This needs to work on (at least) Win32 and *nix. When this path is fed to Cwd::abs_path() on a MSWindows system the dir separator will be '\'. I was under the impression that Cwd only dealt with '/' as a separator. Am I mistaken? What about the (hypothetical and increasingly unlikely) scenario where I want this to also work under a pre-OSX MacOS whose separator is ':'?