JCLggg

8/13/2019 JCLggg

http://slidepdf.com/reader/full/jclggg 1/55

8/13/2019 JCLggg


• JCL or Job Control Language is used to

communicate with the computer’s operating system.

• A JOB is a unit of work the computer is to

perform.• A JOB STREAM consists of JCL

statements , programs that are to be

executed, and data that are to be processed.The data included in the job stream are

called I NPUT STREAM DATA .

8/13/2019 JCLggg


JCL statements :-

• JOB statement :- The first statement in a job

stream must be a job statement whose

function is to identify the job to the system.

• EXEC statement :- The job statement is

usually followed by an exec statement. The

exec statement names the program or the

procedure that is to be executed.

• DD statement :- Following the exec statementare the DD statements (data definition)

statements. The DD statements describe the

data used by the program.

8/13/2019 JCLggg


• The other JCL statements are delimiter, null,

comment, proc & pend.

• An EXEC statement and its DD statements

make up a job step .

• A job may consist of any no. of job steps.

• The job, exec & DD statements have a common

format which is :-

//name operation operand comments

8/13/2019 JCLggg


JCL conventions on a Live

Project• Job executes procedures, procedures have

various steps to execute various programs,

which use parameters and parameter files.

8/13/2019 JCLggg


8/13/2019 JCLggg


8/13/2019 JCLggg


Naming conventions :-

8/13/2019 JCLggg


Jobs will be held in datasets with .cntl or

.jcl extension

e.g. ORSDEVP.REL#15.JCL

Procedures will be held in datasets with

.proclib or .proc extension

e.g. ORSTEST.REL#15.PROCLIB

Parameters used will be held in datasetswith .parm or .parmlib extensions

e.g ORSLIVE.REL#1.PARMS

8/13/2019 JCLggg


Parameters :-

8/13/2019 JCLggg


• There are two kinds of parameters in

the operand field :- positional andkeyword parameters.

• The operating system recognizes

positional parameters by their position in the operand field.

• Keyword parameters can be coded in

any order.

• positional parameters must be codedin a specific order before any

keyword parameter.

8/13/2019 JCLggg


Consider the job statement :-

Positional parameters :-

- e.g.. accounting

information &

programmers name.

- accounting informationmust precede the

programmers name.

- if a positional

parameter /sub parameter is omitted a

comma must be coded in

its place.

Keyword parameters :-

- e.g.. class & msglevel.

- MSGLEVEL=(1,1)

indicates print all the input

JCL & the JCL fromcatalogued procedures &

print all allocation

messages.

- TYPRUN=SCAN causesthe job’s JCL to be checked

for syntax errors &

prevents the job from

executing.

C lli i

8/13/2019 JCLggg


Controlling step execution -

the COND parameter.

• The COND parameter offers a method of testing the returncodes issued by the previous steps to determine whether a

step will be executed.

• The format of a simplified version of the COND parameter

is COND =(value,operator) .

• Value is a no. between 0 and 4095 and operator could be

gt,ge,eq,ne,lt,le.

• The COND parameter causes the value entered to betested against the return codes from the previous steps,

using the operator provided.

•

If the test condition is true,the step is skipped.If the testcondition is alse,the ste is executed.

8/13/2019 JCLggg


Symbolic parameters :-

• Symbolic parameters offer a convenient way of changing

a procedure to fit your requirement.• Consider the example procedure-proglod, sysctl, sym,etc.

are all symbolic parameters.

• Symbolic parameter names may consist of from one to

seven alphanumeric or national characters preceded by

an ampersand. The first character however must be

alphabetic / national.

• Exec statement keyword parameters may not be used asnames of symbolic parameters.For e.g.. &REGION. This

restriction does not extend to DD statement keyword

parameters.For e.g. &DSN can be used as symbolic

parameter.

8/13/2019 JCLggg


Example procedure :-

8/13/2019 JCLggg


8/13/2019 JCLggg


8/13/2019 JCLggg


8/13/2019 JCLggg


Linkage parameter :-

•

Linkage parameters are used in COBOL programs.• Linkage parameters are passed on to the COBOL

programs through JCL by coding ‘ parm= ‘ parameter

in the exec statement.

• Whenever linkage parameters have to be used,

L inkage section has to be coded in the COBOL

program after the data division and the procedure

division should specify the use of linkage section.• //DD400S01 EXEC

PGM=DD400900,PARM='& PROCTYPE&DBNME

&DICTNME'

8/13/2019 JCLggg


8/13/2019 JCLggg


Generation Data Groups(GDG) :-

• A generation data group is a collection,or

group,of cataloged data sets having the samename and related to one another chronologically.

Each of these datasets is called a generation data

set or,simply, a generation .

• Each generation data set is distinguished by

others by the generation number .

