> because I've been told that it's a real "Unix system".
OSX certainly isn't a "real Unix system".
OSX a huge hodgepodge of proprietary crap with a Unix component buried somewhere in the middle of the dung heap to get FOSS proponent to believe that Apple believes in openness.
They were even certified as of 10.5 as a true-to-god Unix system. They have been more unixy than Linux for a while!
Unix, until Linux had made a breakthrough, was a proprietary system. The AT&T Unix, Xenix, AIX, SunOS, you name them. Openness of the source is not a defining characteristic.
OSX certainly isn't a "real Unix system".
OSX a huge hodgepodge of proprietary crap with a Unix component buried somewhere in the middle of the dung heap to get FOSS proponent to believe that Apple believes in openness.