bug#41570: 26.3; dired chown

bug#41570: 26.3; dired chown

[A. Peter Blicher]

Dired chown command complains that chown is not available for windows
systems.  However, windows versions >= 7 (at least) have the "takeown"
command, which while not as comprehensive as the unix chown command at
least allows the current user to take ownership of a file/dir, as long
as the user has admin privileges.  It would be useful for dired to
permit this possibility on windows systems.


In GNU Emacs 26.3 (build 1, x86_64-w64-mingw32)
  of 2019-08-29 built on CIRROCUMULUS
Repository revision: 96dd0196c28bc36779584e47fffcca433c9309cd
Windowing system distributor 'Microsoft Corp.', version 6.1.7601
Recent messages:
Loading faces-pb...done
Loading files-pb...done
Loading vkill...done
For information about GNU Emacs and the GNU system, type C-h C-a.
Type C-x 1 to remove help window.
mwheel-scroll: End of buffer

Quit [2 times]
Making completion list...
funcall-interactively: Buffer is read-only: #<buffer *Completions*>

Configured using:
  'configure --without-dbus --host=x86_64-w64-mingw32
  --without-compress-install 'CFLAGS=-O2 -static -g3''

Configured features:
XPM JPEG TIFF GIF PNG RSVG SOUND NOTIFY ACL GNUTLS LIBXML2 ZLIB
TOOLKIT_SCROLL_BARS THREADS LCMS2

Important settings:
   value of $LANG: ENU
   locale-coding-system: cp1252

Major mode: Lisp Interaction

Minor modes in effect:
   display-time-mode: t
   tooltip-mode: t
   global-eldoc-mode: t
   eldoc-mode: t
   electric-indent-mode: t
   mouse-wheel-mode: t
   menu-bar-mode: t
   file-name-shadow-mode: t
   global-font-lock-mode: t
   font-lock-mode: t
   blink-cursor-mode: t
   auto-composition-mode: t
   auto-encryption-mode: t
   auto-compression-mode: t
   line-number-mode: t
   transient-mark-mode: t

Load-path shadows:
None found.

Features:
(shadow sort mail-extr emacsbug message rmc puny seq byte-opt bytecomp
byte-compile cconv format-spec rfc822 mml mml-sec password-cache epa
derived epg epg-config gnus-util rmail rmail-loaddefs mm-decode
mm-bodies mm-encode mail-parse rfc2231 mailabbrev gmm-utils mailheader
sendmail rfc2047 rfc2045 ietf-drums mm-util mail-prsvr mail-utils
help-fns radix-tree help-mode apropos elec-pair cl-macs time ps cl gv
cl-loaddefs cl-lib paren dired-x easymenu dired dired-loaddefs time-date
mule-util tooltip eldoc electric uniquify ediff-hook vc-hooks
lisp-float-type mwheel dos-w32 ls-lisp disp-table term/w32-win w32-win
w32-vars term/common-win tool-bar dnd fontset image regexp-opt fringe
tabulated-list replace newcomment text-mode elisp-mode lisp-mode
prog-mode register page menu-bar rfn-eshadow isearch timer select
scroll-bar mouse jit-lock font-lock syntax facemenu font-core
term/tty-colors frame cl-generic cham georgian utf-8-lang misc-lang
vietnamese tibetan thai tai-viet lao korean japanese eucjp-ms cp51932
hebrew greek romanian slovak czech european ethiopic indian cyrillic
chinese composite charscript charprop case-table epa-hook jka-cmpr-hook
help simple abbrev obarray minibuffer cl-preloaded nadvice loaddefs
button faces cus-face macroexp files text-properties overlay sha1 md5
base64 format env code-pages mule custom widget hashtable-print-readable
backquote threads w32notify w32 lcms2 multi-tty make-network-process
emacs)

Memory information:
((conses 16 108712 7836)
  (symbols 48 21063 1)
  (miscs 40 71 129)
  (strings 32 33626 939)
  (string-bytes 1 844459)
  (vectors 16 15081)
  (vector-slots 8 528297 8530)
  (floats 8 70 295)
  (intervals 56 510 13)
  (buffers 992 15))

bug#41570: 26.3; dired chown

[Eli Zaretskii]

> From: "A. Peter Blicher" <blicher@comcast.net>
> Date: Wed, 27 May 2020 14:46:39 -0700
> 
> Dired chown command complains that chown is not available for windows
> systems.  However, windows versions >= 7 (at least) have the "takeown"
> command, which while not as comprehensive as the unix chown command at
> least allows the current user to take ownership of a file/dir, as long
> as the user has admin privileges.  It would be useful for dired to
> permit this possibility on windows systems.

