Re: 1.3.62 and fat/msdos/vfat observations

Jacques Gelinas (jack@solucorp.qc.ca)
Mon, 19 Feb 1996 23:06:49 -0500 (EST)


On Mon, 19 Feb 1996, Ulrich Windl wrote:

> On 16 Feb 96 at 16:54, Andreas Kostyrka wrote:
>
> My original idea was something like: UMSDOS currently does two
> things: First it implements UNIX file attributes that MSDOS/FAT does
> not have by maintaining EMD files. Secondly it maps long names that
> DOS/FAT can't handle to "mostly reasonable" substitutes.
> With VFAT we would have a nicer mapping for the second point.
> Admittedly at the first instance I forgot the upper- and lowercasing
> problem and I thought we wouldn't have to remap file names at all.

I think we should handle this with the following strategy. Currently,
Umsdos decide with many rules if a name is acceptable for 8.3 DOS or not.
If it is not acceptable, it is mangled. The mangling involve reducing the
name length and appending a special extension which is unlikely to be
used on any file (this is explained in the umsdos technical documentation
available at sunsite).

The strategy for VFAT should be something like this.

All lower case only names are acceptable. Names with uppercase in it
should be mangled. The mangling is smoother though. The special
extension is simply added to the name and that's it.
This makes the name still easily viewable and avoid most clashes.

The umssync utility will have to be modified to smooth this strategy even
further. umssync is used to promote a non umsdos directory to umsdos.
With that stategy, all names encounter will be accepted but turned to
lower case in the EMD file (--linux-.---). Given that VFAT is case
insensitive, this should work and will avoid renaming the file as seen
from DOS.

I am toying with this strategy for some time now. I can very well
implement this in no time. There is a catch though. I don't use W95 at
all and have no intention to do so. So I will need BETA to try it.
(I will test it on floppies though).

THe biggest problem is not the mangling though. Umsdos has to be
reorganised to either sit on VFAT or FAT. Maybe a VUMSDOS is needed
here. This is mainly kitchen stuff though.

--------------------------------------------------------
Jacques Gelinas (jacques@solucorp.qc.ca)
Use Linux without reformating: Use UMSDOS.