220 11527 <06d34cd5-04d3-4cd1-a384-66a3e98a5429@isocpp.org> article Path: news.gmane.org!not-for-mail From: masse.nicolas@gmail.com Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Re: Feedback to n3940 [Filesystem] Date: Thu, 19 Jun 2014 03:57:38 -0700 (PDT) Lines: 115 Approved: news@gmane.org Message-ID: <06d34cd5-04d3-4cd1-a384-66a3e98a5429@isocpp.org> References: <539D8898.1030103@gmx.de> <9fe25f12-aef5-4e1e-a9ef-e4f47391ad6b@isocpp.org> <539F41FB.4040601@gmx.de> <72d0e0dd-477e-40cb-b0b8-3c8e154cb43f@isocpp.org> <6d7b8bf6-170a-40af-ae94-802bfbd091bf@isocpp.org> <6d07a6d0-7bab-4273-87a2-4ba132e2a97a@isocpp.org> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_Part_7_30039169.1403175458932" X-Trace: ger.gmane.org 1403175469 17080 80.91.229.3 (19 Jun 2014 10:57:49 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Thu, 19 Jun 2014 10:57:49 +0000 (UTC) To: std-proposals@isocpp.org Original-X-From: std-proposals+bncBCCJBHV4UALBBI4EROOQKGQEBJSXDOQ@isocpp.org Thu Jun 19 12:57:42 2014 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-oa0-f72.google.com ([209.85.219.72]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1Wxa2H-0007hu-HE for gclcip-std-proposals@m.gmane.org; Thu, 19 Jun 2014 12:57:41 +0200 Original-Received: by mail-oa0-f72.google.com with SMTP id eb12sf14635982oac.7 for ; Thu, 19 Jun 2014 03:57:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=date:from:to:message-id:in-reply-to:references:subject:mime-version :x-original-sender:reply-to:precedence:mailing-list:list-id :list-post:list-help:list-archive:list-subscribe:list-unsubscribe :content-type; bh=SourO9oOkSSzIen6lfVwntzZEibfTLVWWRpAEIdjM1Y=; b=puR+Rr5bH+PBrvUFv3OBjIppkNetu2p4gwyJ5c62PHvIDvN04LLG5SEmW8e2EK09Nm vxqJIPz9rz1hcRjOvD0Tky5/gQ4lcu0Qmo7Ufv2/jI+ozjg+DH1/twgpli9uul4LGwm1 dKE3UIrpUj1jSHLoupH8Q6IVjhoBHQub5jW9J0t+NtL0C4WX1LfGl0fFr0LIgr9lafDD ZxUjo0QPypODaEmyqv9+oTwBScayUdMUc6ht+dtB972lOvoHdyhr3hDlZalZEX5dTpp5 nrMKNmPJ3DOS+rPIVcxVJbt0CIb63TwVEYQR6Uo6W/dgz1o6wxCimmulChGsS9Js64HN 0BpQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:date:from:to:message-id:in-reply-to:references :subject:mime-version:x-original-sender:reply-to:precedence :mailing-list:list-id:list-post:list-help:list-archive :list-subscribe:list-unsubscribe:content-type; bh=SourO9oOkSSzIen6lfVwntzZEibfTLVWWRpAEIdjM1Y=; b=VXUzE/x2sFcq9JTuBQvUd0Xn/2bp885kBzAhsKBkYcbT39pWjhEf8fKfn1Ox17UwP0 JIRZOGbDyE0fSVWO9ePme7PXcAQycyLG1Hi+R2nNTAknFoGqaEgER9WiipKd3ZtUfmNW 0rm1sNWwM+JdAhSCo/+EZQVNMBnyDB98/0K6qVm7xoSm8ReaU8HISsW6SM/caqkleAkc GqDTNDMg0ysrtt5UwJX9d7kPmcHbkgISsnl4+1dqYcqSrPGAPF8LPyb2ZhMGfGceTr6w u6KGDjppMf3IbOKGaKiZNfbaVK6TPHE8s3gfy0E58h31TgP7KNu0cnxhkE+DNColBIAs 3Hjg== X-Gm-Message-State: ALoCoQnNJiPaFaZFDzSd1HeJlFKdacxaYCIr0aw1DOvwgrCS/WyK+xgr9687OBCV1hRTLARMrioi X-Received: by 10.42.123.148 with SMTP id s20mr1741578icr.8.1403175460585; Thu, 19 Jun 2014 03:57:40 -0700 (PDT) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.182.245.200 with SMTP id xq8ls205701obc.81.gmail; Thu, 19 Jun 2014 03:57:39 -0700 (PDT) X-Received: by 10.182.220.168 with SMTP id px8mr1732obc.32.1403175459523; Thu, 19 Jun 2014 03:57:39 -0700 (PDT) In-Reply-To: X-Original-Sender: massenicolas@gmail.com Precedence: list Mailing-list: list std-proposals@isocpp.org; contact std-proposals+owners@isocpp.org List-ID: X-Google-Group-Id: 399137483710 List-Post: , List-Help: , List-Archive: List-Subscribe: , List-Unsubscribe: , Xref: news.gmane.org gmane.comp.lang.c++.isocpp.proposals:11527 Archived-At: ------=_Part_7_30039169.1403175458932 Content-Type: text/plain; charset=UTF-8 From N3940: *Windows: All permissions except write are currently ignored. There is only > a single write permission; setting write permission for owner, group, or > others sets write permission for all, and removing write permission for > owner, group, or others removes write permission for all. The Cygwin users > guide has extensive discussion of the problems involved. Input from > security experts is needed.* Basically, it seems that the filesystem API is based on POSIX, and does not support ACL-based security. So clearly, such an API will cause problems on windows systems (and probably some other too, but I'm not an expert here). At least an "access" method to check wether a file is readable or writable for example could fix part of the problem. On Thursday, June 19, 2014 8:06:00 AM UTC+2, Jeremy Maitin-Shepard wrote: > > On Wednesday, June 18, 2014 6:18:06 PM UTC-7, Sean Middleditch wrote: >> >> On Wed, Jun 18, 2014 at 5:45 PM, Nevin Liber >> wrote: >> > On 19 June 2014 02:01, Sean Middleditch wrote: >> >> >> >> Clearly more than just `ls` that uses such a basic operation. >> > >> > >> > Again I'll ask you: what is the missing mapping from low level OS API >> to >> > Filesystem API? Is it cross platform, and if not, how do you implement >> it >> > on other platforms? >> >> Maybe I'm missing something, but `status()` tells you nothing about >> whether a file is read-only that I can tell. >> > > What about the permissions() member of file_status? > -- --- You received this message because you are subscribed to the Google Groups "ISO C++ Standard - Future Proposals" group. To unsubscribe from this group and stop receiving emails from it, send an email to std-proposals+unsubscribe@isocpp.org. To post to this group, send email to std-proposals@isocpp.org. Visit this group at http://groups.google.com/a/isocpp.org/group/std-proposals/. ------=_Part_7_30039169.1403175458932 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
From N3940:

