Meiner Meinung nach gibt es Stand heute kein Unix.
Das ist Deine Meinung. Andere haben da eine andere Meinung.
Zitat:
The Open Group is the certifying body for the UNIX trademark. In other words, it has to rubber-stamp your operating system as compliant to its standards before you can call it UNIX. UNIX in all uppercase letters is the badge of compliance.
So, the categories are as follows:
- Unix: A family of operating systems. This family includes both UNIX operating systems and Unix-like operating systems.
- UNIX operating systems: These have been certified as compliant to the standards.
- Unix-like operating systems: These look and operate like Unix, but haven't been certified as compliant.
It's entirely possible, of course, that some operating systems in the "Unix-like" category could be tested tomorrow and found compliant. These are effectively UNIX now, but they can only be categorized as Unix because they don't yet have the rubber-stamp.
There are two standards that certify UNIX:
POSIX and
Single UNIX Specification (SUS). SUS is a superset of POSIX. So, something can be POSIX compliant, but that doesn't make it UNIX. However, if something is SUS-compliant, it's a UNIX.
POSIX and the SUS form large collections of documents (around 3,700 pages). They define the operation and expected behavior of every aspect of a compliant UNIX system. Everything from asynchronous and synchronous I/O, to the scripting interface and user-level programs are cataloged and defined.
So, Is macOS UNIX?
The answer has to be yes.
You can trace its lineage back through FreeBSD to BSD, and from there, back to the Unix distributed by Bell Labs before the license fee increase from AT&T.
But that doesn't matter.
If you write an operating system from scratch right now, as long as it satisfies the requirements of the SUS, it's considered UNIX. And it doesn't matter how you implement it. The XNU kernel at the heart of macOS is a hybrid architecture. It combines Apple's code with parts of the Mach and BSD kernels.
But that doesn't matter, either. What matters is it meets the requirements of the standards against which it's measured.
The BSD part of the XNU kernel provides the POSIX application programming interfaces (such as the various API and BSD system calls). Keeping that element of the BSD kernel intact within XNU is key to gaining certification as a UNIX. It allows XNU to speak compliant and compatible UNIX to the rest of the system.
macOS is a UNIX 03-compliant operating system certified by The Open Group. It has been since 2007, starting with MAC OS X 10.5. The only exception was Mac OS X 10.7 Lion, but compliance was regained with OS X 10.8 Mountain Lion.
Amusingly, just as GNU stands for "GNU's Not Unix,"
XNU stands for "X is Not Unix."
Is macOS Unix or UNIX? And what's POSIX and the SUS? We explain it all.
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