jcl.ppt

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JCL JOB Control Language

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CHAPTERS1) Introduction to JCL

2) Coding JCL

3) The JOB statement

4) The EXEC statement

5) The DD statement

6) More on DD statement

7) Utility programs

8) Procedures

9) Generation data groups

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Chapter 1 – Introduction to JCL

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Typical Workloads to the Mainframe OS

What is a Workload? Any work to be performed by the OS is called workload.

How is the work performed? The OS performs the work by executing the program’s

instructions.

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Typical Workloads to the Mainframe OS contd..

What are the typical workloads to the Mainframe OS?

Batch work Interactive work

BCPJESV

TA

M

Eg. Payroll report

Eg. ATMs

User

OS

Printer

User

OS

Storage device

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Batch Work (also called Batch Processing) Work performed without end user interaction.

Runs in the system background, freeing the user to do other work.

Normally scheduled to run when no interactive processing takes place. But when run concurrently with interactive tasks, batch work are typically given low priority by the OS.

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BCP / JES / VTAM

BCP constitutes the core OS.

JES provides the interface between the BCP and the batch processes.

VTAM provides the interface between the BCP and interactive users.

BCPJES

VT

AM

Batch work Interactive users

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What is a JOB ? The Batch process is called JOB.

To render the Job to the OS we use Job Control Language (JCL). JCL is the way to tell the OS:

which programs are to be executed which datasets are needed by the executing programs.

JCL also describes to the OS: The Job’s name When the job is to be performed by the OS The requestor of the job, among other things

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The various JOBS

BCP

JES

Job1

(Execution of your Application programs; say Cobol , PL/I programs)

Job3

(Execution of Sub-system programs – to start TSO, CICS environments

Job2

(Execution of another user’s Application programs

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The JCL Statements

A Job is coded using JCL. JCL statements look like:

//……. JOB …….

//……. EXEC …….

//……. DD .……

Through these statements you supply information and instructions to OS:

JOB - carries the Job name, the type of job //DSRC062 JOB CLASS= type of job

EXEC - carries the program name

//STEP1 EXEC PGM=Load module’s name

DD - carries the datasets used by the program.

//DD1 DD DSN=Dataset name

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The JCL Statements contd…

One JOB can execute more than one program.

//……. JOB …….

//……. EXEC PGM=…….

//……. DD

//……. EXEC PGM=…….

//……. DD ………….

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Looking back at the Jobs

JES

BCP

Your Job:

//Job1 JOB ….

//…. EXEC Pgm=LM of Cobol program

//… DD …

//… Exec Pgm=LM of PL/I program

//… DD …

Job2

(Execution of Application programs, by another user)

Job3

(Execution of sub-system program – to start TSO, CICS environments

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A Job’s life cycleThe Job Enters the systemThe Job is placed in the Input Job queueThe Job gets Executed by the OSThe Job completes execution and moves to the Output

queue, on to other devices.

Inputqueue

Output queue

View / Purge

J E S

BCP

Printer, Tapes, Disks

Redirect to other devicesJOB

(JCL coded

using TSO)

Execution

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Jobs entering the system through TSO The commonest way of Jobs entering JES is vide a Terminal software

called TSO, Time sharing option

You code JCL with TSO and SUBMIT your JCL into the system for

processing

You can view the output of your Job using TSO before redirecting

the output to the desired destination – Disk, Tape or Printer.

Inputqueue

Output queue

View / Purge

J E S

BCP


Redirect to other devices TSO//Job1 JOB …..//….. EXEC PGM=..

Submit

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Jobs in the Input queue

After the Jobs are submitted: JES gives each job a JOB ID which you can view and Queues the jobs in the Input queue based on the job’s

CLASS coded in the JCL.

Class E I

Output queue

View / Purge

J E S

BCP


Redirect to other devices TSO//Job1 JOB Class=I//….. EXEC PGM=..

Input queue

SubmitJob ID

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Jobs in the Input queue – CLASS codes contd..

Installations establish different Class codes based on the importance or type of job. Class F for “express” jobs which use little CPU time Class P for jobs requiring lots of CPU time and run at some scheduled time Class E for jobs that run in the evenings only Class I for jobs to be run immediately A Class for jobs that use Tapes A Class for jobs that run CICS or IMS system programs and so on

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Jobs in the Input queue – further processing contd..

After jobs get queued, the job’s JCL is:

converted into an internal text

scanned for syntax errors JCL that is correct in syntax remains in the Input

queue. JCL with errors goes to a different disk

dataset called Output queue, which also contains

the execution results of successfully executed

jobs.

E I

Output queueJ E S

BCP

Input queue

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Jobs in the Input queue – Queue Entry

• Each job in the input queue awaiting execution has the

an entry:

Job ID Job Name Job Class Priority

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Jobs in the Input queue – a screen shot

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Jobs getting Executed – Program Initiators

From the Input queue, jobs are “picked” for execution

by the BCP using special programs called Program

Initiators. Program Initiators picks jobs for execution based on the

jobs’ CLASS.

D E E I I P

Output queue

J E S

BCP

Input queue Initiators

1

2

3 4

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Jobs getting Executed – Initiators/Classes contd…

Each Initiator is governed by its own list of Job Classes based

on which it preferentially picks jobs for execution from the input

queue.

D E E I I P

Output queue

View / Purge

J E S

BCP



Input queue

Submit

Job ID

Initiators Class-List

1 E

2 PI

3 IA 4 F

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Jobs getting Executed – Initiators - a screen shot

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Jobs getting Executed – Job completion contd..

The OS Notifies the user when the job completes.

E E P

Output queue

View / Purge

J E S

BCP


Input queue

Submit

Job IDNOTIFY

(When done)

TSO//Job1 JOB …..//….. EXEC PGM=..

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Jobs in the Output queue

JES queues the Jobs’ Output in the output queue.

A job’s output comprises: the Report about the job

which Initiator ran the job

the CPU time taken by the job to run, among other

messages

the Program’s output Like the Payroll report

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Jobs in the Output queueThe job’s outputs are queued based on the Print Classes:

Indicated by MSGCLASS on Job statement for Reports

Indicated by SYSOUT on DD statement for Program’s output

Output queue

View / Purge

J E S

BCP



Input queue

Submit Job ID

Print Class

A

B

X or T

Class

A

E

E

Sysout

MsgClass

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Versions of JES

JES comes in two versions: JES2 which most Mainframe computer systems use JES3 which are used by large networks of Mainframe

computers

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JES Control Statements These are non-JCL statements that are used to communicate with JES.

They provide for instructions, the same way as JCL statements.

A JCL statement to have the OS send you a Notification when your job completes execution:

//……… JOB Notify=TSO-UserID

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JES Control Statements contd..

Equivalent JES control statement:

/*Notify TSO-UserID JES2

//*Notify TSO-UserID JES3

//……… JOB

//……… JOB

JES control statements look like:

/* or //*JES Command ……..

Based on the command, the JES control statements are

coded before or after the JOB statement.

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Chapter 2 – Coding JCL

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Coding JCL statements using TSO

You code JCL using TSO, Time sharing option. A component of TSO called ISPF (Interactive System Productivity Facility) provides a full

screen editor to create source program statements and JCL.

You use TSO to submit your jobs to the OS for processing.

You also use TSO to see the results after processing, using SDSF (Spool Display and Search Facility), a software product you can access from TSO.

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Coding JCL statements - Syntax Syntax - A JCL statement has 5 fields:

ID Name Operation Operands Comments

//DSRC012A JOB NOTIFY=DSRC012 The Job…

//STEP010 EXEC PGM=LM of program The Step…

//DD1 DD DSN=Dataset name,Space=………….,DISP=SHR,x

//

1 727112 803 10

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Coding JCL statements - SyntaxSyntax - A JCL statement has 5 fields:

ID Name Operation Operands Comments

//DSRC012A JOB NOTIFY=DSRC012 The Job…

//STEP010 EXEC PGM=LM of program The Step…

//DD1 DD DSN=Datasetname,Space=………….,DISP=SHR,x

//

7271123 10 801

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Coding JCL statements – Identifier field contd..

//DSRC012A JOB NOTIFY=DSRC062 The Job..

//* The Step…

//STEP010 EXEC PGM=LM of program

//SYSIN DD * The DD..

……Instream data……

/*

//

The Identifier field must be coded in columns 1, 2, 3 Identifies:

a JCL statement if // in columns 1 and 2 Comment statement / JES3 statement if //* in columns 1, 2, 3 Delimiter statement / JES2 statement if /* in columns 1 and 2

1 2 3

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Coding JCL statements – Name field contd..

//DSRC012A JOB NOTIFY=DSRC012 The Job

//STEP010 EXEC PGM=LM of program The Step

//DD1 DD DSN=Dataset name, The DD

// DISP=SHR

Name field must be coded in columns 3 through 10 Names a JCL statement. 1 to 8 alpha-numeric (A-Z,0-9) or national characters (#, @, $). First character must be alphabetic or national. Must be followed by at least one blank space.

3 10

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Coding JCL statements – Operation field contd..



//DD1 DD DSN=Dataset name, The DD

// DISP=SHR

Operation field must be coded from or after column 12 onwards It indicates the type of control statement (JOB, EXEC or DD).

Must be preceded and followed by at least one blank.

12

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Coding JCL statements – Operand field contd..



//DD1 DD DSN=Dataset name,DISP=SHR

//

The Operand (Parameter) field follows the operation field Contains one or more parameters separated by commas

No blanks between the parameters Parameters can be coded up to column 71

71

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Coding JCL statements – Comment field contd..

//DSRC012A JOB NOTIFY=DSRC012 The Job..

//STEP010 EXEC PGM=LM of program The Step..

//* The DD….

//DD1 DD DSN=Dataset name,DISP=SHR

The Comment field can be coded after the operand field, up to column 71 It contains documentation on the JCL statement Must not be used unless there is an operand field and must

follow the operand field Must be preceded by at least one blankNote : The Comment field is different from Comment statement (//*);

though they both serve to code comments.

71

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Coding JCL statements - Continuation of Statements Continuation of the Parameter field on to the next line

If you interrupt the field including the comma before column 71

//DD1 DD DSN=Dataset name,Space=(TRKk,(1,1)),

// DISP=SHR,DCB=…….

If you interrupt the field including the comma at column 71

//DD1 DD DSN=Dataset name,Space=………….,DISP=SHR,x

// DCB=……..

71

71 72

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Chapter 3 -The JOB statement

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The JOB statement

Syntax: //Jobname JOB <Positional Parameters>,<Keyword parameters>

Purpose Marks the beginning of a work load (job) to the OS.

Supplies the necessary information and instructions to the OS

Gives the job a name

Instructs the OS the importance of the job relative to other

jobs

Informs who will pay for the CPU time the job uses

Instructs where the job’s reports must be sent

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The Job statement – a detailed look

//Jobname JOB <Positional Parameters>,<Keyword parameters>

Mandatory.

Usually your TSO userid followed by one character.

Accounting information,

Programmer’s name.

NOTIFY,CLASS,PRTY,

MSGCLASS,MSGLEVEL,

RESTART,TIME, TYPRUN

ADDRSPC, REGION among

others.

Example:

//DSRC012A JOB (012,John),

NOTIFY=DSRC012,CLASS=A,PRTY=15, //

MSGCLASS=T,MSGLEVEL=(1,1)

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Positional and Keyword parameters//Jobname JOB <Positional Parameters>,<Keyword parameters>

Acct. Info.,Prog.name CLASS=..…,NOTIFY=….

