Overview

THIS CHAPTER DESCRIBES THE BATCH FACILITY of OpenVMS, which allows a process to run "unattended," without being connected to an interactive terminal. DCL applications can take advantage of the batch facility to perform time-consuming tasks without tying up the user's terminal. It is important for the DCL programmer to understand the batch environment in order to coordinate the interactive and batch portions of an application and ensure their consistency.

21.1 The Batch Environment

A batch job is a process that runs in the OpenVMS batch environment rather than in the interactive environment. The batch-processing facility is supported by a special program called the queue manager, which runs in its own OpenVMS process. The queue manager is responsible for maintaining a set of batch queues to which users submit batch and print jobs for processing. The remainder of this chapter discusses techniques for using the queue manager and queues to run batch jobs.

A given OpenVMS system can have one or more batch queues, each with its own unique name. Associated with a queue is a set of attributes, which determine how the queue manager selects and runs jobs from the queue. It is up to your system manager to set up the batch queues and define their attributes; this book does not discuss the creation of queues. Almost every OpenVMS system has a standard batch queue named SYS$BATCH.

When you submit a batch job for execution, what you are submitting is a DCL procedure that...