Re: OVRTAPF Using OPT01 -- MIDRANGE-L

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?