On Tue, 6 Jul 2010 06:54:54 -0700, Charles Mills wrote: >It seems to me that it is JCL's "job" to catch the error because the writer >of the PROC has no opportunity to do so. It's an obvious opportunity for a >"dumb user" error -- and it's the job of the "system" (broadly defined to >include JCL, the sysprog who wrote the PROC, etc.) to diagnose it. Quibbling >about syntax versus semantics does not help the user mystified why his JCL >change did not have any apparent affect. The assembler macro facility -- >which uses a syntax that is obviously a first cousin to the JCL PROC >facility -- would catch the error at the macro invocation level. > It's a prevalent habit of coders to exploit naive parameter list parsers by writing scripts which simply append overriding key/value pairs to the end of a default parameter string.
Historically, Linkage Editor and Assembler H permitted this in PARM strings, allowing the later value of the keyword to prevail. With the advent of Binder (IIRC; perhaps it was HLASM; perhaps both), duplicate keys in the PARM string were treated as errors. This was swiftly reverted to the earlier behavior, likely by APAR. But JCL differs from the mode in using the earlier value rather than the later. -- gil ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
