Asynchronously append data to a file, creating the file if it does not yet exist. data can be a string or a Buffer.
data
Buffer
If options is a string, then it specifies the encoding.
options
encoding
The mode option only affects the newly created file. See fs.open() for more details.
mode
fs.open()
The path may be specified as a FileHandle that has been opened for appending (using fsPromises.open()).
path
FileHandle
fsPromises.open()
filename or {FileHandle}
Optional
Fulfills with undefined upon success.
undefined
v10.0.0
Asynchronously append data to a file, creating the file if it does not yet exist.
datacan be a string or aBuffer.If
optionsis a string, then it specifies theencoding.The
modeoption only affects the newly created file. Seefs.open()for more details.The
pathmay be specified as aFileHandlethat has been opened for appending (usingfsPromises.open()).