Understanding the basics

In Language Environment, you can use the following methods to create a child enclave:

Under CICS®, the EXEC CICS LINK and EXEC CICS XCTL commands
Under z/OS®, the SVC LINK command
Under z/OS, the C system() function (see z/OS Language Environment Programming Guide for more information about system())
Under z/OS, the PL/I FETCH and CALL to any of the following PL/I routines with PROC OPTIONS(MAIN) specified:
- Enterprise PL/I for z/OS
- PL/I for MVS & VM
- OS PL/I Version 2
- OS PL/I Version 1 Release 5.1
- Relinked OS PL/I Version 1 Release 3.0–5.1
Such a routine, called a fetchable main in this book, can only be introduced by a FETCH and CALL from a PL/I routine.

The routine performing the FETCH and CALL must be compiled with the PL/I for MVS & VM or Enterprise PL/I compiler or be a relinked OS PL/I routine.

If the target routine of any of these commands is not written in a Language Environment-conforming HLL or Language Environment-conforming assembler, no nested enclave is created.