Positional parameters Must precede keyword parameters Within a list of parameters, must be in specific positions separated by commas Absence of first parameter in a list must be indicated by a comma

Keyword parameters Must follow positional parameters Within a list, can be coded in any position Absence within a list need not be indicated by comma

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The Job statement – ACCOUNTING INFORMATION

Identifies your job for accounting or billing purposes; say to bill for the CPU time used by your job. Format is installation dependent. Optional

Example : //DSRC012A JOB (012)

Additional accounting information can be given (installation dependant):

//DSRC012A JOB (012,1)

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The Job statement – PROGRAMMER’S NAME

Identifies the user ie. you or, the kind of Job. Format is installation dependent. Specified in apostrophes if the programmer’s name parameter contains spaces or special

characters, other than the period or hyphen. Optional

Example : //DSRC012A JOB (012,1),JOHN

//DSRC012A JOB (012,JOHN,CICS),‘PROD CICS’

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The Job statement - CLASS

Queues jobs for execution based on the importance of the

job. The importance in turn depends on the type of the job: A job involving complex statistical calculations

Is a type of job taking a lot of CPU time and to be run in the night only

A job updating a database Is a type of job which is I/O bound and to be run immediately

A job generating reports

Is a type of job to be run in the evenings

A job running system programs

Is a type of job to be run continuously

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The Job statement – CLASS contd.. A Job is assigned a CLASS based on its ‘type’

CLASS is represented by a single alphanumeric character

(A-Z,0-9); fixed by the installation.

CLASS=E may imply type which is run in the evenings

CLASS=9 may imply a job that runs at a specific time

of the day

Example : //DSRC012A JOB (012,John), NOTIFY=DSRC012,CLASS=E

CLASS gives jobs a preference for execution by the OS.

JOB CLASS 1 E 2 P 3 O

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The Job statement – CLASS contd..

Operator can change the CLASS even after the job is submitted.

Operator can also reconfigure Initiators to pick Classes other than what the initiator was originally configured to pick.

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The Job statement – PRTY

Syntax for Priority.

Determines scheduling the jobs belonging to the same

CLASS.

JOB CLASS PRTY 1 E 1 2 E 13

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The Job statement – PRTY contd..

PRTY ranges from values 0 to 15 if JES2 is used

15 being the highest priority. 0-14 in JES3 is used

14 being the highest priority.

Example:

//DSRC012A JOB CLASS=E,PRTY=1

//DSRC012B JOB CLASS=E,PRTY=15

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The Job statement – PRTY contd..

If jobs wait in the queue under the same CLASS and

same PRTY, then the jobs are picked for execution

based on FIFO.

JOB CLASS PRTY 1 E 1 2 E 13 3 E 13

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The Job statement – DPRTY

Syntax for Dispatching Priority

Sets priority for CPU allocation to jobs that are running Your job can get the CPU prior to the other jobs.

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The Job statement - TIME

Establishes a CPU time limit for a job to execute all its

steps.

Syntax is TIME=(MINUTES,SECONDS)

Minutes range from 1 through 357912 (248.55 days) Seconds range from 1 through 59

TIME=(1,30) implies maximum CPU time for this JOB is

1minute and 30 seconds.

System will abend the job with a system completion

code of 322, if the specified TIME is exceeded.

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The Job statement – TIME contd..

Reasons to code TIME While testing a new program which may go into a loop,

unless it is “timed out” automatically (system code 522) Special jobs which need to by-pass any TIME limit barrier

and which must not be “timed out” too Syntax of TIME=1440 or NOLIMIT takes off any CPU time limit

and lets the job run continuously. This job will not be timed out.

Syntax of TIME=MAXIMUM permits maximum CPU time

for a job - 357912 minutes.

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The Job statement – TIME contd..

Examples:

TIME=2 maximum CPU time for this JOB is 2 minutes

TIME=(,2) maximum CPU time allowed is 2 seconds

//DSRC012A JOB NOTIFY=DSRC012,TIME=(,50)

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The Job statement - REGION

Specifies the amount of virtual storage a job can use Every step within the job gets that amount of storage as requested vide

the REGION parameter

Can be specified in kilobytes(K) or Megabytes(M) Syntax is REGION=nK n ranges from 1K to 2096128K

nM n ranges from 1M to 2047M

If not coded, a system default or installation defined

The system allocates the storage above and below the 16 MB line

Example:

//DSRC012A JOB REGION=4092K same as coding

//DSRC012A JOB REGION=4M

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The Job statement – REGION contd…

If the job requires more storage than what it requests,

the system returns a completion code of 804 or 80A.

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The Job statement - ADDRSPCSyntax for Address space

Prohibits or allows a job (its steps) from being paged

Syntax is ADDRSPC=REAL or VIRT (Virtual) REAL locks the job in central storage during execution VIRT, the default, lets the job be paged

Do not use REAL as it will reduce system performance Use REAL only for time-dependant programs and those that dynamically modify channel programs during I/O operations.

Example: //DSRC012A JOB ADDRSPC=REAL

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The Job statement - NOTIFY

• Requests that the OS sends a message about:

• the Job’s completion and

• its completion status – whether normal or abnormal

• Code NOTIFY=your TSO userID, if you want the

system to notify you the above messages.

Example :

//DSRC012A JOB (012,John), NOTIFY=DSRC012

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The Job statement – NOTIFY contd..

The OS giving your job a number (JobID) when submitted.

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The Job statement-NOTIFY–a screen shot contd..

‘Notification’ about completion and completion status.

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The Job statement – NOTIFY contd…• Omitting this parameter may result in you seeing the

OS giving your job, a number (JobID) when submitted

but not its completion and completion status.

To notify someone (userid) not at the job’s origin, code the JES2 ‘NOTIFY node ’ control statement

Example:

/*NOTIFY node.TSOuserid

//DSRC012A JOB CLASS=E,<other parameters>

Code NOTIFY=&SYSUID, if you share your JCL and want that user submitting your JCL to get notified Users need not change your code – the NOTIFY value

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The Job statement - MSGCLASS Syntax for Message Class After the job run, directs the Reporting messages of the OS to

disk areas or printers Reports usually held in the output queue without printing, for viewing vide

TSO.

The reporting messages (commonly called ‘printed output’) include: The JES2 ‘JOB LOG’ stating

whether the job was run

when the job started and stopped

which initiator picked the job for execution

the JES2 ‘JOB STATISTICS’ comprising

the date of job run

the number of lines of JCL code (cards) read by the OS

the JCL submitted is listed (with the JCL statements numbered by the OS).

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The Job statement – MSGCLASS contd…

the ‘ALLOCATION’ messages stating the I/O devices and datasets allocated for each job step

memory allocated for each step

the CPU time taken to execute each step

a completion code - COND CODE/ System completion code, which communicates whether the step executed successfully or not.

the disposition of the datasets after the step executed

The final messages states the CPU time taken to run the entire job (all steps).

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The Job statement – MSGCLASS contd..

MSGCLASS is represented by a single alphanumeric character (A-Z,0-9); fixed by the installation.

MSGCLASS=T may hold messages in the output queue for viewing

from TSO and purged by the user after some specific

time frame

MSGCLASS=A may route messages directly to a printer

MSGCLASS=D may hold messages in the output queue for viewing

from TSO and purged automatically by the system

after some time.

If not coded, defaults to installation standards.

Example: //DSRC012A JOB CLASS=E,MSGCLASS=T

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The Job statement - MSGLEVEL

Syntax for Message Level.

Determines the amount of JCL and Allocation messages to be directed to the device indicated in MSGCLASS

Syntax is MSGLEVEL=(JCL,Allocations) JCL - takes values 0 or 1 or 2

0 print only JOB statement 1 print all user-coded JCL plus procedure JCL

statements 2 print only user-coded JCL statements

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The Job statement – MSGLEVEL contd..

Allocations - takes values 0 or 1 0 print all the allocation messages only if the job ends

abnormally

1 print all the allocation messages whether the job ends

normally or abnormally

Default MSGLEVEL=(1,1)

Example:

//DSRC012A JOB MSGCLASS=T,MSGLEVEL=(1,0)

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The Job statement - TYPRUN

Syntax for Type Run.Prevents job run

to give your JCL a syntax check or to hold your job for later execution

To give your JCL a syntax check use TYPRUN=SCAN SCAN causes your JCL to be checked for coding

errors. The coding errors comprise: mis-spelled and misplaced parameters Invalid characters Unbalanced parantheses

Your job does not run; resources are not allocated.

The syntax error messages are routed to the output

queue and can be viewed.

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The Job statement – TYPRUN contd..

To hold your job for later run, use TYPRUN=HOLD HOLD causes your job to remain in the input queue without going in for execution until explicitly

RELEASEd by the operator for execution; this provided your JCL is syntactically correct.

If incorrect, your job gets routed to the output queue.

To print your JCL to a printer without running the job use TYPRUN=COPY; ensure you assign a printer class to MSGCLASS

Example:

//DSRC012A JOB NOTIFY=DSRC012,TYPRUN=SCAN

To make your job run, do not code TYPRUN

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The Job statement - RESTART

• Enables continuing running of a previously aborted job

• Specifies a starting Step for the new job run

• Syntax is RESTART=STEPNAME

Example:

//DSRC012A JOB RESTART=STEP2//STEP1 EXEC PGM=LM of one program//………//STEP2 EXEC PGM=LM of another program//………

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Chapter 4 - The EXEC statement

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The EXEC Statement

Syntax : //Stepname EXEC <Positional Parameters>,<Keyword parameters>

Purpose Names the EXEC statement Mainly identifies the:

Program to execute (PGM=LM of the program)

Procedure to execute (PROC=Name of the Proc)

(Certain programs like the language compilers which

perform

the same function for all its users, are converted to a

form called PROCEDURES)

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//Stepname EXEC <Positional Parameters>,<Keyword parameters>

The EXEC statement – a detailed look

Optional, but useful for referbacks and locating errors in the job’s reports

PGM or PROC

PARM,COND,TIME,REGION

//Step010 EXEC PGM=Load Module of a Program, Time=(,5)

//DDIN DD ……………….

//Step020 EXEC PROC=Procedure Name (or)

Procedure name

//Step030 EXEC PGM=LM of another program

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The EXEC Statement - PGM / PROC Syntax for Program / Procedure

PGM = Load Module Of User-written Application program. For load modules in user-load libraries, JOBLIB or STEPLIB must be coded.

PGM = Load module of Utility Program. Stored in system library, SYS1.LINKLIB.

Eg. SORT utility

PROC = Procedure Name. Stored in system library SYS1.PROCLIB. For PROCs in user-libraries, JCLLIB must be coded.

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The EXEC Statement - PGM / PROC contd..

Upto 255 steps can be under one JOB

If the load module is not found, the system will abend the step giving a completion code of 806.

Example:

//DSRC012A JOB NOTIFY=DSRC012

//STEP1 EXEC PGM=Load Module of Your Program

//………….........

//STEP2 EXEC PGM=SORT (the LM of Utility Program)

//……….............

//STEP3 EXEC PROC=Procedure Name

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The EXEC Statement - COND

Syntax for Condition.COND defines the conditions under which the OS

must execute a step. Also called Return code.

EXAMPLE:

//Cobol EXEC PGM=Igycrctl

//………..

//Lked EXEC PGM=Hewl,COND=(4,LT,COBOL)

Interpretation: If Condition is satisfied, Do Not Execute the Step

If Condition is not satisfied, Execute the step.

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The EXEC Statement - COND contd..

The Compile/Link-edit JCL:

//LKED EXEC PGM=HEWL,COND=(4,LT,COBOL)

This condition tells the OS that “If 4 is less than the value of

the condition code of the compiler step, then, shut off the

execution of the link-edit program”. This will be true if the

compiler sets its condition code to 0005 or greater.

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COND can be used for two reasons: To define conditions under which you want a step of a normally executing job to be shut off. You

code this in the form COND = (4,LT,StepName) or COND=(4,LT)

To tell the OS to process a step even if a previous step in the job has already abended, or, only if a previous step abended. Ordinarily, the OS would throw out the whole job when a step abends and ignore all steps that follow. You code this in the form COND=EVEN or COND=ONLY.

