TODO find documentation

File is visible to the calling process. This is useful for determining if a file exists, but says nothing about rwx permissions. Default if no mode is specified.

Flag indicating that data will be appended to the end of the file.

Flag indicating to create the file if it does not already exist.

When set, an attempt will be made to minimize caching effects of file I/O.

Flag indicating that the open should fail if the path is not a directory.

Flag indicating that opening a file should fail if the O_CREAT flag is set and the file already exists.

Flag indicating reading accesses to the file system will no longer result in an update to the atime information associated with the file. This flag is available on Linux operating systems only.

Flag indicating that if path identifies a terminal device, opening the path shall not cause that terminal to become the controlling terminal for the process (if the process does not already have one).

Flag indicating that the open should fail if the path is a symbolic link.

Flag indicating to open the file in nonblocking mode when possible.

Flag indicating to open a file for read-only access.

Flag indicating to open a file for read-write access.

Flag indicating to open the symbolic link itself rather than the resource it is pointing to.

Flag indicating that the file is opened for synchronous I/O.

Flag indicating that if the file exists and is a regular file, and the file is opened successfully for write access, its length shall be truncated to zero.

Flag indicating to open a file for write-only access.

File can be read by the calling process.

TODO find documentation

File type constant for a block-oriented device file.

File type constant for a character-oriented device file.

File type constant for a directory.

File type constant for a FIFO/pipe.

File type constant for a symbolic link.

Bit mask used to extract the file type code.

File type constant for a regular file.

File type constant for a socket.

File can be written by the calling process.

TODO find documentation

File can be executed by the calling process. This has no effect on Windows (will behave like fs.F_OK).

Tests a user's permissions for the file specified by path. mode is an optional integer that specifies the accessibility checks to be performed. The following constants define the possible values of mode. It is possible to create a mask consisting of the bitwise OR of two or more values.

• fs.F_OK - File is visible to the calling process. This is useful for determining if a file exists, but says nothing about rwx permissions. Default if no mode is specified.
• fs.R_OK - File can be read by the calling process.
• fs.W_OK - File can be written by the calling process.
• fs.X_OK - File can be executed by the calling process. This has no effect on Windows (will behave like fs.F_OK).

Tests a user's permissions for the file specified by path. mode is an optional integer that specifies the accessibility checks to be performed. The following constants define the possible values of mode. It is possible to create a mask consisting of the bitwise OR of two or more values.

• fs.F_OK - File is visible to the calling process. This is useful for determining if a file exists, but says nothing about rwx permissions. Default if no mode is specified.
• fs.R_OK - File can be read by the calling process.
• fs.W_OK - File can be written by the calling process.
• fs.X_OK - File can be executed by the calling process. This has no effect on Windows (will behave like fs.F_OK).

Synchronous version of fs.access(). This throws if any accessibility checks fail, and does nothing otherwise.

Alias for emitter.on(eventName, listener).

Asynchronously append data to a file, creating the file if it does not yet exist. data can be a string or a buffer.

Asynchronously append data to a file, creating the file if it does not yet exist. data can be a string or a buffer.

Asynchronous close(2). No arguments other than a possible exception are given to the completion callback.

Synchronous close(2). Returns undefined.

Returns a new ReadStream object. (See Readable Stream).vBe aware that, unlike the default value set for highWaterMark on a readable stream (16 kb), the stream returned by this method has a default value of 64 kb for the same parameter.

Returns a new WriteStream object.

Synchronously calls each of the listeners registered for the event named eventName, in the order they were registered, passing the supplied arguments to each.

Returns true if the event had listeners, false otherwise.

Asynchronous fchmod(2). No arguments other than a possible exception are given to the completion callback.

Synchronous fchmod(2). Returns undefined.

Asynchronous fdatasync(2). No arguments other than a possible exception are given to the completion callback.

Synchronous fdatasync(2). Returns undefined.

Change the file timestamps of a file referenced by the supplied file descriptor.

Synchronous version of fs.futimes(). Returns undefined.

Returns the current max listener value for the EventEmitter which is either set by emitter.setMaxListeners(n) or defaults to EventEmitter.defaultMaxListeners.

Asynchronous lchmod(2). No arguments other than a possible exception are given to the completion callback.

Synchronous lchmod(2). Returns undefined.

Asynchronous lchown(2). No arguments other than a possible exception are given to the completion callback.

Synchronous chown(2). Returns undefined.

Asynchronous link(2). No arguments other than a possible exception are given to the completion callback.

Returns the number of listeners listening to the event named eventName.

Returns a copy of the array of listeners for the event named eventName.

Asynchronous mkdir(2). No arguments other than a possible exception are given to the completion callback. mode defaults to 0o777.

Asynchronous mkdir(2). No arguments other than a possible exception are given to the completion callback. mode defaults to 0o777.

Adds the listener function to the end of the listeners array for the event named eventName. No checks are made to see if the listener has already been added. Multiple calls passing the same combination of eventName and listener will result in the listener being added, and called, multiple times.

Returns a reference to the EventEmitter so calls can be chained.

Adds a one time listener function for the event named eventName. This listener is invoked only the next time eventName is triggered, after which it is removed.

Asynchronously reads the entire contents of a file.

Asynchronously reads the entire contents of a file.

Synchronous version of fs.readFile. Returns the contents of the file. If the encoding option is specified then this function returns a string. Otherwise it returns a buffer.

Synchronous version of fs.readFile. Returns the contents of the file. If the encoding option is specified then this function returns a string. Otherwise it returns a buffer.

Synchronous version of fs.readFile. Returns the contents of the file. If the encoding option is specified then this function returns a string. Otherwise it returns a buffer.