AFAIU, 'takeown' is different from 'chown', in that it only allows to
change the file's owner to either the current user or the
Administrators group, it doesn't allow you to change the ownership to
any other user except one of those two.  Also, I think the command
requires elevation, doesn't it (thus you mention "admin privileges")?

So I'm not sure that command is a good replacement for 'chown', but
maybe you have something in mind I'm missing?

Thanks.

bug#41570: 26.3; dired chown

[A. Peter Blicher]

Correct, takeown is not the same as chown.  Also, Windows is not the same as 
Unix, unfortunately.  takeown provides some of the capability of chown, thus 
it would be useful to have that functionality.  Yes, the logged in user must 
have, as far as I know, admin privilege to use it, i.e. be 'elevated'. 
However, I would find that bit of functionality useful.  No, takeown is not a 
replacement for chown, it's just a tiny bit of extra functionality in the 
same vein.

The main reason I have more use for chown in windows compared to when I was 
using Unix is that Windows creates a profusion of different ownerships even 
for files I create under a single user (depending on how they were created), 
resulting in a mess that I often need to clean up.  That mess is most evident 
using Dired, because it shows ownership by default, while usually Windows 
hides that information.

The requirement for elevated privilege is not an issue for me, because I run 
in that mode all the time, against all advice, mainly because Windows' 
permission handling is so screwed up and opaque.  However, for those who 
don't, that might either require extra code to handle, or maybe Windows would 
raise an elevation prompt dialog, not sure.

Thanks for considering it.

--peter



On 5/27/2020 11:44 PM, Eli Zaretskii wrote:
>> From: "A. Peter Blicher" <blicher@comcast.net>
>> Date: Wed, 27 May 2020 14:46:39 -0700
>>
>> Dired chown command complains that chown is not available for windows
>> systems.  However, windows versions >= 7 (at least) have the "takeown"
>> command, which while not as comprehensive as the unix chown command at
>> least allows the current user to take ownership of a file/dir, as long
>> as the user has admin privileges.  It would be useful for dired to
>> permit this possibility on windows systems.
> 
> AFAIU, 'takeown' is different from 'chown', in that it only allows to
> change the file's owner to either the current user or the
> Administrators group, it doesn't allow you to change the ownership to
> any other user except one of those two.  Also, I think the command
> requires elevation, doesn't it (thus you mention "admin privileges")?
> 
> So I'm not sure that command is a good replacement for 'chown', but
> maybe you have something in mind I'm missing?
> 
> Thanks.
> 

bug#41570: 26.3; dired chown

[Eli Zaretskii]

> Cc: 41570@debbugs.gnu.org
> From: "A. Peter Blicher" <blicher@comcast.net>
> Date: Thu, 28 May 2020 08:54:29 -0700
> 
> The main reason I have more use for chown in windows compared to when I was 
> using Unix is that Windows creates a profusion of different ownerships even 
> for files I create under a single user (depending on how they were created), 
> resulting in a mess that I often need to clean up.

The usual remedy for that is to take ownership on the parent directory
of where you are working (and all of its subdirectories), so that it
is owned by your user.  You do that once for a directory high enough
in the directory tree, and all your problems will be solved
henceforth.

bug#41570: 26.3; dired chown

[A. Peter Blicher]

Thanks, but I would be reluctant to do that without checking first all the 
files that might change, because one never knows what danger lurks in side 
effects.

On 5/28/2020 9:16 AM, Eli Zaretskii wrote:
>> Cc: 41570@debbugs.gnu.org
>> From: "A. Peter Blicher" <blicher@comcast.net>
>> Date: Thu, 28 May 2020 08:54:29 -0700
>>
>> The main reason I have more use for chown in windows compared to when I was
>> using Unix is that Windows creates a profusion of different ownerships even
>> for files I create under a single user (depending on how they were created),
>> resulting in a mess that I often need to clean up.
> 
> The usual remedy for that is to take ownership on the parent directory
> of where you are working (and all of its subdirectories), so that it
> is owned by your user.  You do that once for a directory high enough
> in the directory tree, and all your problems will be solved
> henceforth.
> 

