Re: OVRTAPF Using OPT01

[Vern Hamberg <vhamberg@xxxxxxxxxxxxxxxxxxxxxxxxx>]

No criticism of the attempt - I understand why, have done the same stuff 
for years - it's just not possible, AFAIK. I probably got a little 
off-track, assuming that PFs were in the question.

If it's a single-step process that is desired in a program, then use the 
various UNIX-type IFS functions. open() gives you a descriptor, read() lets 
you read a specified number of bytes through this descriptor. Have a DS as 
the buffer and go to town. These are all usable in RPGLE, I believe.

Interesting sidelight - there are optical files (OPTFs), but they are 
really stream files, not device fiels like TAPFs, AFAIK. There's a command, 
WRKOPTF, that is related to WRKOPTVOL. Anyhoo...

Vern

At 08:37 AM 1/21/2004 -0500, you wrote:
> I have used the OVRTAPF to read a tape file like a disk file.  In fact
> that was one of the minor selling points on moving to an As/400 from the
> S/36 with it's limited disk space and limited tape processing.  I think I
> may have even used OVRDKTF, but that was many years ago and since our
> release of OS/400 doesn't support diskette anymore I can safely say it's
> no longer in use.  Don't know if you can do a OVROPTF.  That's why I
> suggested an ifs approach.
> Just reiterating this for Vern so that he can understand why the author
> wanted to at least try this concept.  Granted a CD is no great shakes of
> space, but why use a two step process if you don't need to?
>
> Rob Berendt
> --
>
> Subject
> Re: OVRTAPF Using OPT01
>
> This can't be a physical file, can it, since those can't be written to a
> CD, AFAIK. I mean, the contents of a CD are mounted under /QOPT, and that
> is not part of the library-object system.
>
> If it's a PC-type DB file, is it proprietary to a DBMS like MS Access or
> SQL Server? If it's fixed length or delimited, just use CPYFRMIMPF like
> any
> other IFS file, since that's what  it is.
>
> HTH
> Vern
>
> At 09:49 AM 1/20/2004 -0800, you wrote:
> >Has anyone ever created an application using an OVRTAPF with OPT01?  I'd
> >like to be able to read a DB file from OPT01 and was wondering if I need
> >the OVRTAPF. Is such a thing possible?