| > Okay, but AIX quite notably deviates from that [...] No, I don't think so. It's a complex mature commercial one that goes its own way, but it's still a Unix, wit the core original Unix abstractions and models. It doesn't have a different native API or UI instead or underneath. > But, isn't it true that z/OS natively supports POSIX path name syntax? TBH I have never worked with it and don't know enough to say, but no, I don't think so. It has multiple sets of APIs and its core model is not the Unix model; it predates Unix altogether. What I am saying seems simple and clear to me, but you seem to wish to obfuscate it and then claim that the obfuscated version falsifies the basic premise. POSIX and its 21st century successor the UNIX™ certification process are about compatibility and only compatibility. If it's compatible with the UNIX tests then its makers can say it's a UNIX. I am not debating that. You are. I am saying: If the OS started off Unix-like with the Unix model, a Unix style single filesystem tree, a Unix-like shell, etc. and never had anything else instead or alongside or underneath, that's a Unix-like OS. If it added this later, alongside some other designs, APIs, shells, filesystem layouts etc., then it may end up being 100% compatibile and therefore it may be a UNIX™ but that does not make it a Unix-like OS in design. Is that so hard? |