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

    The mode option only affects the newly created file. See open for more details.

    import { appendFile } from 'fs';

    appendFile('message.txt', 'data to append', (err) => {
    if (err) throw err;
    console.log('The "data to append" was appended to file!');
    });

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

    import { appendFile } from 'fs';

    appendFile('message.txt', 'data to append', 'utf8', callback);

    The path may be specified as a numeric file descriptor that has been opened for appending (using fs.open() or fs.openSync()). The file descriptor will not be closed automatically.

    import { open, close, appendFile } from 'fs';

    function closeFd(fd) {
    close(fd, (err) => {
    if (err) throw err;
    });
    }

    open('message.txt', 'a', (err, fd) => {
    if (err) throw err;

    try {
    appendFile(fd, 'data to append', 'utf8', (err) => {
    closeFd(fd);
    if (err) throw err;
    });
    } catch (err) {
    closeFd(fd);
    throw err;
    }
    });

    Since

    v0.6.7

    Parameters

    Returns void

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

    Parameters

    • file: PathOrFileDescriptor

      A path to a file. If a URL is provided, it must use the file: protocol. If a file descriptor is provided, the underlying file will not be closed automatically.

    • data: string | Uint8Array

      The data to write. If something other than a Buffer or Uint8Array is provided, the value is coerced to a string.

    • callback: NoParamCallback

    Returns void