SNAX/APC Application Programming Manual

Using the Application Program Interface

SNAX/APC Application Programming Manual—138786

1-2

General Programming Considerations

You can write a SNAX/APC TP in any of the following languages:

•

C, as a process

•

COBOL (COBOL85), as a process

•

Extended BASIC, as a process

•

FORTRAN, as a process

•

Pascal, as a process

•

SCREEN COBOL, as a program executed by a terminal control program (TCP)

•

TAL, as a process

All SNAX/APC TPs communicate with the SNAX/APC server through the standard

Tandem interprocess communication mechanism provided by the operating system.

The Data Definition Language (DDL)

Programmers should be familiar with the use of Tandem’s Data Definition Language

(DDL) to include definitions of SNAX/APC verb structures in their TPs. Information

on DDL language-specific definitions may be found in Appendix A, COBOL

Definitions for SNAX/APC. TAL and C Language Definitions for SNAX/APC are also

included on the distribution tape.

You are advised to also check details on each verb in the next section of this manual,

because not all fields are defined, and some are language specific.

Basic and Mapped Conversations

SNAX/APC allows TPs to establish and participate in both basic and mapped

conversations. An implementation of a verb set for each is supplied.

Which Conversation Type to Use

Basic verbs are primarily used by service programs and conversations that require no

user programming: for example, change-number-of-sessions (CNOS) verbs. Mapped

conversations provide a higher-level interface than basic conversations, and relieve the

programmer of much of the concern with the underlying data stream (covered in the last

part of this introductory section). Tandem recommends the use of mapped verbs.

Use GET-TYPE to find out what conversation type the remote TP is using (or ask the

remote TP programmer before starting to code your local transaction program).

Basic Verbs

LU 6.2 requires service TPs (STPs), as part of the LU, to use basic conversations to

provide system-specific functions. Such STPs will take advantage of directly formatting