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#005 Change of behavior for ISPSTART PANEL command invocation since z/OS V2R2 ISPF

By Shigeki Kimura posted Wed September 16, 2020 06:16 AM

  
When ISPSTART is issued with the PANEL parameter and the OPT parameter is not specified, ISPF attempts to retrieve and validate the default command stack profile variable ZSTART. As a result, the initial primary option menu can be displayed with an error message.

Beginning in z/OS V2R2 ISPF, the initial command stack support was made available when invoking ISPSTART with the PANEL keyword. Several changes were made to support this new functionality. These include :
- ZSTART is the default command stack variable.
- To support a command stack being provided in an ISPF variable, ISPF initialization processing puts the name of the variable into the initial ZCMD value. The default is "ZSTART DEFAULT".
- To execute an initial command stack, the )PROC section of the first primary option menu panel executes before the initial display of the panel as well as after display of the panel.

In order to support an initial command stack being provided in an ISPF variable to a primary option menu specified using the PANEL parameter, ISPF puts the variable name (or "ZSTART DEFAULT" when the default cmd_stack_var_name value ZSTART is used) into the ZCMD variable. Then, the )PROC section of the first primary option menu displayed is executed before the initial display of the panel. The primary option menu in this scenario must not perform verification of the ZCMD variable in the )PROC section unless the verification allows for the initial command stack variable name (for example, ZSTART) to be stored in ZCMD.

As an alternative, one can specify a NULL value in the OPT parameter "OPT()", ie. ISPSTART PANEL(primary_panel_name) OPT(), to bypass the processing of the ZSTART variable. This prevents an initial command stack from being executed from the primary option menu which eliminates the error message.

Please note that the above information is also applicable to both ISPF and PDF command invocation in addition to ISPSTART.

For the documentation updates, please refer to ISPF DOC APAR OA59955 closed in August, 2020.

Hope it helps you.
Thanks!
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