On Fri, Nov 13, 2020 at 3:35 PM Andrew Rowley <[email protected]>
wrote:

> On 14/11/2020 12:54 am, Kirk Wolf wrote:
>
> > The new commands (getpds and putpds) use BPAM+BSAM along with our
> existing
> > Co:Z record <-> stream processing framework to allow you to copy PDS
> > members to and from z/OS UNIX files.  Also included are extensive options
> > for ISPF stats processing.
> >
>
> Nice work. I have immediate uses for it.
>
> One question, I see the options:
>
> rdw
> preceed lines with a four byte IBM-style RDW, consisting of a two byte
> network order (big endian) length, followed by two bytes of zeros.
>
> l4
> preceed lines with a four byte network order (big endian) length of the
> record that follows. Note: Unlike the rdw option, this length value does
> not include the size of the length field.
>
> If you are looking at a file, how would you know whether the length
> field is included in the record length?
>

If you were reading a UNIX file, you would need to know whether it had
IBM-style RDWs, or l4 (which is compatible with FILEDATA=RECORD)


>
> The common practice seems to be that the length value in the RDW
> includes the length of the RDW itself. This is observed by other
> products e.g. FTP. Is there a reason to have the option to exclude the
> RDW length?
>
>
-l rdw  has a length that includes the 4-byte RDW length, compatible with
IBM

FYI - the "fromdsn" and "todsn" commands also have these options, but they
read or write a single data set.


> The whole RDW/record length concept causes a lot of confusion - even it
> seems in IBM. Requiring people to choose what type of length field will
> add to the confusion.
>
> Andrew Rowley
> Black Hill Software
>
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