# CFURLWriteDataAndPropertiesToResource(_:_:_:_:) Writes the given data and properties to a given URL. ``` func CFURLWriteDataAndPropertiesToResource(_ url: CFURL!, _ dataToWrite: CFData!, _ propertiesToWrite: CFDictionary!, _ errorCode: UnsafeMutablePointer!) -> Bool ``` ## Parameters `url` The resource to write. `dataToWrite` The data to write. Pass `NULL` to write only properties. `propertiesToWrite` The properties to write. Pass `NULL` to write only data. See [File URL Properties](/documentation/CoreFoundation/file-url-properties) and [HTTP URL Properties](/documentation/CoreFoundation/http-url-properties) for the list of available properties. `errorCode` Upon return, `0` if successful, otherwise contains an error code indicating the nature of the problem. See [`CFURLError`](/documentation/CoreFoundation/CFURLError) for a list of possible error codes. ## Return Value `true` if successful, `false` otherwise. ## Discussion Properties not present in `propertiesToWrite` are left unchanged, hence if `propertiesToWrite` is `NULL` or empty, the URL’s properties are not changed at all. If `url` uses a file scheme and it references a file, the contents of `dataToWrite` are written to the referenced file, overwriting any preexisting data, and the file’s properties are modified according to `propertiesToWrite`. If the file does not exist, but all intermediate directories along the path do already exist, the file is created (otherwise it is not). If `url` uses a file scheme and it references a directory (the last path character is “`/`”), the contents of `dataToWrite` are ignored, but if the parameter value is not `NULL`—and all intermediate directories along the path do already exist—a new directory is created (otherwise it is not). If `url` uses an http scheme, an http `PUT` request is sent to the resource with `propertiesToWrite` as the header fields and `dataToWrite` as the data. --- 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)