Macos is the UNIX?
why,just beacuse that its the bottom layer uses a small amount of bsd code? In my opinion, macos and Unix are completely different. The directories are long directory structures. For example, /application, /system, /user, /volumes, etc. are completely different from the traditional /bin/ /sbin /etc/ /sys directories. The core uses a mixed kernel of mach and xnu, and is not a traditional monolithic kernel of Unix. The application uses older versions, such as sudo1.8.17, bash3.18. This is updated to sudo1.8.28 and bash5.0 under archlinux. You must also get the app store to install the program. Such an os I think it is more like windows
On the contrary, Linux I feel it more like Unix, keep the simple and stupid Unix style, and even some distributions do not provide gui, just shell mode. The directory follows the Unix traditional directory /bin /boot /etc/ /tmp /var and so on, not innovating alone. The core uses the traditional monolithic kernel written by linus. Installing the software needs to be done under the terminal, although different distributions have different command line styles. Give the user great freedom. In addition to the software you think it is not derived from the original code of at&t, but a cloned version of gnu. I really can't see where it is not Unix. Why do many people call it a class of Unix? What are they thinking about?
Is it only use "car"word call the car, Toyota and Mazuda and Ford do not call the car? ? Is it only use “airplanes” call the aircraft, Airbus and Boeing are not called airplanes? ? Different motors, different design styles, different appearances. But their principles are the same. In my opinion, as long as the design philosophy of kernel, shell, and user space is followed, having the same directory structure, shell, and underlying c language design can be called Unix.
Therefore, Unix did not disappear, but changed a vest, with gnu/linux, freebsd mode continues to exist.