Iterate through the fields in an externally described data structure

Hello all,

Here's one to chew on. Is there a way, preferably in RPGLE, to iterate
through the fields in an externally described data structure and display,
print, compare the values. Here's my problem.

I have a file with about 60 fields that needs  an audit when it's changed.
A perfect application for a trigger program. The problem is that they don't
want a copy of the entire record only the fields that have been changed.
I'd like a way to not have to change the trigger program if the database
changes so I want to systematically iterate through the fields in the
before and after buffer and compare the contents. If they are different,
write a record to an audit file. Sort of like the .fields collection in VB.

 I thought of using the output from a QUSLFLD API and comparing values as a
substring of the DS, but I think it would puke on Packed fields.

Any input would be appreciated.


Thanks,

Mark


Mark Walter
Sr. Programmer/Analyst
Hanover Wire Cloth a div of CCX, Inc.
mwalter@hanoverwire.com
http://www.hanoverwire.com
717.637.3795 Ext.3040