JCL Class Ses

8/8/2019 JCL Class Ses

1/273


2/273

2

COURSE OBJECTIVES

Appreciate the need for Job Control Language.

Have an overview of Job Control Language in IBM environment.

Know the structure of Job Control Language statements. Know the usage of the various parameters of Job Control

Language statements.

Know the structure of Job Control Language procedures.

Know the concept of Generation Dataset Groups.

Know the purpose and usage of common IBM utilities.

Be able to write JCLs and test them on MVS workbench.

Appreciate the relation between COBOL program and JCLs.


3/273

3

SESSION -- I


4/273


5/273

5

JOB CONTROL LANGUAGE ( JCL )

Job Control Language is a means of communication between a

program and the MVS Operating System. Without JCL, no program can run on an IBM Mainframe.

JCL is not a procedural language.

Provides primary interface between user and JES ( Job EntrySubsystem ).

Used to perform batch mode processing under MVS.

Within a job, JCL provides the specification necessary for MVS to process the job.


6/273

6

Specifications for a job are

* User identity.

* Data file identity.* Resource Requirement.

* Error handling .


7/273

7

WHY JCL ?

To identify themselves (users) to the system for security andaccounting purposes.

To identify the directory and data files required for the job.

To specify the I/O devices required by the job ( Tape, Disk,Printer).

To specify what action the system should take in exceptional

cases.


8/273


9/273

9

HOW JOB IS EXECUTED

The Initiator selects a job for execution and invokes the

interpreter. The interpreters job is to examine the job information

passed to it by JES and create a series of control blocks in the

address space. For each job step the initiator invokes Allocation Routinesto allocate resources (units, volumes and data sets) required bythe job step.

Contd..


10/273

10

HOW JOB IS EXECUTED ( Contd..)

The Initiator then creates a user region, loads the user programinto it and transfers control to the user program.

When the execution of user program is complete, the initiator

invokes routine to deallocate the resources used by the job step.


11/273

11

OUTPUT LISTING GENERATED AFTER JOBEXECUTION

Job log : is a record of JES messages written to the operatorsconsole as well as the operators reply where appropriate .

JCL listing: lists the JCL steps performed.

The Message Log : shows system messages concerning theexecution of job steps and the allocation and deallocation of datasets.

Sysprint : output listing for sysprint data set which specifiessysout =A


12/273

12

BASIC FORMAT OF JCL STATEMENTS

identifier [name] [operation] [parameters] [comments]

Explanation

Identifier Two slashes starting in column 1. Exceptions: (1) for adelimiter statement,/* starting in column 1;(2) for a

comment statement,//* starting in column 1.

Name O ne to eight alphanumeric or national characters,starting with a letter or national character.

Must begin in column 3 if coded.

Contd..


13/273

13

Operation A valid operation code,such as JOB,EXEC,or DD.

Must be preceded and followed by a space.

Parameters One or more parameters depending on the operation.

Individual parameters are separated from one another

by commas,with no intervening spaces.

Comments Comments may follow the parameters,preceded by one

space and not extending beyond column 71.


14/273

14

E.g.. The statements in the sample JCL can be categorizedinto five different fields.

// Name Operation Parameters Comments// JOB1 JOB (P155),

XYZ,CLASS=A,PRTY=6.

// STEP1 EXEC PGM=PROGRAM1

// REPORT1 DD SYSOUT=A//


15/273

15

SESSION -- II


16/273

16

OBJECTIVES

To understand

Job statement

Positional parameters in JOB statement

Keyword parameters in JOB statement

To try and solve classroom exercises.


17/273

17


18/273

18

JOB STATEMENT

INTRODUCTION

In JCL, a job can be considered as a unit of work that has to beexecuted. It contains several JCL statements that instruct theoperating system what to do.

The job statement identifies the beginning of a job to the

operating system.


19/273

19

// NAME OPERATION PARAMETERS COMMENTS// JOBNAME JOB OPERANDS

COMMENTS

The format of the statement is as given below.


20/273

20

FUNCTION CORRESPONDING JCLPARAMETER

Specification of the job

JOB

Specification of jobname

JOBNAME

Specification of accountinginformation

(ACCOUNTING INFORMATION)

Specification of the programmer name

NAME

JCL PARAMETERS ON THE JOB STATEMENT

Contd..


21/273

21

FUNCTION CORRESPONDING JCLPARAMETER

Categorization of job CLASSSpecification of outputclass to job log

MSGCLASS

Specification of printing the systemmessages

MSGLEVEL

Assignment of priority

to a job

PRTY

Holding a job for later execution

TYPRUN

(JCL PARAMETERS ON THE JOB STATEMENT Contd...)


22/273

22

JOBNAME

The jobname must start in column 3, immediately followingthe double slashes.

It must be followed by at least one space.

Valid names can be 1 to 8 alphanumeric characters in length.

The #, @, and $ symbols can also be included in the name.

The first character of the name must be alphabetic or national.It cannot be numeric.


23/273


24/273

24

POSITIONAL PARAMETERS IN JOBSTATEMENT

Job accounting information parameter.

Programmer name parameter.

.


25/273

25

JOB ACCOUNTING INFORMATIONPARAMETER

Accounting information in an IBM mainframe environment is

used to bill or charge back any job that is run on the mainframe.

The accounting information parameter identifies the accountnumber which will be billed for the CPU time utilized on themainframe.

SYNTAX

( account-number, additional accounting information)


26/273

26

EXAMPLE 1 :

//JOB1 JOB (A123,DEPT1)

JOB1 is the name of the job. JOB is the operation. A123 is theaccount number. DEPT1 is the additional accounting information.Since both the parameters are coded, they are enclosed in the

parenthesis.

EXAMPLE 2 :

//JOB1 JOB A123, DEPT1


27/273

27

PROGRAMMER-NAME PARAMETER

Programmer name parameter specifies two things:

. Programmer name

. Information related to the job being submitted.SYNTAX

It should be coded immediately after the accountinginformation parameter


28/273

28

EXAMPLE :

//JOB1 JOB (A123), VENU

The parameters in this statement are:

The double(//) slashes are required at the start of each JCLstatement, in columns 1 and 2.

JOB1 is the job name and immediately follows the doubleslashes.JOB is the operation.(A123) is the account number. VENU is the programmer name parameter.


29/273

29

KEYWORD PARAMETERS Keyword parameters must follow positional parameters.

They can be coded in any order.

Some of the keyword parameters are :

CLASSPRTYMSGCLASS

MSGLEVELTYPRUNNOTIFY


30/273

30

CLASS PARAMETER

The class parameter assigns a Jobclass to a job.

A Jobclass identifies the nature of the job that is to besubmitted.

Jobs can be short-running or can take a long time, or mayutilize heavy resources.

The Jobclass is used to identify these characteristics to theoperating system, there by categorizing the job being submitted.


31/273

31

SYNTAX

CLASS= Job classWhere job class is any character between A-Z or number

between 0-9.

EXAMPLE :

//JOB1 JOB ( A123), VENU, CLASS=K


32/273

32

PRTY PARAMETER

The PRTY parameter is related to the CLASS parameter. Itassigns priority to jobs which belong to the same class.

SYNTAX

PRTY=priority

Priority can range between 0 to 14, or 0 to 15, depending on what

job entry subsystem (JES2 or JES3) is being run at the time.


33/273

33

EXAMPLE :

//JOB1 JOB (A123), VENU,CLASS=8, PRTY=6//JOB2 JOB (A123), VENU,CLASS=8, PRTY=9

Job 2 will execute before Job1, because it has a higher prioritynumber (9) than Job1.


34/273

34

MSGCLASS PARAMETER

Messages can be categorized into two types.

First, there are those related to the system and the JCL.

Second, there are those that are output by the program or procedure being executed.

The MSGCLASS parameter determines the output device to

which, system messages and JCL messages are written.


35/273

35

SYNTAX

MSGCLASS=output-class-nameWhere output-class-name can be any alphabet (A-Z) or number (0-9).

The output-class-name is related to a specific output device towhich messages are routed.

MSGCLASS


36/273

36

EXAMPLE 1 :

//JOB1 JOB (A123), VENU, CLASS=K,PRTY=6,MSGCLASS=A.

JOB1 is the jobname, JOB is the keyword identifying the JOB

statement,(A123) is the account number, VENU is the author, priority is setto 6,and MSGCLASS is A.


37/273

37

EXAMPLE 2 ://JOB1 JOB (A123),VENU,CLASS=K,PRTY=6,

MSGCLASS=1

The message class is set to 1, which could specify a printer or any other output device.


38/273

38

MSGLEVEL PARAMETER

. The MSGLEVEL parameter is used to specify the JCL and theallocation messages which will be recorded on the output devicespecified in the message class.

As a JCL job is submitted, many kinds of messages aregenerated by the system. These messages can be categorized asfollows :

First, log messages indicating job name, user name, etc. are

routed to the output device.

Contd..


39/273

39

MSGLEVEL PARAMETER (Contd..)

Next, JCL statements comprising that job are output. Messages related to the execution of the job are output.

Finally, the output of the program being executed is output.


40/273

40

SYNTAXMSGLEVEL = (statements, messages)Or

MSGLEVEL = statementsor MSGLEVEL = (,messages)

Where statements may be the number 0,1, or 2, and messages is avalue which can be 0 or 1.

STATEMENTS:Coding a 0 in statements will result in messages related to the jobstatement only being output.

Contd.


41/273

41

SYNTAX (Contd..)

