Optional
cb: Callbackencoding Defaults to 'utf8'
.
mode Defaults to 0644
.
flag Defaults to 'a'
.
Optional
options: EncodingOption & { mode?: Mode | undefined; flag?: OpenMode | undefined; }Optional
cb: CallbackOptional
encoding: BufferEncodingOptional
cb: Callback
Asynchronously append data to a file, creating the file if it not yet exists.