I agree on both points.  I am totally mystified by the presence of O prefix on 
the PATHOPTS values.  It makes it so much hard for me to read; specially 
OWRONLY.  Why not just W, R and WR?  Sheesh.

I will suggest REPLACE instead of CREATE in the RFE.  Although that kind of 
implies behavior like I mentioned in my previous email, which is if the file 
already exists it "deletes" it and the creates a "new" version.  Is that the 
only behavior truly necessary?  Do we need an option where if it exists it 
simply leaves it alone?  I think so in the case of a job that may be reading 
the file.  Specifically, if the file already exists we don't want to truncate 
it at all.  But if it does not exist then we want to create it.  So do we have 
both REPLACE (delete the file and then create it) and CREATE (essentially 
DISP=SHR (I think) if the file already exists and DISP=NEW if it does not 
exist)?

Frank

________________________________
From: IBM Mainframe Discussion List <[email protected]> on behalf of 
Jesse 1 Robinson <[email protected]>
Sent: Friday, June 30, 2017 1:44 PM
To: [email protected]
Subject: Re: Possible RFE for new DISP JCL parameter options

I'm all in favor of the RFE in principle, but I think that choice of keyword is 
crucial. Based on decades of history: what happens in JCL stays in JCL. Forever.

I personally find the OMVS keywords unintuitive and therefore--unless one uses 
them frequently--deucedly difficult to keep straight. In the ancient NDM 
(ancestor of Connect:Direct) 'REPLACE' is used in the sense suggested by Gil: 
if it exists, overwrite it; otherwise create it; copy the data and move on with 
no muss and no fuss.

There are other possible values, but REPLACE seems to be available in JCL. Old 
farts may remember the advent of 'REUSE' in the TSO ALLOCATE command. The 
lengths we had to go to before REUSE move me to nominate the old mechanism as 
the single worst design point of MVS. At least the one that impinged on users 
in the most annoying manner.

Time for an innovation in JCL.

.
.
J.O.Skip Robinson
Southern California Edison Company
Electric Dragon Team Paddler
SHARE MVS Program Co-Manager
323-715-0595 Mobile
626-543-6132 Office ⇐=== NEW
[email protected]


-----Original Message-----
From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf 
Of Paul Gilmartin
Sent: Friday, June 30, 2017 11:38 AM
To: [email protected]
Subject: (External):Re: Possible RFE for new DISP JCL parameter options

On Fri, 30 Jun 2017 11:24:18 -0700, Charles Mills wrote:

>YES!!!
>
>Years ago I wrote and my company sold a mainframe-PC file transfer
>product (in the pre-FTP days), and it supported a DISP operand for the
>creation of mainframe datasets that worked exactly as you describe,
>with two steps under the covers. I'm trying to remember the keyword for the 
>specification.
>Perhaps CREATE. It made sense then (1989) and it makes sense today.
>
Many desktop editors call this REPLACE; SAVE fails for an existing file.

>(It also did a kind of extended SDB under the covers. You could specify
>any one or two of LRECL, RECFM and BLKSIZE and it would intuit the
>others. Had an algorithm that made intelligent guesses. Specify
>RECFM=FB,BLKSIZE=8000 it would give you LRECL=80. Specify
>LRECL=137,BLKSIZE=8000 and it would give you RECFM=VB.)
>
What might it do for RECFM=FB,BKLSIZE=10640 (which happens to be 133 * 80).
    526 $ factor 10640
     Factors of 10640 are 2 2 2 2 5 7 19

It's ambiguous for any number with 2 or more prime factors.

-- gil


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