On Sun, Oct 21, 2012 at 7:48 PM, Asmus Freytag <asm...@ix.netcom.com> wrote: > Anyway, to cut the discussion short, I'd love to see a working example of > any system where metadata are 100% reliable.
I'd like to see an example of any system that's 100% reliable in any way. But you can be pretty sure if you get a file marked .jpg, .gif or .png, that it will in fact be a JPEG, GIF or PNG file, and internal metadata is 100% accurate; GIF always starts with "GIF87a" or "GIF89a", PNG with hex /89 50 4e 47 0d 0a 1a 0a/, and JPEG with hex /ff d8/. Since text has no header, that doesn't work, and unlike images, text file formats are hard to distinguish, with everything be a superset of ASCII, and several of them (ISO-8859-1, CP1252, ISO-8859-15) are practically indistinguishable. -- Kie ekzistas vivo, ekzistas espero.