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Syntax in Normal Mode : COND=(Condition code value,Comparison operator,Stepname)

COND=(Condition code value, Comparison operator)

Condition code value - 0 to 4095.

Comparison operator - GT, LT, GE, LE, EQ, NE

Syntax in Abnormal Mode : COND=EVEN

COND=ONLY

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C79


Condition code values in the range 0 to 4095 leaves a job

still in the normal mode, not the abnormal mode.

Abnormal mode (or Abend) is indicated by a three

position hexadecimal value:

806 Load module not found

80A Inadequate Central storage (Region)

OC7 Data exception

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C80


Condition code values range from 0 to 4095. Any program that you execute, be it a utility program like

the language compiler, or your program, leaves a number

in this range. This number termed the Condition code

(CC) is also called the Return code (RC). Conventional condition code values for IBM supplied

compilers and utility programs:

CC 0000 Program execution was completely successful

CC 0004 Execution was OK but caused warning messages

CC 0008 Program execution was seriously flawed

CC 0012 Program execution was very seriously flawed

CC 0016 Program failed disastrously

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C81


Condition code values for your programs depends on the programming language:

PL/I CALL PLIRETC(Value);

C EXIT(Value);

COBOL MOVE <Value> to RETURN-CODE

MOVE <File status> to Return-Code.

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//Step010 Exec Pgm=A1111

//Step020 Exec Pgm=B2222,Cond=(0,LT,Step010)

Pgm B2222 is not executed if pgm A1111 returns any CC > 0000

//Step030 Exec Pgm=C3333,Cond=(0,Eq,Step010)

Pgm C3333 is not executed if pgm A1111 returns CC 0000

//Step040 Exec Pgm=D4444,Cond=(4,Eq)

Pgm D4444 is not executed if pgm A1111 or pgm B2222 or pgm C3333 returns CC 0004

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C83


//Step010 Exec Pgm=Pgm1 CC 0000

//Step020 Exec Pgm=Pgm2 CC 0004

//Step030 Exec Pgm=Pgm3, Step not run

// Cond=(4,Eq,Step020) because of CC

//Step040 Exec Pgm=Pgm4,Cond=Even CC 0004

//Step050 Exec Pgm=Pgm5,Cond=Only Step not run due to

Cond=Only

//Step060 Exec Pgm=Pgm6 Abend SoC7

//Step070 Exec Pgm=Pgm7 Execution blocked by

Abend

//Step080 Exec Pgm=Pgm8,Cond=Only CC 0000

//Step090 Exec Pgm=Pgm9,Cond=Even CC 0000

//Step100 Exec Pgm=Pgm10,Cond=Even Step executed

Cond=Even and only

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C84


//STEP1 EXEC PGM=READ,COND=((4,GT),(6,LT))

The step is executed for CC 4,5 and 6 and not for 0 to 3,7 and

above.

Note : The OS always wants to by-pass steps to lessen its work.

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C85


A maximum of 8 conditions may be checked in any one step (EVEN & ONLY count as one)

Omitting stepname in the condition, will apply the test to all preceding steps

If one of the steps being checked was not executed, its condition check is ignored

If a Condition is not coded for a step and its previous step abends, then this step is by-passed.

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C86


Whatever the Condition coded, the system bypasses

subsequent steps when : a JCL error is encountered (syntax error,datasets not

found) Datasets allocation error Job enters an Abend mode, unless Cond=Even or Only is

coded Operator cancels the job

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C87

The If/Then/Else/EndIf Statement

This construct is an alternative to coding COND; introduced in OS390.

Allows the outcome of one STEP to determine the execution of subsequent steps.

EXAMPLE:

// IF (STEP040.RC EQ 4) THEN

//STEP050 EXEC PGM=LM of a program

// ELSE

//STEP060 EXEC PGM=LM of another program

// ENDIF

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C88

The If/Then/Else/EndIf Statement contd…

Syntax:

//Name IF (Relational expression) THEN

// Steps to processed when relational expression is true

//Name ELSE

// Step to processed when relational expression is false

//Name ENDIF

Name field is optional. Operation fields are IF,THEN, ELSE and ENDIF.

ELSE is an optional clause.

ENDIF marks the end of the statement.

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C89

The If/Then/Else/EndIf Statement contd… Relational expression field consists of:

Comparison operators - GT, LT, NG, NL, EQ, NE, GE, LE

> < ¬> ¬< = ¬= >= <= Connect operators - AND, OR

& I NOT (¬) operators Keywords:

RC Indicates Return code

ABEND Indicates occurrence of Abend

¬ ABEND Indicates non occurrence of Abend

ABENDCC Indicates a specific system or user abend code

RUN Indicates execution of the specified Step

¬RUN Indicates non execution of the specified step

Examples:

// IF (RC > 8 & Step020.RUN) THEN……..

// IF ¬(Step020.RC > 8) THEN…..

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C90


RC

Indicates that the relational expression tests a Return Code.

Code (stepname.RC, a comparison operator, a RC value) or code

(RC, a comparison operator, a RC value)

IF (Step040.RC EQ 4) THEN …..

RC values range from 0 to 4095 since this is the syntax in normal mode.

ABEND or (ABEND EQ TRUE)

Indicates that the relational expression tests for an Abend condition that occurred in the job prior to the time of evaluation

IF ABEND THEN….. tests true when an abend occurred in any previous step.

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C91


(ABENDCC EQ Sxxx) or (ABENDCC EQ Uxxxx)

Indicates that the relational expression tests for:

System completion code (S followed by hexadecimal value of 3 digits)

User defined completion code ( U followed by decimal value of 4 digits)

IF (ABENDCC EQ SOC4) THEN………

IF (ABENDCC EQ U0100) THEN……..

(Stepname.RUN) or (Stepname.RUN EQ TRUE)

Indicates that the relational expression tests that the specified step (vide stepname) has been executed.

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C92


EXAMPLES:// IF (RC > 8 & RC < 16) THEN……..

// IF (RC = 8 I RC = 12 I RC > 24) THEN……….

// IF ¬(RC > 8) THEN…..

Use parantheses in compound expressions to make the

system evaluate the relational expression in the order in

which you want; else, the order of evaluation will be: First the NOT operator followed by

Comparison operator and then the

Connect operator

// IF STEP6.RC EQ 1 AND ((STEP7.RC EQ 4 OR

// STEP8.RC EQ 1) OR STEP9.RC EQ 4) THEN …….

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C93


You can nest IF/THEN…. statements up to 15 levels.

// IF NOT (STEP1.RC EQ 1 AND STEP2.RC EQ 1) THEN

// IF (STEP4.RC LE 4 AND STEP1.ABEND) THEN

//STEP060 EXEC PGM=Program ONE

// ELSE

//STEP070 EXEC PGM=Program TEN

// ENDIF

// ELSE

//STEP080 EXEC PGM=Program TWO

// ENDIF

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C94

The EXEC Statement - TIME

Establishes a CPU time limit for a program to execute.

If the time limit is exceeded, the system abends the

step with a completion code of 322.

If not coded, the Time parameter takes a value that is

installation defined.

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C95

The EXEC Statement - TIME contd..

If you specify time both in the JOB and EXEC statement, then the time parameter on the EXEC applies for that step and the remaining time limit from the JOB statement is available to the other steps.

//DSRC012A JOB TIME=(1,50)

//Step1 EXEC PGM=PROGRAM1,TIME=(0,30)

//Step2 EXEC PGM=PROGRAM2



//Step2 EXEC PGM=PROGRAM2

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C96

The EXEC Statement - TIME contd..

The limit on the JOB totals to the CPU time usage of all the steps.



//Step2 EXEC PGM=PROGRAM2,TIME=(1)

Note: The OS ignores any limit on the EXEC which is larger than that

coded on the JOB statement.

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C97

The EXEC Statement - REGION The Region parameter specifies the amount of virtual storage which the program (step) can use.

Can be specified in kilobytes(K) or Megabytes(M).

Format : Region=nK or nM

//Step1 EXEC PGM=SORT,REGION=5M

//…………….

//Step2 EXEC PGM=Load Module,REGION=3M

//…………...

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C98

The EXEC Statement - REGION contd…

If REGION is coded on the JOB and EXEC, then the JOB limit overrides any REGION that is larger

//DSRC012A JOB NOTIFY=DSRC012,REGION=2M

//Step1 EXEC PGM=SORT,REGION=5M

//…………….

//Step2 EXEC PGM=Load Module,REGION=3M

//…………...

IF no REGION is coded, system default value or installation-defined default.

If a program requires more storage than coded, step fails with a system completion code of 804 or 80A.

Each step gets only 2M of storage

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C99

The EXEC Statement - PARM

Syntax for Parameter.

Passes data to the load module that is being executed.

A maximum of 100 bytes of data can be passed.

The passed data can be: received by the program - through the program’s

Linkage section and used in the program - if “Procedure division using

Linkage section’s data- area” is coded.

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C100

The EXEC Statement - PARM contd… Example :

1) Pass data vide PARM in the JCL:

//STEP010 EXEC PGM=Load Module,PARM=‘001 JOHN’

2) Access the data in a Cobol program:

IDENTIFICATION DIVISION.

DATA DIVISION.

LINKAGE SECTION.

01 PARM-DATA-AREA.

05 PARM-LEN PIC S9(4) COMP.

05 PARM-DATA1.

10 DATA1-IN X(100).

PROCEDURE DIVISION USING PARM-DATA-AREA.

DISPLAY DATA1-IN.

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C101

The EXEC Statement – PARM contd…

Coding Rules: Use apostrophes around the passed data if the data consists of a space

PARM=‘001 JOHN’

If passed data comprises an apostrophe or an ampersand, code two such characters consecutively. PARM=‘’’Hello World’’’ PARM=‘ABC&&4’

To continue coding data on the next line, code a comma and continue. Also coding apostrophes around continued data is a must. Comma gets included in the byte count.

PARM=‘001,

JOHN’

To code till column 71 and then continue, leave column 72 blank and continue on the next line from column 4 through 16

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C102

Chapter 5 - The DD statement

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C103

The DD statement

DD stands for Data definition.

Defines to the OS, information about the Dataset(s)

which the executing program uses:

//……. JOB …….

//…….. EXEC PGM=LM of a program

//DDname1 DD <Information about the dataset which the

above program uses>

//DDname2 DD ………do.…….

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C104

The DD Statement contd..

The Information supplied, depends on whether the program: Reads from the dataset(s) or Writes into an existing dataset(s) //DDRd DD DSN=<Name of the dataset>,

// DISP=……..

Prints the dataset(s) //DDPrt DD SYSOUT=

Creates new dataset(s) //DDCrte DD DSN=<name of the dataset>,

// DISP=<whether the dataset is new or existing>,

// UNIT=<whether the dataset is to be stored on Disk or

Tape>,

// SPACE=<amount of disk-storage space required>,

// DCB=<information about how the data is to be

stored>

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C105

The DD Statement contd..

Up to 3273 DD statements can be defined in a single Step.

//……. JOB …….

//…….. EXEC PGM=LM of a program

//DDname1 DD <Information about the dataset which the

above program uses>

//DDname2 DD ………do.…….

//DDname3 DD ………do……..

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C106

What is a Dataset ?A store of data – Employee data, Customer data.

Each entity’s data (Employee say) is called a RECORD. Many such records form the Dataset.

Types of Datasets used in Mainframes today :

Broadly based on arrangement of records inside the dataset - Physical sequential (PS) – DSRC012.Empdata Partitioned sequential (PDS) – DSRC012.Empdata(Member1) VSAM type (Sequential, Indexed, Relative) – DSRC012.BaseCluster

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C107

The Disk Volume Table of contents - VTOC A Disk Volume is an assembly of magnetic platters which

provides millions of bytes of storage.

Each disk volume has a unique name called Volume Serial number.

