Using the Generated Copybooks

This document explains how clients built with the COBOL Wrapper use the generated copybooks. It covers the following topics:


IDL Interface Copybooks

The IDL interface copybooks (see folder include) are the API of the COBOL client application using client interface objects. You can customize the Starting COBOL Level for Data Items in Generated Copybooks according to your needs.

If IDL unbounded groups without maximum (/V) or arrays without maximum (for example (A100/V)) are contained in the IDL, these are mapped with keyword UNBOUNDED. In this case:

  • cut and paste the top-level COBOL groups where

    • anywhere deeper the keyword UNBOUNDED is contained into the LINKAGE SECTION

    • no keyword UNBOUNDED is contained into the WORKING STORAGE SECTION

    For details see Using IDL Unbounded Groups or Arrays without Maximum.

For all other IDLs, a starting level greater than one allows you to

  • embed (include) the generated copybook into other existing COBOL structures:

    1 MYGROUP.
      10 . . .
      10 . . .
      10 MYIDL.
      COPY MYIDL.
  • specify usage clauses such as EXTERNAL, GLOBAL etc.:

    1 MYIDL1 GLOBAL.
      COPY MYIDL1.
  • use multiple generated copybooks with duplicate parameter names on IDL level 1 in the same COBOL program:

    1 MYIDL1.
      COPY MYIDL1.
    1 MYIDL2.
      COPY MYIDL2.

More information:

ERXCOMM Copybook

The ERXCOMM copybook (see folder include) holds RPC metadata for RPC clients. Here you provide parameters that are needed to communicate with the broker and are not specific to client interface objects. Upon return from an RPC request it provides, for example, the error code. In this way it defines a context for RPC clients.

For usage, refer to the following sections:

ERXVSTR Copybook

The ERXVSTR copybook (see folder include) is an extension to the ERXCOMM copybook for RPC clients. It enables an RPC client to specify long broker passwords, and long user IDs/passwords for RPC authorization. Its usage is optional.

The RPC communication area extension copybook ERXVSTR is generated for Target Operating System z/OS and RPC clients using a call interface to its client interface object, meaning one of the following Client Interface Types is selected:

For usage, refer to the following sections:

COBINIT Copybook

The COBINIT copybook (see folder include) is generated if option Copybook for RPC Communication Area is selected. Its purpose is to set communication parameters such as COMM-ETB-BROKER-ID, COMM-ETB-SERVER-NAME etc. into the RPC Communication Area. You can set parameters made available through ERXCOMM Copybook and also ERXVSTR Copybook.

COBEXIT Copybook

The COBEXIT copybook (see folder include) is generated if option Copybook for RPC Communication Area is selected. Its purpose is to check and map error codes. COBOL statements that have been commented out are generated into the copybook as an example.