Coding a 1 will result in all JCL in the job being submitted beingoutput.

In addition to this, if any cataloged procedures are invoked, thentheir JCL will also be output.

Coding a 2 will result in only the input JCL statements being printed.

MESSAGES:In the messages field, 0 or 1 can be coded.Coding a 0 will result in all allocation messages being output if the

job terminates abnormally.

Coding a 1 will result in all allocation messages being output,regardless of whether the job terminates normally or abnormally.

MSGLEVEL


42/273

42

EXAMPLE 1 :

//JOB1 JOB (A123),JAI,MSGLEVEL=(1,1)

MSGLEVEL is set to (1,1). All JCL statements will be printed,including allocation messages.

EXAMPLE 2 :

//JOB1 JOB (A123),JAI,MSGLEVEL = 0

Only the JOB statement will be printed.


43/273

43

TYPRUN PARAMETER

. Used to specify whether a job is to be held until it is released,or it is to be scanned for syntax errors.

SYNTAX

TYPRUN=HOLDOr TYPRUN=SCAN

Contd..


44/273

44

TYPRUN PARAMETER (Contd..)

Specification of HOLD parameter results in the job being helduntil further notice. Useful when jobs which utilize a lot of resources are to be held until a time when the system is relativelyunused.

Specification of the SCAN parameter results in the job beingscanned for syntax errors and reports them to the requested output

media


45/273

45

EXAMPLE 1 :

//JOB1 JOB (A123),JAI,TYPRUN=HOLD

JOB1 will be held until it is released by the operator.

EXAMPLE 2 :

//JOB2 JOB (A123),JAI,TYPRUN=SCAN

The JCL will be checked for syntax errors.


46/273

46

NOTIFY PARAMETER

The NOTIFY parameter on the JOB statement automaticallynotifies the specified user when the job is completed.

Example ://JOB10 JOB NOTIFY=JB007

User JB007 will be notified when the job finishes.


47/273


48/273

48

CLASSROOM EXERCISE - II

Write a Job statement wherein job name is JOB1, accounting

information is A123, class is A, message class is B, message level is

default, priority is 10 and typrun = scan.


49/273

49

SESSION -- III


50/273

50

OBJECTIVESTo understand

EXEC statement

Positional parameters and Key word parameters

The following parameters coded on the EXEC statement

PGM ACCT PARMADDRSPC DPRTY PERFORMRD

JOBLIB and STEPLIB statementsTo try and solve the classroom exercises


51/273

51


52/273

52

EXEC STATEMENT

INTRODUCTION

The EXEC statement is the first statement of each job step.

A Job Step is a unit of work that is submitted to the

operating system in the form of collection of JCL statements. A unit of work can be the execution of a program or, it can

be the execution of a procedure that is pre-written and available

for general use by users of the system.


53/273

53

SYNTAX

//stepname EXEC PGM=program-name, keyword parameters

where stepname is the name assigned to the job step, EXEC is the

operation, program-name is the name of the program ( this is a positional parameter ) and keyword parameters follow the positional parameter


54/273

54

STEPNAME

. The STEPNAME is used to give unique and meaningfulnames to each step.

SYNTAX

No special syntax is required for this parameter.

EXAMPLE 1:

//STEP01 EXEC PGM=PROGRAM1

STEP01 is the name of the step. EXEC is coded in the operationfield.PGM is the positional parameter. PROGRAM1 is beingexecuted.


55/273

55

Conditions In Which Stepname Is Mandatory .

When it is necessary to reference a previously executed job step.

When an overriding parameter is used.

When it is required to use a restart parameter. Restart parameter helps to restart the job from the step that failed and avoidsrestarting the entire job consisting several job steps.


56/273

56

POSITIONAL PARAMETERS OF THE EXECSTATEMENT

Positional parameters are characterized by the order in whichthey appear, and they must precede keyword parameter.

There is only one positional parameter in the EXEC statement,that is :

PGM parameter.


57/273

57

PGM PARAMETER

The PGM parameter identifies the name of the program that is

to be executed.

SYNTAX

//stepname EXEC PGM=program-name


58/273

58

KEYWORD PARAMETERS OF THE EXECSTATEMENT

The keyword parameters coded for a job step will apply only tothat step.

Keyword parameters can be coded in any sequence.

Keyword parameters used in EXEC statement are :

ACCT parameter PARM parameter

ADDRSPC parameter DPRTY parameter

PERFORM parameter RD parameter


59/273

59

ACCT PARAMETER

. The ACCT parameter is used to supply accountinginformation for the job step that it is used in.

SYNTAX

ACCT=(account-information,...)Or ACCT=account-informationaccount-information consists of one or more subparameters

defined by installation.


60/273

60

EXAMPLE 1:

//STEP1 EXEC PGM=PROGRAM1, ACCT=(A123,RR)

STEP1 is the stepname, EXEC is the operation. PROGRAM1 is being executed.

The accounting information that follows the ACCT parameter is

specific to this job step only.

EXAMPLE 2:

//STEP2 EXEC PGM=PROGRAM2,ACCT=A123

PARM PARAMETER


61/273

61

PARM PARAMETER

The PARM parameter is used to supply information to a programas it executes.

SYNTAXPARM=value

Where value is a string from 1 to 100 characters long.

EXAMPLE 1 :

//STEP1 EXEC PGM=PROGRAM1,PARM=PRINT

PROGRAM1 is executed, and the string PRINT is supplied to itduring execution.


62/273

62

EXAMPLE 2 :

//STEP2 EXEC PGM=PROGRAM2,PARM=13+10

A special character (+) is included in the string, and therefore thestring is enclosed in apostrophes. The apostrophes are not passed tothe program as part of the string.

PARM


63/273

63

JOBLIB AND STEPLIB STATEMENTS

It is not enough to know the name of the program that is to be

executed. It is essential to know where that program resides.

The EXEC statement identifies the member name only. Its

location in the system has to be specified by the JOBLIB or STEPLIB statements.

JOBLIB STATEMENT


64/273

64

JO S

The JOBLIB statement immediately follows the JOBstatement. It is a DD (Data Definition ) statement , and it specifies where

the program that is specified by the EXEC statement resides.EXAMPLE 1 ://JOB1 JOB (A123),JAI

//JOBLIB DD DSN=M1.TEST.LOADLIB,DISP=SHR //STEP1 EXEC PGM=PROGRAM1

JOBLIB DD statement is used to specify the location of the program that is to be executed. Program1 is a member of the partitioned dataset M1.TEST.LOADLIB.


65/273

65

EXAMPLE 2 :

//JOB1 JOB (1234),JAI//JOBLIB DD DSN=M1.TEST.LOADLIB,

DISP=SHR //STEP1 EXEC PGM=PROGRAM1

//STEP2 EXEC PGM=PROGRAM2Both PROGRAM1 and PROGRAM2 exist in the library calledM1.TEST.LOADLIB.

JOBLIB


66/273

66

EXAMPLE 3 :

//JOB2 JOB (A123),VENU//JOBLIB DD DSN=PROGRAM3,// DISP=SHR,// UNIT=3321,// VOL=SER=PACK1

The UNIT and VOL parameters are used because PROGRAM3is uncataloged.

JOBLIB

STEPLIB STATEMENT


67/273

67

STEPLIB STATEMENT

The function of the STEPLIB statement is the same as the JOBLIBstatement. This statement is coded after the EXEC statement .

Is effective only for that jobstep, instead of the entire job.EXAMPLE :

//JOB1 JOB (1234),VENU

//STEP1 EXEC PGM=PROGRAM1//STEPLIB DD DSN=PROD.LOADLIB1, DISP=SHR //STEP2 EXEC PGM=PROGRAM2//STEPLIB DD DSN=PROD.LOADLIB2, DISP=SHR

Program1 is a member in the PROD.LOADLIB1 and program2 is amember in the PROD.LOADLIB2.


68/273

68

CODING BOTH JOBLIB AND STEPLIBSTATEMENTS

If both the JOBLIB and STEPLIB statements are coded, then theSTEPLIB specification will override that of the JOBLIB for that jobstep

The specification of the JOBLIB will continue for any jobstepthat does not have a corresponding STEPLIB statement.

If the same library is used for all jobsteps, then it is good practiceto code the JOBLIB statement.

EXAMPLE :


69/273

69

EXAMPLE :

//JOB1 JOB (1234),VENU// CLASS=0// MSGCLASS=T//JOBLIB DD DSN=A100.TEST.LOADLIB,// DISP=SHR //STEP1 EXEC PGM=PROGRAM1

//STEPLIB DD DSN=B100. TEST.LOADLIB,// DISP=SHR //STEP2 EXEC PGM=PROGRAM2//STEP3 EXEC PGM=PROGRAM3

//STEPLIB DD DSN=C100. TEST..LOADLIB,// DISP=SHR //


70/273

70

ADDRSPC PARAMETER The purpose of this parameter is to indicate to the system thatthe job should use either virtual or real storage.

Virtual storage results in program addresses being independentof the addresses that actually exist in the computer.

Setting the ADDRSPC to VIRT results in that job step being paged.

If ADDRSPC is set to REAL, then the job step is locked intoreal storage only.


71/273

71

SYNTAX

ADDRSPC=REAL

Or ADDRSPC=VIRT

VIRT indicates virtual storage, and REAL indicates real storageonly.

If ADDRSPC is omitted, virtual is the default.

EXAMPLE 1 :


72/273

72

EXAMPLE 1 ://JOB1 EXEC PGM=PROGRAM1,// ADDRSPC=VIRT

Program1 will be paged.

