[Info-vax] New CEO of VMS Software

[Lawrence D'Oliveiro]

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.

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? 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, 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.

(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.)

>>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”. ;)