[python-win32] The "right" way to handle permission issues

[Mark Hammond]

On 31/05/2011 3:58 AM, Gremlin wrote:
> Hello,
>
> I’m having some trouble with Windows 7 and probably Windows Vista as
> well. My application runs elevated and has to create files and folders
> within the “Program Files”-Folder. (I can’t store the files at another
> place.) I’m using the os module (Python 2.7), rsync, 7zip and gzip to
> create those files.
>
> The trouble is the assignment of permissions to newly created files and
> folders. I’ve already isolated the issue to rsync (I haven’t tested 7zip
> and gzip yet.), files and folders created with open() and os.mkdir are
> created with the right permissions. (At least I suppose that because I’m
> able to delete them without altering the security properties.)
>
> When I look into the security properties of files created by rsync,
> there’s a group labelled with “None” and if I delete this group, I can
> delete the file. But unfortunately this doesn’t work with folders. The
> group will be deleted, while Windows says the security properties
> couldn’t be changed. (I see…) However, I’m able to delete a folder if I
> remove all groups and add myself again.
>
> So my question is: How should I handle this issue within my application?
>
> Of course, I know the function SetNamedSecurityInfo, but I don’t know
> how to use it “right”. What kind of permission should I set? Can I fix
> this issue with this function at all? How can I prevent further trouble
> for my users?
>
> You see, I’m totally clueless so far. So if you can, please help me
> solving this. :|

In general, you should look for a way to stop the app from screwing with 
the permissions in the first place.  tar has a similar problem which can 
be overridden with something like --no-same-permissions.

According to 
http://superuser.com/questions/69620/rsync-file-permissions-on-windows, 
rsync has a --chmod option that might work.

HTH,

Mark