Sunday, 28 July 2013

All You Need To Know About JCL Utility, IDCAMS, IEBCOMPR, IEBCOPY, IEBDG etc.

Welcome Back once again Guys! 

In today's tutorial, You’ll learn how to use the z\OS JCL utility programs that make it easy for you to work with data sets and to generate test data. I will precisely introduce you to various JCL utility and important system libraries. So, let's start with the tutorial. 

JCL Utility
IBM Utility.

What is a Utility Program?

Technically speaking, JCL Utility programs (or just utilities) are the programs that can be used for common data processing functions like copying or printing a data set. With OS/390, you get an older set of utilities known as the MVS utilities.

The MVS utilities are older utilities that are provided by OS/390. Some of these utilities have been replaced by newer utilities or ISPF options. 

The JCL for running a utility program has to provide a DD statement for each ddname that’s used by the utility. The SYSIN data set is normally an in-stream data set that consists of control statements that provide processing specifications. 

All JCL utilities are normally run as batch jobs. z/OS provide a wide variety of function, but only a small number system provided JCL utility exist. Most of you might be aware of the utility IEFBR14, IEBGENER, and IEBCOPY. For VSAM you would normally use IDCAMS for various operations.

There are large utilities created by 3rd party vendors and are widely available on z/OS. The utilities are broadly categorized into two categories:

Data set utilities: These utilities are used for reorganizing data, compare data in two datasets, etc. All these utility run in batch mode.

System Utilities: These utilities are used to perform a wide-ranging operation that is related to data sets and volumes, such as data set names, catalog entries, and volume labels

IBM Utility

What are system libraries?

z/OS has many standard system libraries. A brief description of several libraries is appropriate here. The traditional libraries include: 
  • SYS1.PROCLIB - This is a system library that contains JCL procedures supplied with z/OS. 
  • SYS1.PARMLIB - This system library holds control parameters for z/OS supplied program and various other products. 
  • SYS1.LINKLIB - This library contains many of the basic execution modules of the system. In practice, it is one of a large number of execution libraries that are concatenated.
  • SYS1.LPALIB - This system library holds system execution modules that are loaded into the link  pack area when the system is initialized. 
  • SYS1.NUCLEUS - This system library holds the basic "kernel" modules of z/OS.
  • SYS1.SVCLIB. This library holds operating system routines known as supervisor calls (SVCs).

These libraries are in standard PDS format and are found on the system disk volumes.


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