iSeries (AS/400) CL Programming

Introduction

CL commands are integral to IBMi and when incorporated into programs many procedures can be automated and controlled in a very flexible manner. This course is aimed at programmers and support staff who wish to be able to automate and control operational procedures and system applications or modify and support existing CL programs and procedures.

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

It is expected that delegates will be able to find their way around the system and have a basic understanding of objects, libraries, PDM, SEA, SDA ( or RSE & RDi ). This experience can be gained from the iSeries SYSTEM FACILITIES course.

Course content

• Introduction to the language and environment
  When and Where CL commands can be executed
  CL Program source code & structure (CLP & CLLE)
  Programs, Modules and Procedures (ILE v OPG CL Programming)
  Compiling and Binding (CRTCLPGM, CRTBNCL, CRTCLMOD, CRTPGM)
  
  
• Basic Operations Functions and Variables
  Declaring & Initialising variables (DCL)
  Changing values in variables (CHGVAR)
  Receiving Parameters (PGM)
  Passing variables between programs & procedures (CALL,CALLPRC)
  Intercepting errors (MONMSG)
  Validating object existence (CHKOBJ)
  Multi-member files and overrides (OVRDBF)
  
  
• Using pre-defined messages & data items
  Retrieving system information (RTV commands)
  Message Files, Description and Queues
  Using pre-defined messages (SNDUSRMSG, SNDPGMMSG, RCVMSG)
  
  
• Conditional & Repetitive processing
  Controlling logic with conditions (IF, ELSE, SELECT: WHEN, GOTO)
  Grouping conditional actions (DO, ENDDO)
  Repeating Code (DOUNTIL, DOWHILE, DOFOR)
  Using Modern Sub-Routine coding techniques in CL
  
  
• Data Areas
  Define and use Data area objects and LDA
  Object Locking (ALCOBJ, DLCOBJ)
  Job Control (DLYJOB)
  
  
• Database Files
  Declaration (DCLF)
  Creating Files from CL commands DSP.... RUNQRY....
  Reading Files in CL (RCVF)
  
  
• Display Files
  Decleration (DCLF)
  How to create a basic display file (SDA/RDi)
  Display, Read, Wait (SNDRCVF, WAIT)
  Logic for a Display File program
  Coding screen timeout with password check (CHKPWD)
  
  
• Tools to aid in discovering program bugs
  Program Dump
  Enabling debug for a program
  Interactive Source Debug (OPN & ILE)
  
  
• Creating Basic user Defined CL-Commands
  Program & Command Relationship
  Using Command Source statements (CMD, PARM, PMTCTL, QUAL)
  
  
  Follow on courses : To expand programming skills consider our RPG and SQL suite of courses.
  

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