RE: Need for separate Input and Output Areas in Display File

[Winchester Terry <terry.winchester@xxxxxxxxxxxxxxx>]

Joe,

These areas are level-05 entries copied into your program
by the pre-compiler.  They do not overlap in the example I
provided because your telling the compiler to copy a *single*
input (or output) record format individually. Try it an see :)

You may be thinking of this scenario:

    01  DSPFILE-area.
        copy dds-all-formats     of OE314D.

The above case is where you run into overlapping structures
due to the "redefines" statement inserted by the compiler.
This can cause horrific problems and is best avoided if at
all possible.

Terry

> -----Original Message-----
> From: Joe Pluta [mailto:joepluta@PlutaBrothers.com]
> Sent: Tuesday, August 13, 2002 9:57 AM
> To: cobol400-l@midrange.com
> Subject: RE: Need for separate Input and Output Areas in Display File
>
>
> > From: R. Bruce Hoffman, Jr.
> >
> > no offense intended here, Joe, but that's an RPG programmer's view.
>
> Bruce, you miss my point.  With this code:
>
>        01  DSPFILE-area.
>            copy dds-m1map-o     of OE314D.
>            copy dds-m2ctl-o     of OE314D.
>            copy dds-m2sfl-o     of OE314D.
>            copy dds-m2key-o     of OE314D.
>
> The four data structures OVERLAP.  Changing a field in
> dds-m1map-o will ALSO
> affect all three other formats.  And it's unlikely that those
> changes are
> ones you want.  With this technique, I can't just initialize
> a field in
> dds-m2ctl-o and be assured it will stay that way throughout
> the life of the
> program.
>
> I understand all about MOVE CORR and the joy it brings.  I use it
> extensively in my COBOL version of PSC/400.  But I ran into
> difficulties
> with the above coding technique.
>
> Joe Pluta
> www.plutabrothers.com
>
>
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