I just needed to convert a big (around 200 MB) text file, encoded in UTF-8 and containing Polish characters, all into lowercase. tr to the rescue, right? Well, not quite.

$ echo ŻŹŚÓŃŁĘĆĄ | tr A-ZĄĆĘŁŃÓŚŹŻ a-ząćęłńóśźż
żźśóńłęćą

Probably every day I keep learning new things, without even realizing it most of the time. The vast majority of them are minor or even tiny tidbits of knowledge; but even these might be worth noting down from time to time, especially when they are tiny pitfalls I’d fallen into and spent a couple of minutes getting out. By sharing them, I might hopefully prevent someone else for slipping and falling in.