CICS Considerations
The C Socket programming interface supports writing applications for either a CICS® or batch execution environment. This is also true for the EZASMI macro and the EZASOKET call interface.
However, while the Assembler SOCKET macro and the TCP/IP for z/VSE HLL preprocessor (resolving EXEC TCP calls) allow to explicitly specify the execution environments, this is not possible with the BSD-C socket interfaces.
A programmer can write bimodal modules or applications, being called from either a CICS or batch program. The TCP/IP runtime services act according to the execution environment's requirements. That is, they eventually use CICS services (for example EXEC CICS WAIT) where appropriate.
- IPCICSRQ (TCP/IP for z/VSE only)
- DFHECI
Omitting those two files cause the application to act CICS unfriendly even if running under CICS' control. For example by issuing VSE GETVIS requests instead of CICS GETMAIN.