Re: Test for Windows Administrator permissions from Cygwin terminal|script?

[Martin Wege <martin.l.wege@gmail.com>]

On Sat, Aug 19, 2023 at 10:15 AM ASSI via Cygwin <cygwin@cygwin.com> wrote:
>
> Martin Wege via Cygwin writes:
> > How can I find out whether the current Cygwin terminal has
> > Administrator rights? I want to safeguard our admin scripts with a
> > simple test and bail out with an error if someone wants to do admin
> > stuff (say: regtool) without admin privileges.
>
> Windows really doesn't have a defined notion of what is or is not an
> "administrator".  Each particular definition will be insufficient or
> invalid in certain contexts.  When you're dealing with hardened
> installations (via group policies or otherwise), large windows domains
> and/or server administration you may have to be way more specific than
> just looking at one simple indication.
>
> That said, most commonly the presence of SID S-1-5-32-544 in your user
> token (in Cygwin: gid=544, unless you override it in the group config)
> will be the best simple approximation.  Incidentally, this is what tcsh
> is using on Cygwin to define the "superuser" for the purpose of setting
> the prompt with "%#":
> https://github.com/tcsh-org/tcsh/blob/d075ab5b4155ebff9d30e765733c030c3da5e362/tc.prompt.c#L212
>
> For (ba)sh scripts you can parse the output from id along the lines of
>
> id -G | grep -q '\<544\>' && echo admin || echo "not admin"

Is there any guarantee that the UNIX GID of the "administrator" will
always be "544", regardless of locale or Country-specific version of
Windows?

Also, this might be something for a Cygwin ADMINISTRATOR&PROGRAMMING
FAQ, if there is such a thing.

Thanks,
Martin