Asynchronous realpath(2). The callback gets two arguments (err, resolvedPath). May use process.cwd to resolve relative paths.

The optional options argument can be a string specifying an encoding, or an object with an encoding property specifying the character encoding to use for the path passed to the callback. If the encoding is set to 'buffer', the path returned will be passed as a Buffer object.

Asynchronous realpath(2). The callback gets two arguments (err, resolvedPath). May use process.cwd to resolve relative paths.

The optional options argument can be a string specifying an encoding, or an object with an encoding property specifying the character encoding to use for the path passed to the callback. If the encoding is set to 'buffer', the path returned will be passed as a Buffer object.

Removes all listeners, or those of the specified eventName.

Note that it is bad practice to remove listeners added elsewhere in the code, particularly when the EventEmitter instance was created by some other component or module (e.g. sockets or file streams).

Returns a reference to the EventEmitter so calls can be chained.

Removes all listeners, or those of the specified eventName.

Note that it is bad practice to remove listeners added elsewhere in the code, particularly when the EventEmitter instance was created by some other component or module (e.g. sockets or file streams).

Returns a reference to the EventEmitter so calls can be chained.

Removes the specified listener from the listener array for the event named eventName. removeListener will remove, at most, one instance of a listener from the listener array. If any single listener has been added multiple times to the listener array for the specified eventName, then removeListener must be called multiple times to remove each instance.

Note that once an event has been emitted, all listeners attached to it at the time of emitting will be called in order. This implies that any removeListener() or removeAllListeners() calls after emitting and before the last listener finishes execution will not remove them from emit() in progress. Subsequent events will behave as expected.

Asynchronous rename(2). No arguments other than a possible exception are given to the completion callback.

Synchronous rename(2). Returns undefined.

Asynchronous rmdir(2). No arguments other than a possible exception are given to the completion callback.

Synchronous rmdir(2). Returns undefined.

By default EventEmitters will print a warning if more than 10 listeners are added for a particular event. This is a useful default that helps finding memory leaks. Obviously, not all events should be limited to just 10 listeners. The emitter.setMaxListeners() method allows the limit to be modified for this specific EventEmitter instance. The value can be set to Infinity (or 0) for to indicate an unlimited number of listeners.

Returns a reference to the EventEmitter so calls can be chained.

Asynchronous stat(2). The callback gets two arguments (err, stats) where stats is a fs.Stats object. See the fs.Stats section for more information.

Synchronous stat(2). Returns an instance of fs.Stats.

Asynchronous symlink(2). No arguments other than a possible exception are given to the completion callback. The type argument can be set to 'dir', 'file', or 'junction' (default is 'file') and is only available on Windows (ignored on other platforms). Note that Windows junction points require the destination path to be absolute. When using 'junction', the target argument will automatically be normalized to absolute path.

Asynchronous symlink(2). No arguments other than a possible exception are given to the completion callback. The type argument can be set to 'dir', 'file', or 'junction' (default is 'file') and is only available on Windows (ignored on other platforms). Note that Windows junction points require the destination path to be absolute. When using 'junction', the target argument will automatically be normalized to absolute path.

Synchronous symlink(2). Returns undefined.

Asynchronous unlink(2). No arguments other than a possible exception are given to the completion callback.

Synchronous unlink(2). Returns undefined.

Stop watching for changes on filename. If listener is specified, only that particular listener is removed. Otherwise, all listeners are removed and you have effectively stopped watching filename.

Calling fs.unwatchFile() with a filename that is not being watched is a no-op, not an error.

Note: fs.watch() is more efficient than fs.watchFile() and fs.unwatchFile(). fs.watch() should be used instead of fs.watchFile() and fs.unwatchFile() when possible.

Change file timestamps of the file referenced by the supplied path.

Note: the arguments atime and mtime of the following related functions does follow the below rules:

If the value is a numberable string like '123456789', the value would get converted to corresponding number. If the value is NaN or Infinity, the value would get converted to Date.now().

Synchronous version of fs.utimes(). Returns undefined.

Watch for changes on filename, where filename is either a file or a directory. The returned object is a fs.FSWatcher.

The second argument is optional. If options is provided as a string, it specifies the encoding. Otherwise options should be passed as an object.

The listener callback gets two arguments (event, filename). event is either 'rename' or 'change', and filename is the name of the file which triggered the event.

Watch for changes on filename, where filename is either a file or a directory. The returned object is a fs.FSWatcher.

The second argument is optional. If options is provided as a string, it specifies the encoding. Otherwise options should be passed as an object.

The listener callback gets two arguments (event, filename). event is either 'rename' or 'change', and filename is the name of the file which triggered the event.

Watch for changes on filename, where filename is either a file or a directory. The returned object is a fs.FSWatcher.

The second argument is optional. If options is provided as a string, it specifies the encoding. Otherwise options should be passed as an object.

The listener callback gets two arguments (event, filename). event is either 'rename' or 'change', and filename is the name of the file which triggered the event.

Asynchronously writes data to a file, replacing the file if it already exists. data can be a string or a buffer. The encoding option is ignored if data is a buffer. It defaults to 'utf8'

Asynchronously writes data to a file, replacing the file if it already exists. data can be a string or a buffer. The encoding option is ignored if data is a buffer. It defaults to 'utf8'

The synchronous version of fs.writeFile(). Returns undefined.

Test whether or not the given path exists by checking with the file system. Then call the callback argument with either true or false.

fs.exists() should not be used to check if a file exists before calling fs.open(). Doing so introduces a race condition since other processes may change the file's state between the two calls. Instead, user code should call fs.open() directly and handle the error raised if the file is non-existent.