Can one use the ISPF/SuperCE utility to compare a load module in a PDSE?

Document ID : KB000018787
Last Modified Date : 14/02/2018
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Description:

It is observed that a Copy of a load module under Endevor, via BSTCOPY, from PDSE to PDSE, can result in slight differences within the module, if a Byte compare using SuperCE is done.

It is advisable to do the comparison with PDSM36 (PDSMan) or AMBLIST (IBM); it will show that there is no actual difference in the executable code.

Solution:

Referring to the SuperCE help - tutorial option 17.5 'Comparing load modules' - ISPF compares the entire module, not only the executable code. This would include IDR data which would have compile and linkedit information, as well as other undocumented information for a program object (a load module in a PDSE library).

BSTCOPY will use the Binder API to perform the operation of copying the program object, and this implies effectively a re-Binding of the program.

The best way to compare Load modules, is therefore not to use SuperCE, but instead use either AMBLIST or PDSM36( PDSMAN); these will only consider the executable code, instead of reading the module using BSAM.

Sample JCL forPDSM36:


//PDSM36 EXEC PGM=PDSM36,PARM='mbrname'       
//* 
//PDSMRPT DD SYSOUT=*
//PDSMOLD DD DISP=SHR,DSN=library1
//PDSMNEW DD DISP=SHR,DSN=library2