bug#41570: 26.3; dired chown

[Stefan Kangas]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: "A. Peter Blicher" <blicher@comcast.net>
>> Date: Wed, 27 May 2020 14:46:39 -0700
>>
>> Dired chown command complains that chown is not available for windows
>> systems.  However, windows versions >= 7 (at least) have the "takeown"
>> command, which while not as comprehensive as the unix chown command at
>> least allows the current user to take ownership of a file/dir, as long
>> as the user has admin privileges.  It would be useful for dired to
>> permit this possibility on windows systems.
>
> AFAIU, 'takeown' is different from 'chown', in that it only allows to
> change the file's owner to either the current user or the
> Administrators group, it doesn't allow you to change the ownership to
> any other user except one of those two.  Also, I think the command
> requires elevation, doesn't it (thus you mention "admin privileges")?
>
> So I'm not sure that command is a good replacement for 'chown', but
> maybe you have something in mind I'm missing?

The proposal here was to change chown for takeown in Dired.  From the
discussion, it seems like this is not a technically good solution.

Is there anything more to do here, or could this bug report be closed?

Best regards,
Stefan Kangas

bug#41570: 26.3; dired chown

[A. Peter Blicher]

I'd say that while the windows takeown is crippled compared to chown, it 
would be useful to have an easy way in dired to invoke it, since it is better 
than nothing.  I don't at this point claim that takeown is the same as chown, 
or that dired chown should invoke takeown, just that takeown functionality 
would be useful in dired.

Apparently, with enough fancy footwork it is possible in windows to 
effectively chown, but from what I can see, it's a lot of fancy footwork.

--peter

On 9/3/2020 1:38 PM, Stefan Kangas wrote:
> Eli Zaretskii <eliz@gnu.org> writes:
> 
>>> From: "A. Peter Blicher" <blicher@comcast.net>
>>> Date: Wed, 27 May 2020 14:46:39 -0700
>>>
>>> Dired chown command complains that chown is not available for windows
>>> systems.  However, windows versions >= 7 (at least) have the "takeown"
>>> command, which while not as comprehensive as the unix chown command at
>>> least allows the current user to take ownership of a file/dir, as long
>>> as the user has admin privileges.  It would be useful for dired to
>>> permit this possibility on windows systems.
>>
>> AFAIU, 'takeown' is different from 'chown', in that it only allows to
>> change the file's owner to either the current user or the
>> Administrators group, it doesn't allow you to change the ownership to
>> any other user except one of those two.  Also, I think the command
>> requires elevation, doesn't it (thus you mention "admin privileges")?
>>
>> So I'm not sure that command is a good replacement for 'chown', but
>> maybe you have something in mind I'm missing?
> 
> The proposal here was to change chown for takeown in Dired.  From the
> discussion, it seems like this is not a technically good solution.
> 
> Is there anything more to do here, or could this bug report be closed?
> 
> Best regards,
> Stefan Kangas
> 

bug#41570: 26.3; dired chown

[A. Peter Blicher]

Maybe I should have added that although I still see the usefulness of this 
feature, I have no opinion on whether you should close the bug, since if 
anyone implements this, it's going to be me anyway.

--peter

On 9/3/2020 2:36 PM, A. Peter Blicher wrote:
> I'd say that while the windows takeown is crippled compared to chown, it 
> would be useful to have an easy way in dired to invoke it, since it is better 
> than nothing.  I don't at this point claim that takeown is the same as chown, 
> or that dired chown should invoke takeown, just that takeown functionality 
> would be useful in dired.
> 
> Apparently, with enough fancy footwork it is possible in windows to 
> effectively chown, but from what I can see, it's a lot of fancy footwork.
> 
> --peter
> 
> On 9/3/2020 1:38 PM, Stefan Kangas wrote:
>> Eli Zaretskii <eliz@gnu.org> writes:
>>
>>>> From: "A. Peter Blicher" <blicher@comcast.net>
>>>> Date: Wed, 27 May 2020 14:46:39 -0700
>>>>
>>>> Dired chown command complains that chown is not available for windows
>>>> systems.  However, windows versions >= 7 (at least) have the "takeown"
>>>> command, which while not as comprehensive as the unix chown command at
>>>> least allows the current user to take ownership of a file/dir, as long
>>>> as the user has admin privileges.  It would be useful for dired to
>>>> permit this possibility on windows systems.
>>>
>>> AFAIU, 'takeown' is different from 'chown', in that it only allows to
>>> change the file's owner to either the current user or the
>>> Administrators group, it doesn't allow you to change the ownership to
>>> any other user except one of those two.  Also, I think the command
>>> requires elevation, doesn't it (thus you mention "admin privileges")?
>>>
>>> So I'm not sure that command is a good replacement for 'chown', but
>>> maybe you have something in mind I'm missing?
>>
>> The proposal here was to change chown for takeown in Dired.  From the
>> discussion, it seems like this is not a technically good solution.
>>
>> Is there anything more to do here, or could this bug report be closed?
>>
>> Best regards,
>> Stefan Kangas
>>
> 
> 

