It's no secret that I offer a software product called RPG xTools that includes over 200 pre-written, highly optimized subprocedures for RPG IV developers. In addition, there are several noncommercial subprocedures out there that developers have sort of distributed via email list servers or Web sites. On my own RPGIV.com Web site, I have hundreds of prototypes and source code for programs, procedures, and the like available for free download.

But I think one of the biggest barriers keeping RPG IV programmers from using a subprocedure that someone else has written is the way it is installed and then leveraged in RPG IV source.

For example, to use a subprocedure written by me or anyone else, you typically need to either include a binding directory entry in the CRTBNDRPG or CRTPGM command or add the BNDDIR keyword with the entry to your RPG IV Header specifications. Then, you have know which /COPY to include in the program so that the prototypes are imported for use.

Surprisingly, these two steps are relatively complex to most new RPG IV programmers, and since virtually all RPG IV programmers are relatively new to the RPG IV language constructs, it is an issue.

To solve this problem, it would be nice to steal a page from many of the C compilers and from Java. The compilers for these languages recognize an external setting that tells the compiler, "Hey, this shop has Cozzi's xTools installed, so if this program attempts to call any of its add-on subprocedures, let it."

So the iSeries administrator would only need to install the software and that's it--no /COPY issues, no BNDDIR issues, no library list issues. It would "just work."

It's strange that IBM doesn't do this, considering that they've asked the ISV software industry to write add-on procedures to extend the capabilities of RPG IV and other languages. IBM in no way makes it easy to do this. This is a capability that's been in other compilers for at least a decade--if not longer--and it is certainly a main reason that so many add-on libraries are installed and used by Java developers.

A software vendor should be able to simply give its software to iSeries customers and tell them to run one command or menu option to install it. Done!

The crazy thing is that OS/400 and i5/OS have had "the environment" (a UNIX area for storing job or system-wide values, similar to job attributes and system values in OS/400) on them for years. There's no reason the environment couldn't be leveraged to accomplish this requirement as well.

Why can't RPG IV add-on library vendors, during install, just do something like this?

The first SetEnvVar identifies the add-on library as an RPG IV extension. The word "add-on" says this is an add-on library; the second piece, "cozzi," indicates the software vendor; and "xtools" indicates the product name.

The second SetEnvVar indicates the library where the product is installed.

The third SetEnvVar identifies various options. In this case, the binding directory named XTOOLS/RPGLIB is automatically inserted into compiled RPG IV source code. In addition, the /COPY source file named QCPYSRC in XTOOLS is searched for a member name when a /COPY is used.

The fourth SetEnvVar identifies a default /COPY member that is automatically imported into RPG IV source compiles. Of course, this feature could be turned off and on.

Then, in your source, you would have to do nothing more than call the add-on subprocedures included with the product. If the add-on library were installed without being automatically included in your compiles, you could turn it on via a Header specification or a job-level setting, like so:

This would match the name of the extension or "add-on" that was installed. Of course, other adjustments to settings should be available as well.

About 12 years ago, I made a statement that MS Windows was the easiest platform to program on and the most difficult to program for. I also stated that OS/400 was the easiest platform to program for but the poorest to program on. Today, unless IBM starts adding important industry features to the RPG IV compiler/environment, software vendors may find other platforms a much easier target for which to program.

Bob Cozzi is a programmer/consultant, writer/author, and software developer of the RPG xTools, a popular add-on subprocedure library for RPG IV. His book The Modern RPG Language has been the most widely used RPG programming book for nearly two decades. He, along with others, speaks at and runs the highly-popular RPG World conference for RPG programmers.

Bob Cozzi is a programmer/consultant, writer/author, and software developer. His popular RPG xTools add-on subprocedure library for RPG IV is fast becoming a standard with RPG developers. His book The Modern RPG Language has been the most widely used RPG programming book for more than a decade. He, along with others, speaks at and produces the highly popular RPG World conference for RPG programmers.

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