stop watching for changes on `filename`. If `listener` is specified, only that

particular listener is removed. Otherwise, *all* listeners are removed,

* `filename` {string|Buffer|URL}

* `options` {string|Object}

* `persistent` {boolean} Indicates whether the process should continue to run

* `recursive` {boolean} Indicates whether all subdirectories should be

watched, or only the current directory. This applies when a directory is

`false`

* `encoding` {string} Specifies the character encoding to be used for the

Watch for changes on `filename`, where `filename` is either a file or a

directory. The returned object is a [`fs.FSWatcher`][].

* `filename` {string|Buffer|URL}

* `options` {Object}

* `listener` {Function}

Watch for changes on `filename`. The callback `listener` will be called each

* `file` {string|Buffer|integer} filename or file descriptor

* `data` {string|Buffer|Uint8Array}

* `options` {Object|string}

* `callback` {Function}

Asynchronously writes data to a file, replacing the file if it already exists.

* `file` {string|Buffer|integer} filename or file descriptor

* `data` {string|Buffer|Uint8Array}

* `options` {Object|string}

The synchronous version of [`fs.writeFile()`][]. Returns `undefined`.