Re: Filenames with Win32 special characters (or: Interix filename compatibility)

[Corinna Vinschen <corinna-cygwin at cygwin dot com>]

On Mar 11 19:25, Corinna Vinschen wrote:
> On Mar 11 12:31, Christopher Faylor wrote:
> > On Tue, Mar 11, 2008 at 11:55:45AM +0100, Corinna Vinschen wrote:
> > >On Mar 11 11:50, Corinna Vinschen wrote:
> > >> Case sensitivity is still not possible with this approach.  You
> > >> can get generic case sensitivity in Cygwin with a bit of work.  The 
> > >> magic flag is OBJ_CASE_INSENSITIVE in the object attributes.  However,
> > >> this would not work for fork/exec.
> > >
> > >Oh, and, beginning with Windows XP, you would have to enable case
> > >sensitivity in the kernel. Set the DWORD
> > >
> > >HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\kernel\obcaseinsensitivity
> > >
> > >to 0x0 and reboot.  No worries, this doesn't affect Win32 calls.
> > 
> > I thought this had come up before and that it affected files in
> > Explorer, i.e., you delete file "A" and file "a" gets deleted too or
> > something like that.
> 
> If you created two files which only differ by case, then, yes, Explorer
> will behave somewhat excentric.  What I meant above is, you can still
> just run any Win32 application if you did the above change in the
> registry.  It's not like this breaks the whole system in some way.
> 
> > FWIW, I'm all for getting rid of managed mounts if we can create all of
> > the same stuff transparently.
> 
> Given the uppercase/lowercase problem, it doesn't sound too much that
> we can get rid of managed mounts.  We could change them to use the
> outlined method of using special unicode chars.

Two months later, here's a question:  Should we start to allow real case
sensitivity?  Changing the above registry key is not exactly rocket
science.  I had this idea to change the definition of non-managed and
managed mounts like this:

- non-managed means case-insensitive and not converting chars to the
  UNICODE Private Use Area.  This means sticking to good old Win32
  compatibility.

- managed means, all file operation are using case-sensitivity and
  special chars (:,<,>) are converted to the Private Use Area.
  Still, that won't work with fork/exec, due to using the Win32
  function CreateProcess.

Every time I think about this, I'd also love to get rid of managed
mounts and always be in POSIX mode with case-sensitivity and not
allowing Win32 paths but treating all filenames as POSIX filenames
on input and all that...

But then again, we're Cygwin, not Interix, right?


I'm all torn...
Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Project Co-Leader          cygwin AT cygwin DOT com
Red Hat