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JCLScript Features and Benefits When validating and analyzing IBM z/OS Job Control Language (JCL), JCLScript
provides numerous features and high-level programming language constructs for complementing, customizing and extending PowerJCL's
extensive default processing capabilities, including:
Numerous syntactical constructs suitable for high-level structured programming: IF/ELSE/ENDIF, CASE/ENDCASE, PERFORM/GOBACK,
SET, GOTO, DOWHILE/ENDDO, REPEAT/UNTIL, PUSH/POP stack, DISPLAY/PRINT, EXEC, etc.
Capability of executing programs (load modules), REXX
procedures, CLIST procedures, utilities (i.e., SORT), etc. and passing/returning user-defined parameters using the polymorphic
EXEC statement. All default ddnames (SYSIN, etc.) used by PowerJCL can be dynamically changed to avoid conflicts with executed
programs.
Seamless parameter-sharing
interface to IBM's REXX general purpose programming language, including a transparent variable pool sharing capability. Other
general purpose programming languages (COBOL, etc.) may also be used to further extend PowerJCL's default processing
capabilities.
GETINFO
function which can seamlessly retrieve z/OS operating system information (i.e., SPACE allocation attributes, DCB attributes,
ISPF statistics, member names, directory information, creation/expiration dates, device types, etc.) relating to z/OS libraries,
datasets, volumes, etc.
Capability of natively performing input/output operations (OPEN, CLOSE, GET, PUT) against z/OS
library (partitioned dataset) members and sequential datasets allowing these files and members to be inspected, created and
modified while validating and analyzing JCL.
Input/output
functions include the capability of dynamically allocating z/OS datasets (DD, OUTPUT) using user-defined JCLScript file allocation
variables. File allocation variables are used by the JCLScript ALLOC statement and contain the necessary JCL parameter values
(e.g., DSN, DISP, etc.) to allocate files. Datasets and libraries may also be dynamically unallocated or concatenated using
the JCLScript UNALLOC, CONCAT and UNCONCAT statements.
Example
JCLScript can be used to detect if any installation JCL standards have
been violated. The following JCLScript example demonstrates how to determine if any program libraries specified on STEPLIB
or JOBLIB DD statements are also redundantly contained in the operating system's link pack or link list areas:
If DD.DSN Defined
And
SYS.STMTNAME = 'STEPLIB' or 'JOBLIB'
Set i = 1
DoWhile SYS.LINKLIB.&i
Defined
If SYS.LINKLIB.&i = DD.DSN.NAME
Display '//' SYS.STMTNAME ' DSN=' DD.DSN.NAME
' IS IN LINKLIB...'
ExitDo
EndIf
Set i += 1
EndDo
EndIf
Example
The following JCLScript example displays any SPACE parameters
that may appear on DD statements:
If Sys.StmtType = 'DD' ;JCL Statement Type = DD?
And
DD.Space Defined
*-- Display SPACE sub-parameter values individually...
Display 'DD.Space = ' DD.Space
Display 'DD.Space.PriQty = ' DD.Space.PriQty
Display 'DD.Space.SecQty
= ' DD.Space.SecQty
Display 'DD.Space.DirQty = ' DD.Space.DirQty
*-- Display SPACE sub-parameter values using a DOWHILE loop...
Set
i = 0
DoWhile DD.Space.&i defined
Display 'DD.Space.' &i ' = ' DD.Space.&i
Set i +=
1
EndDo
EndIf
Example
The following JCLScript example demonstrates how a library member
(specified with a DSN=library(member) JCL parameter) can be dynamically allocated using the JCLScript ALLOC
statement:
Del TEMPDD.*
Set TEMPDD.DSN.NAME
= DD.DSN.NAME
Set TEMPDD.DSN.MEMBER = DD.DSN.MEMBER
Set TEMPDD.DISP.STATUS = 'SHR'
UnAlloc DD = TEMPDD
Alloc DD = TEMPDD
...
