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This job will cause z/OS to execute a program, IEFBR14. z/OS will also create and catalog a
disk dataset, RALPHB.STD.OUT. Syntax information and more detail about these statements
can be found in the publication OS/390 MVS JCL Reference, GC28-1757.
JCL is either directly or indirectly involved almost every technique that is used to invoke
executable programs in z/OS. Batch is just one of several vehicles that exploit JCL. But it is
the JCL and not the batch that is really important. It takes time to gain a comprehensive,
proficient working knowledge of JCL, but it is not usually necessary to learn a lot of JCL to
work in the z/OS environment.
A number of enhancements and components have been introduced over the years to
minimize the amount of JCL you need to learn to be proficient. Some of these enhancements
and components are JCL procedures, Storage Management Subsystem (SMS), and even the
Interactive System Productivity Facility/Product Development Facility (ISPF/PDF). But JCL is
still fundamental to the environment. Most JCL is created today through ISPF/PDF. The
interface that supports ISPF/PDF is TSO/E.
1.1.5 TSO/E
TSO/E provides a z/OS interactive, command-line interface similar to the shell in the UNIX
environment. Of course, this similarity cannot be taken too far. A sample TSO/E command is:
ALLOCATE DA('RALPHB.STD.OUT') OLD
This command will allocate the existing z/OS disk dataset, RALPHB.STD.OUT. However, this
dataset could also have been created through TSO/E dynamic allocation by using the same
ALLOCATE command. Syntax information and more detail about these commands can be
found in OS/390 TSO/E Command Reference, SC28-1969.
We compared TSO/E to the shell and mentioned that both use a command line interface.
Many people think the command line interface is difficult to work with. This was evidenced by
the acceptance of Windows over the older DOS operating system. The distaste for the
command line interface also gave rise to the X Window system in UNIX.
In z/OS, TSO/E has given way to ISPF/PDF, which uses panel-driven dialogs, action bars,
and pull-down menus. It lets users make alphanumeric requests from various panels, and
provides action bars and pull-down menus as an alternative to the panel dialog interface.
1.1.6 ISPF/PDF
This is a widely used interface that almost everyone uses with TSO/E. ISPF/PDF takes a little
time to enunciate, so many people refer to it simply as ISPF.
We mentioned that ISPF/PDF is used to build JCL job streams and submit the jobs. It also
supports the System Display and Search Facility (SDSF), which is used to monitor job
execution and then review the jobs after termination.
But ISPF/PDF is used for much more. It provides a user-friendly full screen editor. It allows
users to invoke a number of z/OS utilities or issue TSO/E commands. It also provides an
environment that facilitates the development and management of interactive applications.
A wide range of other TSO/E-based interactive applications are supported and invoked
through ISPF/PDF. For example, a few of the other interactive applications that can be
invoked from under this ISPF/PDF umbrella are the OMVS UNIX shell, the ISHELL, RACF
panels for securing the z/OS traditional and open environments, WLM interfaces for