• Guru: Dealing With RPG Errors and Embedded SQL

  April 8, 2019 Ted Holt

  Hey, Ted! I’m having trouble using some of the new techniques I learned at the RPG and DB2 Summit. Below is a screen shot of a program I am writing. I cannot figure out why the compiler doesn’t like it. Can you see anything that would be causing the declarations to fail?

  — Mike

  I glanced over Mike’s code and noticed that he used a correlation name in the SELECT and WHERE clauses, but did not define that correlation name for any of the tables, like this:

  SELECT x.onefield, x.twofield, x.redfield, x.bluefield
  FROM MYTABLE
  WHERE x.onefield = :TestValue;
  

  He …

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• Building Out The .NET Stack Around Mono for IBM i

  March 13, 2019 Alex Woodie

  The first release of a Mono .NET port to IBM i was issued last year. Since then, the IBM i open source community has been busy building many of the other middleware components that will make it easier for developers to build IBM i applications using Microsoft tooling.

  Mono was ported to AIX and IBM i (via the PASE AIX runtime) last year, which gave IBM i and AIX shops the capability to run the open source .NET runtime on Power Systems servers, thus opening the door to allowing Microsoft‘s highly regarded suite of development tools to be …

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• IBM i Has Been Getting With The Program For Years

  February 4, 2019 Timothy Prickett Morgan

  There are many things that one could constructively criticize IBM about when it comes to the Power Systems platform running the IBM i operating system. But, in recent years at least, one of those things would not be – and could not be – that the company has not done enough to embrace the most important elements of the modern programming toolbox.

  In fact, the company has done and increasingly good job of embracing and extending the compilers, interpreters, frameworks, and models of the programming languages that have gone mainstream since Java first took the stage at the beginning of …

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• Guru: Speed Up Command-Line PHP

  January 21, 2019 Alan Seiden

  While PHP runs quickly via the Apache web server, command-line PHP scripts (run from PASE directly or via CL or RPG) have a lag on start-up. In this article, I show how to speed up PHP when called from the command line (known as PHP-CLI).

  Why does PHP-CLI (command line PHP) have a slow start-up? While several reasons are often given, I’ve found the culprit to be the loading of PHP extensions that are enabled by php.ini and other configuration files of Zend Server. Examples of extensions are ibm_db2, simplexml, and Zend’s proprietary components.

  Within a normal web server environment, …

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• Guru: Addressing A Legitimate Question

  December 10, 2018 Ted Holt

  This is the last Monday issue of The Four Hundred for 2018. My, how time flies! I like to do something different at year end. In previous years I have solved Sudoku puzzles, found my way through mazes, solved the peg game, and more. This year I wish to honor a request that has come from various people and to address what they consider to be a legitimate question.

  As I wrote recently, the question I hear occasionally goes something like this: “Why bother with service programs? Why not use dynamic calls?” Rather than insult the …

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• Guru: When Is An Error Not An Error?

  November 26, 2018 Jon Paris

  When is an error not an error? When it is expected! In this article I want to discuss the use of RPG’s MONITOR op-code and discuss ways in which it might change the way you code RPG. I was prompted to write up my thoughts on this subject as a result of being quizzed by students at a recent RPG & DB2 Summit as to why I was using Monitor blocks rather than more conventional RPG techniques in my examples.

  So what do I mean by expected? Basically I mean those errors that you know are going to happen …

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• Guru: Learn %PARMS! Solve Two CL Problems!

  October 8, 2018 Ted Holt

  Those wonderful people at IBM have done it yet again! They have gladdened my existence with new CL functionality that solves two problems, and I will never have to face those problems again. Let me tell you about the new %PARMS built-in function.

  The %PARMS function returns the number of parameters that are passed into a CL procedure (i.e. a CL program or a CL module). In the past, I have monitored for message MCH3601. That works in some situations, but not in all. The %PARMS function gives me an unambiguous way to know whether a parameter was passed or …

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• ARCAD Debuts RPG Code Checker

  October 3, 2018 Alex Woodie

  If you write RPG, or know somebody who does, then you realize that mistakes can and will happen. However, beyond the obvious syntax errors, which should be detected immediately by the code editor, are instances where the code is sloppy or just poorly written. Those are the instances where ARCAD Software hopes to help with its new CodeChecker offering.

  ARCAD-CodeChecker, as the product is officially called, does just that: Detect poor quality RPG code before it makes it into production. If you’ve coded a bug into the program, made a design error, or taken 1,000 lines to write something that …

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• Guru: Data-Centrism, Step Zero

  September 10, 2018 Ted Holt

  I hear a lot these days about the need for data-centric information systems. That is as it should be. The proper way to support an organization is to remove logic from application programs and put it into the database through such devices as constraints and triggers. However, before many shops can take the first step in that direction, they need to take what I call step zero.

  Step zero in data-centric computing is to remove hard-coded data values from programs and put them into the database. Just as the database manager should enforce business rules (e.g. we don’t ship to …

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• Guru: Refactoring RPG – GOTO

  August 27, 2018 Ted Holt

  When I first learned COBOL, I coded loops the way all the programmers in my shop did — with GO TO. Paragraph names were labels, not routines. Then I took a class in COBOL and learned structured programming. I’ve never looked back. I wish other people felt the same way, because I don’t like to work on GOTO-laden programs.

  Injudicious use of branching — in RPG that would be the GOTO and CABxx op codes — is a major reason I refactor. GOTO plays havoc with program “logic”, a word I hesitate to use in this context. The minute someone …

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