list of illegal characters for mac files

While many Unix systems save file names exactly as provided, and are able to differentiate between example.txt and Example.txt, this won’t work on other systems.įilesystems such as File Allocation Table (FAT) or Extended File Allocation Table (EXFAT) always convert filenames to uppercase: example.txt will be stored as EXAMPLE.TXT, as will Example.txt, or exaMple.txt. Oh no, normalization! ¶ĭifferent operating systems, file systems, or tools normalize names given to files, and this can go wrong in many ways: Don’t create files that differ only in case ¶ This matters because the files, directories, or repositories that you may at some point share with friends, colleagues, or the entire internet should successfully make it to those other people’s computers, and on those computers they should be usable for their intended purpose.Īs you will see in some examples below, having a completely fail-safe file name is the first step in ensuring this.Ĭoincidentally, a short deep-dive into interoperability hacks for file names will probably also teach you some fascinating facts about your own or other operating systems, file systems, or common tools that you may not have known yet. Other people take it to the edge of bikeshedding and beyond: “Let’s start each file name with the ISO 8601 date format of its first modification for better sorting!”īut between the two extremes, there are a surprising amount of interoperability considerations - practices and tips to ensure cross-platform compatibility - in order to create file names that work on your own as well as on anyone else’s machine.

This may sound mundane to some - “yeah, I guess I can’t manage data if it doesn’t have a file name, but what’s the big deal? I already know that I shouldn’t use spaces in file names”. One of the most fundamental data management tasks is naming files.

How to name a file: Interoperability considerations ¶

List of illegal characters for mac files