book

Who Knew You Could Do That with RPG IV? Modern RPG for the Modern Programmer

Name: Who Knew You Could Do That with RPG IV? Modern RPG for the Modern Programmer
ISBN: 9780738442105

by Rich Diedrich, Jim Diephuis, Susan Gantner, Jeff Minette, Jon Paris, Kody Robinson, Tim Rowe, Paul Tuohy

December 2016

Intermediate to advanced

410 pages

12h 13m

English

IBM Redbooks

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Front cover
Notices
Trademarks
Preface
AuthorsNow you can become a published author, too!Comments welcomeStay connected to IBM Redbooks
Chapter 1. Introduction to RPG IV
1.1 Why update this book on RPG IV now?1.2 Evolution of the RPG IV language1.2.1 Examples in this book are based on IBM i 7.21.3 The future for RPG IV1.3.1 A future for RPG programmers1.4 A roadmap1.4.1 Step 1: RPG IV and RDi1.4.2 Step 2: Modularization by using ILE1.4.3 Step 3: Using database features1.4.4 Step 4: Modernizing the user interface1.5 RPG IV sources on the web
Chapter 2. Programming RPG IV with style
2.1 Just another programming language2.2 RPG is free-form2.2.1 The modern free-form RPG2.2.2 The basics of /Free coding2.2.3 Unsupported op-codes2.2.4 Op-codes that tend to produce unclear and error-prone source code2.2.5 Liberating data and file definitions2.2.6 Data declarations2.2.7 More on data definitions2.2.8 Defining prototypes and subprocedures2.2.9 Miscellaneous topics2.2.10 Moving to free-form2.3 Modern RPG programs and subprocedures2.4 Naming2.4.1 The names2.4.2 Case2.4.3 Special characters2.4.4 Underscore2.4.5 Named constants2.4.6 Naming conventions2.5 Comments2.5.1 Summary comments2.5.2 Detailed commenting2.5.3 Other commenting2.5.4 Positions 1 - 52.6 Structuring code2.6.1 Declarative code2.6.2 Executable code2.6.3 Multipath comparison2.6.4 Embedded SQL2.7 Using templates and qualified data structures2.8 Qualifying wherever possible2.9 Strings2.10 Subroutines2.11 Older functions2.11.1 RPG built-in indicators2.11.2 Compile-time arrays2.11.3 Multiple occurrence data structures2.11.4 Do not use GOTO, CABxx, or COMP2.11.5 Do not use obsolete IFxx, DOUxx, DOWxx, or WHxx opcodes2.11.6 Use SELECT, WHEN, OTHER, ENDSL for multipath comparison2.12 Embedded SQL2.13 Global definitions2.14 Parameters and prototyping and procedure interfaces2.14.1 Parameters2.14.2 Return value2.14.3 Copy members2.15 The Integrated Language Environment2.15.1 ILE programs2.15.2 Service programs2.15.3 Binding directories2.15.4 Activation groups
Chapter 3. Subprocedures
3.1 Subprocedure terminology3.1.1 ILE modules3.1.2 Main procedure3.1.3 Built-in functions3.1.4 Subroutines3.2 Advantages of using subprocedures3.3 The anatomy of a subprocedure3.3.1 Subprocedure definition3.3.2 Procedure-interface definitions3.3.3 Order of coding the source elements3.3.4 Calling your subprocedures3.4 Moving from subroutines to subprocedures3.4.1 Why use subprocedures3.4.2 Subroutine example DATESUBR3.4.3 Transforming a subroutine to a subprocedure3.4.4 DATEMAIN1 subprocedure example3.5 Using subprocedures efficiently3.5.1 Using /COPY members for prototypes3.5.2 Prototype for the main procedure3.5.3 Subprocedures using subprocedures3.5.4 Using an ILE service program3.6 More on subprocedures3.6.1 The power of prototyping3.6.2 Parameter passing styles3.6.3 Using procedure pointer calls
Chapter 4. An ILE guide for the RPG programmer
4.1 Introduction to ILE4.1.1 Modules4.1.2 Service programs4.1.3 Binding: Creating programs and service programs4.1.4 Binding directories4.1.5 Service program exports4.1.6 Binder language source4.1.7 Activation groups4.1.8 CL commands used with ILE and RPG4.2 ILE tips for the RPG programmer4.2.1 Creating programs from modules (binding by copy)4.2.2 Binding service programs to programs4.2.3 Service programs, binder language, and signatures4.2.4 Using binding directories4.2.5 Activation groups4.2.6 Call stack and error handling4.3 Additional CL commands and useful ILE APIs4.3.1 Additional CL commands4.3.2 Some useful APIs to get information about ILE objects4.4 More information about ILE and shared open data paths
Chapter 5. Application programming interfaces
5.1 Finding APIs5.2 C functions5.2.1 Prototype mapping example5.2.2 A more complex prototype mapping example5.3 POSIX interfaces5.3.1 Accessing the IFS5.4 IBM i system interfaces5.4.1 Standard techniques5.4.2 List objects (QUSLOBJ) API5.5 Creating a reusable API5.5.1 Making a web service5.6 Things to remember
Chapter 6. Database access with RPG IV
6.1 Externalizing input and output6.1.1 What is meant by externalizing6.1.2 Putting theory into practice: An example of externalizing I/O6.1.3 Externalizing example: Overview6.1.4 Externalizing example: Separating database logic from display logic6.1.5 Externalizing example: Implementing changes6.1.6 Externalizing example: Other possibilities6.1.7 Summary6.2 Embedded SQL6.2.1 Rules for embedding SQL statements6.2.2 SQL preprocessor6.2.3 Error and exception handling6.2.4 Using a cursor6.2.5 An embedded SQL program example6.2.6 Source code for the SQLEMBED program6.3 Stored procedures6.3.1 Creating an external procedure6.3.2 Creating an SQL procedure6.3.3 Starting a stored procedure and returning the completion status6.3.4 A stored procedure example6.4 DB2 call level interface6.4.1 Differences between DB2 CLI and embedded SQL6.4.2 Writing a DB2 CLI application6.4.3 Initialization and termination6.4.4 Transaction processing6.4.5 Diagnostic tests6.4.6 Data types and data conversion6.4.7 Functions6.4.8 Introduction to a CLI example6.5 Trigger programs6.5.1 Adding a trigger program to a file6.5.2 Creating a trigger program6.6 Commitment control6.6.1 File journaling6.6.2 Using commitment control with RPG native file operations6.6.3 Using commitment control with embedded SQL6.6.4 Using commitment control with the CLI interface6.7 A note about globalization6.8 More information about database access with RPG IV
Chapter 7. Exception and error handling
7.1 Introduction to exception and error handling7.2 What is an exception/error7.3 Trapping at the program level7.3.1 Program exception/errors7.3.2 The fatal program7.3.3 File exception/errors7.3.4 Can it get any easier7.4 Trapping at the operation level7.4.1 Error extender7.4.2 Status codes7.4.3 Monitor groups7.4.4 Information data structures7.4.5 ILE condition handlers7.5 Subprocedures and exception/errors7.5.1 Percolation7.5.2 Trapping percolated errors7.5.3 Identifying a percolated message7.6 ILE CEE APIs7.6.1 Condition management APIs7.6.2 Activation group and control flow APIs7.6.3 Further information7.7 Priority of handlers7.8 The embedded SQL problem7.9 Using percolation: Try, throw, and catch7.9.1 A traditional approach7.9.2 Throw7.9.3 Catch7.9.4 Using throw and catch7.9.5 The problem with throw and catch7.10 Conclusion

