An application program can run commands and programs in a command/program invocation environment. This environment eliminates the need for MVS™ task initialization and termination each time you invoke a command or program. This support provides a potential performance benefit to users by helping to reduce system overhead associated with the initialization and termination of commands and programs.

You can invoke unauthorized commands and programs on a command/program invocation platform using the platform initialization and termination routines of the TSO/E service facility. The TSO/E service facility is an interface that allows a TSO/E user to invoke functions such as commands, programs, CLISTs, and REXX execs from an application program. For more information on the TSO/E service facility, see . You can invoke authorized commands and programs on a command/program invocation platform, even if you are not using the TSO/E service facility.

In order for commands and programs to run in the command/program invocation platform environment, your installation must first specify the eligible commands and programs on the appropriate platform support statement in the IKJTSOxx member of SYS1.PARMLIB. The PLATCMD statement identifies commands that are eligible to run on a command/program invocation platform. Similarly, the PLATPGM statement identifies programs that are eligible to run on a command/program invocation platform. TSO/E determines authorization for commands and programs from the list of authorized commands and programs that you maintain. For more information on command and program authorization, see Specifying authorized commands/programs, and commands not supported in the background.