Common Desktop Environment

This document serves as a developer's guide for integrating and maintaining applications using the ToolTalk service within the Common Desktop Environment (CDE). It explains how ToolTalk enables independent applications to communicate and inter-operate without direct knowledge of each other, addressing challenges like tool interchangeability, control integration, network-transparent events, automatic invocation, distributed objects, and persistent objects.

The ToolTalk service works by allowing applications to create and send messages (either "notices" for events or "requests" for operations) and by enabling recipients to register "message patterns" to specify which messages they want to receive. The service handles message distribution, which can be scoped to specific user sessions or files.

The guide outlines the necessary steps for modifying applications to utilize ToolTalk, including defining a message protocol, incorporating the ToolTalk API header files, initializing the service, joining ToolTalk sessions, registering message patterns, and sending/receiving messages. It also details the creation and installation of Ptype files, which describe the messages an application can handle.

Key tools and functionalities covered for development and debugging include:

• TTSnoop: An interactive utility for constructing, sending, and monitoring ToolTalk messages and patterns.
• ToolTalk Tracing (tttrace): A command-line tool to observe message traffic through the ttsession server and client interactions, with options for filtering and output control.
• The Messaging Toolkit: A higher-level interface of the ToolTalk API that simplifies common integration tasks by providing functions for managing communication endpoints, file events, session activities, and handling message contracts.
• New ToolTalk Functions: Discusses recent additions to the ToolTalk API, particularly functions for mapping filenames between local and canonical network paths and utilities for error logging and printing message/pattern details.

The document emphasizes practical application for developers familiar with ToolTalk, UNIX commands, and system terminology, focusing on CDE-specific functionalities rather than in-depth general ToolTalk API details.