• The main advantage of using a GDG is that the

same JCL can be reused without change.• Generation group index contains information on

how many generations are to be retained and what

to do when the index gets full.

8/13/2019 JCLggg


Defining a generation group

index using IDCAMS :-

• IDCAMS is the name of the access method

services utility program that performs functions

vital to the virtual storage access method(VSAM).• IDCAMS requires a region of 300K , a SYSPRINT

DD statement for messages and a SYSIN DD

statement for control statements.

• The command format :-DEF INE GDG (PARMS) .

8/13/2019 JCLggg


Define GDG parameters :-

Parameter Abbrv MeaningNAME GDD name.

LIMIT LIM The no. Of generations permitted for this gdg.

The max is 255.

EMPTY EMP If empty is specified, all data sets are to be

removed from the index when the limit is

reached.

NOEMPTY NEMP NOEMPTY is the default.

OWNER User identification (optional).

SCRATCH SCR If scratch is specified,the dataset is scratched

when the dataset is removed from the index.

NOSCRATCH NSCR NOSCRATCH is the default.

TO (date) Dataset retention period.

FOR(days) Dataset retention period.

8/13/2019 JCLggg


8/13/2019 JCLggg


Creating and accessing a generation :-

• The generation number may be relative or absolute.

• If the DS name in the group is

DDSNUS.DEVTDV.DD460302,

then to access the current generation,you code

DSN=DDSNUS.DEVTDV.DD460302(0).To access the previous generation, you code

DSN= DDSNUS.DEVTDV.DD460302(-1) the generation

before would be

DSN= DDSNUS.DEVTDV.DD460302(-2).

• If you want to create a new generation, you code

DSN= DDSNUS.DEVTDV.DD460302(+1).

8/13/2019 JCLggg


• The absolute no. used by the system is in the form

GXXXXVYY,where xxxx is a generation no. from0000 to 9999 and yy is a version no. from 00 to 99.

• Thus the generation specified as DSN=

DDSNUS.DEVTDV.DD460302(0) might appear to

the system, for e.g.. ,as

DDSNUS.DEVTDV.DD460302.G0006V00. Then

the data set with a relative no. of (-1) would be DDSNUS.DEVTDV.DD460302.G0005V00, (+1)

would be DSNUS.DEVTDV.DD460302.G0007V00.

8/13/2019 JCLggg


Deleting a generation group

index using IDCAMS...

8/13/2019 JCLggg


Lib i

8/13/2019 JCLggg


Libraries :-

•

Another name for a library is a partitioned data set(PDS).

• Libraries can be created,accessed & modified using

utility programs like

IEFBR14,IEBGENER,IEBPTPCH,IEBUPDTE,

IEBCOPY,etc.

• IEFBR14,IEBGENER & IEBCOPY are the most

frequently used utilities on any project.

8/13/2019 JCLggg


IEFBR14 :-

• Strictly speaking it is not a utility program

because it does nothing. It clears register 15 and

BR(branch) 14.

• It is used to create or delete a library based on the DD statement parameters.

• The following slide consists of an example of

IEFBR14.

8/13/2019 JCLggg


8/13/2019 JCLggg


IEBGENER :-• IEBGENER uses four data sets described by

SYSPRINT, SYSIN, SYSUT1 & SYSUT2.• SYSPRINT is the DDNAME of the data set that

IEBGENER uses to write messages.

• SYSIN is the DDNAME of the data set that

contains the control statements to tell IEBGENER

how the input data set should be modified while it

is being copied.

• SYSUT1 is the DDNAME of the input data set that IEBGENER is to copy.

• SYSUT2 is the DDNAME of the output data set

that is to be created.

8/13/2019 JCLggg


Example of IEBGENER :-

8/13/2019 JCLggg


Note :

8/13/2019 JCLggg


Note :-

• The SYSOUT parameter :- sysout is a keyword

parameter that assigns a data set to an outputclass.

• The DUMMY parameter :- The sysin DD

statement in the example contains the parameter

dummy. Dummy is a positional parameter thatindicates that the data set is not to be processed.

• The * parameter :- The * is a positional

parameter that indicates that input stream data follow immediately after the DD statement (if

coded after sysut1 DD statement.). The delimiter

statement, which has /* in column 1 & 2, indicates

the end of input stream data.

Note :

8/13/2019 JCLggg


Note :-

• Specifying ddnames in a program :-

In a COBOL program the DDNAME is specified

in the ASSIGN clause: ‘ SELECT SALEFI LE

ASSIGN TO SALES ’. The DD name would then

be // sales DD ....• Temporary data set :- A temporary data set name

consists of two ampersands( && ) followed by an

unqualified data set name.

8/13/2019 JCLggg


IEBCOPY :-

• IEBCOPY is a utility program that may be used to

copy one or more members from an existing PDS

to a new or existing PDS, to make a backup copy

of a PDS, and to reorganize a PDS in order to

reclaim the unused space

DFSORT i JCL

8/13/2019 JCLggg


DFSORT using JCL :-

• Sorting means putting records in a data set into a

specified order.

