The Command Processor parameter list

The Command Processor parameter list (CPPL) is a 4-word parameter list. When the TSO/E TMP attaches a Command Processor, it creates a CPPL in subpool 1 and passes the address of the CPPL to the Command Processor in register 1. The TSO/E TMP shares subpool 78 with the Command Processor, but it does not share subpool 0. In turn, the Command Processor or program must share subpool 78 with any lower-level tasks.

Notes:

Programs that use the TSO/E Environment Service to establish a TSO/E environment should share subpool 78 with any commands or programs that they invoke.
The TSO/E Environment Service returns the address of a Command Processor parameter list to programs that specify the CPPL address parameter.
A program running under the TSO/E TMP and Service Routines cannot invoke the TSO/E Environment Service.

The interface between the TMP and an attached Command Processor is shown in Figure 1.

Figure 1. Interface between the TMP and a Command Processor IKJB7001

The interface between the TSO/E Environment Service and a calling program is shown in Figure 2.

Figure 2. Control block interface between the TSO/E Environment Service and a calling program

You can use the IKJCPPL DSECT, which is provided in SYS1.MACLIB, to map the fields in the CPPL. Use the address contained in register 1 as the starting address for the DSECT, and then reference the symbolic field names within the IKJCPPL DSECT to access the fields in the CPPL. Use the DSECT because it protects the Command Processor from any changes to the CPPL. Table 1 describes the contents of the CPPL.

Table 1. The Command Processor parameter list (CPPL)
Number of bytes	Field name	Contents or meaning
4	CPPLCBUF	The address of the command buffer for the currently attached Command Processor.
4	CPPLUPT	The address of the user profile table (UPT). Use the IKJUPT mapping macro, which is provided in SYS1.MACLIB, to map the fields in the UPT.
4	CPPLPSCB	The address of the protected step control block (PSCB). Use the IKJPSCB mapping macro, which is provided in SYS1.MACLIB, to map the fields in the PSCB.
4	CPPLECT	The address of the environment control table (ECT). Use the IKJECT mapping macro, which is provided in SYS1.MACLIB, to map the fields in the ECT.