On Tue, Nov 3, 2009 at 11:48 AM, Paul Gilmartin <paulgboul...@aim.com>wrote:
> On Tue, 3 Nov 2009 00:39:03 -0600, Chris Craddock wrote: > > > >The PARM interface is older than dirt and even though we can all agree > with > >hindsight that it was a momentously stupid design, it is nevertheless a > >formal, documented interface and literally thousands of badly written > >programs work correctly ONLY because the initiator is never going to give > >them a parameter string of more that 100 characters.<snip> > > > The Assembler CALL interface (likewise older than dirt) plus Rexx ATTCHMVS > and many other language calling interfaces (mostly newer than dirt) have > long supported parameters longer than 100. Are you suggesting that these > facilities are fraught with incompatibilites? Perhaps so risky that > the facilities should be curtailed? The existence of these other > interfaces, at least to AC=0 programs, makes the JCL PARM limit a > barrier that surrounds and protects little. If the JCL PARM limit were > relaxed, all old programs would continue to work exactly as they do now, > when passed the PARMs they are now being passed, completely oblivious > of any new capability. > When you call a batch job step program through another interface than "EXEC PGM=" you are taking responsibility for ensuring that the program's interface requirements are met. And you're right there are many such programs that can safely and easily be called exactly as you describe. That's completely and utterly not the point. There exists an unknowably large pool of programs that were written as batch job step programs with no expectation or intention of ever being invoked through any other interface. If you tried to call one of those via an assembler CALL interface, or ATTACHMVS, or any other permutation you can cook up and pass it more than 100 bytes of PARM data, you would break that program in an unpredictable way. Your prescription of "well don't do that" is fine in a world where everyone knows what they are doing and pays attention to the rules. That doesn't resemble the world we live in though. -- This email might be from the artist formerly known as CC (or not) You be the judge. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