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C108

The Disk Volume Table of contents contd..

Recorded on each disk volume is the VTOC which is a dataset to keep track of all datasets stored on that volume.

The VTOC is one level above the level of PDS directory.

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C109

The SYSTEM CATALOGHighest level of information above the level of VTOC.

The system catalog is a critical dataset on a special disk volume and contains information on where (on which disk volume) each dataset is stored.

Dataset Name Location (name of the Volume)

DSRC012.COBOL.PGMS ZTSO03

DSRC012.JCL.PGMS ZTSO01

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C110

The SYSTEM CATALOG contd..

Use TSO to view the System Catalog.

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C111

The DD Statement - a detailed look

//DDname DD <Positional parameters>,<Keyword parameters>

*

Data

Dummy or NullFile

Dsn,

Disp,

Unit,

Volume,

Space,

Dcb

Mandatory. If omitted, the dataset is concatenated with the one defined in the previous DD statement.

Sysout

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C112

The DD statement - *

Marks the beginning of Instream data to a load module. Can be compared to passing data to a load module using

the PARM parameter on the EXEC statement.

Format :


//DDname DD *

<…………..Instream data……..>

/*

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C113

The DD statement - * contd..

Instream data to a Cobol program:

In the JCL:

//STEP010 EXEC PGM=LM of a Cobol program

//SYSIN DD *

001 JOHN …..

/*

In the Cobol program:

IDENTIFICATION DIVISION.

DATA DIVISION.

WORKING-STORGAE SECTION.

77 DATA1-IN PIC X(80).

PROCEDURE DIVISION.

ACCEPT DATA1-IN.

The load module can be User-written program or

Utility program.

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C114

The DD statement - * contd..

Instream data to Utility programs:

//STEP010 EXEC PGM=SORT //………………………………… //………………………………… //SYSIN DD * SORT FIELDS=……… /*

The end of data is indicated by the delimiter - /*

The instream cannot contain // as data in columns 1,2

when * is used.

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C115

The DD statement - DATA

DATA is functionally the same as ‘*’ operand, except

that instream data can contain // in columns 1,2

//STEPNAME EXEC PGM=LM of a program

//DDname DD DATA

………Instream data………..

………Instream data……….

/*

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C116

The DD statement-Delimiter for Instream data

What if instream data consists of /* in columns 1 & 2

and, /* is used to delimit the instream data too ?

//SYSIN DD DATA/*abc…../*

Under such situations delimit vide the DLM parameter

which indicates the new delimiter to be used. DLM can be used for * and DATA

//SYSIN DD DATA, DLM=‘$$’/*abc…..$$

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C117

The DD statement - DUMMY / NULLFILE

DUMMY assigns a ‘dummied’ status to a dataset: Any I/O requests on the dataset is bypassed No devices and space is allocated to the dataset

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C118

The DD statement - Dummy / Nullfile contd..

WHY DUMMY ?

Used to test a program flow without actually processing the

dataset An attempt to read a dummied dataset results in an EOF exit;

A write request in the program is ignored.

For Utility programs, used to cut-off control statements

(instream data) to the program

//Step1 EXEC PGM=IEBGENER //…… //SYSIN DD DUMMY

Any unwanted outputs listings can be suppressed.

Note: The other syntax is to code DSN=NULLFILE.

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C119

The DD statement - Keyword Parameters

If data is to be accessed from Disk or Tape, the parameters are: DSN - Dataset Name - DSRC012.ITC.PGMS.

DISP - Status of the dataset - New or Existing.

UNIT - Hardware device where the dataset resides – Disk or Tape.

VOL - Identification of the disk or tape.

SPACE - Amount of space required by the dataset on the disk.

DCB - Data Control Block information of the dataset.

//DDname DD DSN=<Dataset name>,

// DISP=SHR

If data is to be sent to Terminal or Printer: SYSOUT parameter; none of the above.

//DDname DD SYSOUT=<Terminal>

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C120

The DD statement - DSN

Syntax for Dataset Name

Names the full qualified name of the physical dataset

used by the load module.

Dataset name is maximum 44 characters long with a

period after every 8 characters (or less). Maximum

length is inclusive of period.

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C121

The DD statement - DSN contd..

Classified into Permanent and Temporary datasets Permanent datasets are used as a data-store on disks

and tapes. Temporary datasets are used as work areas within a

job; they last only for the duration of the job. A Temporary dataset name starts with && followed by 1

to 6 characters - DSN=&&TEMPRY Absence of DSN coding also denotes a temporary dataset.

A DSN coding without && indicates a Permanent dataset.

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C122

The DD statement - DSN contd..

Code for Permanent dataset:

//DD8 DD DSN=DSRC12.EMP.DEVL

Code for Temporary dataset:

//DD8 DD DSN=&&TEMP

If the dataset (DSN) is not found in the system catalog,

the system throws a “JCL error”.

Dataset names (DSN) cannot be duplicated in the VTOC.

If duplicated, the system returns a “CC of 8”.

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C123

The DD statement – DISP (Status)

Syntax for Disposition. DISP=({Status}{,Normal-disposition}{,Abnormal-disposition})

Status specifies the existence of a dataset at the start of the step (not start of the job) - whether NEW, OLD, MOD, SHR

NEW – specifies that the dataset is new and does not exist when the

step begins. OLD – specifies that the dataset exists when the step begins.

Gains exclusive control of the dataset for the duration

of the step and safeguards against concurrent access to the

dataset.

Over-writes existing data. MOD – Extends the dataset (if existing) or creates a new one (if not

existing).

Gains exclusive control of the dataset. SHR – specifies that the dataset can be shared with other jobs

during the step.

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C124

The DD statement - DISP(Normal termination) contd.. Normal termination disposition specifies what the OS must do to the dataset if the step

terminates normally - whether to CATLG, UNCATLG, PASS, KEEP, DELETE CATLG – specifies that the OS must record information about the dataset like its Name, its Unit, Volume identifier in the

system catalog when it is newly created or, update the entry if existing. You cannot catalog a temporary dataset. KEEP – specifies to the OS that newly created datasets need not have a catalog entry but just be retained on the volume. UNCATLG – specifies that the OS removes all entries from the catalog, but retain the dataset on the volume. PASS – specifies to the OS that subsequent steps will access the dataset and that the dataset need not be cataloged (if

new) or the catalog entry need not be updated (if existing). Can PASS PS and PDS but not VSAM datasets. Common to code DISP=(NEW,PASS) when you create a temporary dataset.

DELETE – specfies to the OS that the dataset must be uncataloged and deleted from the system when the step ends normally.

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C125

The DD statement- DISP(Abnormal termination) contd..

Abnormal termination disposition specifies what to do with the dataset when the step terminates abnormally - whether CATLG, UNCATLG, KEEP, DELETE.

Note: For SMS managed datasets, KEEP always reverts to

CATLG, since all SMS managed datasets must be cataloged.

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C126

The DD statement – DISP contd..

PDS and DISP

To create a new member of an existing PDS, code DISP=OLD or SHR, not NEW, since DISP refers to the partitioned dataset as a whole not to the member.

The PDS directory is updated to know about the new member.

VSAM datasets and DISP

Code DISP=OLD or SHR only for DD statements that access a VSAM dataset.

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C127

The DD statement – DISP (Defaults) contd..

If DISP parameters are not coded, the following defaults:

DISP Coded as : Defaults to :If not coded ………………….(NEW,DELETE,DELETE)

(OLD)………………………...(OLD,KEEP,KEEP)

(SHR)…………………………(SHR,KEEP,KEEP)

(,CATLG)…………………….(NEW,CATLG,CATLG)

(MOD)……………………….. If dataset does not exist :

(NEW,DELETE,DELETE)

If dataset exists :

(OLD,KEEP,KEEP)

(MOD,CATLG,)……………..(NEW/OLD,CATLG,)

DELETE) DELETE)

Disposition of OLD deletes existing records from the dataset. So,

to append records, code MOD.

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C128

The DD statement - UNIT

UNIT requests the type of device - Disk or Tape, required to store a

dataset.

SYNTAX :

UNIT=Hardware address 0C4

(or)

Device Model number 3390

(or)

Symbolic device Group name SYSDA

(or)

Virtual Input / Output VIO

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C129

The DD statement – UNIT contd.. EXAMPLES:

//DDN DD DSN=DSRC012.New.DS,

// DISP=(NEW,CATLG,DELETE),

// UNIT=3390

//DDB DD DSN=…….

// UNIT=3480

Note: System Catalog entry may state DEVICE instead of UNIT.

Implies a disk drive based on

Model number

Implies a tape drive based on

Model number

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C130

The DD statement – UNIT(Hardware Address) contd..

Hardware Address Every I/O device (Disk drive, Tape drive, Printer, Terminal) has a unique label called Hardware Address The OS communicates with these devices using their addresses You can specify where to store your dataset using these Addresses, represented by three hexadecimal

characters – D5A, A58, 0C4.

EXAMPLE: //DD8 DD DSN=DSRC012.New.DS,


// UNIT=A58

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C131

The DD statement – UNIT (Model Number) contd..Device Model number

IBM convention for every item it manufactures Disks carry Model Numbers like 3390, 3380 Tapes carry numbers like 3490, 3480. Printers and all other I/O devices carry an IBM convention. The OS maintains a list of addresses for each Model number.

EXAMPLE: //DD8 DD DSN=DSRC012.New.DS,


// UNIT=3390

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C132

The DD statement – UNIT (Group Name) contd..Symbolic Group name

Installations group hardware addresses of ‘similar’ devices destined for a specific purpose (production-preferred high speed disk drives, or drives to store test datasets) and give a unique name to each group. Say, addresses of disk drives for some specific purpose are listed under a group named SYSDA. The OS selects any available

disk from the group list SYSDA, to store the dataset.

//DD8 DD DSN=DSRC012.New.DS,


// UNIT=SYSDA

Symbolic names facilitates smooth phasing-in of newly added devices, by adding their addresses to a group list. (The JCL code need

not be changed).

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C133

The DD statement – UNIT (VIO) contd.. Virtual Input / Output

Represents the storage disk that the OS uses for its virtual storage operations.

//DD8 DD DSN=DSRC012.New.DS,


// UNIT=VIO

VIO used to store: Work datasets, as in a compiler program Temporary datasets, used within a job

Cannot retain the datasets in VIO permanently. Lasts only for the duration of the job.

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C134

The DD statement - UNIT (Volumes) contd..

Along with UNIT, we can specify the number and name of the VOLUME of that Unit required. VOLUME is the name of a specific UNIT. One unit can have

many volumes. Say, a disk unit 3390 can have many volumes named Pack01, Pack02. And a tape unit can have many volumes named 038272, 013267, 020133.

Syntax:

UNIT=(3390,2),VOL=SER=(PACK01,PACK02)

where PACK01 and PACK02 are the names of the two volumes of

3390 disk unit.

For SYSDA, ‘Volume’ is not applicable. The OS selects any available disk from the list SYSDA.

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C135

The DD statement - UNIT contd..

Code UNIT only for New and existing Uncataloged datasets.

(Unit need not be coded for existing Cataloged datasets since the OS can locate the dataset from the System Catalog).

If your dataset is to be sent to a Printer or Terminal, code SYSOUT instead of UNIT.

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C136

The DD statement - UNIT contd..

While creating New datasets, if UNIT is not coded: Defaults to installation-defined devices based on purpose:

Unit Volume

For Development datasets 3390 ZTSO01

For Testing datasets 3391 ZRSO06

For SMS managed datasets, defaults to STORAGE CLASS:

Storage Class Unit Volume

SCTSO 3390 ZTSO03

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C137

The DD statement- UNIT (Common problems) contd..Common problems with UNIT

If you forget to code DISP at the dataset that you are reading,

//DDRd DD DSN=DSRC012.OLD.DS

you will get an error message SPACE NOT SPECIFIED FOR

DATASET or INCORRECT DEVICE TYPE SPECIFIED.

