Re: Wiping a file on open in RPG

I found it interesting some years ago to look at the _R* functions - there are some functions there that just are not available in RPG - IBM just didn't choose to include them.


There was a community-offered generic tool to work with data in RPG - probably a service program. This was in RPG III, IIRC, and there were things it would not handle - like columns with null attributes, maybe. We used it when I worked at RJS Software.


So I looked at the _R* functions, and they could have handled all that the tool did not, so far as I could tell. Never did continue with it - would be interested, just for fun, to see it again, though.


Cheers
Vern

On Thu, 11 Jan, 2024 at 1:31 PM, Rob Berendt <robertowenberendt@xxxxxxxxx> wrote:


To: rpg programming on ibm i

Tried to see if there was an Fspec option on an OUTPUT file to say
overwrite and I didn't see any. And nothing grabbed me by the gills on
OVRDBF. You might be best off with your proposed solution. Even tried the
following to see if there was some default on an OUTPUT file and ended up
with 10 rows when I ran it twice (even used JHHL rpg):
FT20240111 O E DISK
* create table rob.t20240111 (myts timestamp) RCDFMT R20240111
C 1 DO 5
C EVAL MYTS = %TIMESTAMP()
C WRITE R20240111
C ENDDO
C SETON LR

On Tue, Jan 9, 2024 at 3:24 PM James H. H. Lampert via RPG400-L <
rpg400-l@xxxxxxxxxxxxxxxxxx<mailto:rpg400-l@xxxxxxxxxxxxxxxxxx>> wrote:

On 1/9/24 12:11 PM, Bryan Dietz wrote:

i scanned some source i accumlated for "_Ropen"

it can be used in RPGLE.

Right. I've had more than one occasion to use runtime calls more
idiomatic to C, but here, I was looking for something that was
RPG-native and RPG-idiomatic.

And Scott said:

I mean... yes you can do this, but... if the only reason is to
clear the file, wouldn't it be easier to just run CLRPFM prior to
opening it?

I quite agree. In this case, lacking a native equivalent, it would
probably be easier to make the file USROPN, and wipe the file by
shelling out a CLRPFM with QCMDEXC, than to use the _Rxxxxx calls.

--
JHHL
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