Re: Using API's ?

Yes Scott it did happen to me and remember I was not originally using the
QSYSINC files. I was doing what you were recommending, creating beautiful
headers of my own. I wish I could remember the exact API but I would imagine
it was one of the work management API's as that was the sort of thing my
employer had me working on at that time (Late 80s early 90s). Programs were
working wonderfully one day and then after we installed a new release BOOM
all sorts of things started blowing up. I found the common thread of trouble
and it was all related to one API. I ended up having to compare the QSYSINC
with my include and low and behold there was a difference (one good enough
to cause a decimal data error if I remember correctly) Again I am not sure
which version of the OS it was that caused this problem, but it definitely
was a source of major grief.

Second I never code my API programs in CL. Almost all my programs require
the use of pointers or iterating over huge lists of things. CL is just way
too inefficient when it comes to that sort of thing.

Sorry that you doubt me... but I guess that is bound to happen sometimes.

Sincerely
Eric


______________________________________________
Eric N. Wilson
President
Doulos Software & Computer Services
2913 N Alder St
Tacoma WA 98407


----- Original Message -----
From: Scott Klement <infosys@klements.com>
To: <RPG400-L@midrange.com>
Sent: Thursday, September 09, 1999 3:19 PM
Subject: Re: Using API's ?


> Eric,
>       If IBM changed the parameters, or the layout of a data struct,
> programs would stop working when you upgraded to the new release.
> Its true that if you had used QSYSINC, its POSSIBLE that all you'd
> have to do is recompile the program to make it work.  But not really
> CERTAIN...
>
> However:
>       1) You can't use header files in CL programs, so any CL program
>           using an API would need to be changed anyway.
>       2) There aren't header files for the Unix-type APIs, so if they
>           changed these, you'd have a problem anyway.
>       3) In most of the APIs IBM uses a "format" code and a data
>           structure so they can change the API without screwing up
>           backwards compatability.
>
> I've got lots of programs that survived the conversion from V3R1 to
> V3R2 that didn't use QSYSINC.
>
> So, I guess I'm wondering why you're making this statement?   Did it
> really happen to you?  If so, I'd be very interested in the specifics!
> WHAT did they change, and in WHICH API?!
>
>
>
>
> "Eric N. Wilson" <doulos1@home.com> wrote:
> > I have learned my lesson about creating my own headers for API's, I
> >  will
> > give you a hint "DON'T EVEN THINK ABOUT IT". Early on in the
> >  development of
> > APIs on the AS/400 (V3R1???) IBM had the fields to a certain API
> >  defined one
> > way then on the next release certain very important fields changed
> >  their
> > lengths/types. Now I know that that is not to ever happen again but
> >  just to
> > be safe I will continue to ?COPY QSysInc/QRPGLESRC,xxxxx just safer
> >  all
> > around.
> >
> > ______________________________________________
> > Eric N. Wilson
> > President
> > Doulos Software & Computer Services
> > 2913 N Alder St
> > Tacoma WA 98407
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