Correct this problem by coding DISP=SHR that you forgot, not

UNIT.

You will get this same error message if you code an incorrect UNIT

with a Cataloged dataset.

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C138

The DD statement - SPACE Specifies how much space to allocate for a new disk dataset.

Disk is often called DASD in the mainframe environment. Syntax:

SPACE=(S1,(S2,S3,S4),S5) S1 - the Unit of space in Cylinders(CYL),Tracks(TRK), Blocks of

records(a number representing block size), Record length S2 – Primary (initial) quantity of units S3 - Secondary quantity of units if primary is exceeded; but

allocated only when the dataset expands.

(S3 X 15 or 16 or 123 secondary allocations - called Extents) S4 - Number of Directory blocks (applicable for PDS only) S5 - Releases the unused space requested

EXAMPLE:

SPACE=(TRK,(5,2)) You get 5 tracks + (2 X 15) tracks

= 35 tracks

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C139

The DD statement – Space (CYL / TRK) contd..

Disk surfaces are divided into Tracks of recording space Group of tracks make a Cylinder Many cylinders make a disk Volume

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C140

The DD statement - Space (CYL/TRK) contd..

Different models of IBM Mainframe disks have different track capacities, number of cylinders and device capacities.

Disk Bytes/Track Tracks/Cylinder Total Total

Volume Cylinders Bytes

Model

3390-1 56664 15 1113 0.946 Gb

3390-2 56664 15 2226 1.892 Gb

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The DD statement – Space (EXTENTS) contd..

The smallest unit of space on mainframe disks is one whole track. The OS cannot split tracks for use by other datasets

One or more contiguous tracks or cylinders allocated to a dataset are called an EXTENT An EXTENT is a piece of disk space. Your primary space allocation is 1 extent. When you request SPACE=(TRK,(5,2)) you get:

1 primary extent and 15 secondary extents

5 tracks + (2 X 15) tracks

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The DD statement – Space (Block size) contd..

You can specify space request by Block size instead of Tracks or Cylinders. EXAMPLE:

SPACE=(3840,200) You get 200 blocks each holding

3840 bytes = 768,000 bytes on the disk

If you code a secondary allocation:

SPACE=(3840,(200,60)) …plus (60 X 3840 bytes X 15 Extents)

as secondary allocation

Since one track is the minimum unit of space, if block size requested works out smaller than one track, you still get one track of disk space.

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The DD statement – SPACE (Record Length) contd.. Applicable only for SMS managed datasets Code AVGREC parameter along with Space parameter Do not code BLKSIZE in the DCB keyword parameter

//DDN DD DSN=DSRC012.DS,


// UNIT=SYSDA,

// AVGREC=U,

// SPACE=(133,10000)

// RECFM=FB,

// LRECL=133

With AVGREC=U:

The 133 in Space parameter is the average Record length in bytes

=U means that the 10000 is a “unit” estimate of the quantity of records to be written.

You get (10000 records X 133 bytes) of space

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The DD statement – SPACE (Record Length) contd.. //DDN DD DSN=DSRC012.DS,


// UNIT=SYSDA,

// AVGREC=U,

// SPACE=(133,10)

You get (10 records X 133 bytes) of space.

For Secondary allocation request: SPACE=(133,(10,2))

AVGREC can support record quantities by thousands (AVGREC=K) and by millions (AVGREC=M)

// AVGREC=M,

// SPACE=(133,10)

You get (10,000,000 records X 133 bytes) of space.

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The DD statement-SPACE (Directory Blocks) contd..

While creating a PDS, the SPACE parameter is to include a request for Directory Blocks

Space=(TRK,(1,2,7)) You get 1 + (2 X 15) = 31

tracks and create 7 Directory

blocks. Each directory block

can store information about 5

members; implies 35

members can be allocated.

Space=(TRK,(1,,7)) When you do not want

secondary space for the PDS.

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The DD statement - SPACE contd..

EXAMPLES:

//DDN DD DSN=…….,

// DISP=…..,

// UNIT=3390,

// Space=(TRK,10) Allocates a PS with 10 tracks of space.

Space=(TRK,(5,,1)) Allocates a PDS with no secondary

space and 1 directory block.

Space=(3840,(200,60)) Allocates (200 X 3840) + (60 X

3840 X 15) of disk space.

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The DD statement - SPACE contd.. You receive the secondary space requested for your dataset only as the dataset expands; as you use it

You can get up to 16 extents of secondary space per dataset per disk volume for a PS

If you use more than one disk volume for a PS dataset, it can spread up to 16 secondary extents on each volume A PDS cannot span disk volumes

The limit of 16 extents per dataset per disk volume does not apply to VSAM datasets, which can exist with up to 123 extents

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The DD statement – SPACE (RLSE) contd..

Causes all of the whole unused tracks to be freed for use by other datasets

Syntax: SPACE=(6200,300,RLSE) Releases unused tracks.

SPACE=(6200,(300,60),RLSE) Releases unused tracks in the

last active secondary.

SPACE=(80,1,RLSE) No space is released since

space is less than a track for any disk volume model.

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The DD statement – SPACE (RLSE) contd..

RLSE does not work if a step abends

Does not work if the dataset is not closed normally

Does not work when the dataset is shared

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The DD statement - DCB Syntax for Data Control block

Specifies to the OS, the characteristics of the dataset used: Whether the records are of fixed length F

or variable length V

or Undefined length U The logical record length LRECL Size of record-blocks n * LRECL

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The DD statement – DCB (DCB merge) contd..

The OS uses this information to work on the datasets. The OS puts the information specified in this DCB parameter of the DD statement, into its own memory area called Data

Control Block. The OS actually uses this Data Control Block to work on the datasets. The OS gets information into its data control block from three sources and follows this sequence, called the DCB merge,

in seeking information into its data control block: The program being executed Your DCB parameter in the DD statement The label of the dataset (information in the VTOC)

If your program provides the OS all the information, then the

information specified in your JCL and in the dataset label is

ignored by the OS.

Provide the information vide DCB in JCL instead of program since, changing in JCL is easier – say, the BLKSIZE.

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The DD statement – DCB (RECFM) contd..

Syntax : DCB=(RECFM=F/FB/FBA/V/VB/VBA/U,

LRECL=n,

BLKSIZE=multiples of n)

FB Fixed length records and records are blocked VB Variable length and records are blocked U Undefined length A Used to control printers.

EXAMPLE: DCB=(RECFM=FB,LRECL=80,BLKSIZE=8000)

Blocks 100 records; each record 80 bytes in length.

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The DD statement – DCB (LRECL) contd..LRECL – The length of the logical record

For fixed length records, the dataset contains records all of the same length and hence LRECL = the actual length of the data-bytes. LRECL for fixed length records can range from 1 to 32,760 bytes. You can access all 32,760 bytes.

For variable length records, the length of the records vary from an average to a maximum. So, the LRECL = longest data-bytes length + 4 bytes; the 4 bytes called the RDW(record descriptor word) is pre-pended to each record and indicates the actual length of the record in its first two bytes LRECL can be as high as 32,760 but only 32,752 are accessible.

For Undefined format, code LRECL=0. Conventionally used to store load modules.

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The DD statement – DCB (BLKSIZE) contd..

BLKSIZE – The size of a ‘block’ of records; otherwise called the Physical record. Blocking of records improves processing speed

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The DD statement – DCB (BLKSIZE) contd.. For fixed length blocked records (RECFM=FB)

Block size is multiples of LRECL. Must not be larger than 32,760 bytes.

Example: DCB=(RECFM=FB,LRECL=80,BLKSIZE=8000)

For variable length blocked records (RECFM=VB) Block size is multiples of LRECL plus 4 bytes, for Block descriptor word (BDW) which is pre-pended to the block of

records. The first two bytes of the BDW indicates the length of the block.

Example: DCB=(RECFM=VB,LRECL=84,BLKSIZE=8404)

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The DD statement – DCB (BLKSIZE) contd..

For Undefined format (RECFM=U) records, let the OS

determine the block size.

DCB=(RECFM=U,LRECL=0)

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The DD statement contd…

For SMS managed datasets, the Space and DCB can

be set to an installation-defined DATACLASS based

on the attributes required for the dataset.

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Chapter 6 - More on the

DD STATEMENT

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CONCATENATING DATASETS

REFERBACKS

SPECIAL DD STATEMENTS

Other DD Statements for :

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CONCATENATING DATASETS Is used when you want to process two or more datasets in sequence as if they were a single dataset.

Say, three sequential datasets are monthly reports - Jan.DS, Feb.DS, Mar.DS. To get a quarterly report you can concatenate them.

//IN DD DSN=Jan.DS,DISP=SHR// DD DSN=Feb.DS,DISP=SHR// DD DSN=Mar.DS,DISP=SHR

Say, you want the OS to search several load module libraries for a member:


//STEPLIB DD DSN=DSRC012.LOADLIB1,DISP=SHR// DD DSN= DSRC012.LOADLIB2,DISP=SHR// DD DSN= DSRC012.LOADLIB3,DISP=SHR

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Rules for Concatenation The sequence in which the datasets are coded is the sequence in which they are concatenated We can concatenate PDS, PDS members and PS datasets, but not VSAM datasets. Cannot concatenate PDS

wholly with sequential datasets. All datasets must have the same RECFM. The LRECL must also be the same for fixed-length records. LRECL need not be same for variable-length records as long as you place the dataset with the longest LRECL

on the first DD statement. BLKSIZE need not be same You can concatenate as many as 114 PDS as PDSs. No concatenation limit on the PDS members or on PS. Datasets can reside on different devices.

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HOW TO CONCATENATE?Concatenate datasets by coding a DD statement for each dataset

//IN DD DSN=Jan.DS,DISP=SHR

// DD DSN=Feb.DS,DISP=SHR

// DD DSN=Mar.DS,DISP=SHR

DDname should be coded for the first DD statement only

If DUMMY dataset is coded, the rest of the datasets down are not processed

//DD1 DD DSN=A1.PDS,DISP=SHR// DD DUMMY// DD DSN=C1.PDS,DISP=SHR

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REFERBACKS - * Backward reference (referback) is used to copy information from a previous DD statement (within the same job) thus simplifying JCL code. Referback can also be applied to PGM parameter on the EXEC statement On the DD statement, this can be applied to three parameters:

DSN VOL DCB

Syntax:

Parameter=*.StepName.DDname

PGM=*.LKED.SYSLMOD

DSN=*.Step010.DD1

Note : If the DDname points to a DD statement in the same job step,

you can omit the StepName.

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EXAMPLE Referback on a DD statement

//DSRC012A JOB NOTIFY=DSRC012//STEP010 EXEC PGM=PGM1//DD1 DD DSN=EMP.PDS,DISP=(NEW,CATLG),

// DCB=(LRECL=80,RECFM=FB,BLKSIZE=800),

// …………………………

//DD2 DD DSN=INP.PDS,DCB=*.DD1, ……..

//STEP2 EXEC PGM=PGM2

//DD2 DD DSN=STU.PDS,DCB=*.STEP010.DD1, …..

Referback on a PGM parameter

//DSRC012A JOB NOTIFY=DSRC012//STEP010 EXEC PGM=HEWL

//SYSLMOD DD DSN=PDS(M1),DISP=SHR

//……………………..

//STEP020 EXEC PGM=*.STEP010.SYSLMOD

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SPECIAL DD STATEMENTS

JOBLIB

STEPLIB

SYSPRINT

SYSIN

SYSABEND

SYSMDUMP

SYSUDUMP

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JOBLIB Used to identify a program library (PDS) to search first when attempting to locate load modules

(PGM=) executed within the entire JOB

Must be placed after the JOB statement and before the first EXEC statement in the JOB

More than one program library can be concatenated

If a STEPLIB is specified in a JOB that also has a JOBLIB, the STEPLIB takes precedence when searching for a program

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EXAMPLE

If two load modules are members of the same PDS then execute the load modules by


//JOBLIB DD DSN=<PDS name>,DISP=SHR

//STEP1 EXEC PGM=<LM member name>

//………….


