FHG Volume: 8 Archives

Two A-maze-ing Programs

December 17, 2008 Ted Holt

Note: The code accompanying this article is available for download here.

My family and I are preparing to celebrate Christmas. I’m enjoying the lights, the carols, and the decorations. I feel festive. I feel like doing something just for fun. Thus, the two programs I wrote for today’s Four Hundred Guru are of no practical value of which I’m aware, but goodness, did I have fun writing them!

Consider the following text file, the contents of which is a maze.

IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII
IB             I         I I I         I
IIIIIIIIIIIIII I IIIIIII I I   II IIIIII
II             I I       I I

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End-of-Year Odds and Ends

December 17, 2008 Timothy Prickett Morgan

Merry Christmas, intelligent i professional! Let’s end the year with a few little tips, including two unusual ways to use OPNQRYF’s %ABSVAL function from reader Victor Pisman. May 2009 be the best year ever for all of us.

–Ted

Run Qshell from CL Procedures

Q: Do you have a simple example of using Qshell with a script? I think I can muddle through setting up the script. I am unsure of how to call it from a CL procedure.

A: You can use the dot utility to run a script that you’ve created in the IFS. This command

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Admin Alert: Upcoming i5/OS and AnyNet End of Service Dates

December 17, 2008 Joe Hertvik

To finish out 2008, let’s look ahead to some upcoming end of service dates that can affect shops running i5/OS V5R3 in 2009 and shops that are still using AnyNet to connect older twinax-based printers and other devices to System i and Power i machines. If you’re in these categories, you should be aware of the following issues.

A New Year, A New i5/OS Upgrade?

If any of your partitions are running i5/OS V5R3, be aware that IBM will discontinue support for i5/OS V5R3 on April 30, 2009. Of course, this doesn’t mean that your software will no longer work.

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Four Ways to Avoid Problems Caused by Global Data

December 10, 2008 Ted Holt

Junior J. Programmer modifies an RPG program. His testing works properly. The user’s test works properly. The user approves the change, the modified program is installed, and everything is copasetic until a few months later when the program gets stuck in a loop. What happened, and why is Junior not entirely to blame?

Here’s the code Junior added to the program:

C     1             DO        5             X                 1 0
C                   EXCEPT    PLINE
C                   ENDDO

What could go wrong with such simple code?

It turns out that the subroutine that contains Junior’s code is also conditionally and indirectly executed from another part

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Where’s the Service Program?

December 10, 2008 Hey, Ted

We have two environments: a homegrown system for financials and a canned ERP system for manufacturing. We have written a service program containing subprocedures that access manufacturing data. This service program is stored in a library that is in the manufacturing system’s library list, but is not in the financial system’s library list. Now we need a financial program to use a routine from this service program.

We add manufacturing libraries to the end of the finance library list when we create the finance program so the compiler finds the service program and binds to it. It would be nice

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Admin Alert: The Dangers of User Profiles with Privileges

December 10, 2008 Joe Hertvik

Handling user profile authorities is one of the more critical i5/OS administrative duties. In particular, there are three crucial user parameters that must be set up correctly to prevent your users from inadvertently accessing objects and functions that they should not be using. Today, I’ll look at how you can work with these values to prevent several avoidable security pitfalls.

The Hierarchy of User Authority

Before you can work with user authorities, you must understand what they do. Here is the basic hierarchy of user profile security settings and how they relate to each other.

System privileges–Eight user profile

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There’s Power in Edit Words

December 3, 2008 Hey, Ted

I am trying to use an edit word to insert hyphens into an account number. I must be doing something wrong, because leading zeros don’t show up. I’ve used edit codes for years, but rarely edit words. Can you help?

–Laurie

You’re not doing anything wrong. That’s the way edit words work, Laurie. The system blanks out everything before the first non-zero digit, including editing characters. The good news is there’s a way around it.

Let’s illustrate with an example that many of your fellow readers will be familiar with: those nine-digit Social Security numbers without which Americans can’t do

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SQL and Conversion Strategies

December 3, 2008 Hey, Ted

I just read your article Common Table Expressions Ease System Conversion. Instead of changing each SQL statement to add a common table expression, I’d suggest you create permanent views that join the new files. Give the views the same names and the same column names as the original file. Because a view doesn’t have a key, you can have as many views as you want without any performance decrease. A permanent view can also be used for Query/400. In this way queries do not have to be changed.

–Birgitta Hauser

I am always delighted to find mail from Birgitta

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Admin Alert: Tuning i5/OS Storage Pools for Performance

December 3, 2008 Joe Hertvik

Most i5/OS administrators know about setting up automated performance tuning and they also know how to assign individual storage pools to different subsystems. But many people don’t know that they can also tune storage pools for more efficient system processing. This week, I’ll cover some of the finer points of storage pool configuration and how a little extra tuning can make a big difference in memory performance.

Two Ways To Tune Pools

Individual storage pools adjustments can be made by using the green-screen Work with Storage Pools (WRKSHRPOOL) command or by using iSeries Navigator (OpsNav). The key is to tweak

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Getting Started With AJAX

November 19, 2008 Paul Tuohy

In this article, we will see how AJAX works by looking at a simple example of using AJAX to retrieve the description (from the server) for a code entered on a Web page.

Remember one of the main benefits of AJAX is that communication between the Web page and the server is asynchronous. This means that the Web page may be updated with information from the server without the user having to click any submit button.

An Example

Figure 1 shows the Web page initially displayed to the user, and it also shows the contents of the page after the

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