Re: Class Notes for a PL/I Course.

---In [email protected], <giuseppe@...> wrote :

> > > Am I right betting a variable length dataset can't have a zero length
> > records?
> > I haven't worked with VS datasets, but I know that regular V[B] datasets
> > can have records with zero length. (At least in MVS, yes; in VM/CMS, no.)

> Ouch. Thanks.

> But I bet that if I use 0xFFFF for logical EOF I'm on
> the safe side?

The RDW will be a minimum of 4 or 5. So you can
use an RDW of 0 to indicate EOF, which is what
COPYFILE will do if you do a binary copy of a
RECFM=VB to RECFM=FB.

An RDW of 4 is a zero-length record. There's
no concept of an RDW of 0. The RDW is the
length of the data plus 4 bytes for the RDW
itself, so logically has to be a bare minimum
of 4.

BFN. Paul.