Windows: Al= l permissions except=20 write are currently ignored. There is only a single write permission; setti= ng=20 write permission for owner, group, or others sets write permission for all,= and=20 removing write permission for owner, group, or others removes write permiss= ion=20 for all. The Cygwin users guide has extensive discussion of the problems=20 involved. Input from security experts is needed.
Basically, it seems that the filesystem API is based on POSIX, and does no= t support ACL-based security.
So clearly, such an API will cause problem= s on windows systems (and probably some other too, but I'm not an expert he= re).
At least an "access" method to check wether a file is readable or = writable for example could fix part of the problem.

On Thursday, Jun= e 19, 2014 8:06:00 AM UTC+2, Jeremy Maitin-Shepard wrote:
On Wednesday, June 18, 2014 6:= 18:06 PM UTC-7, Sean Middleditch wrote:
On Wed, Jun 18, 2014 at 5:45 PM, Nevin Liber <ne...@eviloverlord.= com> wrote:
> On 19 June 2014 02:01, Sean Middleditch <se...@middleditch.u= s> wrote:
>>
>> Clearly more than just `ls` that uses such a basic operation.
>
>
> Again I'll ask you:  what is the missing mapping from low lev= el OS API to
> Filesystem API?  Is it cross platform, and if not, how do you= implement it
> on other platforms?

Maybe I'm missing something, but `status()` tells you nothing about
whether a file is read-only that I can tell.

What about the permissions() member of file_statu= s?

--

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