How Unix-like is MacOS X?

prospective_user asks: "I am a heavy user of Unix, spend most of my time running Linux and am considering getting myself an iBook, after seeing a considerable amount of exposure Macs/Apple have in both Slashdot and the O'Reilly Network. Given that MacOS X is based on FreeBSD/Mach, I suppose that the usual Unix libraries and environments (like ncurses and tcl/tk) are available in MacOS X (which I hope is true, for text-based applications). In fact, I'm concerned about the Unix side of MacOS X and also plan on running Debian/PPC on it, but I plan to primarily use MacOS X. So, before having an (uncertain) investment in a new platform, it would be reasonable to have a bit more of background on it and thus, the questions: how well does MacOS X support traditional Unix applications? For instance, how do the following applications run under MacOS X (which I use the most): teTeX, GNU Emacs, mutt and fetchmail?" Note that the submittor isn't asking if OSX is or is not a Unix; we've fielded that question already. No, the question here is where does OSX differ from the other unicies.

"Also regarding the investment in a new platform and coming from the x86 world, I'm a bit interested about the PowerPC performance in comparison to what I could get with a x86 notebook. I've read some articles and pages that suggest that PowerPCs may not be fast (or, in fact, may be quite slower than their x86 counterparts):

Some of the sources I've read are: these pages, from D. J. Bernsteins's website, and this article on processor performance from the GMP website.

Also, as some later questions, can the portable Macs be plugged to non-mac monitors? And does MacOS X feature a packet filter like Linux or other BSDs do?

Any comments and experiences with these machines are welcome. Thanks."

Comments

Not very Unixlike at all, I'm afraid.

[Starship Trooper]

I too looked forward to the day my iBook came when I ordered. I would no longer have to sift through the duality of Linux's raw power and Windows' ubiquity and application support: I would have the best of both worlds! When I first plugged the iBook in and eagerly opened Terminal.app, I was pleased to be greeted by the lovely '%' tcsh prompt. 'ls' worked. 'du' worked. 'ifconfig' worked. Even "find . -name *.c -exec grep -l '{}' ';'" worked!

But as I dug deeper, the initial euphoria wore off. While MacOS X gives the impression of being a Unix, as one digs deeper into the system, it becomes more and more clear that it is anything but Unix:

• No /etc. Well, technically, there is a /etc, but it is incredibly empty compared to what you may be used to in FreeBSD or Linux. None of the system's configuration is included in standard POSIX text files; Apple has opted to move everything into what they call a "NetInfo" registry. This is awful, to say the least. Obviously, Apple has failed to learn anything from the problems Microsoft's reliance on a central registry have propagated, and it wasn't long before I ended up having to reinstall MacOS X due to a corruption of the NetInfo database.
• Not everything is a file. MacOS X violates this essential tenet of the Unix interface by hiding the implementation of several core functions such as keyboard and mouse I/O behind a "CoreGraphics" ObjC library. There is no /dev/mouse or /dev/kbd or any of the easy-to-use device nodes I've grown accustomed to coding for on Linux.
• Everything above the Unix layer is proprietary. The Unix world on MacOS X is completely separate from the GUI world. The Unix directories are completely hidden from the Finder, and likewise one cannot start GUI apps from the console. There is none of the tight CLI-GUI integration seen in AmigaOS or BeOS or even Windows.

If you're looking for Unix, I suggest you make room on your iBook's drive for Linux, which runs very well on Mac hardware, and is much faster than MacOS X to boot. I'm afraid all of MacOS X's vaunted Unixness is little more than FUD.