As a result of recent Mac troubles, I moved my iTunes library to a Linux file server and setup iTunes on my old TiBook to access the library over an AFP share using netatalk.

This worked unexpectedly well, until I noticed something very odd: I could no longer access any file whose name contained an accented character such as “é”. These files showed up in directory listings but were not readable. The filesystem complained that the file just did not exist. After a whole evening lost trying to find fault with everything from Mac OS X to netatalk, I found myself in unfamiliar Unicode territory:

It turns out there are two ways to represent certain accented characters such as “é” in Unicode, either using unique code points (U+00E9, “latin small letter e with acute”) or using a regular ASCII character “e” with a combining diacritical mark (U+0065, “latin small letter e” followed by U+0301, “combining acute accent”). The first form is known as “precomposed” and is the standard for filenames on Linux, while the latter “decomposed” form is standard on Mac OS X.

The Mac ap