CICS TG ECI and ESI Version 2 for C Overview

This documentation is for the CICS Transaction Gateway ECI and ESI Version 2 for C. This application programming interface (API) provides support for C-language ECI and ESI applications to access CICS servers from multiplatform machines remote to the Gateway daemon. Such an application must connect to a Gateway daemon over TCP/IP before flowing an ECI or ESI request to the target CICS server. The API is supported on the following platforms:

  • AIX
  • HP-UX on Itanium
  • Linux on Intel
  • Linux on POWER
  • Linux on zSeries
  • Solaris
  • Windows

The API is not supported on z/OS but connectivity from a remote ECI or ESI application to CICS TG for z/OS is supported.

ECI and ESI version 2 C sample programs are provided with the CICS TG product, the samples are installed in the following directories:

  • <install_path>/samples/c/eci_v2
  • <install_path>/samples/c/esi_v2
Helpful links

The types and functions which make up this API are defined in header files ctgclient.h, ctgclient_eci.h, ctgclient_esi.h and eci_channel.h.

When running on AIX, HP-UX, Solaris or Linux, the ECI and ESI version 2 API disables signal handling for the SIGPIPE signal.

When an application written for ECI and ESI version 2 is ready for deployment the appropriate CICS TG DLL or shared object file must be made available on the remote system. The CICS TG file for deployment with the application varies with operating system and application architecture:

AIX, 32-bit and 64-bit <install_path>/lib/libctgclient.a
Windows, 32-bit <install_path>\lib\ctgclient.dll
Windows, 64-bit <install_path>\lib64\ctgclient.dll
Other supported platforms, 32-bit <install_path>/lib/libctgclient.so
Other supported platforms, 64-bit <install_path>/lib64/libctgclient.so
Note
The ECI and ESI version 2 interface is for the C-language and it does not contain any C++ classes, the sections of documentation relating to Class Hierarchy duplicate the information for Data Structures.