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Difference between DUMMY and NULLFILE


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enrico-sorichetti

Superior Member


Joined: 14 Mar 2007
Posts: 10888
Location: italy

PostPosted: Mon Oct 17, 2016 4:31 pm
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Difference between DUMMY and NULLFILE?

There is no difference


Quote:
NULLFILE
Specifies a dummy data set. NULLFILE has the same effect as coding the DD DUMMY parameter. NULLFILE must be coded as a single-word parameter. For instance, IBM does not support the use of NULLFILE to obtain a dummy data set for these (or other) formats:
When followed by a member name
As a qualifier in a qualified data set name
As a temporary data set name.


and demonstrated here
Code:

********************************* TOP OF DATA **********************************
                         J E S 2  J O B  L O G  --  S Y S T E M  S Y S 1  --  N

12.34.51 JOB04443 ---- MONDAY,    17 OCT 2016 ----
12.34.51 JOB04443  IRR010I  USERID ENRICO   IS ASSIGNED TO THIS JOB.
12.34.51 JOB04443  ICH70001I ENRICO   LAST ACCESS AT 12:34:32 ON MONDAY, OCTOBER
12.34.51 JOB04443  $HASP373 ENRICO1  STARTED - INIT 1    - CLASS A - SYS SYS1
12.34.51 JOB04443  IEF403I ENRICO1 - STARTED - TIME=12.34.51
12.34.51 JOB04443  IEF404I ENRICO1 - ENDED - TIME=12.34.51
12.34.51 JOB04443  $HASP395 ENRICO1  ENDED
------ JES2 JOB STATISTICS ------
  17 OCT 2016 JOB EXECUTION DATE
           14 CARDS READ
           58 SYSOUT PRINT RECORDS
            0 SYSOUT PUNCH RECORDS
            3 SYSOUT SPOOL KBYTES
         0.00 MINUTES EXECUTION TIME
        1 //ENRICO1  JOB NOTIFY=ENRICO,
          //             CLASS=A,MSGCLASS=X,MSGLEVEL=(1,1)
          //* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
          //*
        2 //G       EXEC PGM=IEBGENER
          //*
        3 //SYSIN     DD DUMMY
          //*
        4 //SYSPRINT  DD SYSOUT=*
        5 //SYSUT1    DD DISP=SHR,DSN=ENRICO.TEST.ZA
        6 //          DD DISP=SHR,DSN=ENRICO.TEST.ZB   
        7 //          DD DISP=SHR,DSN=ENRICO.TEST.ZC
          //*
        8 //SYSUT2    DD SYSOUT=*
ICH70001I ENRICO   LAST ACCESS AT 12:34:32 ON MONDAY, OCTOBER 17, 2016
IEF236I ALLOC. FOR ENRICO1 G
IEF237I DMY  ALLOCATED TO SYSIN
IEF237I JES2 ALLOCATED TO SYSPRINT
IEF237I 0AB3 ALLOCATED TO SYSUT1
IEF237I 0AB4 ALLOCATED TO
IEF237I 0AB1 ALLOCATED TO
IEF237I JES2 ALLOCATED TO SYSUT2
IEF142I ENRICO1 G - STEP WAS EXECUTED - COND CODE 0000
IEF285I   ENRICO.ENRICO1.JOB04443.D0000101.?           SYSOUT
IEF285I   ENRICO.TEST.ZA                               KEPT
IEF285I   VOL SER NOS= STOR03.
IEF285I   ENRICO.TEST.ZB                               KEPT
IEF285I   VOL SER NOS= STOR04.
IEF285I   ENRICO.TEST.ZC                               KEPT
IEF285I   VOL SER NOS= STOR01.
IEF285I   ENRICO.ENRICO1.JOB04443.D0000102.?           SYSOUT
IEF373I STEP/G       /START 2016291.1234
IEF374I STEP/G       /STOP  2016291.1234 CPU    0MIN 00.06SEC SRB    0MIN 00.01S
IEF375I  JOB/ENRICO1 /START 2016291.1234
IEF376I  JOB/ENRICO1 /STOP  2016291.1234 CPU    0MIN 00.06SEC SRB    0MIN 00.01S
DATA SET UTILITY - GENERATE
IEB352I WARNING: ONE OR MORE OF THE OUTPUT DCB PARMS COPIED FROM INPUT