EXAMPLE 2 ://JOB2 EXEC PGM=PROGRAM2,// ADDRSPC=REAL

PROGRAM 2 will utilize real storage only, and will not be paged.


73/273

73

DPRTY PARAMETER Used to assign Dispatching Priority to the job step.

Dispatching priority is used by the system to determine theorder in which tasks are to be executed.

Dispatching priority is different from class priority. Class

assigns a priority to the job, and DPRTY assigns a priority to the job step.


74/273

74

SYNTAX

DPRTY=(value1,value2)

Where value1 ranges from 0 to 15 and specifies the priority of the job step.

Higher the number, higher the priority.

Value 2 ranges from 0 to 15.

DPRTY is computed as follows: DPRTY=(value1)*(16)+ value2


75/273

75

EXAMPLE :

//JOB1 JOB (A123),VENU//STEP1 EXEC PGM=PROGRAM1,// DPRTY=(12,9)

The priority in step1 is determined as :

( 12 * 16 ) + 9 = 192 + 9 = 201

PERFORM PARAMETER


76/273

76

PERFORM PARAMETER

The PERFORM parameter is used to specify the PerformanceGroup for the job step.

A Performance Group determines the rate at which the jobsteps in a job have access to system resources and is helpful inoptimizing system performance.

SYNTAX

PERFORM=nwhere n ranges from 1 to 999.


77/273

77

EXAMPLE :

//JOB1 JOB (A123), VENU//STEP1 EXEC PGM=PROGRAM1,// PERFORM=10

STEP1 is assigned the performance group10. The number 10 will be installation defined.

RD PARAMETER


78/273

78

RD PARAMETER

The RD ( Restart Definition) is used to specify automatic restartof a job if it abends.

It also fully or partially suppresses the CHKPT ( Checkpoint)macro instruction, so that no checkpoints are taken as a programexecutes.

A Checkpoint is taken by the system to record the status of a program as it executes.

Checkpoints enable to restart a job from the last successfulcheckpoint rather than from the beginning of the run .

SYNTAX


79/273

79

RD=R Or RD=RNCOr RD=NR Or RD=NC

Where R for restartRNC for restart with No Checkpoint

NR for No Automatic Restart NC for No Checkpoint.


80/273

80

EXAMPLE 1 :

//JOB1 JOB (A123), VENU

//STEP1 EXEC PGM=PROGRAM1,// RD=R

The operator can perform automatic step restart if the job abends.The checkpoint macro is not suppressed.


81/273

81

EXAMPLE 2:

//JOB2 JOB (B123),VENU//STEP2 EXEC PGM=PROGRAM2,// RD=RNC

The operator can perform automatic step restart if the job stepfails. Checkpoints are suppressed.

CLASSROOM EXERCISE


82/273

82

Write a JCL with job name JOB1 , consisting of 4 steps. Step1 isexecuting program COBOL1, Step2 executes COBOL2, Step3

executes COBOL3 and Step4 executes COBOL4. COBOL1 resideson TRNG.NTP4.COB1, COBOL2 is in TRNG.NTP4.COB2,COBOL3 and COBOL4 lie in TRNG.NTP4.COB3. The PARM

parameters associated are

Step1 ------- PRINT, Step2-------- READ, STEP3---------WRITE

Step4--------- SAVE


83/273

83

SESSION -- IV

OBJECTIVES


84/273

84

To understand The usage of following additional parameters coded on

both JOB and EXEC statement.REGIONCOND

TIME The DD statement Concept of Temporary datasets and Permanent datasets.

DSN parameter coded on the DD statement.To try and solve classroom exercises.


85/273

85

REGION PARAMETER


86/273

86

At the time that a job is run, a default amount of work space isautomatically assigned to it. This default can be overriden viathe REGION parameter.

SYNTAX

REGION=value1K Or REGION=value2M

Where value1 is the storage in multiples of 1024 bytes, andvalue2 is storage in multiples of one million bytes. The K and Mmust follow value1 and value2.


87/273

87

EXAMPLE 1 :

//JOB1 JOB (A123), VENU//STEP1 EXEC PGM=PROGRAM1,// REGION=96K

REGION parameter is coded in the EXEC statement, and is used tospecify that this job step can utilize 96 thousand bytes of storage.


88/273

88

EXAMPLE 2 :

//JOB1 JOB (A1230),VENU//STEP1 EXEC PGM=PROGRAM1,

// REGION=88K

REGION parameter is in the EXEC statement and is set to 88K.


89/273

89

EXAMPLE 3:

//JOB3 JOB (A123),VENU,// REGION=3M//STEP1 EXEC PGM=PROGRAM3

REGION is coded on the JOB statement. The system will allocate3 million bytes of storage for job3.

REGION CODED ON THEJOB STATEMENT


90/273

90

JOB STATEMENT

Usually the system will provide a default region size in which the job is to execute. However this can be overriden by using theREGION parameter coded on the JOB statement. If enough storagespace is not specified the job will terminate abnormally.

REGION CODED ON THEEXEC STATEMENT

The REGION parameter coded on an EXEC statement requestsstorage only for that individual job step.If enough storage is notspecified the job will abend .

COND CODED IN THE JOB STATEMENT


91/273

91

COND CODED IN THE JOB STATEMENTA COND parameter coded on the JOB statement applies to all jobsteps within the job, and it overrides COND parameters coded on

the EXEC statement, if they exist.

SYNTAX

COND=(comparison-code,condition)

Where comparison-code is a number between 0 and 4095, andcondition specifies the type of comparison to be made between the

comparison-code that has been coded, and the return code of the prior step.


92/273

OPERATORS CODED ON THE COND


93/273

93

Operator Explanation

GT Bypass current step if comparision-codeis greater than the return code.

GE Bypass current step if comparision-codeis greater than or equal to return code.

LT Bypass current step if comparision-codeis less than return code.

OPERATORS CODED ON THE CONDPARAMETER

OPERATORS CODED ON THE COND


94/273

94

Operator Explanation

LE Bypass current step if comparison-code

is less than or equal to return code.EQ Bypass current step if comparison-codeis equal to return code.

NEBypass current step if comparison-codeis not equal to return code.

OPERATORS CODED ON THE CONDPARAMETER (Contd...)


95/273

95

EXAMPLE :

//JOB1 JOB (A123),VENU,// COND=(4,LT)//STEP1 EXEC PGM=PROGRAM1//STEP2 EXEC PGM=PROGRAM2


If a condition code less than 4 is returned at any stepthen the subsequent steps would not be executed.

COND CODED IN THE EXEC STATEMENT


96/273

96

COND CODED IN THE EXEC STATEMENT

The condition parameter coded on the EXEC statement applies

only to the Job Step that it is coded in.

This job step is executed or bypassed, depending on the returncodes returned by one or more prior job steps.

SYNTAX

COND=(comparison-code condition)


97/273

97

Comparison-code ranges between 0 and 4095,conditionspecifies the type of comparison to be made between thecomparison-code that has been coded, and the return code of the

prior step.Contd....

COND=(comparison-code,condition)or COND=(comparison-code,condition, stepname...)

or COND=EVENor COND=ONLY


98/273

98

Step name specifies the name of the preceding step whosereturn code is to be checked.

The keyword ONLY is used to specify that the step in which

it is specified is to be executed only if any of the prior stepsterminate abnormally.

COND


99/273

99

EXAMPLE :

//JOB1 JOB (A123),VENU//STEP1 EXEC PGM=PROGRAM1//STEP2 EXEC PGM=PROGRAM2,// COND=(8,EQ,STEP1)

The COND parameter is used to specify that step2 should be bypassed if 8 is equal to the return code issued by step1.

TIME PARAMETER


100/273

100

This is an optional keyword parameter and is used to specifythe amount of CPU Time that a job or step is permitted to utilize

before it is terminated.

CPU Time is the time that a job takes to execute.

When coded in the JOB statement, it specifies the amount of

CPU time that the JOB is allowed to use. When coded in the EXEC statement, it specifies the amount of CPU time that the job step is allowed to use.

If the TIME parameter is not specified, then the installationdefined TIME parameter is used.

SYNTAX

TIME ( i )


101/273

101

TIME=(minutes)or TIME=(minutes,seconds)

or TIME=(,seconds)

EXAMPLE ://JOB1 JOB (A123),VENU,//STEP1 EXEC PGM=PROGRAM1,// TIME=5

5 minutes of CPU time is assigned to STEP1.

TIME Coded On Both JOB Statement AndEXEC Statement


102/273

102

EXEC Statement

If the TIME parameter is coded on both the JOB and EXECstatements, then the TIME parameter on the EXEC statement willoverride the TIME parameter on the JOB statement .

CLASSROOM EXERCISE

Write a JCL where job name is JOB1,programs to be executed are


103/273

103

j ,p gCOBOL1, COBOL2, COBOL3, COBOL4.

COBOL1 and COBOL2 are in TRNG.NTP4.COB,

COBOL3 is in TRNG.NTP4.COB3 and COBOL4 is inTRNG.NTP4.COB4.

Region for COBOL2 is 40K and CPU time is 10 min.

COBOL4 must be executed only if COBOL3 has terminatednormally.


104/273

DD ( DATA DEFINITION ) STATEMENT


105/273

105

INTRODUCTION

The data definition statement is used to identify the source of input and the placement of output information.

On successful execution of a job, the data can be:

Deleted. Kept. Cataloged. Passed to subsequent job steps. Uncataloged.

