How the subject was approached.
These were the basic steps taken.
- Phase 1 - The Benchmark
- Code a small COBOL program to increment and display a counter
- Code a REXX routine which used LINKPGM to invoke the above directly
- Phase 2 - Pre-initialisation
- Code an Assembler program to drive the LE pre-initialisation program CEEPIPI
- Code a REXX routine which used LINKPGM to invoke the Assembler program, which in turn invoked the COBOL program
At this point the pre-initialisation concept was working.
- Phase 3 - Adding a second parameter
- Code a second COBOL program to accept two parameters to test passing data back to REXX
- Modify the Assembler program to handle two parameters as input
- Code a second REXX routine to pass two parameters again using LINKPGM
At this point the ability to pass data back and forth to the HLL program was confirmed.
- Phase 4 - Do something useful
- Code a third COBOL program to perform queries against a VSAM KSDS
- Modify the REXX routine to ensure the receiving variable was large enough
- Modify the Assembler program to invoke the VSAM driver
At this point the ability to process a VSAM KSDS from REXX was established