Re: howto make system calls (newbie question)

[Kilgallen@eisner.decus.org.nospam (Larry Kilgallen)]

In article <Xns909B95495DD5Fcharleshixsonearthli@207.217.77.25>, charleshixson@earthling.net (Charles Hixson) writes:

>>In article <9d8ute$8tt9@news.kvaerner.com>, "Tarjei T.
>>Jensen" <tarjei.jensen@kvaerner.com> writes: 
>>> 
>>>...
>>No, absent a specific explanation to the contrary, or
>>specification of some particular operating system, console
>>I/O should mean I/O to the console.  On the machines I use,
>>ordinary unprivileged users are _not_ allowed to write to the
>>console (if they were, their output would get intermixed).
>>
> Do you mean that all of your users are restricted to batch 
> compile/execution cycles?  Then slave sysin to the card reader 
> and sysout to the line printer (Unit5 and Unit6, I think they 
> were called.)

No, but users of interactive terminals (or emulators thereof)
do not have access to the _console_.  There is only one console
on the system.  There could be tens or hundreds of users (depending
on the size of the machine).  From the console one can issue hardware
commands to stop the machine, etc.

>>And do they cover protected subsystem ACEs, which I need for
>>VMS ? I am sure that MVS, OS/400 and other operating systems
>>have their own unique ACE types, to say nothing of different
>>processing rules. As I said, it cannot be made universal
>>across operating systems. 
> 
> No.  But perhaps a higher level description could be.  It might 
> not have the total functionality of low-level system calls, but 
> one often doesn't need that. (I have only used VMS twice, so 
> forgive me if I don't know what an ACE is.)

By ACE I mean "Access Control Entry", the fundamental building
block of an Access Control List.  I was under the impression
the same term was used for Unix and Windows.  It is the most
common method of complying with the C2 rules of the Orange Book.
While various operating systems have Access Control Lists
for file protection, the parsing rules differ from one OS to
another.  Some early Unix implementations came without ACLs,
but I think the need for C2 evaluation cured that for any
serious implementations.