//………….

The OS searches the JOBLIB DSN for the two load modules.

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STEPLIB The STEPLIB DD statement is used to identify a program library to search first when attempting to

locate load modules (PGM=) executed during the JOB STEP

More than one program library can be concatenated

If a STEPLIB DD is specified in a JOB that also has a JOBLIB, the STEPLIB takes precedence when searching for a program

JOBLIB / STEPLIB is used to specify private program libraries

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EXAMPLE If two load modules are stored as members of two different PDSs, then execute the load modules by



//STEPLIB DD DSN=PDS1, ……..

(where the above LM is stored)

//………….

//STEP2 EXEC PGM=<LM member name >

//STEPLIB DD DSN=PDS2, ……….

(where the above LM is stored)

//………….

The OS searches the respective STEPLIB DSNs for the two load

modules.

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SYSPRINT Specifies that an execution report of the load module (PGM) is required. It defines the output file containing the execution

messages.EXAMPLE:

//STEP1 EXEC PGM=IEBGENER

//SYSPRINT DD SYSOUT=*

//SYSUT1……………

//

Note:

The SYSOUT parameter specifies the output stream dataset. It routes the report to the class (device) mentioned. SYSOUT=CLASS-code, is the syntax. The class can be any alphanumeric character or an asterisk(*), which refers to the device coded in the MSGCLASS parameter of JOB statement.

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SYSIN Used to begin an Input stream dataset; supplies data to the load module Instream datasets begin with the parameters * or DATA in the SYSIN DD statement

Format:

//SYSIN DD * or DATA, or DSNEXAMPLE:

//STEP2 EXEC PGM=LOAD1

//STEPLIB DD DSN=EMP.PDS,DISP=MOD

//SYSIN DD *

HELLO WORLD

/*

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SYSABEND,SYSUDUMP,SYSMDUMP

These are Abnormal termination dumps used to find the

source of an error when a program abnormally terminates

Coded after the EXEC statement

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SYSUDUMP Used to request a formatted dump of the program area, including the contents of the register, a

traceback of subroutines called and information about all the datasets used

The dump can be allocated to the SYSOUT CLASS, DASD or TAPE.

SYNTAX:

//STEP010 EXEC PGM=LM of an Application program

//SYSUDUMP DD SYSOUT=Class

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SYSABEND

Used to request a dump similar to that of SYSUDUMP and

additionally the system nucleus.

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SYSMDUMP

Similar to the request of SYSABEND but the dump is

unformatted.

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Chapter 7 - UTILITY PROGRAMS

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What is a Utility program? A program used by all users for the same purpose.

Say, a compiler program (IGYCRCTL) used for compiling Cobol source codes. A linkage-editor program (HEWL) used for link-editing the above compiled object codes.

Utility programs provide many useful functions Creating datasets Copying datasets Sequencing datasets Deleting datasets and so on

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IBM Utility programs contd…

IBM supplied utility programs that you run in batch are:

The IBM Utilities VSAM IDCAMS utility

Used only on normal Used on normal and VSAM

datasets datasets

Both the utilities’ functions can be and are easier done using TSO or ISPF

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Utility programs - IDCAMS contd…

The JCL statements for invoking the utility programs take the form: The IDCAMS Utility

//Stepname EXEC PGM=IDCAMS


This prints the IDCAMS messages

//DDname DD DSN=…….

You can code more than one DD statement depending on the

operation; say to copy from one DSN to another.

//SYSIN DD *

Command statements

/*

REPRO -

INFILE(DDname1) -

OUTFILE(DDname2)

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Utility programs - IDCAMS contd…

The Commands perform the operations which include:

COMMAND OPERATION

DEFINE To allocate a dataset

REPRO To copy from one dataset to another

DELETE To delete a dataset

PRINT To print a dataset

RENAME To rename a dataset

LISTCAT To list the system catalog information on

datasets

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Utility programs – IBM Utilities contd… The JCL statements in IBM Utilities take the form:

//Stepname EXEC PGM=the utility program-name


This prints the utility program’s messages

//SYSUT1 DD …………..

Based on the operation, specifies the input dataset

//SYSUT2 DD …………..

Specifies the output dataset based on the operation

//SYSIN DD *

Control Statements

/*

COPY INDD=SYSUT1,

OUTDD=SYSUT2

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Utility programs – IBM Utilities contd… The Control statements vary based on the utility program and the operation (to allocate or copy or delete datasets)

IEBGENER Copies sequential datasets. Use IDCAMS REPRO

statement instead. Note that members of PDS are

sequential datasets too.

IEBCOPY Copies PDSs (use IDCAMS REPRO) and

Compresses a PDS

IEBCOMPR Compares datasets. Instead use the SUPERC

utility of ISPF which can be run on-line or in batch.

IEHLIST Lists DASD information. USE IDCAMS LISTCAT

statement instead.

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Utility programs – IBM Utilities contd…

IEHPROGM Renames, deletes, catalog and uncatalog

datasets, creates special datasets called

Generation data groups (GDG). Use IDCAMS

ALTER, DEFINE, DELETE statements instead.

IEBUPDTE Maintains PROCS and Source libraries.

IEFBR14 Allocates datasets. USE IDCAMS DEFINE

statement instead.

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IEFBR14 program

Commonly called a NULL program

Uses: To allocate (empty) datasets – PS, PDS As a house-keeping measure to check the existence of a dataset

(using DISP parameter )

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IEFBR14 - To create a new dataset (PS) contd..To create a ‘new and empty PS’ which is to store fixed length records each of 80 bytes.

//DSRC012A JOB NOTIFY=DSRC012//STEP010 EXEC PGM=IEFBR14//SYSPRINT DD SYSOUT=*//DDNEW DD DSN=DSRC012.NEW.DS,// DISP=(NEW,CATLG,DELETE),// SPACE=(TRK,(1,1)),// DCB=(LRECL=80,

// RECFM=FB,

// BLKSIZE=8000)

Conventionally, new datasets are allocated using ISPF or TSO instead of the above program.

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IEFBR14 – To create a new PDS contd..

To create an empty, New, Fixed PDS Dataset. In the Space parameter, code the directory blocks as:

// SPACE=(TRK,(1,1, number of directory blocks))

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IEFBR14 - Create PS with variable length records contd..

To create a new dataset with variable length records, the

longest record being 80 data-bytes.

In the DCB parameter, code:

// DCB=(LRECL=84,RECFM=VB,BLKSIZE=8404)

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IEFBR14 - For house-keeping on datasets


//STEP010 EXEC PGM=IEFBR14//SYSPRINT DD SYSOUT=*//DDNEW DD DSN=DSRC012.NEW.DS,// DISP=(NEW,CATLG,DELETE),// SPACE=(TRK,(1,1)),// DCB=(LRECL=80,

// RECFM=FB,

// BLKSIZE=8000)

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IEBGENER Uses:

To copy sequential datasets To reformat records while copying

Can be compared to selecting specific columns

To specify conditions while copying Can be compared to selecting specific rows

To re-block copied records Changing the LRECL and BLKSIZE

To concatenate datasets To write instream data into a dataset

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IEBGENER – To copy contd..

To copy sequential datasets For backing-up purposes For expanding space allocation



//SYSUT1 DD DSN=<Input dataset to be Read from>

//SYSUT2 DD DSN=<Output dataset to be Written into>

//SYSIN DD DUMMY

// The input dataset can be a PS or a member of PDS The output dataset can also be a PS or a PDS member The input and output datasets can both be PS or PDS members Output datasets as PS apply to backing-up operations on tapes

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IEBGENER – To copy contd..

To copy an input sequential dataset to many members of a PDS Code Generate Maxname and Member name.




//SYSUT1 DD DSN=<Input dataset>

//SYSUT2 DD DSN=<Output PDS>

//SYSIN DD *

Generate Maxname=3

(To create 3 members in the output)

Member name=(mem1,mem2,mem3)

(mem1,mem2,mem3 will have the contents of sysut1)

/*

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IEBGENER - To Reformat data during copy contd.. By reformatting, you can select data-bytes to be output

Code Generate Maxflds and Record Field in the control statement (similar to Inrec Fields in Sort utility)

Say, to output only the Empnum and Salary data-bytes, in

the order of Salary and Empnum:




//SYSUT2 DD DSN=<Output dataset>

//SYSIN DD *

Generate Maxflds=2

Record field=(5,1,CH,6)

field=(5,46,CH,1)

(Length,Location in input,Format,Location in the output)

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IEBGENER - To Reformat data during copy contd.. And to have some character-literals in the output, say, two asteriks between Salary and Empnum fields (similar to ‘X’ in the

Sort utility), code Maxlits:




//SYSUT2 DD DSN=<Output dataset>

//SYSIN DD *

Generate Maxflds=2,Maxlits=2


field=(5,46,CH,1)

(Length,Location in input,Format,Location in the output)

field=(2,’**’,,6)

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IEBGENER - To Reformat data during copy contd..

If output is to be routed to the three PDS members, but to perform reformatting only in the second member

//SYSIN DD *

Generate Maxname=3,Maxflds=2

Member name=mem2

Record field=(5,1,ch,8)

field=(5,46,ch,1)

field=(2,’**’,,6)

Member name=(mem1,mem3)

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IEBGENER – To specify conditions contd…

To select rows of records based on some criteria, say, employees getting a salary of 1000, code Maxgps and Record Ident (similar to Include / Omit Cond of Sort utility)




//SYSUT2 DD DSN=<Output PDS>

//SYSIN DD *

Generate Maxgps=1

Record Ident=(5,’01000’,46)

(length,<condition>,start-byte)

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IEBGENER - To re-block records contd..Re-blocking can involve:

Altering the BLKSIZE sub-parameter of the DCB in the output Altering the LRECL too

Code GENERATE control statement

Say to alter the LRECL in output:




//SYSUT2 DD DSN=<Output dataset>, …….

DCB=(LRECL=100,……..,BLKSIZE=10000)

//SYSIN DD *

Generate Maxflds=1


/*

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IEBGENER – To concatenate datasets contd..

To concatenate two datasets (note the PGM and the SYSUT1 DD statements)




//SYSUT1 DD DSN=<First unsorted dataset>

// DD DSN=<Second unsorted dataset>

Concatenation

//SYSUT2 DD DSN=<The concatenated dataset>

//SYSIN DD DUMMY

//

•

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IEBGENER - To write instream data contd..

To write instream data into a dataset




//SYSUT1 DD *

<Instream data>……

/*

//SYSUT2 DD DSN=<Output dataset to be Written into>

//SYSIN DD DUMMY

//

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IEBCOPY – To copy as a PDSTo copy a PDS as a PDS

Often used to expand the space allocation or change the directory space. Say, to increase the directory blocks: //STEP010 EXEC PGM=IEBCOPY


//SYSUT1 DD DSN=Existing PDS name,DISP=(Shr,Delete)

(say, this PDS has 10 directory blocks)

//SYSUT2 DD DSN=New PDS name,

// ………………………………………

// SPACE=(TRK,(10,5,50),RLSE),…….

(you request 50 directory blocks)

//SYSIN DD *

COPY INDD=SYSUT1,OUTDD=SYSUT2

/*

You can merge many input PDSs too. DDnames are necessary for merge.

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IEBCOPY contd..

You can further rename the new PDS to that of the deleted

PDS. Use IDCAMS ALTER command.

//STEP010 EXEC PGM=IDCAMS


//SYSIN DD *

ALTER <New PDS name> NEWNAME(Original dataset

name)

/*

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IEBCOPY contd..