DD STATEMENT


106/273

106

// Name Operation Parameters Comments

// dd name DD Operands

Comments

DD NAME

The ddname identifies the name of the data definition


107/273

107

The ddname identifies the name of the data definitionstatement.

As a job executes, the system performs device and spaceallocations for each ddname specified.

Each ddname should be unique within the jobstep.

EXAMPLE ://JOB1 JOB A123,VENU//STEP1 EXEC PGM=PROGRAM1

//NAME1 DD DSN=DATA1 NAME1 is the DD name.

DD NAMES RESERVED FOR THE SYSTEM

USE


108/273

108

The following names are reserved for the system use and maynot be used to define DD statements:

//JOBLIB //JOBCAT

//SYSABEND //SYSIN

//SYSCHK //STEPLIB

//STEPCAT //SYSUDUMP

//SYSOUT //SYSOUD

//SYSDBOUT

DSN PARAMETER


109/273

109

The DSN parameter is a keyword parameter on the DDstatement. It is used to specify the name of the data set to theoperating system.

SYNTAX

DSN=data-set-nameWhere data-set-name can be qualified or non-qualified.


110/273


111/273

111

EXAMPLE:

//JOB1 JOB A123,VENU//STEP1 EXEC PGM=PROGRAM1// DD DSN=PROJECT1.GROUP2.DATA(TEST1)

TEMPORARY DATA SETS


112/273

112

A temporary data set is created during a job execution and

deleted after job completion. A temporary data set is recognized as such if the DSN parameter is omitted.

The system assigns a unique name to it, and reference is made toit by referencing the stepname and ddname. This is called a refer

back.

EXAMPLE 1:

//JOB1 JOB A123,VENU


113/273

113

//JOB1 JOB A123, VENU//STEP1 EXEC PGM=PROGRAM1//DATA1 DD//STEP2 EXEC PGM=PROGRAM2//DATA2 DD *.STEP1.DATA1

Step1 executes PROGRAM1 and a data set DATA1 is createdin the next statement.

Step2 executes PROGRAM2 and the temporary data set

DATA1, created in STEP1 is referenced via referback. * indicatesa referback.

A temporary data set is also recognized by starting the datasetname with two ampersands in the DSN parameter .


114/273

114

p p

EXAMPLE 2 :

//JOB1 JOB A123,VENU//STEP1 EXEC PGM=PROGRAM1//DATA1 DD DSN=&&ABCD

Here ABCD is prefixed with two ampersands and is a temporary

dataset.

PERMANENT DATA SETS

A permanent data set is not deleted after a job is completed and


115/273

115

A permanent data set is not deleted after a job is completed andmay be cataloged, if requested.

It is coded by setting a DSN parameter that is equal to aqualified or non-qualified name.

EXAMPLE :

//JOB1 JOB A123,VENU//STEP1 EXEC PGM=PROGRAM1

//DATA1 DD DSN=MIS.PROJECT.COBOL(FILE1)

CLASSROOM EXERCISE

Write a JCL where job name is JOB1 Two programs COBOL1 and


116/273

116

Write a JCL where job name is JOB1, Two programs COBOL1 and

COBOL2 are executed and they are in TRNG.NTP4.COB. A

temporary dataset NTP is created by step1 and is used by step2. Use

refer back technique.


117/273

117

SESSION -- V

OBJECTIVES

To understand


118/273

118

The following parameters and their sub-parameters coded on

the DD statement.

DISP

UNIT

To interpret the examples using the above parameters and their sub-parameters.

To try and solve the classroom exercises.

DISP PARAMETER

DISP is a keyword parameter, used to instruct the system as toth t t t f d t t d th t t b t k ith th


119/273

119

the current status of a data set, and the steps to be taken with thedata set upon normal and abnormal termination of the job.

SYNTAX

DISP=(status,normal-disposition,abnormal-disposition)

The status field indicates the current status of the data set i.ewhether it exists or has to be created.

Contd...


120/273

SUB-PARAMETERS ON DISPPARAMETER


121/273

121

Status Normal disposition Abnormal disposition NEW DELETE DELETEOLD KEEP KEEP

MOD CATLG UNCATLGSHR UNCATLG CATLG

PASS

NEW SUB-PARAMETER


122/273

122

Coding DISP= NEW indicates that a new data set is to becreated.

If the data set is to reside on a direct access volume, such asdisk then the UNIT and SPACE parameters must also be coded.

NEW is also the default, if nothing is coded in the statusfield.

EXAMPLE :


123/273

123


//STEP1 EXEC PGM=PROGRAM1//DATA DD DSN=PROJECT1.GROUP1.JCL.(TESTDATA),// DISP=NEW

Program1 is executed and the data set is created. The nextstatement utilizes the DISP parameter to inform the operatingsystem that this is a new data set

OLD SUB-PARAMETER

Coding OLD in the status field results in the operating systemsearching for an existing data set with the name specified in the


124/273

124

searching for an existing data set with the name specified in theDSN parameter.

The data set becomes available exclusively to the step in whichit is referenced.

EXAMPLE ://JOB1 JOB A123,VENU//STEP1 EXEC PGM=PROGRAM1//DATA DD DSN= PROJECT1.GROUP1.JCL(TESTDATA),// DISP=OLD

MOD SUB-PARAMETER The MOD subparameter is used to modify sequential data


125/273

125

The MOD subparameter is used to modify sequential datasets.

The MOD parameter does the following things :

If the sequential data set does not exist, then the system

replaces MOD with NEW, and creates it.

If the data set already exists, use of the MOD subparameter results in the reader/writer of the device positioning itself just

after the last record, so that records can be added to it easily.

SHR SUB-PARAMETER

Setting DISP=SHR allows multiple jobs to read the same data sethi h l d i


126/273

126

which already exists.

EXAMPLE :

//JOB1 JOB A123,VENU//STEP1 EXEC PGM=PROGRAM1//INPUT1 DD DSN=USER1.GROUP1.JCL.NAMEFILE// DISP=SHR

CLASSROOM EXERCISE

h b d


127/273

127

Write a JCL where job name is JOB1 and two programs COBOL1

and COBOL2 are being executed. Both the programs reside in

TRNG.NTP4. COBOL1 creates a new permanent dataset which

will reside in TRNG.NTP4.DATA1 and it is referred by COBOL2.

NORMAL-DISPOSITION FIELD

The normal disposition field in the DISP parameter is used toindicate what to do with the data set upon normal termination of the


128/273

128

p job.

SYNTAX

DISP=(status, normal-disposition ,abnormal-disposition)

The sub-parameters that can be coded here are :

DELETEKEEPCATLGUNCATLGPASS

DELETE SUB-PARAMETER

The delete sub-parameter indicates that the data set beingreferred is to be deleted after the successful termination of the job


129/273

129

referred is to be deleted after the successful termination of the job.

EXAMPLE :

//JOB1 JOB A123,VENU//STEP1 EXEC PGM=PROGRAM1//NAME1 DD DSN=TEMPFILE,// DISP=(OLD,DELETE)

TEMPFILE is a pre-existing data set that is deleted upon thesuccessful termination of the job JOB1.

KEEP SUB-PARAMETER

The KEEP subparameter indicates that the data set is to beretained or kept upon successful execution of the job.


130/273

130

p p j

This parameter should be used with permanent data sets.

EXAMPLE :


//STEP1 EXEC PGM=PROGRAM1//NAME1 DD DSN=BOOKS,// DISP=(OLD,KEEP)

A permanent data set called BOOKS is retrieved and kept after ithas been read.


131/273

UNCATLG SUB-PARAMETER

The UNCATLG subparameter is used to remove the entry of thedata set from the system catalogs.


132/273

132

The data set itself is not deleted.

EXAMPLE :


//STEP1 EXEC PGM=PROGRAM1//NAME1 DD DSN=DISK.OUTPUT,// DISP=(OLD,UNCATLG)

The pre-existing data set, called DISK.OUTPUT, is removed fromthe system catalogs. If the data set is not found the job terminatesabnormally.

PASS SUB-PARAMETER

Setting DISP to PASS specifies that the data set is to be passed toa subsequent job step within the same job.

Th d ill i b d b if i


133/273

133

The data set will continue to be passed to subsequent steps, if itis not utilized by any intervening job steps.

The data set can be used by any subsequent step.

Both temporary and permanent data sets can be passed to

subsequent steps. Data from a prior step can be referenced by its name, or by thereferback syntax.

If this subparameter is used with tape data sets, then the tapesremain mounted between job step.

EXAMPLE 1 :

//JOB1 JOB (K123),JAI//STEP1 EXEC PGM=PROGRAM1//DATA1 DD DSN=FILE1,


134/273

134

DISP=(NEW,PASS)

//STEP2 EXEC PGM= PROGRAM2//DATA2 DD DSN=FILE1,DISP=(OLD,DELETE)

PROGRAM1 creates a new dataset called FILE1.

The DISP parameter is used to pass it on to subsequent stepswithin that job.

In STEP2, FILE1 which is passed from the prior step isaccessed. Hence the DISP parameter is : DISP=(OLD,DELETE)

EXAMPLE 2 :

//JOB1 JOB (K123),JAI//STEP1 EXEC PGM=PROGRAM1//DATA1 DD DSN=FILE1,


135/273

135

DISP=(NEW,PASS)

//STEP2 EXEC PGM= PROGRAM2//DATA2 DD DSN=*.STEP1.DATA1,

DISP=(OLD,DELETE)

Data passed from STEP1 is accessed in STEP2 via Referback.Referback follows the following syntax :

DSN=*.stepname.ddname

Where * is required, stepname is the name of the step, andddname is the DD statement name.

