DMARC-Filter: OpenDMARC Filter v1.4.2 delorie.com 63NMulY41491819
Authentication-Results: delorie.com; dmarc=pass (p=none dis=none) header.from=cygwin.com
Authentication-Results: delorie.com; spf=pass smtp.mailfrom=cygwin.com
DKIM-Filter: OpenDKIM Filter v2.11.0 delorie.com 63NMulY41491819
Authentication-Results: delorie.com;
	dkim=pass (1024-bit key, unprotected) header.d=cygwin.com header.i=@cygwin.com header.a=rsa-sha256 header.s=default header.b=NUsnSNch
X-Recipient: archive-cygwin AT delorie DOT com
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org BA5EA4B99F6B
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cygwin.com;
	s=default; t=1776985005;
	bh=nrxqk5ON4tF5lcLZmM1ioRLd8iyFjQBu9qa4LWftc4w=;
	h=Date:Subject:To:References:In-Reply-To:List-Id:List-Unsubscribe:
	 List-Archive:List-Post:List-Help:List-Subscribe:From:Reply-To:Cc:
	 From;
	b=NUsnSNchPQnHeb0rs4UyscWOAyAAAi/bdgbSWkov2GDQzEItqIbaGLRySxMUz2GYr
	 va0wu31JcXxWJ8Qi82dgnGotMf8MOXq1NbL9DRwF4cjmDrjVQGM6ut30vtsiCNt+Wd
	 nJI0rOEdz3EdqTutPyfTdcMYWuBDi7fAfL0L9MnE=
X-Original-To: cygwin AT cygwin DOT com
Delivered-To: cygwin AT cygwin DOT com
DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 865F24BAE7EF
ARC-Filter: OpenARC Filter v1.0.0 sourceware.org 865F24BAE7EF
ARC-Seal: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1776984956; cv=none;
 b=XFhjKQaoMwLebCPaodT30q5vD8JpcD2rvnyiazxMw5oqq4gE6cCViMNGyQ3eBYeBPQSlLJtunb1rnfvzfu3AkgMbR6v80+I1Od+w2vSakIRBPhUNON9ovYxah94LObhoTssf50aJnO5vMmPlYZREimenuVQ6Cs4N/rR80XS1rbA=
ARC-Message-Signature: i=1; a=rsa-sha256; d=sourceware.org; s=key;
 t=1776984956; c=relaxed/simple;
 bh=HiuX6/5vyMFTV+hM5kUxmpzpOFV2V+uQmQRBYus/JC4=;
 h=Message-ID:Date:MIME-Version:From:Subject:To:DKIM-Signature;
 b=l4TubDOTdQrMnI0zRt71libocZgPrIGbLFv+1tB8h0x+DCOpr0savXVCqaAD1PMisBRWKtnDvgITROGnTMiyKDmUnVS2oyx5AcR9cASGFAFltZICuavpgG1zRYsvDKCde8eWOQLxs5LasOmDJ+PkoTj1+7R4ZibRuq1Vp4m6rVg=
ARC-Authentication-Results: i=1; server2.sourceware.org
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 865F24BAE7EF
Message-ID: <c528f22b-1279-4d31-a99d-d868a20b51c8@SystematicSW.ab.ca>
Date: Thu, 23 Apr 2026 16:55:53 -0600
MIME-Version: 1.0
User-Agent: Mozilla Thunderbird
Subject: Re: Getting Windows "MACHINE SID" without fork() & exec()?
Content-Language: en-CA
To: General Cygwin discussions and problem reports <cygwin AT cygwin DOT com>
References: <CALWcw=HNsScw6AcFU5-g1nvy7g+NRWZ-B2LMFFaHAoTWkkN17g AT mail DOT gmail DOT com>
 <a5a7e6dc-eb6d-4bf9-b7cb-a2971a3d72aa AT gmail DOT com>
Organization: Systematic Software
In-Reply-To: <a5a7e6dc-eb6d-4bf9-b7cb-a2971a3d72aa@gmail.com>
X-Stat-Signature: ntc14u8cppep3txrjrmtpysocberczgj
X-Rspamd-Server: rspamout04
X-Rspamd-Queue-Id: 7F01320025
X-Session-Marker: 427269616E2E496E676C69734053797374656D6174696353572E61622E6361
X-Session-ID: U2FsdGVkX1//nDYpPfcEMSbWPLtTpocv3Via7IYEnl0=
X-HE-Tag: 1776984954-676171
X-HE-Meta: U2FsdGVkX19nG8ByP8Gz7xV2jGI4MRrXe4AChoXy7MB1L0I0e/kO8eiwtBqjAzu7YmZxqA6meQPpfffNDfwIlLY13SUA2evBjiYiDIl4rIw3mAMa+boZRUPcEdXcE5ATBpYqObhUWTiP4z6WNzJyTy62HvT9cJjwmllDnhIxlFegDdIQ4FiIp/KBQXvjXKUDjO5h4nJQI4JyLedXbaegqXVcZJ9U8NJnvGRcBsd9d9ID+CBp0vUDIzo4mLH1XvWxwLULD8Fk04fG0kccZHU1CIj6CGGTsQkb86pjBzkY6gKIsV3qHAGJku3AxuvFA5w+rukGNMfxOV5hW/JKDdrEgvEsi9GeQxNqGK56iYceZ5NWvXMoyQ3Xq8ynHg/3niew2kWfiyYaOQ1xll99m4Fgb7EhBn9yKHaRlwJK2gSXtBo+7x7FBVcmeG5tbHZHE/KE9Pm9D0+IBVM=
X-BeenThere: cygwin AT cygwin DOT com
X-Mailman-Version: 2.1.30
Precedence: list
List-Id: General Cygwin discussions and problem reports <cygwin.cygwin.com>
List-Unsubscribe: <https://cygwin.com/mailman/options/cygwin>,
 <mailto:cygwin-request AT cygwin DOT com?subject=unsubscribe>
List-Archive: <https://cygwin.com/pipermail/cygwin/>
List-Post: <mailto:cygwin AT cygwin DOT com>
List-Help: <mailto:cygwin-request AT cygwin DOT com?subject=help>
List-Subscribe: <https://cygwin.com/mailman/listinfo/cygwin>,
 <mailto:cygwin-request AT cygwin DOT com?subject=subscribe>
From: Brian Inglis via Cygwin <cygwin AT cygwin DOT com>
Reply-To: General Cygwin discussions and problem reports <cygwin AT cygwin DOT com>
Cc: Brian Inglis <Brian DOT Inglis AT SystematicSW DOT ab DOT ca>
Content-Type: text/plain; charset="utf-8"; Format="flowed"
Errors-To: cygwin-bounces~archive-cygwin=delorie DOT com AT cygwin DOT com
Sender: "Cygwin" <cygwin-bounces~archive-cygwin=delorie DOT com AT cygwin DOT com>
Content-Transfer-Encoding: 8bit
X-MIME-Autoconverted: from base64 to 8bit by delorie.com id 63NMulY41491819