The JCLScript GET statement or a utility, user program,
REXX procedure, etc. can subsequently be used to read and process the individual member records. This example uses JCLScript
file allocation variables to specify JCL parameters for the allocation of a library member and is equivalent to the following
static JCL specification:
//TEMPDD
DD DSN=dsname(member),DISP=SHR
Example
The following JCLScript example demonstrates how a temporary
dataset can be dynamically allocated using the JCLScript ALLOC statement:
del dfsparm.*
set dfsparm.disp.status = 'new'
set dfsparm.disp.normal
= 'delete'
set dfsparm.disp.abnormal = 'delete'
set dfsparm.space.type = 'trk'
set dfsparm.space.priqty = 1
set dfsparm.space.secqty = 1
set dfsparm.unit.device
= 'sysda'
set dfsparm.dsorg = 'ps'
set dfsparm.recfm
= 'fb'
set dfsparm.lrecl = 80
set dfsparm.blksize
= dfsparm.lrecl * 293
unAlloc dd = dfsparm
Alloc dd = dfsparm
This example uses JCLScript file allocation variables to specify JCL parameters for
the allocation of a temporary dataset and is equivalent to the following static JCL specification:
//DFSPARM DD DISP=(NEW,DELETE,DELETE),
// SPACE=(TRK,(1,1)),
// UNIT=SYSDA,
// DSORG=PS,
// RECFM=FB,
//
LRECL=80,
// BLKSIZE=23440
Example
The following
JCLScript example demonstrates how all JCL statement parameters and their values can be inspected using JCLScript:
Set Stmt = Sys.StmtType
If
&Stmt is not null
Set i = 0
DoWhile &Stmt..JCLPARM.&i Defined
Case
When i = 0
Display 'JCLPARM.'
&i ' = ' &Stmt..JCLPARM.&i
When Other
Set Parm = &Stmt..JCLPARM.&i
Display 'JCLPARM.' &i
' = '
&Stmt..JCLPARM.&i
'=' &Stmt..&Parm
EndCase
Set i += 1
EndDo
EndIf
This example uses several JCLScript system and JCL variables (stmttype.JCLPARM.nn,
etc.) to access JCL parameters and will display output similar to the following:
JCL statement: //
SET UNIT=SYSDA
//ddname DD DSN=dsname,
// DISP=(NEW,CATLG,DELETE),
// UNIT=&UNIT,
// SPACE=(CYL,(3,3),RLSE),
// DCB=(RECFM=FB,LRECL=1000,BLKSIZE=0)
JCLScript output: JCLPARM.0
= 5
JCLPARM.1 = DSN=dsname
JCLPARM.2 = DISP=(NEW,CATLG,DELETE)
JCLPARM.3 = UNIT=SYSDA
JCLPARM.4 = SPACE=(CYL,(3,3),RLSE)
JCLPARM.5 = DCB=(RECFM=FB,LRECL=1000,BLKSIZE=0)
Example
The following JCLScript example uses a computation from “Frequently Asked Questions about Calendars” to calculate the current day of week:
Set year = sys.date.year
;yyyy
Set month = sys.date.month ;mm
Set day = sys.date.day ;dd
Perform GetDay
...
Exit
:GetDay
Set
weekday.0 = 'Sunday'
Set weekday.1 = 'Monday'
Set weekday.2 = 'Tuesday'
Set weekday.3 = 'Wednesday'
Set
weekday.4 = 'Thursday'
Set weekday.5 = 'Friday'
Set weekday.6 = 'Saturday'
Set a = (14 - month) / 12
Set
y = year - a
Set m = month + 12*a - 2
Set d = (day + y + y/4 - y/100 + y/400 + (31*m)/12) % 7
Display 'Day
of Week = ' weekday.&d
GoBack
Example
The following JCLScript example demonstrates how the library names and
the individual name segments specified on a JCLLIB statement can be inspected for conformance to installation JCL standards:
If SYS.STMTTYPE = 'JCLLIB'
And JCLLIB.ORDER Defined
Set i = 0
DoWhile JCLLIB.ORDER.&i Defined
Display 'DSN.' &i ' = ' JCLLIB.ORDER.&i
Set j
= 0
DoWhile JCLLIB.ORDER.&i..&j Defined
Display 'SEGMENT.' &j ' = ' JCLLIB.ORDER.&i..&j
Set j += 1
EndDo
Set i += 1
EndDo
EndIf This example uses the JCLLIB.ORDER.nn variables
to access JCLLIB statement library names and name segments. |
E-JCL Software, Inc. is an IBM Business Partner. Copyright © 2014 E-JCL Software, Inc. All rights reserved. |
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