EXAMPLE 3 :

//JOB1 JOB (K123),JAI


136/273

136


//DATA1 DD DSN=&&XYZ,// DISP=(NEW,PASS)//STEP2 EXEC PGM= PROGRAM2//DATA2 DD DSN=*.STEP1.DATA1,

// DISP=(OLD,DELETE)

The Refer back method is used to access the temporary dataset&&XYZ, which was created in STEP1.

CLASSROOM EXERCISE

Write a JCL where job name is JOB1 and two programs P1 and


137/273

137

Write a JCL where job name is JOB1 and two programs P1 and

P2 are executed. A PDS is created by P1 and is exclusively used

and should be retained on normal termination of the job.

ABNORMAL-DISPOSITION FIELD

The abnormal disposition field tells the system what to do withthe data set upon abnormal termination of the job. This subparameter is required only if the abnormal disposition


138/273

138

This subparameter is required only if the abnormal dispositionis different from the normal disposition.

DISP=(status,normal-disposition, abnormal-disposition )

The following subparameters can be used in this field :

DELETEKEEPUNCATLGCATLG

The description of each of the above parameters remain the sameexcept that now they refer to abnormal termination of the job.

EXAMPLE 1 :

//JOB1 JOB A123,JAI//STEP1 EXEC PGM=PROGRAM1


139/273

139

//DATA1 DD DSN=FILE1,// DISP=(NEW,CATLG,DELETE)

The dataset called FILE1, is created. If the job terminatessuccessfully, the system is informed that it should be cataloged.If the job terminates unsuccessfully, the system is instructed todelete it.

EXAMPLE 2 :



140/273

140

//STEP1 EXEC PGM=PROGRAM2//DATA1 DD DSN=FILE1,// DISP=(NEW,CATLG,KEEP)

A new dataset FILE1 is created and on successful termination of

the job the system is instructed to catalog it. Upon unsuccessfultermination, the system is instructed to retain the dataset, but notto catalog it.

EXAMPLE 3 :



141/273

141


//DATA1 DD DSN=FILE1,// DISP=(OLD,CATLG,DELETE)

The system is informed that FILE1 is a old data set. Upon

successful termination of the job, this dataset is to be cataloged.Upon unsuccessful termination of the job, it is to be deleted.

CLASSROOM EXERCISE

Write a JCL where job name is JOB1 and two programs P1 and P2


142/273

142

are executed . A PDS is created as a result of the execution of

program P1 and should be cataloged on normal termination of the

job and should be deleted on abnormal termination of the job. This

PDS should be referred back by step 2 where in program P2 is

executed.

DISP DEFAULTS

The status field defaults to NEW


143/273

143

If the status is NEW the default for normal disposition isDELETE and if the status is old the default for normal dispositionis KEEP.

The abnormal disposition field defaults to the same value as thenormal disposition field.

UNIT, VOL AND LABEL PARAMETERS

The DD statement is used to supply the input and output


144/273

144

information to the operating system.

The UNIT parameter is coded on the DD statement to specifyan input or output device that is to be accessed.

The VOL parameter is also coded on the DD statement toidentify specific disk tape volume(s).

The LABEL parameter is used to specify information specificto tape datasets.

UNIT PARAMETER

INTRODUCTION

In an IBM mainframe environment input and output devices can


145/273

145

In an IBM mainframe environment, input and output devices can

be categorized in different ways. The following characteristics can be used to identify them to the operating system:

All devices have an address assigned to them at the time that

they are added to the system. Devices can be referenced via thisaddress.

Device can be distinguished by a number which indicates the

numeric model.Contd...

UNIT PARAMETER (Contd...)


146/273

146

Certain types of devices can be grouped together, and the groupgiven a name. Devices can be referenced via group name.

If a device is specified in one job step, then a subsequent step

may request the same device by referencing the ddname of theDD statement in which the unit was originally specified.


147/273

SYNTAX

The general syntax for the UNIT parameter is :

d dd


148/273

148

UNIT=device-address

UNIT=device-type

UNIT=device-group-name

UNIT=AFF=prior-ddname

UNIT=(device,DEFER)


149/273

SPECIFICATION OF DEVICE TYPE

A device type is identified by the model number assigned to thatdevice by IBM. In order to code the device type on the UNIT parameter, one


150/273

150

needs to know the devices that are being used by the installation.EXAMPLE:

//JOB1 JOB A123,JAI

//STEP1 EXEC PROGRAM2//DATA1 DD DSN=FILE2,// UNIT=3380.

A dataset called FILE2, which resides on a 3380 disk unit, isaccessed.

Unit parameter

SPECIFICATION OF DEVICE GROUP

A device group name is a symbolic name which is assigned to a


151/273

151

g p y g

group of devices when the system is generated.

Devices are often grouped together based on their function.For example, SYSDA is traditionally assigned to direct access storagedevices.

Unit parameter

EXAMPLE :

//JOB1 JOB A123,JAI//STEP1 EXEC PROGRAM3


152/273

152

//DATA1 DD DSN=FILE3,// UNIT=SYSDA

A data set called FILE3 resides on any of the devices which aregrouped under the symbolic name SYSDA.

UNIT parameter

CLASSROOM EXERCISE

Write a JCL where job name is JOB1 which executes a program

P1 and creates a dataset called ABC on unit 3380


153/273

153

P1 and creates a dataset called ABC on unit 3380.

AFF SUB-PARAMETER

The AFF subparameter can be used to reference a device,specified in a prior DD statement. AFF stands for affinity. This kind of specification results in unit affinity, that is same


154/273

154

unit is reused.SYNTAX

//ddname1 DD UNIT=TAPE

//ddname2 DD UNIT=AFF=ddname1ddname1 is the name of the DD statement in which the device for the UNIT parameter was originally specified .

ddname2 is the name of the DD statement in which the AFF parameter is used to reference the prior DD statement.


155/273

DEFER SUB-PARAMETER

The DEFER subparameter is coded on the UNIT parameter soh i d f i f h l h i f il


156/273

156

that it may defer mounting of the volume that it references, untilthe data set that resides on it is opened.

It prevents volumes from being mounted until they are actually

needed, thereby freeing up resources for other jobs. If the defer parameter is encountered for a volume that isalready mounted , then it is simply ignored.

UNIT parameter

SYNTAX

//ddname DD UNIT=(device,,DEFER)


157/273

157

The extra comma in the middle is used to specify the device countsubparameter.

The device count subparameter identifies the number of tapesrequired for the job.

EXAMPLE :

//JOB1 JOB C123,VENU//STEP1 EXEC PGM=PROGRAM1//NAME1 DD DSN=DATA1,


158/273

158

//NAME1 DD DSN DATA1,// UNIT=(TAPE,,DEFER)

DEFER parameter is used to specify that DATA1 resides on tape,and that the tape need not be mounted until the system specificallyrequests it.

This request will be issued by the system at the time that JOB1 is

executed and PROGRAM1 requires access to DATA1.


159/273

159

SESSION -- VI

OBJECTIVES

To understand The following parameters and their sub-parameters coded onthe DD statement.


160/273

160

VOLSPACE

DCB

To interpret the examples using the above parameters and their sub-parameters.


VOL PARAMETER

INTRODUCTION

The VOL parameter is also coded on the DD statement and is


161/273

161

pused to identify specific tape(s) or disk volume(s). VOL or VOLUME can be used interchangeably on the DD statement.

This parameter is used to identify the volume serial number of the device on which a given data set is to be written or on which adataset resides.

VOL PARAMETER (Contd..)

Position Within A JCL Statement


162/273

162


// ddname DD VOL= Comments

CORRESPONDING JCL PARAMETERSFUNCTION SUBPARAMETERS

CODED ON THE VOLSTATEMENT .

Specification of serial SER


163/273

163

number Referencing VOLspecification

REF

Allowing acces to volume by

all users

This is the default, unless

coded otherwise.Inhibiting dismounting of volume by single user

PRIVATE

Specification of sequence in

which volumes are to bemounted.

SEQ

TYPES OF LABELS

VOLUME LABEL

This contains the volume serial number, and is used for identification purposes by the system.


164/273

164

p p y y

DATA SET LABEL

Data set labels are found at the beginning and at the end of tape data sets. They consist of 80 byte records that contain information for thedata set. Both types of labels reside on the volume itself as data.

TYPES OF VOLUMES

Volumes can be classified by the type of access available to theusers . They can be categorized as follows:


165/273

165

PRIVATE

These are accessible to a single user only. Tapes are always private.

PUBLIC

These are accessible to all users.

SER SUB-PARAMETER

The SER subparameter coded on VOL in the DD statement is


166/273

166

used to request specific volumes.

SYNTAX

VOL=SER=serial number.Or VOL=SER=(serial number1, serial number2 )

Vol parameter

EXAMPLE :


167/273

167

//JOB1 JOB A123,VENU//STEP1 EXEC PGM=PROGRAM1//NAME1 DD DSN=DATA1,// VOL=SER=23456

DATA1 is accessed on a volume whose serial number is 23456

REF SUB-PARAMETER

The REF subparameter is a shortcut method used to specify avolume which has been previously defined within the same job.


