Am 03.07.2017 um 05:45 schrieb Mike Horvath:

> I have installed dozens of programs over the past decade. and this
> "drawback" only occurs with POV-Ray!

Dozens over a decade is a pretty small sample size.

You might be surprised about the curious habits of diverse installers.
Heck, I've seen commercial(!) software that cannot even be installed in
"C:\Program Files" because it can't handle blanks in file names. And
yes, that was well within the last decade.

Give us a break. We're writing this software in our spare time for free.


> Every other program ever has asked me for privileges during installation
> if needed.

Virtually no installer does that. Most rely on the operating system
asking you for privileges /before/ the installer actually runs.

Of course you could presumably write a custom installer that doesn't
reveal to the OS beforehand that it needs admin rights, and only invokes
UAC via some API later; but since installers virtually always require
admin rights, it's rarely done that way. Instead, installers typically
seem to advertise to the OS (via a manifest) that they want the highest
privilege level available to the user, and that's that.

Since this is the mechanism POV-Ray uses, there is no need to ask for
privileges on demand; POV-Ray always gets the privileges it may need
during installation -- unless you try to install it as a locked-down
user and pick a target directory a locked-down user never gets access to
anyway.


> the simple fact is that the POV-Ray installer is not doing
> so! And WTF is a "privilege of obtaining admin privileges"? You just
> made this up.

No, I haven't. It's not the official nomenclature, but it's effectively
how UAC works: A user with "admin rights" (or however they call it in
the English version) no longer has (permanent) admin privileges. The
only privilege over a locked-down user is that he is prompted by UAC if
needs be, to obtain admin privileges temporarily.


Modern Linux distros, BTW, use a very similar mechanism for desktop
installations -- though their "UAC dialog equivalent" includes a
password prompt, and internally the admin privileges are tracked via the
"effective user ID" (as opposed to the "current user ID"; the former
determines what privileges a user has, while the latter governs stuff
like their home directory and such); to my knowledge, Windows tracks
only "the" user account, but switches between the regular user account
without admin privileges, and a "twin" user account with admin privileges.

So the difference in security between contemporary Linux distros and
Windows' UAC (as far as that particular concept is concerned) is
essentially just the password prompt in the dialog, which prevents a
physical intruder from obtaining admin-level access on your machine
while you're away from keyboard. In professional environments where this
is a problem, a professional edition of Windows can be used, allowing to
enable such a password prompt even on Windows.

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