Version 9.6
 —  Software AG IDL Extractor for COBOL  —

Introduction to the IDL Extractor for COBOL


Introduction

The Software AG IDL Extractor for COBOL inspects a COBOL source and its copybooks for COBOL data items to extract. It can also extract directly from copybooks. In a user-driven process supported by an Extractor Wizard, the interface of a COBOL server is extracted and - with various features offered by a Mapping Editor - modelled to a client interface. The property view to which the editor is connected supports you in mapping the COBOL server to the client interface.

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The results of this process are two related files mapping the client interface to the COBOL server:

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Extractor Wizard

The extractor wizard guides you through the extraction process. The wizard supports the following tasks:

The extractor wizard is described in a step-by-step tutorial; see Using the IDL Extractor for COBOL - Overview.

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Mapping Editor

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The COBOL Mapping Editor is the tool to map the COBOL server interface selected in the Extractor Wizard to IDL. This section gives a short overview of the mapping features provided:

See COBOL Mapping Editor for more information.

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Supported COBOL Interface Types

The IDL Extractor for COBOL supports as input a COBOL server with various interface types. This section covers the following topics:

The interface type you are mostly working with can be set in the preferences. See IDL Extractor for COBOL Preferences.

CICS with DFHCOMMAREA Calling Convention

The IDL Extractor for COBOL supports CICS programs using the standard DFHCOMMAREA calling convention.

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The following illustrates roughly how you can determine whether a COBOL server follows the DFHCOMMAREA calling convention standard:

LINKAGE SECTION.
01 DFHCOMMAREA.
   02 OPERATION                       PIC X(1).
   02 OPERAND-1                       PIC S9(9) BINARY.
   02 OPERAND-2                       PIC S9(9) BINARY.
   02 FUNCTION-RESULT                 PIC S9(9) BINARY.

PROCEDURE DIVISION USING DFHCOMMAREA.
   . . .

Typically DFHCOMMAREA programs have a DFHCOMMAREA data item in their Linkage Section and address this item in the PROCEDURE DIVISION header. If you find this in your COBOL source it's a clear indication it is a DFHCOMMAREA program. But even if this is missing, it can be a DFHCOMMAREA program, because there are alternative programming styles. If you are unsure, consult a COBOL CICS specialist or see CICS DFHCOMMAREA under COBOL Parameter Selection for more information.

See Step 4: Define the Extraction Settings and Start Extraction for more information on extracting COBOL servers with this interface type.

CICS with Channel Container Calling Convention

The IDL Extractor for COBOL supports CICS programs using the channel container calling convention.

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The following illustrates roughly how you can determine whether a COBOL server follows the Channel Container standard.

WORKING-STORAGE SECTION.
01 WS-CONTAINER-IN-NAME               PIC X(16) VALUE "CALC-IN".
01 WS-CONTAINER-OUT-NAME              PIC X(16) VALUE "CALC-OUT".
. . .
LINKAGE SECTION.
01 LS-CONTAINER-IN-LAYOUT.
   02 OPERATION                       PIC X(1).
   02 OPERAND1                        PIC S9(9) BINARY.
   02 OPERAND2                        PIC S9(9) BINARY.
01 LS-CONTAINER-OUT-LAYOUT.
   02 FUNCTION-RESULT                 PIC S9(9) BINARY.

PROCEDURE DIVISION.
   . . .
   EXEC CICS GET CONTAINER (WS-CONTAINER-IN-NAME) SET (ADDRESS OF LS-CONTAINER-IN-LAYOUT) ...
   . . .
   EXEC CICS PUT CONTAINER (WS-CONTAINER-OUT-NAME) FROM (ADDRESS OF LS-CONTAINER-OUT-LAYOUT) ...
   . . .

Channel Container programs use EXEC CICS GET CONTAINER in their program body (PROCEDURE DIVISION) to read their input parameters. Output parameters are written using EXEC CICS PUT CONTAINER. There is no clear indication in the linkage or working storage section to identify a channel container program. If you are unsure, consult a COBOL CICS specialist for clarification.

See Step 4: Define the Extraction Settings and Start Extraction for more information on extracting COBOL servers with this interface type.

CICS with DFHCOMMAREA Large Buffer Interface

This type of program has a defined DFHCOMMAREA interface to access more than 31 KB of data in CICS. The interface is the same as the webMethods WMTLSRVR interface. This enables webMethods customers to migrate to EntireX.

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Technically,

See Step 4: Define the Extraction Settings and Start Extraction for more information on extracting COBOL servers with this interface type.

Micro Focus with Standard Linkage Calling Convention

Standard call interfaces with a given number of parameters are supported. Every parameter addresses a fixed COBOL structure.

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Technically, the generated COBOL server skeleton contains

See Step 4: Define the Extraction Settings and Start Extraction and Standard Linkage under COBOL Parameter Selection for more information on extracting COBOL servers with this interface type.

Batch with Standard Linkage Calling Convention

Standard call interfaces with a given number of parameters are supported. Every parameter addresses a fixed COBOL structure.

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Technically, the COBOL server contains

See Step 4: Define the Extraction Settings and Start Extraction and Standard Linkage under COBOL Parameter Selection for more information on extracting COBOL servers with this interface type.

IMS MPP Message Interface (IMS Connect)

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IMS message processing programs (MPP) get their parameters through an IMS message and return the result by sending an output message to IMS. The IDL Extractor for COBOL enables extractions from such programs.

The COBOL server contains:

See Step 4: Define the Extraction Settings and Start Extraction and IMS MPP Message Interface (IMS Connect) in COBOL Parameter Selection for more information on extracting COBOL servers with this interface type.

IMS BMP with Standard Linkage Calling Convention

IMS batch message processing programs (BMP) with PCB parameters are directly supported. You have the option to specify a PSB list as input to the extractor to locate PCB parameters.

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Technically, the COBOL server contains

See Step 4: Define the Extraction Settings and Start Extraction and IMS BMP Standard Linkage under COBOL Parameter Selection for more information on extracting COBOL servers with this interface type.

What to do with other Interface Types?

Other interface types, for example CICS with non-DPL-enabled DFHCOMMAREA, can be supported by means of a custom wrapper. If you have to extract from such a COBOL server, proceed as follows:

  1. Implement a custom wrapper, providing one of the supported interface types above.

  2. Extract from this custom wrapper.

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Server Mapping File (SVM)

The SVM file (Server Mapping File) completes the Software AG IDL file with a mapping from the programming-language-neutral parameter definition in the IDL file to the parameters and data types expected by the COBOL server. In contrast to a CVM file, an SVM file is deployed to the server environment, see Server Mapping Deployment.

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The SVM file contains

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SVM File Deployment

SVM files obtained using the extraction process are required by the RPC server for correct mapping from the language-neutral parameter definition in the IDL file to the COBOL server. Therefore, the SVM file has to be deployed to the RPC server.

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