Re: Database details -- general

[frank@clark.net]

I thank Tim Conway for his elaborate explanation about his intentions with
regard to a database. Alas, it assumes a great deal of knowledge about
such programs, while most of us just want to jump in. I have used data
bases very little, but I do know that that there is a standard format
based upon "dbase" that can be used by many, many software packages. The
dbase4 program itself is quite elaborate, and I'm only familiar with a
downscale version called Alpha5. This may not be the best way to go, but
at least you can swap data discs around with others who have a dbase-based
software program.

As promised, I peeked at the hexadecimal code of a .dbf file. Here is how
one starts: It goes hexadecimal, then character (^C means control-C), then
what it means if *I* know.

03 ^C End of text
5F _  Underscore
01 ^A Start of heading
12 ^R DC2, whatever that is

B2 don't know
05 ^E Enquiry, whatever *that* is
00 nothing, not even a blank space
00

82 don't know
02 ^B start of text
16 ^V Synchronous idle
05 ^E

Twelve 00s

00
00
04 ^D end of transmission
00

Four more 00s

41 A
55 U
54 T
48 H

4F O
52 R
31 1 (This was the first variable in my file)
00
6C l
61 a
74 t
43 C (Different things come after different variables. I don't know why.)

Four 00s

3C <
00
00
00

12 more 00s

41 A
55 U
54 T
48 H

4F O
52 R
32 2
00     (There aren't any spacees betweeen these groups of four. I'm
       just using them for easier reading.)

BE I can see it as some kind of funny symbol. Try typing the alt-191,
   the decimal equivalent in a word processor program.
9A U-umlaut
85 a-grave accent
43 C            (I have not idea what this means. Possibley it has
something to to with the length of the field.)

But sometimes there is an FE (?), 08 ^H backsapce, or 19 ^Y End of medium
instead of 3C <. Anyhow, after all the variables and the 00s, there comes

0D ^M carriage return
00
20 space
Then the first author starts.
A great many 20s
Second author
More 20s
....
last variable
more 20s

Then the second entry in the same pattern
Third entry
and so on till the end.

That's it. The spaces (20s) are determined by the length of the variables.

There are now funny symbols at the end.

I should tell you that the first few characters tell your computer NOT to
haul it up as a WordPerfect text, so you can't go in an edit it that way.

But the important thing to know is that the text is all in ASCII and there
is none of the funny stuff Tim talked about.

I have a wonderful program, called DOSSHELL, that was deleted from the
later versions of DOS, that lets you peek at the hexadecimals in a file,
though you can't print or edit. It also will arrange *all* files in
alphabetical (or date or size...) *regardless* of where they sit in a
directory tree. So you can look at all your "GOULD" files together. You
can peek at each one in succession, first by seeing the hexadecimals on
the left 3/4 of the screen and the same in ASCII on the right quarter.
you do this by pressing F9. Press it again and you get ASCII.

Now ASCII runs only 128 characters, ending with 7E ~ tilde, which is
actually 126. 127 is delete, I think. 0 is the first character. But
ANSI runs from 129 to 255 in decimal or 80 to FF in hexadecimal. I don't
know what all of these are. 155 (decimal) is the cents sign. It's the same
in WordPerfect, when you type alt-155 (the 155 from the keyboard).

But WP uses the alt keys that are in the first 31 hexadecimal keys, which
are non-printing instructions. Unfortunately I at length found out that I
used one of these. When I uploaded my files to my UNIX account, it got
garbled royally and kept adding in +0+0+0 everytime I went to the top of
my document. So I dumped the thing in hexadecimal and found out some very
strange stuff indeed! What I tried was just editing the text to replace
umlauts, accents, and so forth with unaccented characters. Everything wend
smoothly and I discovered wherein the erroy lay.

Now if you can't understand the above, you certainly won't understand what
Tim was talking about. I'm not deriding Tim, just pointing out the
advantages of dbase.

Frank