This is the mail archive of the cygwin mailing list for the Cygwin project.

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: NTFS write-protect flag translation (tar? rsync?) only one-way?

-----Original Message-----
From: Cygwin On Behalf Of Larry Hall (Cygwin)
Sent: Wednesday, 6 April 2011 1:20 AM
Subject: Re: NTFS write-protect flag translation (tar? rsync?) only one-way?

> On 4/5/2011 3:36 AM, Christian Gelinek wrote:
> > Hi everyone,
> >
> > I have a problem with the tar command with the "extract permissions
> > information" option being set.
> >
> > I am running Cygwin (CYGWIN_NT-6.1-WOW64 1.7.8(0.236/5/3) 2011-03-01 09:36)
> > under Windows 7 (Windows 7 Professional N Ver 6.1 Build 7600) with NTFS and
> > the CYGWIN=ntsec environment variable.
> >
> > It appears that when tar reads files for adding to archives, it correctly
> > interprets the Windows-set "R" attribute, which is also seen by ls under
> > Cygwin. After extracting the files using tar though, only Cygwin's ls
> > command seems to be aware of the read-only attribute; the attrib command (as
> > well as Explorer and other Windows-apps) see and handle the file as being
> > writeable.
> The read-only attribute is a "Windows" thing.  Cygwin's utilities focus on
> supporting POSIXy/Linuxy ways of doing things.  You can't expect Cygwin's
> tools to manage all of Window's permission facilities in the same way as
> Windows does.  The read-only flag is one case where you'll see a divergence.
> If you need that flag set, you'll need your own wrapper to set it based on
> the POSIX (or ACL) permissions.  The read-only attribute really is quite
> anachronistic though IMO.  It conflicts with the more powerful ACLs.  If
> you have the option, it's better not to use that flag.

IMO the behaviour is inconsistent if the flag is used/interpreted on one (the read) operation but NOT being written/changed on the other (write) operation. My approach would be either drop it completely or support it on both ends (the preferred option). By the looks of it 
(see, this problem has been addressed and potentially solved before, so I wonder if something is broken here.

The background to all this is that I am using RCS (I know, almost as anachronistic as the read-only attribute, but that's dictated by my workplace) under both Windows and Linux and RCS relies heavily on the read-only attribute of files to be correct. IMO, it wouldn't hurt if the Cygwin tools would write the Windows read-only attribute when they create a Cygwin read-only file?


Problem reports:
Unsubscribe info:

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]