# createFile(named:in:attributes:packer:context:replyHandler:) Creates a new file item and map its disk space. ``` func createFile(named name: FSFileName, in directory: FSItem, attributes newAttributes: FSItem.SetAttributesRequest, packer: FSExtentPacker, context: FSContext, replyHandler reply: @escaping @Sendable (FSCreateFileKOIOResult?, (any Error)?) -> Void) ``` ``` func createFile(named name: FSFileName, in directory: FSItem, attributes newAttributes: FSItem.SetAttributesRequest, packer: FSExtentPacker, context: FSContext) async throws -> FSCreateFileKOIOResult ``` ## Parameters `name` The new file’s name. `directory` The directory in which to create the file. `newAttributes` Attributes to apply to the new file. `packer` An extent packer you use to pack the file’s allocated disk space. `context` An object that enables context-aware file system decisions throughout the operation. `reply` A block or closure to indicate success or failure. If creation succeeds, pass an instance of [`FSCreateFileKOIOResult`](/documentation/FSKit/FSCreateFileKOIOResult) containing the newly-created [`FSItem`](/documentation/FSKit/FSItem), its [`FSFileName`](/documentation/FSKit/FSFileName), its [`FSItem.Attributes`](/documentation/FSKit/FSItem/Attributes), the updated [`FSItem.Attributes`](/documentation/FSKit/FSItem/Attributes) of the parent directory, the volume’s update free space, along with a `nil` error. If creation fails, pass the relevant error as the second parameter; FSKit ignores the [`FSCreateFileKOIOResult`](/documentation/FSKit/FSCreateFileKOIOResult) instance in this case. For an `async` Swift implementation, there’s no reply handler; simply return the result instance or throw an error. ## Discussion This method allows the module to opportunistically supply extents, avoiding future calls to [`blockmapFile(_:offset:length:flags:operationID:packer:replyHandler:)`](/documentation/FSKit/FSVolume/KernelOffloadedIOHandler/blockmapFile(_:offset:length:flags:operationID:packer:replyHandler:)). Only perform this technique opportunistically. In particular, don’t perform additional I/O to fetch extent data. Packing extents in this method requires that `attributes` defines a size greater than 0. An implementation that doesn’t supply the extents can ignore the packer and call the corresponding method in the [`FSVolume.Handler`](/documentation/FSKit/FSVolume/Handler) protocol, [`createItem(named:type:in:attributes:context:replyHandler:)`](/documentation/FSKit/FSVolume/Handler/createItem(named:type:in:attributes:context:replyHandler:)). --- 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)