Transcript 12 IBM OS/JCL: DD Statements

12
IBM OS/JCL:
DD Statements
//TPEIN
//

DD UNIT=TAPE,DSN=PR.FLE,
DISP=(OLD,KEEP,KEEP)
The DD Statement:
– Defines a data set to the operating system.
– Notifies the operating system that a data set is to be
either accessed or created.
– Identifies the device requirements of the data set:
 Type of I/O unit required.
 Specific volumes to be mounted on the unit.
//TPEIN
//

DD UNIT=TAPE,DSN=PR.FLE,
DISP=(OLD,KEEP,KEEP)
The DD Statement:
– Further defines characteristics of the data set



The length of each record;
The format of the record;
Whether the data set already exists or is to be created during
the job step.
– Specifies what is to be done with the data set when the
job completes.
Tape DD Statement
//TPEIN
//
DD UNIT=TAPE,DSN=PR.FLE,
DISP=(OLD,KEEP,KEEP)

DDNAME - one to eight alphanumeric
characters. The first character must be alphabetic.

The DDNAME comes from the External
Reference name in the SELECT Clause of the
ENVIRONMENT DIVISION of a COBOL
program.
INPUT-OUTPUT SECTION.
FILE-CONTROL.
SELECT CARD-FILE ASSIGN UR-2540R-S-CARDIN.
SELECT PRINT-FILE ASSIGN UR-3203-S-PRTFLE.
SELECT TAPE-IN ASSIGN UT-3420-S-TPEIN.
SELECT TAPE-OUT ASSIGN UT-3420-S-TPEOUT.
SELECT DISK-IN ASSIGN DA-3375-S-DSKIN.
SELECT DISK-OUT ASSIGN DA-3375-S-DSKOUT.
DATA DIVISION.
01 CARD-FILE.
05 EMP-NO PIC X(5)
05 EMP-NAME.
10 EMP-LAST PIC X(25).
10 EMP-FIRST PIC X(25).
10 EMP-MIDDLE PIC X.
//TPEIN
//

DD UNIT=TAPE,DSN=PR.FLE,
DISP=(OLD,KEEP,KEEP)
DD – Operation
- Data Definition
//TPEIN
//

DD UNIT=TAPE,DSN=PR.FLE,
DISP=(OLD,KEEP,KEEP)
UNIT - Identifies the data set as a tape file
//TPEIN
//

DD UNIT=TAPE,DSN=PR.FLE,
DISP=(OLD,KEEP,KEEP)
DSN (DSNAME) –
Data Set Name
 Identifies the name of the file as recorded in
the header label when the file was created.

Fig. 12.4: The UNIT parameter
specifies a physical device.
UNIT=device
select from
unit or device address (channel/device address).
device type (2501, 3330, etc.)
group name (READER, PRINTER, etc.)
//TPEIN
//
//

DD UNIT=TAPE,DSN=PR.FLE,
DISP=(OLD,KEEP,KEEP),
VOL=SER=2992
DISP - Identifies the status of the data set:
Subparameter 1 - at the beginning of the job step;
 Subparameter 2 - If the job step terminates
normally;
 Subparameter 3 - If the job step terminates
abnormally.

Fig. 12.6: The disposition (DISP)
parameter specifies the file’s status.
DISP=(a,b,c)
file status following abnormal job step termination
file status following successful job step termination
file status at start of job step
Start of step
dispositions
End of step
dispositions
NEW
OLD
SHR
MOD
KEEP
PASS
DELETE
CATLG
UNCATLG
//TPEIN
//
//

DD UNIT=TAPE,DSN=PR.FLE,
DISP=(OLD,KEEP,KEEP),
VOL=SER=2992
DISP - Identifies the status of the data set:

Subparameter 1 - at the beginning of the job step;
//TPEIN
//

OLD

NEW

DD UNIT=TAPE,DSN=PR.FLE,
DISP=(OLD,KEEP,KEEP)
NEW,DELETE,DELETE
SHR , PASS,CATLG
,CATLG,UNCATLG
,UNCATLG,
- The data set was created in an earlier job or
job step.
- The data set is being created in the current
job step.
//TPEIN
//
//

DD UNIT=TAPE,DSN=PR.FLE,
DISP=(OLD,KEEP,KEEP),
VOL=SER=2992
DISP - Identifies the status of the data set:

Subparameter 2 - If the job step terminates
normally;
//TPEIN
//





KEEP
DELETE
PASS
CATLG
UNCATLG
DD UNIT=TAPE,DSN=PR.FLE,
DISP=(OLD,KEEP,KEEP)
NEW,DELETE,DELETE
SHR , PASS,CATLG
,CATLG,UNCATLG
,UNCATLG,
- The data set is to be saved for future use.
- The data set is scratched.
- The data set will remain mounted.
- The data set cataloged to the Tape Library.
- The data set is uncataloged from the Tape
Library.
//TPEIN
//
//

DD UNIT=TAPE,DSN=PR.FLE,
DISP=(OLD,KEEP,KEEP),
VOL=SER=2992
DISP - Identifies the status of the data set:

Subparameter 3 - If the job step terminates
abnormally.
//TPEIN
//




KEEP
DELETE
CATLG
UNCATLG
DD UNIT=TAPE,DSN=PR.FLE,
DISP=(OLD,KEEP,KEEP)
NEW,DELETE,DELETE
SHR , PASS,CATLG
,CATLG,UNCATLG
,UNCATLG,
- The data set is to be saved for future use.
- The data set is scratched.
- The data set cataloged to the Tape Library.
- The data set is uncataloged from the Tape
Library.
Common sense dictates:
//TPEIN
//
DD UNIT=TAPE,DSN=PR.FLE,
DISP=(OLD,KEEP,KEEP)
Common sense dictates:
//TPEIN
//
DD UNIT=TAPE,DSN=PR.FLE,
DISP=(NEW,CATLG,DELETE)
//TPEIN
//
//
21
DD
UNIT=TAPE,DSN=PR.FLE,
DISP=(OLD,KEEP,KEEP),
VOL=SER=2992
//TPEIN DD UNIT=TAPE,DSN=PR.FLE,
//
DISP=(OLD,KEEP,KEEP),
//
DCB=(RECFM=FB,LRECL=300,BLKSIZE=600)

DCB Parameter - supplies data set characteristics to be included
in the data control block.
– RECFM – Record Format
– LRECL – Logical Record Length
– BLKSIZE – Block Size
22
Fig. 12.5: The DCB parameter. The
DSORG, MACRF, and DDNAME must be
coded in the program DCB.
DCB=(list of parameters)
Typical parameters include:
LRECL=n
logical record length
BLKSIZE=n block size
RECFM=x
record format, where x is one or more of:
F
fixed length
V
variable length
B
blocked
A
ASA characters
Parentheses are required if more than one DCB parameter is coded
Disk DD Statement
//DISKIN DD UNIT=DISK,DSN=PR.FLE,
SYSDA
//DISKIN DD UNIT=DISK,DSN=PR.FLE,
SYSDA

UNIT - Identifies the data set as a disk file
//DISKIN DD UNIT=DISK,DSN=PR.FLE,
SYSDA
&&PR.FLE

DSN (DSNAME) –
– Data Set Name
– Identifies the name of the file as recorded in the header
label when the file was created.
– && used to indicate a temporary data set
Fig. 12.7: The SPACE parameter.
SPACE=(type,(primary,secondary,index),RLSE,CONTIG)
contiguous
space
return (release) any
unused space to the
system when the job
step ends
units of space to hold an
ISAM index, or blocks of
space to hold a library
directory
secondary space allocation
primary space allocation
type of space allocation in cylinders
(CYL), tracks (TRK), or blocks
//DISKOUT DD UNIT=DISK,DSN=PR.FLE,
SYSDA
//
SPACE=(TRK,(10,10),RLSE,CONTIG),
CYL,
BLKSIZE,
//
DISP=(NEW,CATLG,DELETE)



Type of space allocation
– Primary Allocation
– Secondary Allocation
Release Any Unused Space
All Space Must Be Contiguous
//DISKIN DD UNIT=DISK,DSN=PR.FLE,
//
DISP=(OLD,KEEP,KEEP)
NEW,DELETE,DELETE
SHR , PASS,CATLG
,CATLG,UNCATLG
,UNCATLG,

OLD

NEW

SHR
- The data set was created in an earlier job or
job step.
- The data set is being created in the current
job step.
- The input data set will be shared by another job.
//SYSIN


DD *
Allows a file to be inputted via the system’s default
input device.
The asterisk indicates that the data follows this DD
statement.
31
//SYSOUT