PROCESSING ENDED AT EOD   

za
zb
zc
******************************** BOTTOM OF DATA ********************************                                                                             


Code:

********************************* TOP OF DATA **********************************
                         J E S 2  J O B  L O G  --  S Y S T E M  S Y S 1  --  N

12.35.31 JOB04444 ---- MONDAY,    17 OCT 2016 ----
12.35.31 JOB04444  IRR010I  USERID ENRICO   IS ASSIGNED TO THIS JOB.
12.35.31 JOB04444  ICH70001I ENRICO   LAST ACCESS AT 12:34:51 ON MONDAY, OCTOBER
12.35.31 JOB04444  $HASP373 ENRICO1  STARTED - INIT 1    - CLASS A - SYS SYS1
12.35.31 JOB04444  IEF403I ENRICO1 - STARTED - TIME=12.35.31
12.35.31 JOB04444  IEF404I ENRICO1 - ENDED - TIME=12.35.31
12.35.31 JOB04444  $HASP395 ENRICO1  ENDED
------ JES2 JOB STATISTICS ------
  17 OCT 2016 JOB EXECUTION DATE
           15 CARDS READ
           58 SYSOUT PRINT RECORDS
            0 SYSOUT PUNCH RECORDS
            3 SYSOUT SPOOL KBYTES
         0.00 MINUTES EXECUTION TIME
        1 //ENRICO1  JOB NOTIFY=ENRICO,
          //             CLASS=A,MSGCLASS=X,MSGLEVEL=(1,1)
          //* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
          //*
        2 //G       EXEC PGM=IEBGENER
          //*
        3 //SYSIN     DD DUMMY
          //*
        4 //SYSPRINT  DD SYSOUT=*
        5 //SYSUT1    DD DISP=SHR,DSN=ENRICO.TEST.ZA
        6 //          DD DUMMY                                                 
        7 //          DD DISP=SHR,DSN=ENRICO.TEST.ZB
        8 //          DD DISP=SHR,DSN=ENRICO.TEST.ZC
          //*
        9 //SYSUT2    DD SYSOUT=*
ICH70001I ENRICO   LAST ACCESS AT 12:34:51 ON MONDAY, OCTOBER 17, 2016
IEF236I ALLOC. FOR ENRICO1 G
IEF237I DMY  ALLOCATED TO SYSIN
IEF237I JES2 ALLOCATED TO SYSPRINT
IEF237I 0AB3 ALLOCATED TO SYSUT1
IEF237I DMY  ALLOCATED TO
IEF237I 0AB4 ALLOCATED TO
IEF237I 0AB1 ALLOCATED TO
IEF237I JES2 ALLOCATED TO SYSUT2
IEF142I ENRICO1 G - STEP WAS EXECUTED - COND CODE 0000
IEF285I   ENRICO.ENRICO1.JOB04444.D0000101.?           SYSOUT
IEF285I   ENRICO.TEST.ZA                               KEPT
IEF285I   VOL SER NOS= STOR03.
IEF285I   ENRICO.TEST.ZB                               KEPT
IEF285I   VOL SER NOS= STOR04.
IEF285I   ENRICO.TEST.ZC                               KEPT
IEF285I   VOL SER NOS= STOR01.
IEF285I   ENRICO.ENRICO1.JOB04444.D0000102.?           SYSOUT
IEF373I STEP/G       /START 2016291.1235
IEF374I STEP/G       /STOP  2016291.1235 CPU    0MIN 00.04SEC SRB    0MIN 00.00S
IEF375I  JOB/ENRICO1 /START 2016291.1235
IEF376I  JOB/ENRICO1 /STOP  2016291.1235 CPU    0MIN 00.04SEC SRB    0MIN 00.00S
DATA SET UTILITY - GENERATE
IEB352I WARNING: ONE OR MORE OF THE OUTPUT DCB PARMS COPIED FROM INPUT         

