Re: Msdos name alias patch for 2.1.48
Matt Brown (matt@eigen.co.uk)
Mon, 11 Aug 1997 12:46:01 +0100
david parsons writes:
> Marcin Dalecki <dalecki@sub994.sub.uni-goettingen.de> wrote:
> >Sorry. MS-DOS ** IS NOT ** case insensitive.
>
> Hmm? Unless MS-DOS maps all filenames to upper or lower case before
> writing them into the directories, it is; if I use my vi-clone to
> write `foo' (via the creat() system call, or whatever that maps to
> for a software interrupt), I can then retrieve that file via open().
>
> >It is ONLY
> >command.com....
>
> I don't use command.com as my default shell on MS-DOS, and `foo', `fOo',
> and `FOO' still retrieve the same file.
>
> If they're all written to the fs as upper case, this is great
> (experiences with OS/2, which writes filenames in mixed case on fat
> filesystems, doesn't make me too certain about this bold assumption),
> but it's certainly not command.com that enforces case insensitivity.
MSDOS is definitely case-insensitive at the system call level. MSDOS
also smashes case on write. The FAT filesystems itself is not
case-smashing; some systems like the aforementioned OS/2 write mixed
case into the FAT 8.3 area. However, if I remember right, this
confuses certain tools etc.
I spent far too much time dealing with MSDOS to remember this wrong (I
spent several years making my living by disassembling and analysing
computer viruses) so I'm pretty sure the above is correct.
-Matt (ltns, btw)