DD SYSOUT=A
Allows a file to be outputted to the system’s default
output device.
Normally implies printer output.
The value of SYSOUT is dependent upon your
installation.
32
//DISKIN

DD DUMMY
Allows a file to be ignored, or dummyed out. This
process will be allowed as long as the logic of the
program will allow the file to be dummyed out.
33
//DISKIN
//
34
DD UNIT=DISK,DSN=PR.FLE,
DISP=(OLD,KEEP,KEEP),
CONCATENATING DATA SETS
// INDATA DD DSN=CURORDR,UNIT=TAPE,
//
VOL=SER=K90221,
//
DISP=(OLD,KEEP,KEEP)
//
DD DSN=PREVORDR,UNIT=AFF=INDATA,
//
VOL=SER=14552,DISP=(OLD,KEEP,KEEP)
//
DD DSN=INV,UNIT=AFF=INDATA,
//
VOL=SER=866221,DISP=(OLD,KEEP,KEEP)
Data Control Block Table

As the Job Stream JCL is checked, the information in the
DD statements is used to create an entry for the data sets
in the DCB Table.

Once the DCB Table is completed, the JCL is then
checked for accuracy and validity.

If any errors are discovered, they are documented on the
JCL Listing (MSGLEVEL parameter) and the job is not
run.
Backward References

Using the DCB Table entries, Backward References
(Refer Backs) can take place.
Backward References
//OSJCL
//
//
//STEP1
//DD1
//
//DD2
//
//DD3
//
38
JOB
(OSJCL,’04/03/98’),’M. R. IZZO’,
CLASS =T,MSGLEVEL=(1,1),
MSGCLASS =A
EXEC PGM=CALC
DD
UNIT=TAPE,DSN=FILE1,
DISP=(OLD,KEEP,KEEP)
DD
UNIT=TAPE,DSN=FILE2,
DISP=(OLD,KEEP,KEEP)
DD
UNIT=TAPE,DSN=FILE3,
DISP=(NEW,PASS,DELETE)
//REPORT
DD SYSOUT=A
//SYSUDUMP DD SYSOUT=J
//CRDIN
DD *
* Card Input
*
/*
//STEP2
EXEC PGM=CALC2
//DD4
DD UNIT=TAPE,DSN=*.STEP1.DD3,
//
DISP=(OLD,KEEP,KEEP)
//REPORT2 DD
SYSOUT=A
//SYSUDUMP DD
SYSOUT=J
//
DCB Table
STEP NAME
STEP 1
DD Name
DSN
UNIT
DISP
DD1
FILE1
TAPE
Old, Keep Keep
DD2
FILE2
TAPE
Old Keep Keep
DD3
FILE3
TAPE
New Pass Delete
REPORT
SYSOUT=A
SYSUDUMP
SYOUT=J
CRDIN
STEP2
RECFMT
DD4
*
*.STEP1.DD3
TAPE
DCB Table
STEP NAME
STEP 1
DD Name
DSN
UNIT
DISP
DD1
FILE1
TAPE
Old, Keep Keep
DD2
FILE2
TAPE
Old Keep Keep
DD3
FILE3
TAPE
New Pass Delete
REPORT
SYSOUT=A
SYSUDUMP
SYOUT=J
CRDIN
STEP2
RECFMT
DD4
*
FILE3
TAPE
New Pass Delete
DCB Table
STEP NAME
STEP 1
DD Name
DSN
UNIT
DISP
DD1
FILE1
TAPE
Old, Keep Keep
DD2
FILE2
TAPE
Old Keep Keep
DD3
FILE3
TAPE
New Pass Delete
REPORT
SYSOUT=A
SYSUDUMP
SYOUT=J
CRDIN
STEP2
RECFMT
DD4
*
FILE3
TAPE
OLD,KEEP,KEEP
DCB Table
STEP NAME
STEP 1
DD Name
DSN
UNIT
DISP
DD1
FILE1
TAPE
Old, Keep Keep
DD2
FILE2
TAPE
Old Keep Keep
DD3
FILE3
TAPE
New Pass Delete
REPORT
SYSOUT=A
SYSUDUMP
SYSOUT=J
CRDIN
STEP2
RECFMT
DD4
*
FILE3
TAPE
REPORT2
SYSOUT=A
SYSUDUMP
SYSOUT=J
New Keep Keep
DCB Table
STEP NAME
STEP 1
DD Name
DSN
UNIT
DISP
DD1
FILE1
TAPE
Old, Keep Keep
DD2
FILE2
TAPE
Old Keep Keep
DD3
FILE3
TAPE
New Pass Delete
REPORT
SYSOUT=A
SYSUDUMP
SYSOUT=J
CRDIN
STEP2
RECFMT
DD4
*
FILE3
TAPE
REPORT2
SYSOUT=A
SYSUDUMP
SYSOUT=J
Old Keep Keep
Compiler Return Codes

