# nullDevice The file handle associated with a null device. ``` class var nullDevice: FileHandle { get } ``` ## Return Value A file handle associated with a null device. ## Discussion You can use null-device file handles as “placeholders” for standard-device file handles or in collection objects to avoid exceptions and other errors resulting from messages being sent to invalid file handles. Read messages sent to a null-device file handle return an end-of-file indicator (an empty `NSData` object) rather than raise an exception. Write messages are no-ops, whereas [`fileDescriptor`](/documentation/Foundation/FileHandle/fileDescriptor) returns an illegal value. Other methods are no-ops or return “sensible” values. When using this method to create a file handle object, the file handle owns its associated file descriptor and is responsible for closing it. ## See Also [`init(fileDescriptor:)`](/documentation/Foundation/FileHandle/init(fileDescriptor:)) Creates and returns a file handle object associated with the specified file descriptor. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)