bug#41570: 26.3; dired chown

[Stefan Kangas]

retitle Add "takeown" command for Dired on Windows
thanks

"A. Peter Blicher" <blicher@comcast.net> writes:

> I'd say that while the windows takeown is crippled compared to chown, it
> would be useful to have an easy way in dired to invoke it, since it is better
> than nothing.

Thanks.  I know too little about Windows to have an opinion, but
hopefully someone more familiar with that platform will chime in.

Best regards,
Stefan Kangas

bug#41570: 26.3; dired chown

[Eli Zaretskii]

> From: Stefan Kangas <stefan@marxist.se>
> Date: Thu, 3 Sep 2020 20:38:23 +0000
> Cc: "A. Peter Blicher" <blicher@comcast.net>, 41570@debbugs.gnu.org
> 
> > AFAIU, 'takeown' is different from 'chown', in that it only allows to
> > change the file's owner to either the current user or the
> > Administrators group, it doesn't allow you to change the ownership to
> > any other user except one of those two.  Also, I think the command
> > requires elevation, doesn't it (thus you mention "admin privileges")?
> >
> > So I'm not sure that command is a good replacement for 'chown', but
> > maybe you have something in mind I'm missing?
> 
> The proposal here was to change chown for takeown in Dired.  From the
> discussion, it seems like this is not a technically good solution.
> 
> Is there anything more to do here, or could this bug report be closed?

IMO, it should be closed.  Users who want the chown capability on
Windows will have to find a utility that is a more faithful emulation
of its Posix namesake.

bug#41570: 26.3; dired chown

[Stefan Kangas]

Eli Zaretskii <eliz@gnu.org> writes:

> IMO, it should be closed.  Users who want the chown capability on
> Windows will have to find a utility that is a more faithful emulation
> of its Posix namesake.

OK, I'm therefore closing this bug report now.

bug#41570: 26.3; dired chown

[Richard Stallman]

[[[ To any NSA and FBI agents reading my email: please consider    ]]]
[[[ whether defending the US Constitution against all enemies,     ]]]
[[[ foreign or domestic, requires you to follow Snowden's example. ]]]

Perhaps the Dired O command should give an immediate error, perhaps

  Changing a file's owner not supported on this OS.  Switch to GNU/Linux.

This would at least explain the situation.

-- 
Dr Richard Stallman
Chief GNUisance of the GNU Project (https://gnu.org)
Founder, Free Software Foundation (https://fsf.org)
Internet Hall-of-Famer (https://internethalloffame.org)

bug#41570: 26.3; dired chown

[Eli Zaretskii]

> From: Richard Stallman <rms@gnu.org>
> Date: Fri, 04 Sep 2020 23:17:42 -0400
> Cc: 41570@debbugs.gnu.org, stefan@marxist.se, blicher@comcast.net
> 
> Perhaps the Dired O command should give an immediate error, perhaps
> 
>   Changing a file's owner not supported on this OS.  Switch to GNU/Linux.

But this is not true: if one has a 'chown' command available (and I
do), it will and should work as intended.

bug#41570: 26.3; dired chown

[Richard Stallman]

[[[ To any NSA and FBI agents reading my email: please consider    ]]]
[[[ whether defending the US Constitution against all enemies,     ]]]
[[[ foreign or domestic, requires you to follow Snowden's example. ]]]

  > > Perhaps the Dired O command should give an immediate error, perhaps
  > > 
  > >   Changing a file's owner not supported on this OS.  Switch to GNU/Linux.

  > But this is not true: if one has a 'chown' command available (and I
  > do), it will and should work as intended.

I was replying to a message which seemed to say there was none, but I
don't claim to know anything about Windows.

Whatever the situation may be, the message could give users suitable
advice.  "Install the chown command to make this work" could be used,
provided the chown command in question is free software.


