On 2024-03-10 19:30, Dan Shelton via Cygwin wrote:
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 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.
Always editing /etc/nsswitch.conf
forth and back is not a elegant solution, aside from race conditions
with other users on a system
Plus you need to terminate all processes in a tree and/or restart cygserver to
pick up any changed information.
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
That web page does not even define services (and it is not the same as the
services database), better info is available on the linked page:
https://man7.org/linux/man-pages/man5/nsswitch.conf.5.html
but none of those Linux services/sources apply on Cygwin.
The Cygwin getent man page does not document the current implementation; and
getent --help does not explain what a service configuration is: possibly the
same as the line you specify after db_enum, or maybe just one source?
Rely on /etc/nsswitch.conf; a bit better explanation is available if you install
Cygwin man-pages-linux then run:
$ man -m linux getent
and, as above, none of those Linux services/sources apply on Cygwin.
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.
This facility is a generic lookup using certain sets of functions accessing
information from various sources defined in comments in Cygwin's
/etc/nsswitch.conf, so if you pass in nonsense, you just will not get a match,
and nothing will be output.
You will only get an error if information required to perform a lookup is
unrecognized, for example option, database, or missing, for example key, where
enumeration is not supported.
Perhaps using meaningful commands on existing but elusive groups above like:
$ getent -s local group mywingrp1
$ getent -s primary group mywingrp1
may produce results that match what you should expect, and possibly even
$ getent -s 'local primary' group mywingrp1
may produce output.
--
Take care. Thanks, Brian Inglis Calgary, Alberta, Canada
La perfection est atteinte Perfection is achieved
non pas lorsqu'il n'y a plus rien à ajouter not when there is no more to add
mais lorsqu'il n'y a plus rien à retirer but when there is no more to cut
-- Antoine de Saint-Exupéry
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