• Merging is closely related to sorting;it means

combining records from two or more sorted

datasets into one data set that is in the sameorder.

• The sort program requires three pieces of

information:where to find the input data,which

fields in the records to do the sorting on, andwhere to put the sorted output data set.

8/13/2019 JCLggg


Example of DFSORT :-

8/13/2019 JCLggg


8/13/2019 JCLggg


• The sort program expects its input to be supplied

under the DDNAME SORTIN and writes itsoutput under the DDNAME SORTOUT .

• The DD statements SORTWK01 through

SORTWK06 provide work areas for the sort

program.

• Sort program uses SYSOUT DD statement for

messages.

•

SYSIN DD statement defines the control statementdata set.

Sort control statements :

8/13/2019 JCLggg


Sort control statements :-

The most commonly used sort control statements are

SORT and MERGE .• A typical control statement would look like :

SORT FIELDS=(1,10,CH,A) .

• The syntax for the fields parameter is

FIELDS=(position,length,format,sequence...) or

FIELDS=(position,length,sequence...),

FORMAT=format .

• Position is the starting byte of the control field in therecord. Length is the length in bytes of the control field.

Format is the format of the data in the control field.

8/13/2019 JCLggg


• Commonly used values for format are ZD for

zoned decimal, PD for packed decimal, BI for

binary, AC for ASCII character, CH for EBCDICcharacter, AQ for EBCDIC character using

alternative collating sequence.

• Sequence is either A for ascending or D for

descending.

• The include & omit statements : The include &

omit statements are used to select the records to

be included in the sort. By selecting records forthe sort, you can decrease the amount of time the

sort requires.

8/13/2019 JCLggg


8/13/2019 JCLggg


• The operator sub parameter may be

GT,GE,EQ,NE,LT & LE.

• The last sub parameter, value , may be either a field in the record-specified by its own position,

length & format, or a constant.

• Numeric constantsare coded as simple values, such as 15 or -20. Character constants are

enclosed in apostrophes and preceded by a c,as in

c’dec’. Hexadecimal constants are enclosed in

apostrophes and preceded by an x,as in x’f1f2c3’. • If more than one test is coded, the tests are joined

by the boolean operator AND or OR ..

8/13/2019 JCLggg


• A typical include statement would look like :

INCLUDE COND=(29,1,CH,EQ,C’L’)

The INREC & OUTREC statements :

These statements are used to reformat the records.

•

The INREC statement is used before sort to shorten the records by eliminating unwanted

fields. This results in faster sorting.

• The OUTREC statement is used after the sort to

improve readability.• INREC & OUTREC have identical formats:

I NREC FIELDS=(nX,position,length,al ign,...)

OUTREC FIELDS=(nX,position,length,al ign,...)

8/13/2019 JCLggg


• The first sub parameter,nX ,is optional; it specifies

the no. of spaces to be inserted in the reformatted

record.

• The next two parameters, position & length ,

specify the field in the input record.• The third sub parameter, align , is optional; the

possible values being H, F, and D specify

alignment on a half-word, full-word, and double-

word boundary respectively.

Merging :

8/13/2019 JCLggg


Merging :-

• When you merge, you start with two or more

sorted data sets and create a new data set that is

in the same sorted order.

• While merging you must specify more than one

input data set. These data sets have the DD namesSORTINnn , where nn may range from 01 to 16.

• SKIPREC & EQUALS / NOEQUALS options are

not used on the merge statement.

• The sort control statements are normally coded in

a parameter f i le .

8/13/2019 JCLggg


Example of sort control statements :-

8/13/2019 JCLggg


VSAM D t t

8/13/2019 JCLggg


VSAM Data sets :-

• There are three types of VSAM data sets : key

sequence data sets,entry sequence data sets, andrelative record data sets.

• For VSAM data sets, unlike non-vsam data sets, a

utility program, IDCAMS is used to perform functions like :

- Allocating space on DASD

- Supply description of the data set

- Set the data set’s disposition- Load the data set

- Print the data set

8/13/2019 JCLggg


• DEFINE CLUSTER is the command using which

all the descriptive information about the VSAM

data set is supplied.

• REPRO command may be used to load data into a

VSAM data set.

• PRINT command is used to obtain a listing of a

VSAM data set.

• FILE-AID utility from ISPF primary menu( v.1 )

can be used to allocate / manage VSAM data sets.

8/13/2019 JCLggg


Example of defining cluster :-

8/13/2019 JCLggg


8/13/2019 JCLggg


Date post:	04-Jun-2018
Category:	Documents
Upload:	rohit-jaiswal
View:	219 times
Download:	0 times

JCLggg

Documents