# CFURLSetResourcePropertyForKey(_:_:_:_:) Sets the URL’s resource property for a given key to a given value. ``` func CFURLSetResourcePropertyForKey(_ url: CFURL!, _ key: CFString!, _ propertyValue: CFTypeRef!, _ error: UnsafeMutablePointer?>!) -> Bool ``` ## Parameters `url` The URL. `key` The name of one of the URL’s resource properties. `propertyValue` The value for the resource property defined by `key`. `error` The error that occurred if the resource value could not be set. ## Return Value `true` if the resource property named `key` is successfully set to `value`; otherwise, `false`. ## Discussion This function synchronously writes the new resource value out to disk. Attempts to set a read-only resource property or to set a resource property that is not supported by the resource are ignored and are not considered errors. If an error occurs, this method returns `false` and populates the object pointer referenced by `error` with additional information. > Note: > This method applies only to URLs for file system resources. ## See Also [`CFURL`](/documentation/CoreFoundation/CFURL) --- 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)