You can alter the BLKSIZE but not the LRECL using

IEBCOPY

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IEBCOPY contd..

Determining the IEBCOPY operation to be performed: To request a COPY operation, specify partitioned data sets as input and output

Used to expand the space allocation, change the directory space or change the blocking size.

To request an UNLOAD operation, specify a partitioned input data set and a sequential output data set

Use to create a back-up copy on tape.

To request a LOAD operation, specify a sequential input data set and a partitioned output data set

Used to restore a PDS from tape to DASD.

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IEBCOPY – To copy to a new PDS contd…

To copy selective members from a PDS to a new PDS

Use SELECT MEMBER or EXCLUDE MEMBER in the control

statement along with COPY operation. Select and Exclude are mutually exclusive.

//STEP010 EXEC PGM=IEBCOPY


//SYSUT1 DD DSN=Existing PDS name,DISP=SHR

//SYSUT2 DD DSN=New PDS name,DISP=(New,Catlg),

// ……………………………

//SYSIN DD *

COPY INDD=SYSUT1,OUTDD=SYSUT2

SELECT MEMBER=(member1,member2……..)

/*

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IEBCOPY contd…

You can assign a new name to the copied member SELECT MEMBER=(member1,(member2,newname), ……..)

For a COPY operation on an PDS with members existing, you can replace identically named members in the output dataset

SELECT MEMBER=(member1,,R)

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IEBCOPY – To compress a PDS contd..

To restore unused space for use.

//STEP010 EXEC PGM=IEBCOPY


//INOUT DD DSN=Existing PDS name,DISP=Old

//SYSIN DD *

COPY INDD=INOUT,OUTDD=INOUT

/*

Since input and output datasets are the same, must code COPY

control statement.

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IEBCOMPRUses

To locate data-differences between two datasets. Comparison occurs at the record-level. Normally used to ensure accuracy of back-ups taken. Can compare two sequential or partitioned datasets.

To compare two PDSs:

//// //STEP010 EXEC PGM=IEBCOMPR //SYSPRINT DD SYSOUT=* //SYSUT1 DD DSN=<Dataset1>,DISP=Old //SYSUT2 DD DSN=<Dataset2>,DISP=Old //SYSIN DD *

COMPARE TYPORG=PO /*

RC of 0 implies no data-differences. RC of 8 implies differences.

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SORT Program - DFSortCan be invoked vide SORT verb in COBOL

Vide JCL you invoke as a job step

To sequence character data and numeric data in ascending or descending order Character data – sequenced from left to right; comprises aphabetic, alphanumeric and numeric characters. In

ascending order:

+9 and then -9 (+ comes before -)

Numeric data – sequenced based on the numeric value, taking sign too into consideration. In ascending order: -9 and then +9 (-9 is less than +9)

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SORT Program – DFSort contd…

To reformat data to be sorted Can be compared to selecting specific columns

To specify conditions for selecting data Can be compared to selecting specific rows

To concatenate datasets and sort

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C209

SORT Program - To sequence a dataset contd.

Character data and Numeric data are sorted differently.

The following fields are listed in ascending sequence for both character and numeric data.

As character data

+9, -9 (+ comes before -)

b9, -9 (Blank comes before -)

b999, 0009 (Blank comes before zero)

As Numeric data

-9, +9 (-9 is less than +9)

-9, 9 (-9 is less than 9)

9, 999 (9 is less than 999)

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SORT Program - To sequence a dataset contd. Sort order of alphanumeric data (character data) is called its Collating sequence, which specifies the sort order of

each character in the character set Two main collating sequences are EBCDIC and ASCII; the mainframe OS uses EBCDIC EBCDIC ASCII

blank blank

.<(+I=&!…….=“ !”#…….()+,-./

a through z 0 through 9

A through Z :;< = >?@

0 through 9 A through Z

[\]……

a through z

{I}-

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C211

SORT Program - To sequence a dataset contd.

To Sequence A Dataset Consider the following layout of a PS with fixed length

records:

Empno :starting at absolute byte 1, for 5 bytes long

Empname :at absolute byte 6, for 25 bytes long

Department :at absolute byte 31, for 15 bytes long

Salary :at byte 46, for 5 bytes long

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SORT -To sequence a dataset contd..

The PS being populated with the following records:

11111sujit admin 10000

55555danny marketing 15000

22222ajay admin 07000

33333mala projects 20000

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SORT -To sequence a dataset contd.. To sort in ascending order of Empno, the JCL is: //DSRC012A JOB NOTIFY=DSRC012

//STEP010 EXEC PGM=SORT


//SYSOUT DD SYSOUT=*

//SORTIN DD DSN=<the unsorted dataset>

//SORTOUT DD DSN=<The destination dataset name for

sorted data>

//SYSIN DD *

SORT FIELDS=(1,5,CH,A)

/*

The control statement supplies a Sort-Key implying:

Start sorting the record at the absolute byte address (1),

Length, the number of bytes to be included in sorting (5) ,

Format of sorting (EBCDIC character),

Sequence of sorting (ascending)

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SORT -To sequence a dataset contd..

The sorted dataset will contain :

11111sujit admin 10000

22222ajay admin 07000

33333mala projects 20000

55555danny marketing 15000

Note: For VB records, the first data-byte is 5.

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SORT -To sequence a dataset contd.. The Sort control statement takes the form:

SORT FIELDS=(Sort-key1, Sort-key2, ……)

(Start, Length, Format, Order)

Starting Length of data Ascending,

data-byte to be sorted. Descending

position in the

record. Data-

bytes 1 to CH EBCDIC character

4092 only can AC ASCII character

be the start bytes FS Signed numeric character

in the sort-key. D1 User-defined data type.

The keys are listed from left to right in the major to minor order.

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SORT -To reformat data to be sorted contd..

By reformatting: You can select data-bytes (columns) to be output and sort on those columns Since the start data-byte in the sort-key can be only within the first 4092 data bytes, to

consider data beyond 4092 bytes as the start data-byte, you can reformat.

To reformat, code: Before sort fields,INREC FIELDS to reformat the record before sorting After sort fields, OUTREC FIELDS to reformat the record after sorting

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Before sorting, to include only employee number and salary field and to sort in descending order of salary field:

//SYSIN DD *

INREC FIELDS=(1,5,46,5)-----------------------1111110000

SORT FIELDS=(6,5,CH,D) 5555515000

/* 2222207000

3333320000

The sorted dataset will contain:

3333320000

5555515000

1111110000

2222207000

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If data beyond 4092 bytes, say, at the 5000th byte is to be considered as the start position in the sort-key and sequencing to be done in ascending order of that field, then :

//SYSIN DD *

INREC FIELDS=(1,5,5000, say length of 3)


/*

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To reformat data-bytes after sorting, OUTREC FIELDS is used. Also used to space out fields in the output.

To obtain only the Empno and Salary fields in the output, but to sort on Empname field in ascending order:

//SYSIN DD * SORT FIELDS=(6,25,CH,A) ------------------------- 22222ajay……. OUTREC FIELDS=(1,5,46,5) 55555danny….. 33333mala……

11111sujith……

The output dataset will contain: 2222207000

5555515000

3333320000

1111110000

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To include character-literals, say, spaces between the Empno and Salary fields in the output dataset:

Code OUTREC FIELDS=(1,5,2X,46,5)

The output dataset will contain: 22222 07000

55555 15000

33333 20000

11111 10000

Two spaces

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C221

SORT – To specify conditions contd..

To select records (rows) based on some criteria, INCLUDE COND or OMIT COND is used

Takes the form,Include / Omit Cond=(Start-byte,Length,Format,Comparison,Constant)

Code before Sort Fields and Inrec Fields

//SYSIN DD *

Include / Omit Cond=

Inrec Fields=

Sort Fields=

/*

Decimal constant 12,-16,222,46

Hexadecimal “ X’nnnn…nn’

Character “ C’character-literals’

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SORT – To specify conditions contd..

To select employees getting a salary of 1000 and sort in ascending order of employee number

//SYSIN DD * INCLUDE COND=(46,5,CH,EQ,C’1000) SORT FIELDS=(1,3,CH,A)/*

Conversely, Omit Cond can be used to exclude employees with salary of 1000.

INCLUDE and OMIT are mutually exclusive

Can use connect operators AND and OR to form several logical conditions

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SORT - To concatenate datasets & sort contd.. To Merge two unsorted datasets into one sorted dataset (note the SORTIN DD statements and the control statement)





//SORTIN DD DSN=<First Unsorted Dataset>

// DD DSN=<Second Unsorted Dataset>

Concatenation

//SORTOUT DD DSN=<SORTED DATASET>

//SYSIN DD *


/*

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SORT - To concatenate datasets & sort contd..To Merge two datasets using MERGE FIELDS instead SORT FIELDS

Requires sorting of the datasets to merge.(Note the two SORTIN DD statements and the control statement)





//SORTIN01 DD DSN=<First Sorted dataset>

//SORTIN02 DD DSN=<Second Sorted dataset>

//SORTOUT DD DSN=<SORTED DATASET>

//SYSIN DD *

MERGE FIELDS=(1,5,CH,A)

/*

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C225

DFSORT – Merge Fields

It is erroneous to ‘merge’ (MERGE FIELDS) two

datasets of varying LRECL But can ‘concatenate’ two varying length datasets as

long as the highest LRECL is coded first. The concatenated output will take on the highest LRECL

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C226

Chapter 8 - PROCEDURE

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PROCEDURE (PROC) – What is it ?JCL used repeatedly by several users to perform the same function.

Say language compiler and linkage editor programs

//Cobol EXEC PGM=IGYCRCTL//SYSIN DD DSN=COBOL source pgm//…………other DD statements…………

//SYSLIN DD DSN=OBJECT module//Lked EXEC PGM=IEWL//SYSLIN DD DSN=OBJECT Module//…………other DD statements………….

//SYSLMOD DD DSN=LOAD Module

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PROCEDURE (PROC) – What is it ? contd…

Consider Utility programs




//SORTIN DD DSN=<Unsorted Dataset Name>

//SORTOUT DD DSN=<Sorted Dataset Name>

//SYSIN DD *


/*

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Why do we need PROCS ?

No repetitiveness of same code by all users

Eliminates coding errors

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Converting a JCL to PROC

8 steps to convert a JCL to a Procedure First code an Instream Procedure Then convert the Instream Procedure to a Cataloged

Procedure

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Step1 – Test the ‘Raw’ JCL code







//SYSIN DD *


/*

//

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Step 2 – Code PROC / PEND statements Separate the JOB statement from the remaining JCL statements, with a PROC operation giving the PROC a name.


//SORTPROC PROC

//PSTEP010 EXEC PGM=SORT





//SYSIN DD *


/*

// PEND

//

Separate the null statement(//) from the JCL with a PEND statement.

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Step 3 – Remove control statements Remove any control statement and put it into a member of a PDS.


//SORTPROC PROC






//SYSIN DD DSN=<PDS(Mem1)>, DISP=SHR

// PEND

//

Change the JCL to refer to that dataset.


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Step 4 – Use Symbolic parameters (&) Replace the parameter-values that will change from run to run with SYMBOLIC parameters (&), which are place holders

for the actual values.


//SORTPROC PROC


//SYSPRINT DD SYSOUT=&To

//SYSOUT DD SYSOUT=&To

//SORTIN DD DSN=&Unsorted Dataset

//SORTOUT DD DSN=&Sorted Dataset

//SYSIN DD DSN=&PDS(Mem1), DISP=SHR

// PEND

//

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Step 5 – Code default values for Symbolics If applicable, code default values for the symbolic parameters, on the PROC statement.


//SORTPROC PROC To=‘ * ’






//SYSIN DD DSN=&PDS(Member), DISP=SHR

// PEND

//

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Step 6 – Test the PROC instream the job Code, ‘EXEC the Proc-Name’ and assign the actual values to the symbolic placeholders.


