OpenEuphoria

RE: DOS undocumented feature

• Posted by rforno at tutopia.com Jul 21, 2002
• 380 views

Yes, it is a good idea.
I have another one: store the attributes, set them to no-system, no-hidden,
read the files, and afterwards restore the original attributes. It is a bit
dangerous, however.
Independently of attributes, in Windows there are some files that can't be
accessed, for example the swap file. There are some others that are "in use"
by some other program, and can't be deleted, for example, without restarting
Windows. I found a way to treat some files that can't be deleted; they *can*
be moved to some other directory, and then you can delete them. Strange, uh?
----- Original Message -----
From: Kat <gertie at PELL.NET>
Subject: Re: DOS undocumented feature


>
> On 21 Jul 2002, at 12:15, Robert Craig wrote:
>
> >
> > Ricardo Forno writes:
> > > While trying to enhance your DUPFILE.EXW program
> > > with some additional options, I discovered what seems
> > > to be an undocumented feature of DOS under
> > > Windows 98 SE. This happens only in a DOS window,
> > > not when you restart in DOS mode.
> > > As you know, . means the current directory, and .. means the parent
> > > directory. But ... means the parent of the parent directory,
> > > .... the parent of the parent of the parent, and so on.
> >
> > That apparently doesn't work on XP. Only . and .. work.
> >
> > > So, maybe the number of possible platforms should be increased.
> >
> > I'm not sure what you mean. dupfile.exw works (more or less) on all
> > platforms. Only "." and ".." are reported by the system calls that dir()
> > uses. I guess "..." and "...." are supported artificially by the
> > Win 98 command-line processor.
>
> Which means you can write Eu code to artificially support it too, Ricardo.
> Same as adding a huge long path with create_directory().
>
> > > Do you know why some files processed by DUPFILE.EXW when run
> > > through ex raise a "Critical error" condition?
> >
> > That's what DOS does when a DOS program tries to open a locked file.
> > Not very helpful. It will help if you close all your Windows apps
> > before scanning the whole drive with ex dupfile.exw.
>
> Even less helpful, Rob. What about checking the file attributes before any
> operations on them, Ricardo?
>
> Kat
>
>
>
>