Test whether file is owned by a specific group from bash or powershell level?

[Eliot Moss]

On 6/20/2025 8:15 AM, Sebastian Feld via Cygwin wrote:
> Does Cygwin or POSIX have a tool to test whether a file is owned by a
> specific group?
> 
> Win32, like Linux and POSIX, has the concept that files have an owner,
> and a group (ref:https://learn.microsoft.com/en-us/windows/win32/api/aclapi/nf-aclapi-getsecurityinfo).
> 
> How can I test whether a file is owned by a given group name, or not?
> /usr/bin/test -g and -G do not help because they only look and gid,
> egid. But I want to pass the group's name as an argument.

With some help from the web, I found this:

   find foo -prune -printf '%g\n'

This prints the group name, giving a gid only if it can't find the name of the group

Also this:

   stat --format=%G foo

Then you can compare the result against the group you have in mind.

I found this all out with web search and running a few quick tests under cygwin.

Regards - Eliot Moss