Function writeSync

lib/fs.js:1079–1130

* Synchronously writes `buffer` to the * specified `fd` (file descriptor). * @param {number} fd * @param {Buffer | TypedArray | DataView | string} buffer * @param {{ * offset?: number; * length?: number; * position?: number | null; * }} [offsetOrOptions] * @param {number} [length]

(fd, buffer, offsetOrOptions, length, position)

 * @returns {number}
 */
function writeSync(fd, buffer, offsetOrOptions, length, position) {
  const ctx = {};
  let result;

  let offset = offsetOrOptions;
  if (isArrayBufferView(buffer)) {
    if (typeof offset === 'object') {
      ({
        offset = 0,
        length = buffer.byteLength - offset,
        position = null,
      } = offsetOrOptions ?? kEmptyObject);
    }
    if (position === undefined)
      position = null;
    if (offset == null) {
      offset = 0;
    } else {
      validateInteger(offset, 'offset', 0);
    }
    if (typeof length !== 'number')
      length = buffer.byteLength - offset;
    validateOffsetLengthWrite(offset, length, buffer.byteLength);

    const h = vfsState.handlers;
    if (h !== null) {
      const vfsResult = h.writeSync(fd, buffer, offset, length, position);
      if (vfsResult !== undefined) return vfsResult;
    }

    result = binding.writeBuffer(fd, buffer, offset, length, position,
                                 undefined, ctx);
  } else {
    validateStringAfterArrayBufferView(buffer, 'buffer');
    validateEncoding(buffer, length);

    if (offset === undefined)
      offset = null;

    const h = vfsState.handlers;
    if (h !== null) {
      const bufAsBuffer = Buffer.from(buffer, length);
      const vfsResult = h.writeSync(fd, bufAsBuffer, 0, bufAsBuffer.length, offset);
      if (vfsResult !== undefined) return vfsResult;
    }

    result = binding.writeString(fd, buffer, offset, length,
                                 undefined, ctx);
  }
  handleErrorFromBinding(ctx);
  return result;
}

/**
 * Writes an array of `ArrayBufferView`s to the