Re: 5250 programming: F3, F12 and CALLed programs

Am 11.08.2025 um 09:49 schrieb Patrik Schindler <poc@xxxxxxxxxx>:

Am 10.08.2025 um 23:50 schrieb Daniel Gross <daniel@xxxxxxxx>:

we use a char(2) parm that is passed to every interactive program, and it returns there a "return code".

Very lean and interesting approach! Thanks!
I still fail to grok that that — due to them by default being a pointer —, passed parameters are inherently bidirectional.

Yes they are - until you use the CONST keyword. In this case it's still a pointer, but the content is "unmutable" - at least, the compiler enforces that - you can stall change the contents using some tricks - but that's a story for another day.

That said - we always define program (entry) parameters as CONST - unless we really need to use it to communicate something back.

There is an idea, to allow VALUE for program parameters:

-> https://ibm-power-systems.ideas.ibm.com/ideas/IBMI-I-4546

I think that would be quite useful, and would set the dynamic program call on par with the procedure call - even if it's technically something completely different.

So I voted for that idea, and it's a "future consideration" meanwhile ... but who knows, when the RPG goddess will gift us that feature ;-)

BTW: Messages are more or less something for exceptions IMHO - and the new SND-MSG opcode makes it very easy to use (I know, you don't have that on your 170).

Regards,
Daniel