Mailing List Archive

Support open source code!


[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: not-even-newbie printer question



Peter Evans <peter@example.com> writes in tlug@example.com:

> No. It's said to be written in assembler, and to derive (legally) from
> software developed for a dedicated word processor called Atex. But the
> first Xy goes way back to MS-DOS pre 2.11 [was that the number?]; it
> doesn't support subdirectories.

No.  PC DOS 2.0 had subdirectories.  I think it was only versions 1.1
and 1.0 that didn't.  The subdirectory support was incredibly ill
thought out and coded to typical Microsoft quality standards. They
mapped a Unix-like structure, including fake "." and ".."  entries, to
what was still a CP/M disk format.  Without inodes and an inode cache,
it was horribly inefficient to use more than a level or two.  For
example, the current directory was stored as a text string internally.
To find "..", the code used that string and tacked on a "\.." to the
end, then performed a complete lookup from "\". Since they used a
fixed size buffer and didn't do any length sanity checking, you can
probably guess what happened if you had a very long pathname for the
current directory and then tried to back out of it by cd ".."'ing.

Anyway, PC DOS 2.11 was a bugfix release that didn't fix very many
bugs and unbundled the programmer's reference so that you now had to
pay extra for it.

That was all 17 years ago and the pain and horror haunts me even today ...


Home | Main Index | Thread Index

Home Page Mailing List Linux and Japan TLUG Members Links