Re: DOSEMU/DOSBOX question

[Paul Lagasse pglagasse@xxxxxxxx]

(apologies to the list; I accidentally hit the send button on an empty
email as I was starting this posting)

Wally Bass wrote:
> Well, my take is that is would be a fairly small undertaking to create
> a small DOS command which, given a long filename as its argument,
> would produce the DOSEMU mangled name. Do you think it would it be
> useful to try to produce such a module?
This wouldn't be much of a benefit to me, as I've always pretty much
8.3'd every file I'd ever want to access in Xy, but others might find it
useful.
> >(BTW, in Xy I can also see the hidden Linux backup for "howdy
> >etc," ie "howdy de do.htm.dos.txt~" -- which displays as
> >HOWDY~3I.TXT. If I open this in Xy and edit and save it, the
> >Linux file "howdy...txt~" no longer exists, and I get two new
> >files (whose Linux names are howdy~3i.txt and howdy~3i.bak).
> Oh, oh. I'm very sorry to hear that. That alone may make DOSEMU
> virtually unusable for anything other than 8.3 lower case names.
>
> ....
> So, some questions would be: (1) which XY were/are you using, and (2)
> did/do you have any "save a copy of the original" options turned on in
> XY? (I guess XY has such options, but I never have used them, and I've
> forgotten.) If so, you might want to try a similar experiment with
> "save original" turned off, and see if that changes the behavior.
I use Xy4. I had the autobackup option turned on in SETTINGS.DFL (df
bk=1); when I turn it off, Xy4, in both Dosemu and Dosbox, will preserve
the original filename untouched (both long filenames and the
capitalization [or lack thereof] of the original filenames are
preserved). So, if saving a copy of the original file is not important,
long filenames and any unusual ulc spelling in a filename will be
preserved as long as "bk=0".

re
>  the actual logic, I think, adds the suffix
[ie, an extension of three underscores]
> only if the *last* period in the filename is in the first position of
> the filename, so I don't believe that the "___" extension will get
> added for a filename like ".abc." (and, boy, just thinking about this
> makes it clear how hard it is to really anticipate the name mangling
> in detail using a black box approach, without looking at the code).
You're right about ".abc." -- Xy4/Dosemu shows a directory listing of
'ABC~4C' for ".abc." Note that it got mangled, even though its length
would suggest there's no need for that. Apparently all hidden files that
start with "." get mangled. ".j", for example, becomes "J~00.___". If I
create file called "abc" after creating ".abc." Dosemu doesn't mangle
"abc" to give it a distinctive name (this is consistent, I guess, with
Dosemu's showing Readme.txt, README.TXT, and readme.txt as three
instances of README.TXT in Xy4's directory listing).
If I edit ".abc." in Xy4 (bk=0), the file name is preserved; if I change
the default to "bk=1" and edit the file, the filename becomes "abc~4c"
(both .'s are removed from the filename when it's viewed in a Nautilus
[Gnome filemanager] window.

Don't know if this quirk is interesting, but I created the following files:

test.txt
Test.txt
TEST.txt
.test.txt
test.txt~
In Xy4 or in "DOS" in Dosemu, "dir t*.*" will display all the files
(with the hidden ones mangled), but "dir test.*" will only display the
first three. In Dosbox, the first command display all the files (with
all but one mangled), and the second command displays just one file (the
unmangled one). I also found that Dosbox and Dosemu use different
approaches to determining which file to open when you "ca text.txt" --
In Dosemu, if there are multiple files with the same name (save for
capitalization), Xy opens the file whose name is in all lowercase
letters; if none of the files are all lowercase (ie, if the choices are
Test.txt and TEST.txt), I'm not sure what drives the choice, despite
several tests. In Dosbox, Xy opens the file that is unmangled but I
can't determine, having run several of tests, how Dosbox chooses the
file that is unmangled. So it seems like it's best to settle on a
capitalization style that suits the DOS emulator you're using, and to
avoid varying from that (and avoid giving a file a name that is the same
-- except for capitalization -- as that of another file in the same
directory).

Paul

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