Re: Calculate hash for a *very* large file

Dan,

Here's one issue that may byte you with the hash....

When you have the data on the i, you're dealing with EBCDIC, on the Windows
server the data will be ASCII.

You'd need to convert the data to ASCII on the i before calculating the hash
if you expect it to match the has calculated on Windows.

Having said that, you might for instance consider a program that runs in
PASE to produce the hash. Since PASE is ASCII, I believe the system will
translate the data for you automatically.

HTH,
Charles


On Thu, Jun 18, 2009 at 2:38 PM, Dan <dan27649@xxxxxxxxx> wrote:

Problem: We FTP files from the i to a Windows server. On a few occasions,
we have had corruption even though FTP reports the transfer completed
successfully. The largest of these files have a record length of 2000
bytes, and have record counts approaching 3 million on some days.

Determining that corruption occurred often happens weeks later, after the
original source data is removed from the i.

The current thinking around here is to use a hash code. We already found a
few tools that can create a hash on the file that sits on the Windows
server. However, when I searched in the midrange.com archives, I found
several references to the QC3CALHA API. Unfortunately, it appears to be
limited to a data length that can be defined in Binary(4). I presume that
the data length would be the product of the record length and number of
records in the file.

I found another link in the archive that provided source code for an
application and that appears to use a stream file as input:
http://archive.midrange.com/rpg400-l/200303/msg00008.html
It's been too many years, but can a native library/file object name be
specified as a stream file?

Any advice would be greatly appreciated!
- Dan
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