Module 5 — DCL Scripting & Automation

Overview

This module covers DCL scripting fundamentals, including symbols, lexical functions, command procedures, flow control, batch processing, and error handling. You’ll learn how to automate routine tasks and build reliable operational scripts.

Exam: Multiple‑Choice Questions

1. Which symbol type is local to a command procedure?

Global symbol
Local symbol
System symbol
Process symbol

2. Which command executes a DCL command procedure?

@filename
RUN filename
EXEC filename
DO filename

3. Which lexical function returns the current process name?

F$PROCESS
F$GETJPI
F$IDENTIFIER
F$STRING

4. Which command submits a command procedure to a batch queue?

RUN/BATCH
SUBMIT
QUEUE/EXECUTE
START/BATCH

5. Which DCL feature allows you to detect and handle errors within a script?

SET CONTROL
ON ERROR THEN
IF $STATUS
WHEN FAILURE DO

Hands‑On Exercises

Exercise 1 — Create Basic Symbols

Create a local symbol:
MYVAR = "Hello"
Display it:
SHOW SYMBOL MYVAR
Create a global symbol:
MYGLOBAL == "World"
Display it:
SHOW SYMBOL/GLOBAL MYGLOBAL

Exercise 2 — Write a Simple Command Procedure

Create a file named HELLO.COM containing:
$ WRITE SYS$OUTPUT “Hello from DCL!” $ EXIT

Code

Execute it:
@HELLO

Exercise 3 — Use Lexical Functions

Display the current process name:
WRITE SYS$OUTPUT F$PROCESS()
Display the current default directory:
WRITE SYS$OUTPUT F$ENVIRONMENT("DEFAULT")

Exercise 4 — Add Flow Control

Create a script:

$ IF F$SEARCH(“TEST.DAT”) .EQS. “” THEN GOTO NOTFOUND $ WRITE SYS$OUTPUT “File exists.” $ EXIT $ NOTFOUND: $ WRITE SYS$OUTPUT “File not found.” $ EXIT

Code

Run it and test both conditions.

Exercise 5 — Submit a Batch Job

Create a batch script:
$ WRITE SYS$OUTPUT “Batch job running…” $ EXIT

Code

Submit it:
SUBMIT BATCHJOB.COM
Check queue status:
SHOW QUEUE/BATCH

Scenario‑Based Troubleshooting Challenges

Scenario 1 — Script Fails Silently

A DCL script exits without printing expected output.

Expected approach:

Check $STATUS
Add SET VERIFY
Add SET NOON
Check symbol scoping

Scenario 2 — Batch Job Never Starts

A submitted batch job remains in “Holding” state.

Expected approach:

Check queue status
Check queue limits
Check job quotas
Check batch queue startup

Scenario 3 — Lexical Function Returns Unexpected Value

A script using F$GETJPI returns blanks.

Expected approach:

Verify correct item code
Check privileges
Check quoting and syntax

Answer Key

The answer key for this module is located at:
answers/module5-answers.md