From: Dan Shelton <dan.f.shelton@gmail.com>
To: cygwin@cygwin.com
Subject: Re: Switching groups with newgrp - how to get the new group with |GetTokenInformation()| ?
Date: Mon, 11 Mar 2024 02:30:17 +0100 [thread overview]
Message-ID: <CAAvCNcC=RpUgEia3vcZXqRD4CgyYnFRWXA3O+Kwfi3kQTNjD8A@mail.gmail.com> (raw)
In-Reply-To: <ZezUG1aiwd3t28U7@xps13>
On Sat, 9 Mar 2024 at 22:27, Glenn Strauss via Cygwin <cygwin@cygwin.com> wrote:
>
> On Wed, Mar 06, 2024 at 02:01:06PM +0100, Corinna Vinschen via Cygwin wrote:
> > On Mar 5 23:38, Dan Shelton via Cygwin wrote:
> > > On Sat, 24 Feb 2024 at 14:11, Corinna Vinschen via Cygwin
> > > <cygwin@cygwin.com> wrote:
> > > >
> > > > On Feb 23 22:15, Dan Shelton via Cygwin wrote:
> > > > > HOWEVER, there is another Cygwin bug:
> > > > > "getent group mywingrp1" does not list any group members, even after
> > > > > "net localgroup mywingrp1 mywinuser44 /add", which is a POSIX
> > > > > violation.
> > > >
> > > > Not a bug. Two problems:
> > > >
> > > > - Getting members of a group can be an extremly costly operation
> > > > in a domain or, worse, a domain forest, or even worse, if the
> > > > domain or domain forest is remote.
> > > >
> > > > - Alonmg the same lines, getting members of a group can be extremly
> > > > costly in big orgs with thousands of users. Nobody want's to clutter
> > > > up space with the list of members in the "Domain Users" group.
> > > >
> > > > - Permissions to enumerate members of a group are restricted.
> > > > By default only admins and group members are allow to enumerate
> > > > members and this can be restricted further by domain admins.
> > > >
> > > > Therefore we dropped even trying to populate gr_mem, considering
> > > > that even in its original form on Unix systems, it's used only
> > > > to add supplementary groups. To do this right on Windows is even
> > > > more costly than blindly enumerating.
> > > >
> > > > It's not a bug, it's a feature :)
> > >
> > > Could you add an option to getent so that the full lookup can be
> > > requested via command line, pls?
> >
> > That's not possible. getent just calls getpwent/getgrent.
> >
> > > Always editing /etc/nsswitch.conf
> > > forth and back is not a elegant solution, aside from race conditions
> > > with other users on a system
> >
> > So, here we go again.
> >
> > - What exactly are you trying to accomplish by enumerating the accounts?
> > Maybe you won't actually need it for your task at hand.
> >
> > - Why do you have to change nsswitch.conf "back and forth"?
> > Just change it once and you're done.
> >
> >
> > Corinna
>
> Hello
> > > Dan Shelton - Cluster Specialist Win/Lin/Bsd
>
> > > Always editing /etc/nsswitch.conf
> > > forth and back is not a elegant solution, aside from race conditions
> > > with other users on a system
>
> Please check the man page for getent.
>
> man getent
> getent --help
>
> You can use -s or --service to override the service used without
> editing nsswitch.conf. The man page on Linux provides an example
> with a bit more details than the man page for getent under cygwin.
> https://www.man7.org/linux/man-pages/man1/getent.1.html
Is this feature supported under Cygwin /usr/bin/getent?
I tried it, but did not see any change. Even putting garbage into it,
e.g. /usr/bin/getent -s "$(man man)" group foo does not yield an
error.
Dan
--
Dan Shelton - Cluster Specialist Win/Lin/Bsd
next prev parent reply other threads:[~2024-03-11 1:30 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-02-22 17:38 Roland Mainz
2024-02-22 19:11 ` Corinna Vinschen
2024-02-23 13:03 ` Roland Mainz
2024-02-23 15:47 ` Corinna Vinschen
2024-02-23 18:45 ` Roland Mainz
2024-02-23 21:15 ` Dan Shelton
2024-02-24 13:11 ` Corinna Vinschen
2024-03-05 22:38 ` Dan Shelton
2024-03-06 13:01 ` Corinna Vinschen
2024-03-09 21:26 ` Glenn Strauss
2024-03-11 1:30 ` Dan Shelton [this message]
2024-03-11 3:49 ` Brian Inglis
2024-03-11 16:54 ` Corinna Vinschen
2024-03-11 1:28 ` Dan Shelton
2024-03-11 16:56 ` Corinna Vinschen
2024-04-19 23:44 ` Dan Shelton
2024-04-26 9:04 ` Andrey Repin
2024-02-24 16:57 ` Brian Inglis
2024-02-24 12:53 ` Corinna Vinschen
2024-02-24 14:38 ` Will all SIDs fit into |SECURITY_MAX_SID_SIZE| bytes ? / was: " Roland Mainz
2024-02-24 18:57 ` Corinna Vinschen
2024-02-25 21:04 ` Roland Mainz
2024-02-25 22:32 ` gs-cygwin.com
2024-02-26 4:17 ` gs-cygwin.com
2024-02-26 16:12 ` [EXTERNAL] " Lavrentiev, Anton (NIH/NLM/NCBI) [C]
2024-02-26 9:20 ` Corinna Vinschen
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