[Info-vax] New CEO of VMS Software

[Dan Cross]

In article <uncqas$pust$1 at dont-email.me>,
Lawrence D'Oliveiro  <ldo at nz.invalid> wrote:
>On Sat, 6 Jan 2024 23:42:26 -0000 (UTC), Dan Cross wrote:
>
>> I remember pretty specifically maximum user limits on versions of
>> commercial Unix.
>
>How would such limits be enforced? Presumably they only applied to some 
>extra-cost "layered product", not to the core OS.

No, they applied to the OS as a while.

>Because consider that users are defined in /etc/passwd, which is just a 
>text file. How would you limit the number of lines in that?

Ignore lines after some predetermined maximum?  Just not let
more than $n$ users at a time login?  Just because you find it
difficult to conceive of how it was done does not mean that it
was not done.

>And the kernel 
>itself knows nothing of which user/group IDs are "valid" or "invalid", it 
>will happily accept any numbers within the permissible ranges,

Assuming it hasn't been modified.  Remember, commercial Unix
vendors had the source code and modified it.

>regardless 
>of whether they appear in /etc/passwd or not. A network service (like 
>Telnet or SSH or file service) could limit the number of concurrent 
>connections, I suppose. But given there was open-source code available for 
>all of that anyway, it would be easy enough to bypass the limits by 
>replacing the vendor-provided code.

Much of this was before SSH was invented, and way before "open
source" was the force it is today.

>(Unless maybe you're talking about IBM's AIX. I am dimly aware that that 
>had its own proprietary ways of configuring things, that the traditional 
>*nix text-based configuration files were only a partial reflection of 
>that.)

AIX was a pretty standard port of System V at the kernel level,
but they made a lot of changes in userspace.  But then, so did
most of the Unix vendors.

Regardless, even if you could get *around* it, you'd be
violating your license agreement, which isn't a great idea.

>>>Today, the only OS in widespread use with this commonality of function
>>>across disparate hardware configurations is Linux.
>> 
>> Or FreeBSD.  Or OpenBSD.
>
>I did say "widespread". ;)

Yes.  So I mentioned FreeBSD and OpenBSD.  You, undoubtedly,
simply aren't aware of just how widespread they are.

	- Dan C.