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Re: stolen uint's

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From:
Trey Harris
Date:
January 29, 2020 19:36
Subject:
Re: stolen uint's
Message ID:
CALKJ+EssOo5vHi3+RbiVnnB61ksQQ9mbG8iYZEspVoWTUwoDAg@mail.gmail.com
On Wed, Jan 29, 2020 at 14:01 ToddAndMargo via perl6-users <
perl6-users@perl.org> wrote:

> On 2020-01-29 06:34, Trey Harris wrote:
> > I was going to ask about that (but it seemed out of Raku-world, and I
> > don’t even play someone who knows about Windows on TV), but, okay, I’ll
> > bite... what are some examples of the precisely 3-byte + 32-bit null UTF
> > strings you imagine being encoded by this interface? I have never heard
> > of such a small fixed-width UTF data structure before because it’s just
> > so bizarre, and then mandating a null termination so you lose the 4th
> > byte that would make this structure at least somewhat coherent as a
> > UCS-4 codepoint... since there’s no such thing as UTF-24, I assume this
> > is three UTF-8 bytes packed (which I guess is what you mean by “little
> > endian C string”, but that becomes at best ill-defined abutted next to
> > “UTF”)... But, what on earth is it being used for?
> >
> > I’m fascinated, in the way a cat is fascinated by a snake....
>
> Trey,
>
> You are basically setting up a buffer of bytes
> and then telling the WinAPI how long the
> data in the buffer is as well as what type of
> data the buffer contains.


That is clear from the document linked at
https://docs.microsoft.com/en-us/windows/win32/api/winreg/nf-winreg-regsetvalueexw

But what I was asking about and what I don’t understand is what you meant
when you wrote:
> where CbData can either be a UTF little endian C string,
> terminated by a nul or a four byte little endian
> unsigned integer (no two's complement allowed) depending
> on the value of lpValueName (REG_SZ, REG_DWORD, etc.)

Can you explain just this part:
> where CbData can… be a UTF little endian C string,
> terminated by a null

That’s the part I’m fascinated by because it’s just so strange. What’s an
example of a valid value of this type and not the “unsigned integer (no
two’s complement allowed)”?

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