PROCESSING ENDED AT EOD
za
******************************** BOTTOM OF DATA ********************************



Code:

********************************* TOP OF DATA **********************************
                         J E S 2  J O B  L O G  --  S Y S T E M  S Y S 1  --  N

12.58.01 JOB04446 ---- MONDAY,    17 OCT 2016 ----
12.58.01 JOB04446  IRR010I  USERID ENRICO   IS ASSIGNED TO THIS JOB.
12.58.01 JOB04446  ICH70001I ENRICO   LAST ACCESS AT 12:36:15 ON MONDAY, OCTOBER
12.58.01 JOB04446  $HASP373 ENRICO1  STARTED - INIT 1    - CLASS A - SYS SYS1
12.58.01 JOB04446  IEF403I ENRICO1 - STARTED - TIME=12.58.01
12.58.01 JOB04446  IEF404I ENRICO1 - ENDED - TIME=12.58.01
12.58.02 JOB04446  $HASP395 ENRICO1  ENDED
------ JES2 JOB STATISTICS ------
  17 OCT 2016 JOB EXECUTION DATE
           15 CARDS READ
           59 SYSOUT PRINT RECORDS
            0 SYSOUT PUNCH RECORDS
            3 SYSOUT SPOOL KBYTES
         0.00 MINUTES EXECUTION TIME
        1 //ENRICO1  JOB NOTIFY=ENRICO,
          //             CLASS=A,MSGCLASS=X,MSGLEVEL=(1,1)
          //* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
          //*
        2 //G       EXEC PGM=IEBGENER
          //*
        3 //SYSIN     DD DUMMY
          //*
        4 //SYSPRINT  DD SYSOUT=*
        5 //SYSUT1    DD DISP=SHR,DSN=ENRICO.TEST.ZA
        6 //          DD DISP=SHR,DSN=ENRICO.TEST.ZB
        7 //          DD DSN=NULLFILE
        8 //          DD DISP=SHR,DSN=ENRICO.TEST.ZC
          //*
        9 //SYSUT2    DD SYSOUT=*
ICH70001I ENRICO   LAST ACCESS AT 12:36:15 ON MONDAY, OCTOBER 17, 2016
IEF236I ALLOC. FOR ENRICO1 G
IEF237I DMY  ALLOCATED TO SYSIN
IEF237I JES2 ALLOCATED TO SYSPRINT
IEF237I 0AB3 ALLOCATED TO SYSUT1
IEF237I 0AB4 ALLOCATED TO
IEF237I DMY  ALLOCATED TO
IEF237I 0AB1 ALLOCATED TO
IEF237I JES2 ALLOCATED TO SYSUT2
IEF142I ENRICO1 G - STEP WAS EXECUTED - COND CODE 0000
IEF285I   ENRICO.ENRICO1.JOB04446.D0000101.?           SYSOUT
IEF285I   ENRICO.TEST.ZA                               KEPT
IEF285I   VOL SER NOS= STOR03.
IEF285I   ENRICO.TEST.ZB                               KEPT
IEF285I   VOL SER NOS= STOR04.
IEF285I   ENRICO.TEST.ZC                               KEPT
IEF285I   VOL SER NOS= STOR01.
IEF285I   ENRICO.ENRICO1.JOB04446.D0000102.?           SYSOUT
IEF373I STEP/G       /START 2016291.1258
IEF374I STEP/G       /STOP  2016291.1258 CPU    0MIN 00.05SEC SRB    0MIN 00.01S
IEF375I  JOB/ENRICO1 /START 2016291.1258
IEF376I  JOB/ENRICO1 /STOP  2016291.1258 CPU    0MIN 00.05SEC SRB    0MIN 00.01S
DATA SET UTILITY - GENERATE
IEB352I WARNING: ONE OR MORE OF THE OUTPUT DCB PARMS COPIED FROM INPUT                                   

PROCESSING ENDED AT EOD
za
zb
******************************** BOTTOM OF DATA ********************************


edited to change the location of the dsn=nullfile
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