Shameless plug: a few years ago I wrote a little Python library with the aim to "sanitize" filenames in a cross-platform, cross-filesystem manner: https://githu

Shameless plug: a few years ago I wrote a little Python library with the aim to "sanitize" filenames in a cross-platform, cross-filesystem manner: https://github.com/ksze/filename-sanitizer https://github.com/ksze/filename-sanitizer By "sanitize", I mean it should take as input any string for a filename, and clean it up so it looks the same and can be safely stored on any platform/filesystem. This would allow people to, for instance, download or exchange files over the Internet and know deterministically how the filename shall look on the receiving side, instead of relying on the receiving side to clean up the filename. The length of Unicode strings was definitely one of the pain points. Back then I only knew about NFC vs NFD. Now that I have read this article, I realise that my algorithm to determine where to truncate a filename is probably still wrong, and that I need to dig both much deeper and much wider. If anybody wants to help dig some serious rabbit holes, you're most welcome to fork and make PRs.