Returns a file handle associated with a null device.
- iOS 2.0+
- macOS 10.0+
- Mac Catalyst 13.0+
- tvOS 9.0+
- watchOS 2.0+
A file handle associated with a null device.
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
file 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.