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Generating JCL with the Assembler
The assembler macro language can be used to generate JCL. This example
produces DFDSS JCL and control statements. The sample that follows
should be adapted to satisfy local requirements. For a related
technique, see Generating REXX using the
Assembler.
Here is the JCL used to run the assembler. It specifies output to SYSPUNCH and that no object file will be created. SYSPUNCH points to
sysout in the JCL, but it could also be assigned to a dataset:
<![CDATA[
//S1 EXEC ASMC,PARM='DECK,NOOBJECT'
//ASM.SYSPUNCH DD SYSOUT=*
//ASM.SYSIN DD *
]]>
The macros used in this example follow. They use the Assembler's PUNCH instruction to put out the generated JCL:
<![CDATA[
PRINT OFF
.* THESE MACROS GENERATE CONTROL STATEMENTS
MACRO
PREFIX &PFX
.* ASSIGN A VALUE TO THE PREFIX VARIABLE
GBLC &DSNPRF
&DSNPRF SETC '&PFX'
GBLB &PSET
AIF (&PSET).NOJCL
.* GENERATE THE JCL AT THE START (ONLY ONCE)
PUNCH '//RESTORE EXEC PGM=ADRDSSU,PARM=''TYPRUN=NORUN'''
PUNCH '//SYSPRINT DD SYSOUT=*'
PUNCH '//TAPE DD DISP=SHR,DSN=INPUT.DSN'
PUNCH '//DISK DD .....'
PUNCH '//SYSIN DD *'
.* END OF JCL AT THE START
.NOJCL ANOP
.* MESSAGE
MNOTE *,'PREFIX SET TO &DSNPRF'
&PSET SETB 1
MEXIT
MEND
MACRO
.* ASSIGN VALUES IN THE DSN ARRAYS
.* ODSN IS PREFIXED WITH PREFIX VALUE
SDSN &DSN
GBLC &IDSN(10),&ODSN(10)
GBLA &NDSN
GBLC &DSNPRF
&NDSN SETA &NDSN+1
&IDSN(&NDSN) SETC '&DSN'
&ODSN(&NDSN) SETC '&DSNPRF..&DSN'
.* MESSAGE
MNOTE *,'SOURCE DSN &NDSN IS &DSN'
MNOTE *,' RENAMED TO &DSNPRF..&DSN'
MEXIT
MEND
MACRO
.* GENERATE THE CONTROL STATEMENTS
.* FROM THE STORED DSN ARRAYS
DONE
LCLA &LOOP
GBLA &NDSN
GBLC &IDSN(10),&ODSN(10)
.* MESSAGES
MNOTE *,'GENERATING CONTROL STATEMENTS'
MNOTE *,'&NDSN DSNS PROVIDED'
.* GENERATE CONTROL CARD HEADERS
PUNCH ' RESTORE DATASET(INCLUDE( -'
.* PASS 1
.D1 ANOP
&LOOP SETA &LOOP+1
AIF (&LOOP GT &NDSN).D2
.* GENERATE CONTROL CARD TYPE 1
&WORK SETC ' &IDSN(&LOOP) -'
PUNCH '&WORK'
AGO .D1
.* PASS 2
.D2 ANOP
PUNCH ' ) ) -'
PUNCH ' RENUNC('
&LOOP SETA 1
.R1 ANOP
&LOOP SETA &LOOP+1
AIF (&LOOP GT &NDSN).R2
&INDSN SETC '&IDSN(&LOOP)'
&OUTDSN SETC '&ODSN(&LOOP)'
.* GENERATE CONTROL CARD TYPE 2
&WORK SETC ' ( &INDSN , &OUTDSN ), -'
PUNCH '&WORK'
AGO .R1
.R2 ANOP
.* GENERATE THE FINAL CONTROL STATEMENTS AND JCL
PUNCH ' ) - '
PUNCH ' INDD(TAPE) OUTDD(DISK) CANCELERROR -'
PUNCH ' TOL(ENQFAILURE) CATALOG '
PUNCH '/*'
PUNCH '//'
.* MESSAGE
MNOTE *,'JCL GENERATION IS COMPLETE'
.* END OF FINAL STUFF
MEXIT
MEND
.* END OF MACROS
]]>
There are three macros defined:
- PREFIX establishes a prefix value used to rename the selected datasets. Some initial JCL is produced the first time that this macro is used.
- SDSN is used to specify dataset names to be processed.
- DONE is used to complete the JCL generation.
The sample macros provided do not validate their input; depending on
your environment and who might use such a tool, it may be necessary to
add additional logic to the macros. That, however, is beyond the scope
of this document. Now, here is an example of the use of these macros:
<![CDATA[
PRINT ON
.* INVOKE THE MACROS TO GENERATE THE JCL
PREFIX HLQ1.TEMP ** ASSIGN PREFIX
* INPUT THE DATASET NAMES
SDSN SOME.DSN1
SDSN SOME.DSN2
SDSN SOME.DSN3
SDSN SOME.DSN4
SDSN MORE.DSN5
SDSN MORE.DSN6
PREFIX HLQ2.TEMP ** CHANGE PREFIX
SDSN SOME.DSN7
SDSN SOME.DSN8
SDSN MORE.DSN9
SDSN MORE.DSN10
SDSN SOME.DSN11
* GENERATE THE JCL
DONE
END
]]>
So, if you concatenate the JCL, the macros and the example and add a final //, you should be able to produce the JCL output directed to SYSPUNCH.
This article was inspired by an inquiry on the IBM-Main newsgroup.
As has been noted there, SYSPUNCH can also be directed to a temporary
dataset and then submitted by copying it to an INTRDR output. That
would require the addition of a JOB JCL card at many installations.
Feedback
Comments or suggestions can be
sent to the author.
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