• Guru: Environment Variables – Global Variables Wearing Hiking Boots

  November 2, 2026 Gregory Simmons

  Sometimes a program knows one tiny piece of information that another program, several calls farther down the stack, needs to know.

  The obvious solution is to add another parameter. But sometimes that requires that new parameter added to one or more programs in the call stack. Before long, we’re passing a mushroom basket through half the forest even though most of the programs along the way have no interest in what’s inside it.

  There is another option that has been available on IBM i for a very long time: environment variables. IBM i supports both job-level and system-level environment variables. …

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• Guru: Analyzing User Session Statistics, Part 2

  October 26, 2026 Mike Larsen

  In part one of this tip, I showed how to determine the number of times a user signed in and signed out of IBM i for a given period. In this tip, I will show how to get the days a user signed in, and how long their session was active.

  I use the same table function, QSYS2.HISTORY_LOG_INFO, as before. The code (Figure 1 below) is similar to the code used in the first part of this series, but there are some differences I will point out.

  Note that I purposely left the user ID out of the result set …

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• Guru: When RNF0722 Won’t Let Your Legendary RPG Program Compile

  October 12, 2026 Gregory Simmons

  Some RPG programs have been around for decades. They started small enough. Then another calculation was added here, another subroutine there, a /COPY member or two, and years of enhancements, fixes, and changing business requirements.

  Eventually, some of them became colossal. And let’s face it, we all have “legacy” or, as some would argue, “legendary” programs that are older than a lot of our new hires.

  We all know these programs. They’re the ones everybody agrees should be broken apart someday, but they’re also important production programs that still need to be maintained today. And sometimes “today” presents a very …

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• Guru: A Modernization Experiment Using IBM Bob 2.0

  October 5, 2026 Dan Darnell and Eric Whitcomb

  The most common use case for business applications is the CRUD model. The Create, Read, Update, and Delete operations, performed against a business database, are found almost everywhere. Behind every fancy inquiry dashboard with all the graphical bling you can muster are a slew of tried and true so-called “maintenance programs” doing the heavy lifting over the data being presented. Whether it is back-office parameter tables, customer maintenance, or order entry applications, the CRUD model is fundamental. Most of us can whip out a simple green-screen maintenance program with our eyes closed in, oh, a couple hours or so, depending …

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• Guru: Two More Small But Handy RPG Enhancements: LIKE(*EXT) And %LOOKUPNE

  September 28, 2026 Gregory Simmons

  Not every trip into the field calls for hauling the whole pack, and not every search calls for scanning everything by hand. Two of the smaller enhancements in this batch of July PTFs for IBM i 7.5 and 7.6 are exactly that kind of quiet convenience: tools that let you reach for just the piece you actually need instead of doing more work than the job requires.

  DISCLAIMER: The mushroom names and file/field names used in the examples below are purely to give the sample programs some context and make them more interesting. Before foraging for or consuming any wild …

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• Guru: Putting Failure Handling In Its Place

  August 24, 2026 Gregory Simmons

  One of the things I enjoy most about procedure-driven RPG is that it encourages us to think about responsibility. Every procedure should have a clear purpose. It should perform one task well and leave unrelated concerns to other parts of the application.

  That sounds straightforward enough, yet one responsibility often finds its way into nearly every procedure we write: failure handling.

  If you have worked with RPG for any length of time, you have probably encountered applications where nearly every procedure begins with a MONITOR operation. The procedure performs its work, catches any exception that occurs, logs an error, returns …

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• Guru: Claude’s SQL Tip

  August 10, 2026 Ted Holt

  Today’s tip comes to us from Claude, as in the AI chatbot created by Anthropic. I don’t need to introduce him. Many readers of this august publication are far better acquainted with him than I am. I have heard reports of IBM i programmers who have quit writing source code, telling Claude to write it for them. Some folks seem to be right proud of that fact. Furthermore, I’m told that some places no longer allow humans to write source code.

  I had a few ideas in mind for this article and was weighing the merits of each one when …

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• Guru: Beyond Three-Part Naming – Running SQL Across Remote IBM i Systems

  August 3, 2026 Gregory Simmons

  In my article Guru: Finding Data in The Forest – Exploring Three-Part Naming In SQL, I helped you to get started with three-part naming. If you have a network of IBM i systems and haven’t availed yourself of this capability, you may be surprised at just how powerful it can be. Instead of relying on data transfers, replication, or intermediate files, SQL can reach directly into remote systems as though the data were local.

  That works well when you know exactly which remote system contains the data you need. But what happens when your network grows from a handful …

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• Guru: Deterministic Application Development With AI

  July 27, 2026 Dan Darnell and Eric Whitcomb

  Perhaps the key feature of AI is the way answers are obtained by virtue of a conversation with the AI. Contrast this with using a search engine where each “ask” is an independent request with a response.

  An AI conversation has context while search engine interactions do not. More and more, we use AI to create applications through the contextual, iterative, conversational process. As we have ideas we add these to the conversation and our application changes accordingly. Our customers are getting in on the action too. They are providing us with AI generated prototypes for new software or new …

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• Guru: Finding Data In The Forest – Exploring Three-Part Naming In SQL

  June 22, 2026 Gregory Simmons

  Anyone who has spent time foraging for mushrooms knows that location matters. A chanterelle found in the Pacific Northwest is not the same as one discovered in the hardwood forests of the Midwest. Experienced foragers do not simply note what they found. They record exactly where they found it: the region, the forest, and the specific location. Context matters.

  The same is true in SQL. Most IBM i developers are comfortable with two-part naming. A reference like MUSHLIB.FORAGE_LOG identifies both the schema and the object. It tells SQL where to look within a single system, much like noting the forest …

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