Building z/OS batch applications

Learn how to build z/OS batch applications and the steps to consider when doing so.

To build an application for IBM MQ for z/OS that runs under z/OS batch, create job control language (JCL) that performs these tasks:
  1. Compile (or assemble) the program to produce object code. The JCL for the compilation must include SYSLIB statements that make the product data definition files available to the compiler. The data definitions are supplied in the following IBM MQ for z/OS libraries:

    • For COBOL, thlqual.SCSQCOBC
    • For assembler language, thlqual.SCSQMACS
    • For C, thlqual.SCSQC370
    • For PL/I, thlqual.SCSQPLIC

  2. For a C application, prelink the object code created in step 1.
  3. For PL/I applications, use the compiler option EXTRN(SHORT).
  4. Link-edit the object code created in step 1 (or step 2 for a C application) to produce a load module. When you link-edit the code, we must include one of the IBM MQ for z/OS batch stub programs (CSQBSTUB or one of the RRS stub programs: CSQBRRSI or CSQBRSTB).

      CSQBSTUB
      single-phase commit provided by IBM MQ for z/OS

      CSQBRRSI
      two-phase commit provided by RRS using the MQI

      CSQBRSTB
      two-phase commit provided by RRS directly

    Notes:

    1. If we use CSQBRSTB, we must also link-edit the application with ATRSCSS from SYS1.CSSLIB. Figure 1 and Figure 2 show fragments of JCL to do this. The stubs are language-independent and are supplied in library thlqual.SCSQLOAD.
    2. If the application runs under Language Environment, we should ensure you link-edit with the Language Environment DLL instead as described in Building z/OS batch applications using Language Environment.

  5. Store the load module in an application load library.

Figure 1. Fragments of JCL to link-edit the object module in the batch environment, using single-phase commit
⋮
//*
//* WEBSPHERE MQ FOR Z/OS LIBRARY CONTAINING BATCH STUB
//*
//CSQSTUB   DD  DSN=++THLQUAL++.SCSQLOAD,DISP=SHR
//*
⋮
//SYSIN     DD *
  INCLUDE CSQSTUB(CSQBSTUB)
⋮
/*
Figure 2. Fragments of JCL to link-edit the object module in the batch environment, using two-phase commit
⋮
//*
//* WEBSPHERE MQ FOR Z/OS LIBRARY CONTAINING BATCH STUB
//*
//CSQSTUB   DD  DSN=++THLQUAL++.SCSQLOAD,DISP=SHR
//CSSLIB    DD  DSN=SYS1.CSSLIB,DISP=SHR
//*
⋮
//SYSIN     DD *
INCLUDE CSQSTUB(CSQBRSTB)
INCLUDE CSSLIB(ATRSCSS)
⋮
/*

To run a batch or RRS program, we must include the libraries thlqual.SCSQAUTH and thlqual.SCSQLOAD in the STEPLIB or JOBLIB data set concatenation.

To run a TSO program, we must include the libraries thlqual.SCSQAUTH and thlqual.SCSQLOAD in the STEPLIB used by the TSO session.

To run a UNIX System Services batch program from the UNIX System Services shell, add the libraries thlqual.SCSQAUTH and thlqual.SCSQLOAD to the STEPLIB specification in your $HOME?.profile like this: 
STEPLIB= thlqual.SCSQAUTH: thlqual.SCSQLOAD
export STEPLIB
Parent topic: Preparing your program to run