168/273

168

SYNTAX

VOL=REF=referback

Vol parameter

EXAMPLE :

//JOB1 JOB A123,VENU//STEP1 EXEC PGM=PROGRAM1


169/273

169

//NAME1 DD DSN=DATA1,// VOL=SER=VOL1//NAME2 DD DSN=DATA2,// VOL=REF=*.STEP1.NAME1

PRIVATE SUB-PARAMETER

Coding PRIVATE on the VOL parameter results in exclusiveuse of the volume for the data set specified in the job step. Thismeans that only one job can access it at a time.


170/273

170

SYNTAXVOL=PRIVATE

EXAMPLE :

//JOB1 JOB A123,VENU//STEP1 EXEC PGM=PROGRAM1//NAME1 DD DSN=DATA1,

// VOL=(PRIVATE,,,,SER=23456)Vol parameter

RETAIN SUB-PARAMETER

The RETAIN sub parameter is used to indicate that the volumeis not to be dismounted after completion of the job step that it iscoded in.The volume remains mounted until the entire job is


171/273

171

completed.

SYNTAX

VOL=(,RETAIN)

Or

VOL=(,RETAIN,...) Vol parameter

EXAMPLE :



172/273

172

//STEP1 EXEC PGM=PROGRAM1//NAME1 DD DSN=DATA1,// VOL=(,RETAIN,,,SER=TAPE1)

SEQ (SEQUENCE) SUB-PARAMETER

The sequence subparameter is used to specify the sequencenumber of the volume that is to be mounted for a particular

k d l


173/273

173

step.Like PRIVATE and RETAIN it is a positional parameter.

SYNTAX

VOL=(, ,sequence-number)Or

VOL=(, ,sequence-number,...)

Vol parameter

EXAMPLE :

//JOB1 JOB A123,VENU//STEP1 EXEC PGM=PROGRAM1//NAME1 DD DSN=DATA1,// VOL=SER=HUGE

//STEP2 EXEC PGM PROGRAM2


174/273

174

//STEP2 EXEC PGM=PROGRAM2//NAME2 DD DSN=DATA2// VOL=(, ,3,,SER=A123,A124,A125,A126,A127)

STEP1 executes PROGRAM1 and the dataset called DATA1 isaccessed on the volume whose serial number is HUGE.Since nosequence no. is supplied at position 3, processing starts at volume 1.

In STEP2 the VOL parameter is used to specify that processing

should start at volume 3 of a multivolume dataset DATA2.


175/273

SPACE AND DCB PARAMETERS

The SPACE and DCB parameters are coded on the DDstatement.


176/273

176

The SPACE parameter is used to allocate storage for newdata sets on direct access storage devices.

The DCB parameter is used to customize the way data isstored on devices.

SPACE PARAMETER

It is an optional keyword parameter on the DD statement.


177/273

177


// ddname DD SPACE=... Comments

SYNTAX

SPACE=(CYL(primary,secondary,directory),RLSE,CONTIG,MXIG,ROUND)

OR


178/273

178

OR SPACE=(TRK(primary,secondary,directory),

RLSE,CONTIG,MXIG,ROUND)OR

SPACE=(blk(primary,secondary,directory),RLSE,CONTIG,MXIG,ROUND)


179/273

CYL SUB-PARAMETER

The CYL subparameter is used to allocate space in terms of no of cylinders.

EXAMPLE :


180/273

180

EXAMPLE :

//JOB1 JOB A123,JAI//STEP1 EXEC PGM=PROGRAM1//DATA1 DD DSN=FILE1,// UNIT=3390,// SPACE=(CYL,4)

SPACE parameter

REQUESTING SPACE IN BLOCKS

Space can also be requested in terms of blocks. Blocksize isindependent of the device type.

EXAMPLE :


181/273

181

//JOB1 JOB A123,JAI//STEP1 EXEC PGM=PROGRAM1//DATA1 DD DSN=FILE1,

// UNIT=3390,// SPACE=(2400,1000)

Here the space allocated is 1000 blocks having block size of

2400 bytes.

PRIMARY AND SECONDARY SPACEALLOCATION

Primary space is the no of bytes that you expect the dataset willrequire for storage.

Secondary space is the additional space requested if the


182/273

182

Secondary space is the additional space requested if therequested primary space is insufficient.

Secondary space, when allocated, does not have to becontiguous with the location of primary allocation.

Up to 15 extends may be allocated on secondary space.

EXAMPLE :

//JOB1 JOB A123,JAI//STEP1 EXEC PGM=PROGRAM1//DATA1 DD DSN=FILE1,// UNIT=3390


183/273

183

// UNIT 3390,// SPACE=(TRK,(50,25))

50 tracks are assigned as primary space, and 25 as secondaryspace for FILE1.

DIRECTORY SUB-PARAMETER

The DIRECTORY subparameter is used when defining PDS.

Thi i d d h d l i f


184/273

184

This storage space is used to record the names and locations of the members created within the PDS.

This subparameter follows the primary and secondary spacesubparameters.

SPACE parameter

EXAMPLE :


//DATA1 DD DSN=FILE1,


185/273

185

// S ,// UNIT=3390,// SPACE=(TRK,(200,50,10))

200 tracks are assigned as primary space, and 50 as secondaryspace and 10 tracks are requested for storing name and locationinformation for members that will reside in the PDS

RLSE SUB-PARAMETER

The RLSE sub parameter is used to request that space originallyallocated to an output dataset be released when the dataset isclosed.


186/273

186

A dataset is considered to be closed after the successfulcompletion of a write operation.

The release parameter helps free up resources for other jobs.

SPACE parameter

EXAMPLE :



187/273

187

//DATA1 DD DSN=FILE1,// UNIT=3390,// SPACE=(TRK,(200,50),RLSE)

CLASSROOM EXERCISE

Write a JCL where job name is JOB1 , program P1 is executed

creating a dataset FILE1 on Unit 3380 for which the space is


188/273

188

g p

allotted in terms of Tracks with a primary space of 15 tracks and

secondary space of 30 tracks. Ensure that at the end of the job the

unused space is released.

CONTG SUB-PARAMETER

The CONTG subparameter is used to specify that onlycontiguous space should be allocated to the data set.

This parameter applies only to primary space allocations.

EXAMPLE ://JOB1 JOB A123 JAI


189/273

189

//JOB1 JOB A123,JAI//STEP1 EXEC PGM=PROGRAM1//DATA1 DD DSN=FILE1,// UNIT=3390,// SPACE=(TRK, 200, ,CONTG)

The extra comma between the primary specification and the

CONTG parameter is for the RLSE parameter.SPACE param

MXIG SUB-PARAMETER

The MXIG subparameter is used to specify that space requestedshould be allocated on the largest contiguous area of spaceavailable on the volume

EXAMPLE ://JOB1 JOB A123 JAI


190/273

190

//JOB1 JOB A123,JAI//STEP1 EXEC PGM=PROGRAM1//DATA1 DD DSN=FILE1,// UNIT=3390,// SPACE=(TRK, 700,RLSE,,MXIG)

700 tracks of primary space is requested on a 3390 disk in an area

where 700 or more tracks of contiguous space is available.SPACE parameter

ROUND SUB-PARAMETER

The use of this subparameter results in space being allocated asthe entire cylinder instead of just portions of it.

The system computes the amount of storage required, rounds itoff to the nearest cylinder, and allocates that number of cylinders to


191/273

191

y , ythe request.

The advantage associated with the use of this parameter is thatdata will reside, starting with the first track of the cylinder, till theend of the last track. Access time is decreased.

EXAMPLE :


//DATA1 DD DSN=FILE1,// UNIT 3390


192/273

192

// UNIT=3390,// SPACE=(500,50,,,ROUND)

50 blocks of 500 bytes are requested as storage space and the roundsubparameter results in space being rounded to the nearest cylinder .

SPACE parameter

DCB PARAMETER

The DCB parameter lets you specify file characteristics that arestored in the files Data Control Block.

The DCB parameter is coded only for a new data set .


193/273

193

For existing data sets the information is retrieved from the dataset label.

In addition, you dont have to code the DCB parameter for anew data set if your application program supplies the requiredinformation .

The DCB parameter has four sub-parameters

DSORG, RECFM, LRECL and BLKSIZE.

They are keyword sub-parameters so you can code them inany order you want.


194/273

194

SYNTAX :

DCB=(DSORG=xx,RECFM=format,LRECL=length,BLKSIZE=block size)

DSORG SUB-PARAMETER

The DSORG sub-parameter specifies the organization of thedata set.

DSORG Specifies the data sets organization,as followsPS Physical sequential


195/273

195

PS Physical sequentialPO PartitionedDA DirectIS Indexed sequential

EXAMPLE : DCB=(DSORG=PS)

Specifies a sequential data set.


196/273

EXAMPLE 1 :


//DATA1 DD DSN=FILE1,// UNIT=3390,


197/273

197

// DCB=(RECFM=F)

FILE1 is created on a 3390 disk and the parameter F indicates thatthe FILE1 will contain fixed length records.

LRECL PARAMETER

The LRECL ( Logical Record Length ) is used to specify the lengthof the record, in bytes, for fixed or variable length records.

For Fixed Length Record LRECL is equal to the record length.

For Variable Length Record LRECL is set to the size of thelargest record plus 4 bytes which is used by the system to specify


198/273

198

largest record plus 4 bytes, which is used by the system to specifythe actual length of the record that follows.

SYNTAX

LRECL=number

Where number is the length in decimal digits.DCB parameter

EXAMPLE :



199/273

199

//DATA1 DD DSN=FILE1,// UNIT=3390,// DCB=(RECFM=F,LRECL=80)

DCB parameter

BLKSIZE PARAMETER

This parameter is used to specify the blocksize of dataset in bytes. It must be specified as a multiple of the record length for fixedlength records.

