RE: Sharing variables between procedures

>You can't read an externally described file into a field, so the 
following won't work:

Who says you can't?

>From the V5R2 ILERPG reference, section "what's new..."
v Data-structure result for externally-described files
A data structure can be specified in the result field when using I/O 
operations
for externally-described files. This was available only for 
program-described files
prior to V5R2. Using a data structure can improve performance if there are
many fields in the file.


Rob Berendt
-- 
"They that can give up essential liberty to obtain a little temporary 
safety deserve neither liberty nor safety." 
Benjamin Franklin 




"Joe Pluta" <joepluta@xxxxxxxxxxxxxxxxx> 
Sent by: rpg400-l-bounces@xxxxxxxxxxxx
11/14/2003 09:48 AM
Please respond to
RPG programming on the AS400 / iSeries <rpg400-l@xxxxxxxxxxxx>


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Subject
RE: Sharing variables between procedures






> From: Joep Beckeringh
>
> BTW, while I was wondering why you were complicating things with
pointers,
> I noticed that according to the prototype your procedure returns a
pointer
> as well. But the rest of the coding suggests that is a typo.

You're of course correct, Joep.  Thanks for pointing that out.


> In RPG parameter passing is by reference unless specified otherwise.
Since
> you can only specify CONST and VALUE, VALUE is the only way to not
pass by
> reference. That is why you need to pass a pointer by value (otherwise
the
> pointer to the pointer would be passed).

True, but there's a slight problem with I/O.  You can't read an
externally described file into a field, so the following won't work:

FMYFILE    UF A E           K DISK 
DmyDS           E DS                  EXTNAME(MYFILE) BASED(pMYFILE)

PReadMYFILE       B                   export 
D                 PI              N 
d  Key                                 like(MYKEY) value
d  Buffer                              likeds(myDS)


C     Key           chain     MYFILE                Buffer
C                   return    %found(MYFILE) 
 
P                 e 


This syntax is invalid.  The only way I could find to make it work
requires an EVAL, which is what I'm trying to avoid:

d  Key                                 like(MYKEY) value
d  Buffer                              likeds(myDS)

C     Key           chain     MYFILE
C                   if        %found
C                   eval      Buffer = myDS 
C                   endif
C                   return    %found(MYFILE) 
 
As far as I know, there's no way in RPG to specific a parameter to use
the EXTNAME or LIKEREC parameter.  Maybe you can do it somehow in V5R2,
I don't know.

Joe 

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