Re: CL Paramter Passing - revisited - why

Narayanan:

On Tue, 19 February 2002, Narayanan Pillai wrote:

> --- Leif Svalgaard <leif@leif.org> wrote:
> > there will be a million answers to this one.
> > Numeric is packed 15 digits with 10 before the
> > decimal point and 5 after the point.
>
> I learned this when I started out, but I haven't got a
> satisfactory answer to why this happens. I guess I am
> asking whether this is by design or whether this is a
> by-product of some other part of the design?

It's both somewhat by design and a byproduct.

Originally, there was no SBMJOB CMD() parameter. Somewhere back around V1R3 or 
so, IBM enhanced SBMJOB to add the parameter and make the command 'easier' to 
use. Before then, the RQSDTA() parameter was the only way to specify the 
command to execute.

In order to make CMD() work reasonably well, IBM used existing support for 
command prompting, i.e., the command prompter that supports <F4> for commands. 
For most commands, this works very well because almost every command parameter 
has a clear definition; but the PARM() parameter of the CALL command must 
accept just abbout anything. No strong typing, no fixed lengths, etc. Without a 
definition of each PARM() value, the CALL command must rely on some defaults; 
hence, char(32) and dec(15 5).

Further, once the CMD() value is accepted by the SBMJOB command processing 
program, it gets converted into an RQSDTA() value. This eventually becomes the 
actual request message that gets submitted. This all must work whether SBMJOB 
is compiled into a program or entered at a command-line.

Technically, I suppose, the correct way to build a SBMJOB command that submits 
a CALL would still be to construct the RQSDTA() value rather than use CMD().

Here's a simple CLP to experiment with:

   pgm   ( +
           &p1  +
           &p2  +
           &p3  +
         )

   dcl     &p1         *char 50
   dcl     &p2         *char 50
   dcl     &p3         *char 40

dmpclpgm

   return
   endpgm

...and here's a sample command-line CALL that is the first example:

===> call tstcmdparm +
 ('12345678901234567890123456789012abcdefgh     ' +
'IJKLMNOPQR1234567890123456789012abcdefgh          ' +
'12345678901234567890123456789012abcdefgh')

Note that declared lengths are all >32 and that the lengths of the parm values 
don't necessarily match. Changing the PARM() values results in oddities in the 
values shown by DMPCLPGM. Sending it through SBMJOB can show more details.

Tom Liotta



--
Tom Liotta
The PowerTech Group, Inc.
19426 68th Avenue South
Kent, WA 98032
Phone  253-872-7788
Fax  253-872-7904
http://www.400Security.com


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