Chapter 8. Interfacing
8.1 Interfacing with Java8.1.1 Java calling RPG IV8.1.2 RPG IV calling Java8.1.3 Things to remember8.2 Python8.2.1 Calling a stored procedure8.2.2 Toolkit for IBM i8.2.3 Test script8.2.4 Output8.3 PHP
Chapter 9. IBM Rational Developer for IBM i
9.1 Why you should use Rational Developer for IBM i9.1.1 Integrated compile-time error feedback9.1.2 Outlining your program9.1.3 Editing multiple members at the same time9.1.4 Modern editor capabilities9.1.5 Moving from SEU/PDM to RDi9.2 Built on Eclipse9.2.1 iSphere tools9.3 What is new in Rational Developer for IBM i9.3.1 Code coverage monitor9.3.2 Integrated emulator9.3.3 IBM i Access Client Solutions and Run SQL scripts9.3.4 RPG formatter9.3.5 More flexible outline view9.3.6 Native Mac OS X support9.3.7 Commenting and uncommenting in RPG, CL, and DDS9.3.8 Hyperlink navigation within source member9.3.9 Importing and exporting RDi configurations and push-to-client support9.3.10 Smaller usability enhancements9.4 Using the RDi debugger9.4.1 Starting a debug session using service entry point9.4.2 Starting a debug session by using a debug configuration9.4.3 Debug server and preferences9.4.4 RDi debug activities
Chapter 10. Modern RPG comparison as viewed by a young developer
10.1 Fixed format versus free-format10.2 File-Specs10.3 Tables10.4 Parameters10.5 Key lists10.6 Array and error lookups10.7 Calling programs from a program10.8 Read commands10.9 Evaluates, checks, and scans10.10 Select statements10.11 Substring and concatenate10.12 Go-To commands10.13 Embedded SQL in free-format 10110.14 Built-in functions that you need to know
Appendix A. Additional material
Locating the web materialUsing the web material
Related publications
IBM RedbooksOther publicationsOnline resourcesHelp from IBM
Back cover

Overview

Application development is a key part of IBM® i businesses. The IBM i operating system is a modern, robust platform to create and develop applications. The RPG language has been around for a long time, but is still being transformed into a modern business language.

This IBM Redbooks® publication is focused on helping the IBM i development community understand the modern RPG language. The world of application development has been rapidly changing over the past years. The good news is that IBM i has been changing right along with it, and has made significant changes to the RPG language. This book is intended to help developers understand what modern RPG looks like and how to move from older versions of RPG to a newer, modern version. Additionally, it covers the basics of Integrated Language Environment® (ILE), interfacing with many other languages, and the best tools for doing development on IBM i.

Using modern tools, methodologies, and languages are key to continuing to stay relevant in today's world. Being able to find the right talent for your company is key to your continued success. Using the guidelines and principles in this book can help set you up to find that talent today and into the future.

This publication is the result of work that was done by IBM, industry experts, business partners, and some of the original authors of the first edition of this book. This information is important not only for developers, but also business decision makers (CIO for example) to understand that the IBM i is not an 'old' system. IBM i has modern languages and tools. It is a matter of what you choose to do with the IBM i that defines its age.

Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
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