I learned today that, “the default file system of Mac OS X, HFS+ (Mac OS Extended format), is case-insensitive but case preserving.”
In retrospect, it explains some odd behavior I have seen working in the shell, but I never put it together till today. I have a parent dir with 26 children dirs “A,B,C,…”. I type “cd a” by accident, and am surprised when I get no error message, and confused when pwd shows “a” as current dir, yet cd’ing back up a level and looking at the parent dir only shows capital letter sub-dir names. It doesn’t just preserve the case something exists as, it also seems to preserve the case I referred to something with, which seems needlessly complex, but I have to admit is technically cool. I’d hate to have to test it though.