# CFURLCreateFromFileSystemRepresentationRelativeToBase(_:_:_:_:_:) Creates a `CFURL` object from a native character string path relative to a base URL. ``` func CFURLCreateFromFileSystemRepresentationRelativeToBase(_ allocator: CFAllocator!, _ buffer: UnsafePointer!, _ bufLen: CFIndex, _ isDirectory: Bool, _ baseURL: CFURL!) -> CFURL! ``` ## Parameters `allocator` The allocator to use to allocate memory for the new `CFURL` object. Pass `NULL` or [`kCFAllocatorDefault`](/documentation/CoreFoundation/kCFAllocatorDefault) to use the current default allocator. `buffer` The character bytes to convert into a `CFURL` object. This should be the path as you would use in POSIX function calls. `bufLen` The number of bytes in the buffer. `isDirectory` A Boolean value that specifies whether the string is treated as a directory path when resolving against relative path components. Pass `true` if the pathname indicates a directory, `false` otherwise. `baseURL` The URL against which to resolve the path. ## Return Value A new `CFURL` object. Ownership follows the create rule. See [The Create Rule](https://developer.apple.com/library/archive/documentation/CoreFoundation/Conceptual/CFMemoryMgmt/Concepts/Ownership.html#//apple_ref/doc/uid/20001148-103029). ## Discussion This function takes a path name in the form of a native character string, resolves it against a base URL, and returns a new `CFURL` object containing the result. --- 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)