Session and Batch Modes

This section describes how to use sessions and jobs on a 900 Series HP 3000. A detailed description of the steps involved in program development are given in Chapter 3 "Program Development."

The two ways to perform tasks on a Series 900 HP 3000 system are session mode and batch mode. Session mode is interactive. In other words, you log on to the system, it prompts you with information displayed on the screen to determine what you want to do (or tell you what it has done), you enter information telling it what you want to do, and the system executes your commands. Session mode is dynamic; you can submit commands that can alter the outcome of your task, as you go.

Batch mode requires that you set up a job that you can submit all at once to the system for processing. The job contains all the information necessary for the system to perform your task: a log on, a list of commands to execute, and an end-of-job signal. When you submit a job in batch mode, you cannot alter the outcome of the task. The job will run to completion (assuming it does not end abnormally) without any opportunity for you to change the commands in the job.

You can use the MPE/iX command :STREAM to initiate a job, once you have placed all the instructions for the job in a file. This job stream is independent of the session or job that originated the file. You can use it to intiate a job directly from a current session or from a disc file.

Almost all MPE/iX commands execute in either mode. Some give slightly different information depending on the mode in which they are executed, and some are totally interactive and are ignored in batch mode.

Figure 1-9 “Session and Job Commands” shows a comparison of the commands that begin and end a session and job.

Figure 1-9 Session and Job Commands

Figure 1-10 “Session and Job Characteristics” shows a comparison of characteristics of a session and a job. You may not yet be familiar with all of the terms used, but you can get a general idea of the similarities and differences and refer to this figure again when you are more familiar with the 900 Series HP 3000.

Figure 1-10 Session and Job Characteristics

You can identify sessions and jobs currently running on the system by using the MPE/iX command :SHOWJOB. This lists all sessions and jobs, identifies them with a unique number (sessions start with #S, jobs start with #J), gives their state of execution, input priority, and other pertinent information.