RE: Passing a file to a procedure

[Vernon Hamberg <vhamberg@xxxxxxxxxxx>]

Exactly - _RFILE is returned by _Ropen and has pointers to input and 
output buffers, various NULL maps, IO feedback area, etc. All this 
would be placed into a data structure and then passed by whatever 
means available. Some of that stuff might be available to the RPG 
program - I forget whether we can get at the buffers directly. We CAN 
get to the feedback area.

One big problem - there are no /copy members in QYSINC for these 
things. So we'd have to build our own - as many do already for other 
APIs. These will probably not change much - but one should check 
member RECIO in QSYSINC/H to see what's there.

Of course, you can't open a file in RPG using both F-specs and these 
_R* functions. As you said, file-agnostic won't be able to use 
F-specs, unless you don't care about modern elements like 
NULL-capability, which is more and more prevalent as we use CREATE 
TABLE more and more.

Julian Moneypenny some years ago had utilities for file-agnostic 
processing, using an internally-defined file - this has the big 
problem of not handling these new elements I mention above.

Too much fun on a Saturday!!

Vern

At 10:47 AM 11/24/2007, you wrote:

> > From: Vernon Hamberg
> >
> > He wants to pass some kind of reference to an opened file to another
> > program - then work with it - this reference is available in C
>
> What he wants is to be able to pass a file handle.  We don't have file
> handles in RPG (today) and that makes it tough.
>
> > My recommendation is to write what he wants in an ILE C module and
> > bind it into his app with procedure calls from ILE RPG.
>
> Yup, this is the ticket.  It's been forever since I tried to write an ILE C
> file procedure, but it's not black magic for someone with C experience.  You
> could write a wrapper procedure for the open procedure and return the file
> pointer, and then pass that back to your process and close procedures.
>
> He doesn't get to use the RPG syntax, of course, which I think is the issue.
> I think James wants to be able to write file-agnostic RPG syntax, an
> admirable goal.  As Paul points out, the closest you can get via RPG is if
> the files have the same external format.  Otherwise it's embedded SQL.
>
> Joe
>
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