User privacy

[Bret Busby]

On 17/02/2021, Robert Heller <heller at deepsoft.com> wrote:
> At Tue, 16 Feb 2021 15:54:15 +0000 "Ubuntu user technical support, not for
> general discussions" <ubuntu-users at lists.ubuntu.com> wrote:
>
>>
>> Content-Type: text/plain
>>
>> On Tue, Feb 16, 2021 at 04:35:57PM +0100, Volker Wysk wrote:
>> > Am Dienstag, den 16.02.2021, 23:23 +0800 schrieb Bret Busby:
>> > > On 16/02/2021, Volker Wysk <post at volker-wysk.de> wrote:
>> > > > Hi
>> > > >
>> > > > Am Dienstag, den 16.02.2021, 14:18 +0000 schrieb Ian Bruntlett:
>> > > > > Hi,
>> > > > >
>> > > > > I'm sorting out an existing Lubuntu 18.04 laptop for a mother and
>> > > > > daughter. At the moment when I run umask I get the result "0002"
>> > > > > which I
>> > > > > believe means that different users can read each other's files in
>> > > > > their
>> > > > > $HOME directories. They want to stop each other from reading their
>> > > > > files.
>> > > > >
>> > > > > Now I have a rough idea on how to arrange this. I believe a
>> > > > > different
>> > > > > umask value has to be specified however I don't know:-
>> > > > > * What value of umask to use
>> > > > > * Where to set that value so that it is set as the default on
>> > > > > bootup/login.
>> > > >
>> > > > You don't need to touch the umask. Just delete the permissions for
>> > > > "others"
>> > > > on the home directories:
>> > > >
>> > > > chmod o-rwx /home/HOMEDIR1
>> > > > chmod o-rwx /home/HOMEDIR2
>> > > >
>> > > > Bye,Volker
>> > > >
>> > >
>> > > Is it "others" or "group"?
>> > >
>> > > I preferred it when it was numbers; the 777 system, so, for example,
>> > > chmod 007
>> >
>> > It's "others". Each user should have its own private group with the same
>> > name as the user name and only that user in it. So the group ownership
>> > or
>> > permissions should not be a problem.
>> >
>> It always seems to be a rather strange default set-up to configure
>> every new user to have a group of their own.  It makes the whole idea
>> of groups in permissions rather redundant!
>
> Back in the olden days of UNIX on "mainframes" with lots of RS232 ports and
> multiple actual users, users will be in groups (with a defauly group
> "users")
> that match what real life "group" they were part of: eg all of the students
> might be in a group "students" and all of the professors might be in a group
> faculty. Or maybe each research group would have a group. Or something like
> that.

That type of scenario, is to what I was referring.

Except, the UNIX's that I encountered, were on mini-computers, rather
than mainframes, but, the designations have been vapourised, with my
"laptop computers having more resources that multi-campus mainframes
(I believe that my i3 desktop, my i5 laptop, and, my i7 laptop, each
have more power and RAM, than an IBM 3081 that had three 80386 CPU's -
two slaves and a master, that served a multi-campus university in
Perth (WA) , and, more, than a DEC Alpha, which, some years ago, was
classed as a super computer, which required special permission, for
each one to leave the USA, and, if my computers were linked, using
beowulf, as a distributed multiprocessor system, they would truly be
souper-dooper).

When I first learnt systems admin stuff, relating to UNIX (I was also
taught systems admin stuff, relating to DEC RSTS/e and a little to do
with VAX-11 VMS , but, this is going back, over 30 years ago, so, I
have forgotten most of it), we were taught that groups applied to
groups in a human hierarchy, like a body of students comprising a
group, maybe, even, a class, or, level of students, to separate the
groups, and, a separate group for the lecturers, and, a separate group
for systems admins, etc, etc, etc. The UNIX was System V - I can't
remember the rest of its name, and, that was after I had been taught a
little BSD UNIX system 4.2.

But, whilst Linux is classed as a "UNIX-like" operating system, my
experience and usage of Linux, has mostly involved less than 6 users
on a system, compared to the multiple users of a UNIX system (from
memory, a Compaq 386 with 32MB of RAM, was supposed to be able to
serve up to 32 users, at the same time  :), but, a VAX-11 running BSD
4.2, could serve more...).


-- 
Bret Busby
Armadale
West Australia
(UTC+0800)
..............