//SORTPROC PROC To=‘ * ’







// PEND

//STEP010 EXEC PROC=SORTPROC,

// Unsorted dataset=‘Name’,

// Sorted dataset=‘Name’,

// PDS(Member)=‘Name’

This is called an INSTREAM PROCEDURE. You can code 15 instream procs in 1 job.

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Step 7 – Make Instream to Cataloged PROC Remove the JOB Statement //DSRC012A JOB NOTIFY=DSRC012

//SORTPROC PROC To=‘ * ‘




//SORTIN DD DSN=&UNSORTED DATASET

//SORTOUT DD DSN=&SORTED DATASET


// PEND





Remove the PEND and other statements thereafter

Save code in a private PDS member to evolve a cataloged procedure in user private library, or save in the system library SYS1.PROCLIB.

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Step 8 – Test the Cataloged Proc Code an invoking JCL

Code JCLLIB ORDER statement for Cataloged procedures stored in user private libraries.


// JCLLIB ORDER=<Location of Cataloged Procedure>





//

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C239

Using a Procedure Users invoke a Proc by coding ‘EXEC Proc-Name or

PROC=Proc-Name’ Based on the users’s specific processing needs, a PROC can be used by:

Assigning actual values to the symbolic parameters in the proceure Overriding the existing parameters of the EXEC and DD statements in the procedure Nullifying the existing parameters of the EXEC and DD statements in the procedure Adding new DD statements to the procedure Adding new parameters to the EXEC and DD statements in the procedure








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C240

Assigning values to symbolic parameters //SORTPROC PROC To=‘ * ‘








// JCLLIB ORDER=<Location of Cataloged Procedure>





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C241

Overriding the parameters of the Exec and DD


//PSTEP010 EXEC PGM=SORT,Time=(,1)







// JCLLIB ORDER=<Location of Cataloged PROC>



// Sorted dataset=‘Name’,Time.PSTEP010=(,5)

//PSTEP010.SYSIN DD *


/*

// Proc’s Stepname . DDname

Parameter. Proc’s Stepname

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Nullifying the parameters of the Exec and DD Code as with Overriding the parameters but do not pass the value

Code just an equal (=) sign after the parameter


//PSTEP010 EXEC PGM=SORT,Time=(,1)










// Sorted dataset=‘Name’,Time.PSTEP010=

//PSTEP010.SYSOUT DD SYSOUT=

//

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Adding new DD statements to the PROC//SORTPROC PROC To=‘ * ‘











// Sorted dataset=‘Name’

//PSTEP010.SYSIN DD *


/*

//

Proc’s Stepname . DDname

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Adding new parameters to the EXEC and DD Code as with overriding the parameters and pass the values.







//SYSIN DD DSN=&PDS(Member)






// PDS(Member)=‘Name’ // Time.PSTEP010=(,5)

//PSTEP010.SYSIN DD DISP=SHR

//

No TIME parameter

No DISP parameter

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Notes on Procedures A Job can contain 15 instream procedures. An Instream procedure can call a Cataloged procedure. A Cataloged procedure cannot call an Instream procedure. A Cataloged procedure can call a Cataloged procedure. There can exist a maximum of 15 nested ‘PROC statements’ – PROC operation

If each procedure resides in 15 different PDS, then the JCLLIB ORDER must identify those PDS to the OS.

Restart a PROC - Syntax <Job’s Step name . PROC’s Step name> Forward reference – Syntax - //DDName DD DDName=‘fwd’

Then use ‘fwd’ in the name field on any subsequent DD statement

In the invoking JCL of PROCs, overriding statements must come before add-on statements Override DD statements in the order of their occurrence within the PROC.

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Notes on Procedures To override a parameter on all the steps in a PROC with the same value, call the PROC

and code the parameter=its value. You can add-on and override DD parameters only one level down from the invoking step If the called PROC is not found in the private libraries of the JCLLIB order statement, then

the OS searches the system library even though not coded in the JCLLIB statement To override only certain concatenated datasets in a PROC, in the calling JCL, code just

‘DSN’ for those datasets which need not be overidden

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C247

Chapter 9 - GENERATION DATA

GROUPS

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C248

Use of Generation Data Groups A Generation Data Group (GDG) is used for processing data sets that are to be created on a periodical

basis – monthly or weekly or daily or hourly.

Examples : Processing Payroll Invoicing regular customers Income Tax report Backup Statistics Audit Trails

In each processing cycle, a new generation (updated version) of the dataset is generated.

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Referring a GDGAll generations have the same dataset name.

Referred to by the name and a ‘relative generation number ‘

DSN=DSRC012.Tax.State(0) the current tax report

DSN=DSRC012.Tax.State(-1) last year’s tax report

You add a new generation by calling it:

DSN=DSRC012.Tax.State(+1) new generation

Upto 255 relative generations can exist and must be cataloged.

Generations of a GDG are sequential and can reside on disk or tape.

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Advantages of GDG No need to change the JCL between runs

The same DD statements can be used to create each new generation //STEPCRTE EXEC PGM=IEFBR14

//DD1 DD DSN=DSRC012.Tax.State(+1),

// DISP=(NEW,CATLG),

// SPACE=(TRK,(1,5),

// DCB=DSRCO12.MODL.MODL

The system keeps track of adding and deleting successive generations

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Catalog entry for a GDG In the system catalog, each generation has a name with its ‘absolute

generation number’ GDGname.GaaaaVnn, where

aaaa – absolute generation number, 0001 to 9999

nn – version number, 00 to 99

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3 steps to Create a GDG Create an entry for the GDG in the system catalog

This entry is called the GDG Base - DSRC012.BASE.GDG

For non-SMS managed datasets, the second step involves creating a model dataset for supplying the DCB parameters to the new individual dataset belonging to a group. This model dataset must be cataloged.

For SMS managed datasets, this step can be bypassed.

Create the new dataset belonging to a group -

DSN=DSRC012.BASE.GDG(+1)

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CREATING THE GDG BASE Use the IDCAMS utility - DEFINE command


//STEP010 EXEC PGM=IDCAMS


//SYSIN DD *

DEFINE GDG(NAME(DSRC012.BASE.GDG)-

LIMIT(3)-

EMPTY-

SCRATCH)

/*

// NAME

LIMIT

EMPTY / NOEMPTY

Scratch / NoScratch

OWNER

TO / FOR

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CREATING THE GDG BASE contd…

NAME : A GDG name can contain maximum of 35 characters

(Since the GnnnnV00 take up 9 positions we have to keep the name to 35 or less characters)

LIMIT : Specifies how many GDS's (generations) are to be maintained in a group. (Maximum 255)

NAME and LIMIT are the mandatory parameters while defining the GDG base

EMPTY / NOEMPTY : Specifies what action OS should take when the LIMIT value is reached. EMPTY means that all generations should be removed (uncataloged) from the group; NOEMPTY means that just the oldest generation should be removed (uncataloged). NOEMPTY is the default

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CREATING THE GDG BASE contd…

SCRATCH / NOSCRATCH : Specifies whether or not OS should scratch (physical deletion) GDS's as they are removed from the group. NOSCRATCH is the default

OWNER : Specifies 1 to 6 character owner-id for the GDG.

TO & FOR : Specifies the expiration date TO(yyyyddd) or a retention period FOR(dddd) for the GDG

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CREATING THE MODELUse the IEFBR14 utility

//STEP020 EXEC PGM=IEFBR14

//DD1 DD DSN=DSRC012.MODL,


// SPACE=(TRK,0),

// DCB=(LRECL=80,RECFM=FB)

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CREATING THE MODEL contd…

The system can use the DCB values given in the

model as default values when a new GDS is created The DCB values can also be overidden while creating the

new GDS.

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Creating the new generation datasetUse IEFBR14 utility or a user-written application program


//STEP010 EXEC PGM=IEFBR14

//DD1 DD DSN=DSRC012.BASE.GDG(+1),


// SPACE=(TRK,(1,5),

// DCB=DSRCO12.MODL

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Creating the new generation dataset contd..

DSN should be coded for new generations, along with the generation number in parentheses.

Disposition should be CATLG for all new generations

Generations are referred by the same generation number throughout the various steps in the job The system updates the generation number only when the job terminates.

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Creating the new generation dataset contd..

After the job terminates a new generation is added to the GDG and becomes the current generation The former current generation becomes a previous generation Relative generation number is used to uniquely identify every data set in the GDG

The current generation is identified as DSN=GDGname(0). The earlier generation is identified as DSN=GDGname(-1) and the second oldest generation is identified as DSN=GDGname(-2) and

so on. +ve numbers refer to generations not yet created:

DSN=GDGname(+1)

DSN=GDGname(+2),.....).

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Absolute and Relative generation numbers

Consider 3 generations in the catalog:

DSRC062.BASE.GDG

DSRC062.BASE.GDG.G0001V00 (-2)

DSRC062.BASE.GDG.G0002V00 (-1)

DSRC062.BASE.GDG.G0003V00 (0)

CURRENT GENERATION

PREVIOUS GENERATION

OLDEST GENERATION

ABSOLUTE GENERATION NUMBER RELATIVE NUMBER

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Retrieving a generation dataset

To retrieve an individual dataset, code the dataset name along with the relative generation number

If the dataset is coded without the generation number, then all the generations in that group will be concatenated and retrieved

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C263

Deleting a generation dataset

The system will automatically delete the individual GDS as per the GDG

base ‘definition’

We can also delete a specific generation by coding DISP=(Old,Delete)

To delete the GDG Base we have to use IDCAMS command

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GDG NotesIf:

//Step010 EXEC PGM=IEFBR14

//DDGDSA DD DSN=GDG.Index(+1),DISP=(New,Catlg)…….

//…………

//DDGDSB DD DSN=GDG.Index(+2),DISP=(NEW,Catlg)…….

//

After the job terminates normally, (+2) becomes the current relative generation 0,

and (+1) becomes the relative generation (-1).

But see this:

//Step010 EXEC PGM=IEFBR14

//DDGDSA DD DSN=GDG.Index(+2),DISP=(New,Catlg)…….

//

This creates an absolute generation rolling ‘forward’ by +2 ; but the relative

generation rolls back by 1 only (ie) +2 becomes 0, the current relative

generation.

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C265

Q & A If TIME=1, CLASS=A is coded on a JOB statement where class A is

defined for jobs not exceeding 30 secs, will the job run successfully

if it requires 45 secs to process?

• The datasets given in Joblib / Steplib statements cannot be referred back.

State - True/False

• What are the valid DSORG values ?

• What is the purpose of DD * statement?

a) Begins an input data prompt at the system console

b) Begins an in-stream dataset

c) Marks the end of a command stream

d) Includes all datasets within a naming pattern

• If your program abends and you need to print the dump generated by the system we can use -----

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Q & A What will happen if region=0k is coded on job statement?

--------- selectively executes job steps.

//AS1 DD DSN=AAA.BBB,UNIT=AFF=AS0; What device does this dataset use?

a) Device AS0

b) Device in address AS0

c) Device mentioned in AS0 statement

d) Error in coding device

• What will be the system response for the jcl?

//JW1 JOB NOTIFY=DSRC050

• What u mean by include statement in JCL?

• What are the jcl statements that should not be used in INCLUDE groups?

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Q & A //ddname DD DATA and //ddname DD * are equivalent

a) Always 0%

b) When using default delimiters only 100%

• To Create a GDG Dataset we can use both IDCAMS & IEHPROGM

• The STEPLIB statement cannot be used in a cataloged procedure - False

• Recall points on control cards used in SORT• SORTWKnn

• SORT FIELDS=COPY• If you code both SORT KEY and COPY it is a definer error

• MERGE FIELDS

• SUM FIELDS=NONE,XSUM (SORTOFnn)

• All abend codes

jcl.ppt

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