Level W - Warning - Return Code 4

Level C - Condition - Return Code 8

Level E - Errors
- Return Code 12

Level F - Fatal
- Return Code 16
45
Compile, Link, & Execute
//OSJCL
JOB
//
//
//COB
EXEC
//SYSPRINT DD
//SYSUT1 DD
//
//SYSUT2 DD
//
46
(OSJCL,’04/03/98’),’M.R.IZZO’,
CLASS=T,MSGLEVEL=(1,1),
MSGCLASS=A
PGM=IKFCBL00,PARM=‘LOAD’
SYSOUT=A
UNIT=SYSDA,
SPACE=(460,(700,100))
UNIT=SYSDA,
SPACE=(460,(700,100))
//SYSUT3 DD UNIT=SYSDA,
//
SPACE=(460,(700,100))
//SYSUT4 DD UNIT=SYSDA,
//
SPACE=(460,(700,100))
//SYSLIN
DD DSNAME=&&LOADSET,
//
DISP=(MOD,PASS,DELETE),
//
UNIT=SYSDA,SPACE=(80,(500,100))
//SYSIN
DD *
*
* Source Input
/*
47
//LKED
EXEC PGM=IEWL,
//
PARM=(‘LIST,XREF,LET’),
//
COND=(5,LT,COB)
//SYSLIN
DD
DSN=&&LOADSET,
//
DISP=(OLD,DELETE,KEEP)
//SYSLMOD DD
DSN=&&GOSET(GO),
//
DISP=(NEW,PASS,DELETE),
//
UNIT=SYSDA,
//
SPACE=(1024,(50,20,1))
//SYSUT1 DD
UNIT=SYSDA,
//
SPACE=(1028,(50,20))
//SYSPRINT DD
SYSOUT=A
48
//GO
EXEC
//
//TPEIN DD
//
//
//
//
//TPEOUT DD
//
//
//
49
PGM=*.LKED.SYSLMOD,
COND=((5,LT,COB),(5,LT,LKED))
UNIT=TAPE,DSN=PR.FLE,
DISP=(OLD,KEEP,KEEP),
DCB=(RECFM=FB,LRECL=150),
DCB=(BLKSIZE=300),
VOL=SER=00978
UNIT=TAPE,DSN=PR.FLE,
DISP=(NEW,CATLG,DELETE),
DCB=(RECFM=FB,LRECL=150),
DCB=(BLKSIZE=300)
//DSKIN
DD UNIT=DISK,DSN=PR.TRANS,
//
DISP=(OLD,KEEP,KEEP),
//
DCB=(RECFM=FB,LRECL=200),
//
DCB=(BLKSIZE=400)
//DSKOUT DD UNIT=DISK,DSN=ED.PR.TRANS,
//
DISP=(NEW,CATLG,DELETE),
//
SPACE=(TRK,(10,5),RLSE)
//PRT
DD SYSOUT=A
//SYSUDUMP DD SYSOUT=A
//CRDIN
DD *
*
* Card Input
/*
//
50
Fig. 12.1: One data control block is coded
for each file accessed by a program.
*
*
SCREEN
DATA CONTROL BLOCKS
PRINTER
DCB
DCB MACRF=GM,DSORG=PS,
EODAD=QUIT,DDNAME=DATAIN
MACRF=PM,DSORG=PS,DDNAME=LINE
/*
//LINE
//DATAIN
/*
//
DD
DD
parameters
parameters
Load module
Fig. 12.2:
The
linkage
editor
adds an
access
method to
the load
module.
Object module
SCREEN
DCB
MACRF=GM,DSORG=PS,...
PRINTER DCB
MACRF=PM,DSORG=PS,...
Access method for SCREEN
Access method for PRINTER
Other subroutines
Fig. 12.3: The link to a specific
physical device is established at
OPEN time.
SCREEN
DCB DDNAME=DATAIN,...
OPEN
(SCREEN,INPUT)
Access methods and other subroutines
//DATAIN DD
parameters
Magnetic Disk Parameters

