Function appendFileSync

appendFileSync(
    filePath: string,
    contents: WriteSyncFileContent,
    options?: AppendOptions,
): VoidIOResult
Synchronous version of appendFile. Appends content to a file at the specified path.
Parameters
- filePath: string
  The absolute path of the file to append to.
- contents: WriteSyncFileContent
  The content to append (ArrayBuffer, TypedArray, or string).
- Optionaloptions: AppendOptions
  Optional append options.
  
  Options for appending to files.
  - Optionalcreate?: boolean
    Whether to create the file if it does not exist.
    
    Default Value
    true
Returns VoidIOResult
A VoidIOResult indicating success or failure.
See
appendFile for the async version.

Since
1.1.0
Example
```
// Append to file, create if doesn't exist (default behavior)
appendFileSync('/path/to/log.txt', 'New log entry\n');

// Append only if file exists, fail if it doesn't
appendFileSync('/path/to/log.txt', 'New log entry\n', { create: false });
```
- Defined in sync/ops.ts:330