IBM Utilities Tutorial - 01

Q. What are IBM Utilities?

The MVS O/S comes pre-loaded with lots of utility programs, which help us in doing difficult tasks quickly. For example, you might need to create a new dataset(with particular parameters/settings), or you would like to take a backup of a Sequential Dataset. You may intend to work with special kind of VSAM Datasets. In order to accomplish such tasks, we would have to normally type TSO commands. This is very tedious and cumbersome. To make things easy, we can use utility programs provided by IBM. The most widely used IBM Utilities are - IEFBR14 Null program. Can be used to create a dataset, delete a dataset. IEBGENR Create a backup of a sequential dataset IEBCOPY Copy dataset from PDS to PDS or member to member SORT Sort the data in ascending or descending order IDCAMS Create a GDG or VSAM

Q. How is IEFBR14 (null program) used?

IEFBR14 is the IBM supplied DO-NOTHING utility program. Basically, it does nothing. We can use it in our Batch Job if we would like to create dataset, delete dataset using JCL. Normally, its easier to create, and delete datasets through TSO/ISPF. But if we want to do the same, by writing a Batch Job in JCL, we must use IEFBR14. Let’s see a Batch Job(JCL) to create a simple Dataset. //TRGD56A JOB A123,QUASAR,NOTIFY=&SYSUID //STEP01 EXEC PGM=IEFBR14 //DD1 DD DSN=TRGD56.DEMO.DATASET, //   DISP=(NEW,CATLG,DELETE), //   SPACE=(TRKS,(1,1),RLSE), //   DCB=(RECFM=FB,LRECL=80,BLKSIZE=800) //     In the above JCL, we create a new dataset with a storage space 1 primary track and 1 secondary track. Also, it is a Physical Sequential(PS) dataset. The PS has fixed-length records(FB), of length 80. The Block-size is 800.

Note : Every IBM Utility program has a prefix like IEF. IEF – All programs supplied by the JOB Management group have this prefix. IEB – Dataset utility programs have this prefix. IEH – System utility programs have this prefix. IEW – Linkers and Loaders have this prefix. The name IEFBR14 is due to fact, that BR14 stands for Branch to register 14 instruction in the IBM Assembly language.

Q. How is IEBGENR utility program used?

Whenever you want to take a backup of a PS(Physical Sequential) dataset, you must use IEBGENR. The PS dataset, could be a standalone dataset, or a sequential member of a PDS.  Here is the IEBGENR JCL Format : //TRGD56B JOB A123,QUASAR //STEP01 EXEC PGM=IEBGENR //SYPRINT DD SYSOUT=<output-device-class> //SYSUT1 DD <input-dataset> //SYSUT2 DD <output-dataset> //SYSIN DD <control-dataset> Here is a photograph(snapshot) of the Batch Job(JCL) written in the lab, to take a backup of a sequential Dataset(PS).

It can be easily deduced that -
1) This JCL takes a backup of a sequential file using IBM Utility program IEBGENR
2) Input Dataset – LEMOU21.LAB.EDSPS opened in Shareable mode
3) Ouput Dataset containing backup – LEMOU21.LAB.OUT2 created newly
4) SYSOUT=* means that all the allocation, termination and job-step messages should be directed to the default printer (Given by MSGCLASS parameter). You can see them in the JOB Spool.

Contents of Input Dataset(SYSUT1) - LEMOU21.LAB.EDSPS

 

Output Dataset Generated AFTER Running IEBGENR Utility - LEMOU21.LAB.OUT2

 
JOB Spool showing that job-step was executed successfully – COND CODE 00

Learn about the other IBM Utilities in the next few tutorials..

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