iSeries (AS/400) CL Programming

Introduction

CL commands are an inherent feature of the iSeries operating system, and can be used extensively from the command line on the iSeries. Even more CL commands can be used in CL programs. They can be used to provide strong application control, and can be used to automate operations on the iSeries.

What you will learn

On completion of this course, you will be able to:

• Use SEU to enter and prompt CL commands.
• Write CL programs that process display and database files.
• Trap errors in CL programs and use debug.
  
• Define and use variables and parameters.
• Learn to use data areas.
• Learn the SNDPGMMSG command.
  
• Create better commands

Who should attend

Application development staff who will be responsible for the development of operating procedures, or applications on the iSeries using CL programming.

Pre-requisites

Delegates should be familiar with the application development environment on the iSeries, including PDM, SEU, SDA, objects and libraries. This experience can be gained from the iSeries SYSTEM FACILITIES course.

Course content

• Displaying command details.
• Running commands in batch.
• Changing command defaults.
• CL program structure.
  
• Calling procedures.
• Compiling CL source.
• Ending a CL program.
• Declaring and initialising variables with parameters.
• Display and change variables.
• Use display files.
• Declaring a File.
• Reading a database file.
• Creating files from CL commands.
• Using out-files from CL commands.
• CPYF command.
• Display File Processing in a CL program.
• Coding a 'Screen Time-Out'.
• Messages and Event Driven Programs.
• Executing and checking CL commands inside variables.
• Using APIs.
• Multi member database files and overrides.
• Conditional processing.
• The IF and ELSE commands.
• DO, ENDDO and nesting.
• The GOTO command.
• Retrieve commands.
• Processing messages from a message queue.
• Break Message Handling Programs.
• Message descriptions.
• Send user message.
• Error messages.
• Trapping errors in a CL program.
• Debugging programs.
  
• Enabling programs for debug.
• Add and remove break points.
• Object locking.
• Moving around the source.
• Interactive source debug.
• Accessing data areas in a CL program.
• Delaying a program.
• Job control with delay job.
• Useful validation commands (CHKOBJ, CVTDAT).
• Creating a CL command (CRTCMD).
• Command source statements.
• The CMD, PARM and PMTCTL statements.
• The QUAL, ELEM and DEP statements.
• Validity Checker Program.
• Checking passwords. .

Materials

A course manual with supporting documentation is provided. The course includes exercises to develop many CL programs that can be used in an application environment.

Schedule