Overview

THE REVIEW OF BASIC DCL CONCEPTS and facilities was completed in the previous chapter. The remainder of the book describes how to use these facilities to create real programs: programs that are useful, correct, and robust. The proposed techniques are directed toward the development of complex procedures, applications composed of multiple procedures, or applications to be used by many people. If you are just writing a 20-line procedure for personal use, don't worry about following every guideline to the letter. Pick and choose the ones that are pertinent to your task.

The term DCL environment refers to a collection of information that guides the actions and responses of the DCL command interpreter. The environment information affects the operation of DCL commands, the content of messages displayed by DCL, and the behavior of command procedures. Commands are available for setting and displaying the various items of information making up the environment. This chapter describes the most important aspects of the environment:

• Verifying command procedures.

• Hiding predefined personal commands.

• Setting message components.

• Setting process privileges.

• Setting the user identification code (UIC).

• Changing the default directory.

7.1 Aspects of the Environment

The following sections describe some important aspects of the DCL environment. These environment features will be important in the remainder of this book.