Test for Windows Administrator permissions from Cygwin terminal|script?

[Andrew Schulman]

> Hello,
> 
> 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.

https://superuser.com/questions/660191/how-to-check-if-cygwin-mintty-bash-is-run-as-administrator/874615#874615