-- 
Dr Richard Stallman
Chief GNUisance of the GNU Project (https://gnu.org)
Founder, Free Software Foundation (https://fsf.org)
Internet Hall-of-Famer (https://internethalloffame.org)

bug#41570: 26.3; dired chown

[Eli Zaretskii]

> From: Richard Stallman <rms@gnu.org>
> Cc: stefan@marxist.se, 41570@debbugs.gnu.org, blicher@comcast.net
> Date: Sat, 05 Sep 2020 23:54:25 -0400
> 
>   > >   Changing a file's owner not supported on this OS.  Switch to GNU/Linux.
> 
>   > But this is not true: if one has a 'chown' command available (and I
>   > do), it will and should work as intended.
> 
> I was replying to a message which seemed to say there was none, but I
> don't claim to know anything about Windows.

There are ports of GNU Coreutils floating around.

> Whatever the situation may be, the message could give users suitable
> advice.  "Install the chown command to make this work" could be used,
> provided the chown command in question is free software.

If the suggestion is to tweak the text of the error message a little
on non-Posix platforms, it'd be fine by me.  Patches welcome.

bug#41570: 26.3; dired chown

[A. Peter Blicher]

I think rms is misunderstanding the issue.

RMS:  Chown works fine on posix platforms, and I think we all agree it 
doesn't need any change in emacs for those platforms.  The problem is that 
the functionality of chown does not exist in simple form on Windows, but 
there is a crippled version, called takeown.  It's already the case in emacs 
that trying to do chown in Dired under Windows yields an error message.  The 
bug related to whether there should be some functionality added to do what 
the crippled version, takeown, does when one tries to chown in emacs under 
windows.

--peter

On 9/6/2020 7:19 AM, Eli Zaretskii wrote:
>> From: Richard Stallman <rms@gnu.org>
>> Cc: stefan@marxist.se, 41570@debbugs.gnu.org, blicher@comcast.net
>> Date: Sat, 05 Sep 2020 23:54:25 -0400
>>
>>    > >   Changing a file's owner not supported on this OS.  Switch to GNU/Linux.
>>
>>    > But this is not true: if one has a 'chown' command available (and I
>>    > do), it will and should work as intended.
>>
>> I was replying to a message which seemed to say there was none, but I
>> don't claim to know anything about Windows.
> 
> There are ports of GNU Coreutils floating around.
> 
>> Whatever the situation may be, the message could give users suitable
>> advice.  "Install the chown command to make this work" could be used,
>> provided the chown command in question is free software.
> 
> If the suggestion is to tweak the text of the error message a little
> on non-Posix platforms, it'd be fine by me.  Patches welcome.
> 

bug#41570: 26.3; dired chown

[Richard Stallman]

[[[ To any NSA and FBI agents reading my email: please consider    ]]]
[[[ whether defending the US Constitution against all enemies,     ]]]
[[[ foreign or domestic, requires you to follow Snowden's example. ]]]

  >   It's already the case in emacs 
  > that trying to do chown in Dired under Windows yields an error message.

My suggestion is to adjust the error message so that it clearly explains
the situation.

Many programs sometimes report an error with an error message 
that doesn't tell the user what is wrong.  It is worth some effort
to make our error messages explain clearly to users what the problem is
and what caused it.  That way, they can tell what to do.

-- 
Dr Richard Stallman
Chief GNUisance of the GNU Project (https://gnu.org)
Founder, Free Software Foundation (https://fsf.org)
Internet Hall-of-Famer (https://internethalloffame.org)

bug#41570: 26.3; dired chown

[A. Peter Blicher]

Well, I'd agree with that.  Right now the message I get is "chown not 
supported on this system"  The ambiguity is (a) sorry, we haven't gotten 
around to implementing that yet, vs (b) Your OS version doesn't provide the 
functionality to do it.

It wouldn't probably hurt to say "Try the Windows command line command 'takeown.'

--peter

On 9/7/2020 7:54 PM, Richard Stallman wrote:
> [[[ To any NSA and FBI agents reading my email: please consider    ]]]
> [[[ whether defending the US Constitution against all enemies,     ]]]
> [[[ foreign or domestic, requires you to follow Snowden's example. ]]]
> 
>    >   It's already the case in emacs
>    > that trying to do chown in Dired under Windows yields an error message.
> 
> My suggestion is to adjust the error message so that it clearly explains
> the situation.
> 
> Many programs sometimes report an error with an error message
> that doesn't tell the user what is wrong.  It is worth some effort
> to make our error messages explain clearly to users what the problem is
> and what caused it.  That way, they can tell what to do.
>