It must be equal to at least the record length plus four bytes for variable length records


200/273

200

variable length records.

It must be set to the size of the largest block for undefined lengthrecords.

SYNTAX

BLKSIZE=number DCB parameter

EXAMPLE :

//JOB1 JOB A123,JAI//STEP1 EXEC PGM=PROGRAM1//DATA1 DD DSN=FILE1,// UNIT=3390


201/273

201

// UNIT=3390,//

DCB=(RECFM=FB,LRECL=80,BLKSIZE=1600)

DCB parameter

BUFNO PARAMETER

The BUFNO parameter is used to specify the number of buffersto be allocated to virtual storage for the dataset.SYNTAX

BUFNO=number

EXAMPLE 1:


202/273

202

//JOB1 JOB A123,JAI//STEP1 EXEC PGM=PROGRAM1//DATA1 DD DSN=FILE1,// UNIT=3390,// DCB=(RECFM=FB,LRECL=80,// BLKSIZE=1600,// BUFNO=40) DCB parameter

CLASSROOM EXERCISE

Write a JCL where job name is JOB1, program P1 is executed to

create a dataset FILE1 on unit 3380,volume serial number 234, the

space allotted as primary is 4 cylinders and secondary is 45


203/273

203

cylinders , unused space to be released at the end of the job, code

for contiguous space, the record format is Fixed block, Record

length is 80 and Block size is 1600.

SESSION -- VII


204/273

204

OBJECTIVES

To understand The function of DUMMY and Concatenated data sets

The function of special DD statements like SYSOUT, SYSIN

SYSUDUMP, SYSABEND The use of DLM, DEST, HOLD, OUTLIM parameters coded


205/273

205

on the DD statement. Importance and usage of Procedures.

Use of symbolic parameters in Procedures

The concept of Generation Data Groups


CODING DATA SETS AND I/O ON THE DDSTATEMENT

Types of data sets are

Dummy

Concatenated


206/273

206

Special DD statements are :

SYSOUT SYSIN

SYSUDUMP

SYSABEND

DUMMY PARAMETER

The Dummy parameter is coded on the DD statement to test theexecution of a program without actually reading or writing to adata set.

Position In JCL :



207/273

207


// ddname DD DUMMY Comments

If DUMMY or NULLFILE is read, then the Operating System

passes an EOF indicator to the program that is being executed.

EXAMPLE 1 :

//JOB1 JOB A123,JAI//STEP1 EXEC PGM=TEST1//DATA1 DD DUMMY

The program TEST1 is executed and a DUMMY dataset isaccessed.


208/273

208

EXAMPLE 2 :

//JOB1 JOB A123,JAI//STEP1 EXEC PGM=TEST2//DATA1 DD DSN=NULLFILE

CONCATENATING DATASETS

A dataset can be concatenated and perceived as one file by theoperating system by coding each applicable dataset name one after the other.

EXAMPLE 1 :


209/273

209

//JOB1 JOB A123,JAI//STEP1 EXEC PGM=CONCAT1//DATA1 DD DSN=FILE1// DD DSN=FILE2// DD DSN=FILE3.

FILE1 , FILE2, FILE3 are concatenated.

SYSUDUMP DD STATEMENT

Sysudump is coded in the name field of the DD statement.

Used to obtain a dump of the contents of various registers andvariables in case of abnormal termination of the job.

EXAMPLE 1 :


210/273

210

EXAMPLE 1 :

//JOB1 JOB A123,JAI//STEP1 EXEC PGM=PROGRAM1//SYSUDUMP DD DSN=DUMPFILE,// UNIT=3390,

// SPACE=(CYL,(1,1),RLSE)


211/273

SYSIN DD STATEMENT

SYSIN is conventional DD name assigned to input data streams

which is the data entered when the job is submitted.POSITION IN A JCL :


// SYSIN DD * or DATA Commentsd f ll


212/273

212

< data follows >/*

The * or DATA indicates to the Operating System that inputshould be accepted from the keyboard or coded in the JCL. /* indicates the end of input data stream in the JCL.

The * or DATA parameter can not be coded in procedures.

EXAMPLE 1 :

//JOB1 JOB A123,JAI

//STEP1 EXEC PGM=PROGRAM1//SYSIN DD */*

EXAMPLE 2 ://JOB1 JOB A123,JAI


213/273

213


//SYSIN DD DATA/*

In the second e.g. the use of DATA allows us to use specialcharacters // and /* in the data segment.

DLM PARAMETER

The DLM parameter specifies the delimiting character that is to be used to mark the end of the input data stream.

EXAMPLE :

//JOB1 JOB A123,JAI//STEP1 EXEC PGM=PROGRAM1//SYSIN DD DATA DLM=@@


214/273

214

//SYSIN DD DATA,DLM=@@/*@@

Here the delimiter is@@ and not /* which is also a part of the

input data stream.

DEST PARAMETER

The DEST parameter is used to route output to a specificdestination, which may or may not be a remote location.

POSITION IN JCL

// N O i P C


215/273

215


// ddname DD DEST Comments

SYNTAX

The syntax depends on the Job Entry Subsystem being used. In aJES2 environment the syntax is:

DEST=RMTxxxxOr DEST=RMxxxxOr


216/273

216

DEST=Rxxxx

Or DEST=UhhhOr DEST=Nxxxx

Or Contd.......

SYNTAX ( Contd..)

DEST=NnnnRyyOr DEST=LOCAL

RMT, RM and R stand for Remote Terminal. U specifies a localterminal N specifies a node


217/273

217

terminal. N specifies a node.

For the syntax :DEST=NnnnRyyy

N specifies node, and R specifies a remote workstation connectedto the node.

EXAMPLE 1 :

//JOB1 JOB A123,JAI//STEP1 EXEC PGM=XYZ//DATA1 DD DSN=FILE1,// SYSOUT=A,// DEST=RMT1190


218/273

218

Here the output is directed to output device assigned to class A andits location is designated by the code RMT1190.

EXAMPLE 2 :

//JOB1 JOB A123,JAI//STEP1 EXEC PGM=XYZ//DATA1 DD DSN=FILE1,// SYSOUT=A,// DEST=LOCAL


219/273

219

// DEST=LOCAL

Output is routed to the local device.

HOLD PARAMETER

Hold parameter is used to specify whether the output is to be printed immediately or held until further notice.

POSITION IN JCL



220/273

220

// ddname DD HOLD Comments

SYNTAX

HOLD=YES/NO

EXAMPLE :

//JOB1 JOB A123,JAI//STEP1 EXEC PGM=ABCD//DATA1 DD DSN=FILE1,// SYSOUT=A


221/273

221

// SYSOUT=A,// HOLD=YES.

OUTLIM PARAMETER

The OUTLIM parameter is used to limit the number of linesthat are output to the destination specified in the SYSOUT.

POSITION IN JCL


222/273

222


// ddname DD OUTLIM Comments

EXAMPLE 1 :

//JOB1 JOB A123,JAI//STEP1 EXEC PGM=OUT1

//DATA1 DD DSN=FILE1,// SYSOUT=A,// OUTLIM=1000.


223/273

223

Output routed to the printer is limited to 1000 lines.


224/273

224

JCL PROCEDURE

A JCL procedure is a pre-written segment of code that can be included in a job stream.

The use of procedures helps minimize duplication of code

and probability of error.

JCL procedures can be either :


225/273

225

p

Cataloged proceduresor

In-stream procedures

IN-STREAM PROCEDURES

Statements of an in-stream procedure appear in the job thatinvokes the procedure and are not members of any PDS.

An in-stream procedure is available only to the job that containsit.


226/273

226

Same instream procedure can be invoked more than once from

within a job.

In-stream procedures are used mostly for testing procedures thatwill eventually be cataloged.

EXAMPLE :

Creating and Executing an Instream Procedure

//JOB1 JOB A123,JAI//INPROC1 PROC//STEP1 EXEC PGM=OUT1//DATA1 DD DSN=FILE1,// DISP=SHR //STEP2 EXEC PGM=OUT2


227/273

227

//STEP2 EXEC PGM=OUT2

//DATA2 DD DSN=FILE2,// DISP=SHR // PEND//STEP77 EXEC PROC= INPROC1

//

CATALOGED PROCEDURES

Statements of a cataloged procedure are written and stored in a partitioned data set.

A cataloged procedure can be invoked by any job in the system.

SYS1 PROCLIB is the system procedure library


228/273

228

SYS1.PROCLIB is the system procedure library.

It contains mostly system oriented procedures.

You can also establish alternate procedure libraries,which youcan use instead of SYS1.PROCLIB.

EXAMPLE 1 :

//CATPRO PROC//STEP1 EXEC PGM=OUT1//DATA1 DD DSN=FILE1,// DISP=SHR //STEP2 EXEC PGM=OUT2//DATA2 DD DSN=FILE2,// DISP=SHR


229/273

229

NOTE : A cataloged procedure should never contain a PENDstatement

Execution Of The Procedure :

//JOB1 JOB A123,JAI//PROCLIB DD DSN=USER.TEST.PROCLIB,// DISP=SHR //JOBLIB DD DSN=USER.TEST.JOBLIB,// DISP=SHR //STEP10 EXEC CATPRO


230/273

230

The PROCLIB DD statement defines the location of thecataloged procedure.

The EXEC executes the cataloged procedure.

OVERRIDING PARAMETERS INPROCEDURES

Used to override the parameters of a Procedure for the duration of a job, without actually changing the contents of the original

procedure.

