EXEC parameters for changing COBOL application programs

The following parameter attributes apply:

Length of parameter list

Normally, MVS allows a 100-byte PARM string for an EXEC PGM statement. However, AR/CTL uses some of these bytes during processing. Therefore, 61 bytes is the maximum allowable length of the PARM string on the EXEC statement for an application program that uses AR/CTL.

Original operating system parameters

According to standard MVS linkage conventions, register 1 points to the original operating system parameter list. However, AR/CTL uses this register for other purposes and provides access to a copy of the original parameter list through MVS name token services.

Member ASMORIGP of the sample library contains model code (written in Assembler language) that you can adapt and include in an application program if the program needs access to a copy of the original parameter list. This sample shows how to fetch the operating system parameter list. The address of the list is located at offset +8 (byte 9) of the TOKEN field.

This sample also shows a quick way for the application program to detect whether AR/CTL is active. The sample sets the return code to zero if AR/CTL is active and to a nonzero value if AR/CTL is not active or a problem is detected.