(E)JES Run-Time Environments
(E)JES provides support for interactive users in the following environments:
- TSO Command Processor (no ISPF services needed)
- Phoenix TP Monitor (a stand-alone multi-user VTAM environment)
(E)JES provides three basic programmable environments.
The (E)JES batch interface provides much of the power of the on-line environment to automated programs or scripts. It may be used to automate specific functions under the control of a TSO/E CLIST, REXX exec, or any program written in System/390 assembler language or compatible high-level language. The batch interface may be invoked as:
- A TSO Command Processor. In this environment, (E)JES uses TSO GETLINE/PUTLINE services to receive commands and surface responses.
- A program invoked via MVS LINK or ATTACH services or high-level language equivalents. In this environment, (E)JES uses QSAM to receive commands and surface responses.
Application Programming Interfaces
The Application Programming Interface is similar to the batch interface in concept, but provides much more powerful programming capabilities. The API can be called from programming languages such as Assembler, COBOL, PL/I, and C. It supports ordinary problem state and privileged callers alike.
You can also harness the versatility of REXX to interface and interact with (E)JES. This support provides a REXX program with nearly all of the capabilities available to an interactive (E)JES user.
The (E)JES Java Application Programming Interface offers Java programmers the same powerful programming resources that are available through other (E)JES APIs.
On occasions when users want to run IBM-, ISV-, or user-written REXX execs that leverage IBM's ISFCALLS REXX host command environment for SDSF, such execs will usually run unchanged with (E)JES.