• 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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• Guru: DB2 For i XML Composition And The IFS

  June 11, 2018 Michael Sansoterra

  Hey, Mike! Regarding Composing An XML Document From Relational Data, Part 1, I have built an XML document using DB2 and i. When I run the query, I get a worthless result set. How do I use the SQL XML functions to get a usable XML file?

  This question comes from reader RA, and he doesn’t exaggerate. The result set from his XML-based query looks like this:

  ....+....1....+....2....+....3....+....4....+
  ************Beginning of data************** 
  
  XMLDATA 
  -------- 
  #CGULIB#
  
    1 RECORD(S) SELECTED.
  
   ************End of Data********************
  

  Notice that DB2 for i does nothing to make the XML attractive to human eyes as the entire XML …

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• Guru: Ready or Not! Part 3 Of Big Changes In RDi V9.6, Compare/Merge, Code Coverage, and More

  June 4, 2018 Susan Gantner

  This is the third in my series of tips on RDi V9.6. In this one I’ll cover the new compare and merge support, along with improvements to code coverage and a few other smaller enhancements in V9.6. I originally thought this would be the last in the series, but IBM recently made available a new point release that introduced enough new features to mean I’ll be adding at least one more tip.

  Compare And Merge

  The ability to compare the content of two source members is not new to RDi, but with V9.6 the facility now offers the option to …

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• 30 Years And Just Getting Started: IBM i Celebration Looks Ahead

  April 4, 2018 Dan Burger

  It’s been said many times that you can’t move forward if you keep looking back. What you’ve accomplished is not the end point. It’s the foundation for building toward the future. You can look back to see what you’ve missed, but it takes forward thinking to make up for it.

  This week is the beginning of a lengthy celebration spotlighting “30 years of innovation and we’re just getting started.” The IBM i team launched a website yesterday with a focus on the future, an emphasis on innovation and a reliance on social media (and IT Jungle) to spread the …

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• Guru: Use SQL To Find Duplicate Source Code

  March 12, 2018 Ted Holt

  According to Brian Tracy, “good habits are hard to develop but easy to live with; bad habits are easy to develop but hard to live with. The habits you have and the habits that have you will determine almost everything you achieve or fail to achieve.” This is as true in programming as in anything else we may do.

  Unfortunately, even those of us who strive for good work habits often have to follow the work of people who did not. One bad habit I come across occasionally is known in software engineering as WET solutions. WET stands for “write …

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