Re: Describing RPG IV

On 2/12/07, James H H Lampert <jamesl@xxxxxxxxxxx> wrote:

"Chris Pando" wrote:
> I do this [access files whose names are not known at
> compile time] all the time. Before calling the program,
> I'll do a DSPFFD (of the 'unknown file) to an outfile,
> and then open the file as program-described, mapped to a
> buffer. . . . It isn't difficult, much less
> extremely difficult. . . .

Uh, do a DSPFFD to an outfile before calling the
program?!?

While I'll admit that this sounds potentially a bit easier
to deal with than QUSLRCD and QUSLFLD, much less QDBRTVFD,
it also sounds like a slow and messy way to get the
meta-data.

Doing a DSPFFD to a spoolfile, and then processing that, is slow and messy
(and the way I wrote it the first time, in 1985 or so). The whole thing is
buried in a service program; I call it with a file name, and I'm
returned a pointer
to the various data structures. If I'm ever in there, I'll update the
logic to use
APIs (I'm always eager to use a new API), but as it ain't broke, I'm
not going to
fix it.

But  getting the meta-data is only part of the battle.
Until EXTFILE was added (and thank God the designers set
THAT up so that the object of the clause can be a
variable!), you had to use an OVRDBF just to get the file
to open.

Live and learn. I'll have to explore what EXTFILE can do; I can't say I've ever
used that keyword.

Chris
--
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