RE: Generate hash code for a source member?

Dan,

First, you don't really need any of the "official" hash algorithms.
That keeps things simple.  Read the source record in as an array of 32
bit integers.  Crossfoot the array. Add to the total for the member.
Repeat for each record.  Final value is your hash.

Also, keep track of how many times your total overflows.  Eg: If new
total is less than old total, you over flowed.  Keep the count.  When
doing the other side, the "total" and the overflow should match.

This is not an elegant solution by any means, but it would be very easy
to do and would work.  Probably easiest to do out of RPG actually.
Just zero the array before reading records.  That way you don't even
care what the record length is.

Bob

-----Original Message-----
From: mi400-admin@midrange.com [mailto:mi400-admin@midrange.com]On
Behalf Of Dan Bale
Sent: Thursday, May 09, 2002 9:45 AM
To: MI400@midrange.com
Subject: [MI400] Generate hash code for a source member?

(Cross posted on Midrange-L, RPG400-L, & MI400)

Has anyone invented this wheel?  I'm looking for a way to compare
source
members on different systems to determine whether or not they are
identical - Yes or No.  If different, I don't care how different.

Because I don't really want to save & restore whole source files
between two
systems, my thinking was to create a hash code for each source member
based
on the contents.  Create a file with fields:  Library Name, File Name,
Source Member Name, Hash Code.  FTP the file from the system A to
system B
and compare the two.  I'm fairly confident that the two source files
are
identical, but I need to be sure.

Is a hash code generator what I'm looking for here?  Feed in
Library/File(Member) and get back a 16(?)-byte hash code?  If so, does
anyone have one that runs on V3R2?

- Dan Bale
(I am *NOT* "Dale"
http://archive.midrange.com/midrange-l/200105/msg00281.html )
SAMSA, Inc.
989-790-0507
DBale@SAMSA.com
  Quiquid latine dictum sit altum viditur.
  (Whatever is said in Latin seems profound.)


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