Exception vs function-check; ILE vs OPM

["Peter Dow" <pcdow@xxxxxxxxx>]

Hi Everyone,

 

I'm getting a little confused from RTM re exception vs function check and how error handling occurs when mixing OPM and ILE RPG programs. A particular vendor's menu program was originally written in RPG, and was recently converted to ILE RPG. It allows the user to enter commands using either native syntax or Sys/38 syntax. When executing a menu option, the way they determine which is which is to assume it is AS/400 syntax and call QCMDEXC passing the command, with an indicator on the CALL. If it fails, they try again with QCAEXEC. If that fails, the user is notified.

 

With ILE RPG, this method fails. The particular menu option in question happened to be a CHGDTA command. Yes, DFU. Even better (<G>) it was a Sys38 DFU. So the initial call to QCMDEXC shows an *ESCAPE message in the job log from CHGDTA saying the DFU program specified is not a DFU program (understandable), but then returns without setting on the error indicator, so no call to QCAEXEC is ever made.

 

Compiling the menu program in ACTGRP(*CALLER) or DFTACTGRP(*YES) makes no difference.

 

After reading and re-reading the manual, it seems to get down to the difference between an exception (a *ESCAPE, *NOTIFY or *STATUS message sent to the call stack entry as the result of a runtime error) and a function check (an exception message that is not handled by any call stack entry back to a control boundary or OPM). Both QCMDEXC and QDZCMDP (the CPP for CHGDTA) are OPM programs.

 

Based on all that, it appears either QDZCMDP or QCMDEXC somehow "handled" the exception message so that it does not become a function check. So finally, my question is, what does "handling" the message consist of? And is there anyway to change this behavior to mimic the OPM behavior without modifying the menu program?

 

TIA

 

Peter Dow
Dow Software Services, Inc.
909 425-0194 voice
909 425-0196 fax