Re: Variable length MODS

[tomh@xxxxxxxxx]

Let's say that there are 3 entries in the PFRTBLF file that I can use.  SizeLabels will = 15, which is ALLOC'd to ptrLabels.  What happens if I try to access Labels(4) in my program?  Will I get an array bounds error?  Will I get weird data?

"Peter Dow" <pcdow@yahoo.com> Sent by: owner-rpg400-l@midrange.com 04/13/01 01:49 AM Please respond to RPG400-L

To:        <RPG400-L@midrange.com>         cc:                 Subject:        Re: Variable length MODS

Hi Tom,

Welcome to the wonderful world of pointers. Define your MODS as based on a
pointer, with OCCURS set to a high number. No storage is actually used for
this definition. Once you know how many occurrences you need, set the basing
pointer to ALLOCate memory for NbrLabels * size of one MODS occurrence.

d ptrLabels                     s                *
d Labels                         s          5  0         dim(9999)
based(ptrLabels)
d SizeLabels                   s        10  0

d ptrTot1                        s                *
d Tot1DS                       ds                  occurs(9999)
based(ptrTot1)
d    amt1                                    7  2    dim(7)
d SizeTot1DS                 s        10  0

d ptrTot2                        s                *
d Tot2DS                       ds                  occurs(9999)
based(ptrTot2)
d    amt2                                    8  2    dim(7)
d SizeTot2DS                 s        10  0

c*  Read thru labels file, counting all of the useable label records
c*  Store that count in NumLabels to give us the number of Occurs for each
DS

c                    eval         SizeLabels = %size(Labels) * NumLabels
c                    alloc        SizeLabels              ptrLabels

c                    eval         SizeTot1DS = %size(Tot1DS) * NumLabels
c                    alloc        SizeTot1DS            ptrTot1

c                    eval         SizeTot2DS = %size(Tot2DS) * NumLabels
c                    alloc        SizeTot2DS            ptrTot2

 * At this point you can refer to Labels, Tot1DS, or Tot2DS as you normally
would, e.g.

c                    eval         Labels(5) =  10

or

c         7         occur       Tot1DS
c                    eval          amt1 = amt1 + 73.5

I haven't done this in awhile, but I'm sure someone will correct me if I got
anything wrong ;)

hth,
Peter Dow
Dow Software Services, Inc.
909 425-0194 voice
909 425-0196 fax




----- Original Message -----
From: tomh@simas.com
To: rpg400-l@midrange.com
Sent: Thursday, April 12, 2001 3:38 PM
Subject: Variable length MODS



I need to build several MODS (multiple-occurence data structures), but I
don't know the number of occurences that I'll need for them until I read
some data from a file.  Of course, I could just set the OCCURS on the D-spec
to a high number, but would rather just create enough occurences to handle
the data.

Something like this:

d Labels                         s                dim(NumLabels) inz

d Tot1DS                       ds               occurs(NumLabels) inz
d amt1                                       7  2    dim(7)

d Tot2DS                       ds               occurs(NumLabels) inz
d amt2                                       8  2    dim(7)

c*  Read thru labels file, counting all of the useable label records
c*  Store that count in NumLabels to give us the number of Occurs for each
DS

Tom

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