SYNTAX


231/273

231

SYNTAX

//name Exec procedure-name//procstep.ddname DD modified-parameter

EXAMPLE

//PROC1 PROC//STEP1 EXEC PGM=PROGRAM1//DD1 DD DSN=FILE1,DISP= SHR // STEP2 EXEC PGM=PROGRAM2//DD2 DD DSN= FILE2 ,DISP=SHR

To execute this procedure with a modification in the disposition of FILE1 from SHR to OLD, and the data set name FILE2 to NEWFILE, It is done as:


232/273

232

//JOB1 JOB A123,VENU//PROCLIB DD DSN=USER.TEST.LIB1// DISP=SHR //EXEC1 EXEC PROC1//STEP1.DD1 DD DSN=FILE1,DISP= OLD// STEP2.DD2 DD DSN= NEWFILE ,DISP=SHR

SYMBOLIC PARAMETERS

Symbolic parameters are used to create procedures for generalized use .

Symbolic parameters provide a convenient means of assigningdifferent values to parameters in commonly used JCL procedures.


233/273

233

To code a symbolic parameter in a procedure, you code anampersand(&) followed by a name.

For e.g.DISP=&STAT or SYSOUT=&DEVICE

SPECIFYING SYMBOLIC PARAMETER VALUES

To supply values to symbolic parameters, you code them on theEXEC statement that invokes the procedure.For e.g.

//STEP10 EXEC CATPRO,DEVICE=AHere the &DEVICE symbolic parameter is given a value of A.

EXAMPLE ://NEWPRO PROC//STEP1 EXEC PGM=CALC


234/273

234

//DATA1 DD DSN=TRNG.NTP.COB (&FILE1 ),// DISP=SHR To supply a value to the &FILE1 symbolic parameter,you invoke

the procedure as

//STEP20 EXEC NEWPRO, FILE1=ASH7

ASSIGNING DEFAULT VALUES TO SYMBOLICPARAMETERS

To assign a default value to a symbolic parameter , you define it onthe procedures PROC statement.

EXAMPLE ://NEWPRO PROC STAT=SHR //STEP1 EXEC PGM=UVW//DATA1 DD DSN=TRNG.NTP.COB(DATFILE),


235/273

235

( )

DISP =&STATIf the programmer doesn't code STAT on the EXEC statement thatinvokes this procedure, the default STAT=SHR will be used .

EXAMPLE :

Suppose you have a procedure as follows :

//NEWPRO PROC FILE1=NEWFILE,STAT=SHR,// DEVICE=CYL,FORMAT=FB

//STEP10 EXEC PGM=CALC//DATA1 DD DSN=&FILE1,// DISP=&STAT,UNIT=3380,// SPACE (&DEVICE (5 10))


236/273

236

// SPACE=(&DEVICE,(5,10)),// DCB=(RECFM=&FORMAT)

Contd...

If you invoke the previous procedure as

//STEP1 EXEC NEWPRO

The parameters on the DATA1 DD statement will take thefollowing default values :

//DATA1 DD DSN=NEWFILE1,// DISP=SHR,UNIT=3380,// SPACE=(CYL(5 10))


237/273

237

// SPACE=(CYL(5,10)),// DCB=(RECFM=FB)

Contd..

Similarly in the previous procedure,if you want to supply differentvalues to the DSN and DISP parameters and want the other

parameters to take the default values,then you invoke the procedure as :

//STEP1 EXEC NEWPRO,FILE1=MYFILE,STAT=OLD

The parameters on the DATA1 DD statement will take thefollowing values :


238/273

238

//DATA1 DD DSN=MYFILE,// DISP=OLD,UNIT=3390,// SPACE=(CYL,(5,10)),// DCB=(RECFM=FB)


239/273

239

THE CONCEPT OF GENERATION DATAGROUPS (GDGs)

Generation Data Groups are a group of data sets which arerelated to each other chronologically and functionally.

Data processing applications are cyclical in nature. Theyconsist of new input which is stored inside a file. At a later stagethis existing data is updated with new data , to produce a new file.


240/273

240

g p p

The original file is considered as the older generation, and the newone as a new generation.

Contd...

THE CONCEPT OF GENERATION DATA

GROUPS (Contd..)

Generations can continue until a specified limit is reached.This specifies the total number of generations that can exist atone time. Once this limit is reached, the oldest generation isdeleted.


241/273

241

SESSION -- VIII


242/273

242


243/273


244/273

244

IBM UTILITIES

A utility is a useful tool that helps in expediting a task.

MVS provides a number of prewritten utility programs that

can be used by the analysts, system programmers andapplication programmers to assist them in organizing data.

A UTILITY program performs a basic function, i.e., it does a


245/273

245

routine job which is required repeatedly in an installation.

CLASSES OF IBM UTILITIES

SYSTEM UTILITY PROGRAMS

System Utility Programs can be used to maintain and manipulate

system and user data sets.

These programs must reside in an authorized library.


246/273

246

They can be executed as jobs or be invoked as subroutines of anauthorized program.

CLASSES OF IBM UTILITIES

DATA SET UTILITY PROGRAMS:

Data set utility programs can be used to reorganize, change or compare data at the data set or record level.


247/273

247

Can be executed as jobs or be invoked as subroutines of a calling program.


248/273

FREQUENTLY REQUIRED FUNCTIONS

Copy sequential files. Copy partitioned data sets. Catalog data sets. Un catalog data sets. Rename data sets. Compress partitioned data sets. Include members to partitioned data sets when a


249/273

249

Copy transaction is implemented. Exclude members to partitioned data sets whenA copy transaction is implemented.

Compare sequential and partitioned data sets.

Generate generation data groups

Create /delete data sets allocate / de allocate space on data setsor code other functions on the DD statement, without having toexecute a program.


250/273

250

JCL REQUIRED TO EXECUTE THE UTILITIES

The JCL statements, which are required to execute the utility

program, follow a general pattern.//jobname JOB (accounting-information,)

programmer-name//stepname EXEC PGM=utility-name, PARM=value//printname DD SYSOUT=print- device-class// inputfile DD input-file-features// outputfile DD output-file-features// workfile DD work-file-features


251/273

251

// inputdata DD *< --- data statements specific to utility follow --- >

/*

//

SOME IMPORTANT UTILITIES

IEBGENER

IEBCOPY

IEHPROGM

IEBCOMPR

IEFBR14


252/273

252

DFSORT

MERGE

IEBGENER

Most commonly used utility program.

Used to copy one sequential file to another.

The original data set and the destination names must bespecified.

Attributes of both the data sets such as RECFM, LRECL


253/273

253

must be the same.

CORRESPONDING JCL

//jobname JOB accounting-info,programmer-name,// keyword parameters//stepname EXEC PGM=IEBGENER

//SYSPRINT DD SYSOUT=print- device-class//SYSUT1 DD DSN=source-file-features//SYSUT2 DD DSN=destination-file-features//SYSIN DD DUMMY


254/273

254

//

IEBCOPY

Copy Partitioned Data Sets A PDS can be copied to another PDS, or a sequential data set( on a Tape Drive) , which is known as UNLOADING .

Used to restore PDS to direct access devices from a TapeDrive, which is known as LOADING .

Compress Partitioned Data Sets


255/273

255

Include members of a PDS within a copy transaction.

Exclude members of a PDS within a copy transaction

CORRESPONDING JCL

//jobname JOB accounting-info,programmer-name,// keyword parameters//stepname EXEC PGM=IEBCOPY//SYSPRINT DD SYSOUT=print- device-class

//SYSUT1 DD DSN=source-file-features//SYSUT2 DD DSN=destination-file-features//SYSIN DD *

COPY INDD=SYSUT1,


256/273

256

OUTDD=SYSUT2/*//

For loading and unloading the following have to be coded ://SYSIN DD *

COPY INDD=SYSUT1,OUTDD=SYSUT2

/*//

For compressing a data set, the SYSUT2 statement is notrequired and the following have to be coded :


257/273

257

//SYSIN DD *COPY INDD=SYSUT1,OUTDD=SYSUT1

/*

//

To include the members to a PDS the input (SYSUT1) andoutput (SYSUT2) data set names will be the same and thefollowing have to be coded :

//SYSIN DD *

COPY INDD=SYSUT1,OUTDD=SYSUT2SELECT MEMBER = ( mem1, mem2,...)

/*

//


258/273

258

//

IEHPROGM

Catalog a Data Set.

Un catalog a Data Set.

Rename Data Sets. Create an index of a GDG

D l h i d f i i GDG


259/273

259

Delete the index of an existing GDG.

CORRESPONDING JCL

//jobname JOB accounting-information,programmer-name,// key-word parameters//stepname EXEC PGM=IEHPROGM//SYSPRINT DD SYSOUT=print-device-class

//SYSUT1 DD UNIT=unitname,// VOL=SER=vol-no// SYSUT2 DD UNIT=unitname,// VOL=SER=vol-no

//SYSIN DD *


260/273

260

//SYSIN DD */*//

CATALOGING A DATA SET

A data set can be cataloged using the CATLG statement.

SYNTAX :CATLG DSN=data-set-name

VOL=device-name=volume-number.

The above is coded in the SYSIN DD statement.

//SYSIN DD *CATLG DSN d


261/273

261

CATLG DSN=data-set-nameVOL=device-name=vol.no

/*

//

UNCATALOGING A DATA SET

A data set can be uncataloged using the

Documents

JCL Class Ses