UNIT
 DCB
 DISP
 DSNAME
 VOLUME
 SPACE
Fig. 12.8: Some examples.
1. Create a temporary data set on the system work pack.
//DISK
//
//
DD
DSNAME=&&TEMP,UNIT=SYSDA,
DISP=(NEW,PASS),SPACE=(CYL,5),
DCB=(LRECL=120,BLKSIZE=2400,RECFM=FB)
2. Create a cataloged data set on a specific volume.
//RECS
//
//
//
DD
DSN=MU.USERDATA.MIS4,UNIT=3330,
VOL=SER=MIAMI3,DISP=(NEW,CATLG),
SPACE=(TRK,(20,5),RLSE,CONTIG),
DCB=(LRECL=155,RECFM=FB,BLKSIZE=1550)
3. Create a kept data set.
//KEEPIT
//
//
//
DD
SPACE=(CYL,(10,2),RLSE),
DCB=(RECFM=FB,LRECL=72,BLKSIZE=720),
VOL=SER=MYPACK,DISP=(NEW,KEEP),
DSNAME=MYDATA,UNIT=3330
Fig. 12.8: Some Examples
4. Retrieve a passed data set.
//DATA
DD
DSNAME=&&TEMP,DISP=(OLD,DELETE)
5. Retrieve a cataloged data set
//STUFF
DD
DSN=MU.USERDATA.SAN4,DISP=OLD
6. Retrieving a kept data set that has not been cataloged requires UNIT and VOLUME
parameters in addition to DSNAME and DISP
//DDNAME
//
DD
DSNAME=MYDATA,UNIT=3330,
VOL=SER=MYPACK,DISP=(OLD,KEEP)
Magnetic Tape Parameters

UNIT
 DCB
 DISP
 DSNAME
 VOLUME
 LABEL
System Input and Output

Spooling -- slower devices
 System input device
– //SYSIN DD *

System output device
– //SYSOUT DD SYSOUT=A
Fig. 12.9: The DDNAME can be qualified
if it is part of a catalogued procedure.
//JOBNAME
//
JOB
EXEC
//FORT.SYSIN
DD
(9824,18),DAVIS,CLASS=A
FORTRAN
*
FORTRAN source module
/*
//GO.SYSIN
Data
/*
DD
*
Fig. 12.10: Code the library member
name as part of the DDNAME.
DSNAME=library(member)
a member name
parentheses are required
the library name
Fig. 12.11: A complete set of JCL to
support an assemble, link edit, and go
job.
//MU132
JOB
1
2
//
EXEC
ASMGCLG
3
XXASM
EXEC
PGM=IEUASM
4
5
6
7
8
9
10
XXSYSLIB
XXSYSUT1
XXSYSUT2
XXSYSUT3
XXSYSPRINT
XXSYSPUNCH
XXSYSGO
XX
XX
//ASM.SYSIN
DD
DD
DD
DD
DD
DD
DD
DSNAME=SYS1.MACLIB,DISP=SHR
…
…
…
SYSOUT=A
SYSOUT=B
DSNAME=&&LOADSET,DISP=(NEW,PASS),
SPACE=(400,(100,20)),UNIT=SYSDA,
DCB=(LRECL=80,BLKSIZE=400,RECFM=FB)
*
11
Source code
12
13
DD
/*
Fig. 12.11: Continued
14
XXLKED
EXEC
PGM=IEWL
15
DD
16
17
XXSYSLIN
XX
XX
XXSYSLMOD
18
19
20
XXSYSUT1
XXSYSPRINT
/*
DD
DD
DSNAME=&&LOADSET, DISP=(OLD,DELETE)
DCB=(LRECL=80,BLKSIZE=400,RECFM=FB)
DDNAME=SYSIN
DSNAME=&&GOSET(GO),DISP=(NEW,PASS),
SPACE=(1024,(50,20,1)),
UNIT=SYSDA
…
SYSOUT=A
DD
DD
Fig. 12.11: Continued
21
XXGO
22
23
24
//GO.OUTPUT DD
//GO.DISK
DD
//GO.SYSIN DD
Data
25
26
27
/*
//
EXEC
PGM=*.LKED.SYSLMOD
SYSOUT=A
Parameters for program disk file
*