On 2026-04-23 13:27, René Berber via Cygwin wrote:
> On 4/23/2026 11:07 AM, Takeshi Nishimura via Cygwin wrote:
> 
>> Does Cygwin have a secret shell variable or /proc file which contains
>> the current machine's MACHINE SID, without having to resort to calling
>> an external program (no fork(), no exec(), please)?
> 
> Create your own environment variable.  Store it once per bash session 
> with .bashrc for example, or permanently with all the other Windows variables.
> 
> Use PsGetSid to get the value into that variable (i.e. no super user access 
> needed like with regtool.)

No regtool or superuser access needed for most queries and regtool accepts paths:

$ l /proc/registry*/
/proc/registry/:
HKEY_CLASSES_ROOT/  HKEY_CURRENT_CONFIG/  HKEY_CURRENT_USER/ 
HKEY_LOCAL_MACHINE/  HKEY_PERFORMANCE_DATA/  HKEY_USERS/

/proc/registry32/:
HKEY_CLASSES_ROOT/  HKEY_CURRENT_CONFIG/  HKEY_CURRENT_USER/ 
HKEY_LOCAL_MACHINE/  HKEY_PERFORMANCE_DATA/  HKEY_USERS/

/proc/registry64/:
HKEY_CLASSES_ROOT/  HKEY_CURRENT_CONFIG/  HKEY_CURRENT_USER/ 
HKEY_LOCAL_MACHINE/  HKEY_PERFORMANCE_DATA/  HKEY_USERS/

> Ref: https://learn.microsoft.com/en-us/sysinternals/downloads/psgetsid
> 
> Caveat: The first time you run PsGetSid it shows a popup with the license 
> agreement.
> 
> Example:
> XPS-8930: ~
> $ /home/reneb/bin/SysinternalsSuite/PsGetsid
> 
> PsGetSid v1.44 - Translates SIDs to names and vice versa
> Copyright (C) 1999-2008 Mark Russinovich
> Sysinternals - www.sysinternals.com
> 
> SID for \\XPS-8930:
> S-1-5-21-3651791898-1415975337-2452924111
> 
> XPS-8930: ~
> $ /home/reneb/bin/SysinternalsSuite/PsGetsid |& tail -n 3
> S-1-5-21-3651791898-1415975337-2452924111

Do you mean like these values replaced by '*'?

$ regtool list -v /proc/registry/HKEY_USERS/
.DEFAULT\ ()
S-1-5-18\ ()
S-1-5-19\ ()
S-1-5-20\ ()
S-1-5-21-**********-**********-**********-1001\ ()
S-1-5-21-**********-**********-**********-1001_Classes\ ()
...

Of course, if the info is not yours, you probably will need elevated access!

-- 
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 retrancher  but when there is no more to cut
                                 -- Antoine de Saint-Exupéry

-- 
Problem reports:      https://cygwin.com/problems.html
FAQ:                  https://cygwin.com/faq/
Documentation:        https://cygwin.com/docs.html
Unsubscribe info:     https://cygwin.com/ml/#unsubscribe-simple