Subj : ISAM variable-length demark?
To : All
From : Mike Luther
Date : Thu Mar 08 2001 12:30 am
The simple ISAM I'm testing works. The record file is all variable length
ASCII text strings. Currently in BASIC, the record has no ASC(0) characters in
it, but in moving it to C/C++ or something else, that might change, at least
for the final character for a given page. The record is a collage of many
variable length strings, including CR/LF's, tabs. It's a printer text image of
page after page of whatever was printed on the page. Essentially it's an
indexed book to which the keys let you print any page on demand.
I have to be able to scan it later and reconstruct the key(s) file(s), should
they get lost or grunged.
What record demark character (group) would be a good choice to use to break up
the record parade so that I can brute force the file to reconstruct the keys?
Obviously, this sort of thing has been thought about long before this,but it's
new to me...
For my curious reasons, I'd even settle, I think, for the old WordStar page
break deal. It looks like:
Looks to me like it is a chunk of code starting with ASC(1D) and ASC(20) and
ending with ASC(0D) and ASC(8A). However, I don't see any FF ASC(0C) in there.
Obviously, this 37 byte block holds information, most likely page number,
things like that. In that this block quoted above is the actual page break
between page one and page two, is that ASC(01) in the above the start of either
a short or long integer for the page numher, Big Indian -Little Indian or what?
Anyone here recall how to read W/S page break blocks or know where to get that
insight?
It would be nice to have a defined spacer block between the records from which
to get the pointers to the previous record, et. al.
Anyone have any thoughts. I've picked W/S apart years ago, but not this part
of it.
Thanks.
Mike @ 1:117/3001
--- Maximus/2 3.01
* Origin: Ziplog Public Port (1:117/3001)
