A Different View Of IBM i And PASE

PASE is the AIX runtime environment that is integrated into the IBM i operating system. Most IBM i community members know of it. Comparatively few actually know it. It’s not a wild guess to say most IBM midrange shops that use the TCP/IP networking stack, the Java virtual machine, the Apache Web server, or the PHP runtime are unaware that these were crafted for AIX and are running inside of PASE. There’s reason to believe that PASE awareness may be on the rise. What’s that mean, if anything, to you?

PASE brings added functionality to the IBM i OS by supporting software solutions that fit the category of the right tool for the right job. Instead of pounding a square peg into a round hole, admit that sometimes what you have available simply isn’t the right fit. Sometime you have to look beyond the known and into the unknown. It also allows IBM to code certain features once and use them across AIX and IBM i.

“There are just a lot of people who have never found themselves on that side of the fence and they don’t know what features are there,” says Caleb Shingledecker, a software engineer with experience using open source applications in the PASE runtime. “It becomes useful in cross-platform development when you have a tool that runs on Linux or Unix and can use it on IBM i as well. It opens possibilities that people haven’t thought about in many instances.

“I’ve used it for development work that targets IBM i, by leveraging tools that exist on Linux and Unix. It avoided having to pull in an external piece of hardware, which just brings more complexity. The difference is the ease of access (in PASE) compared to access through a network connection. I want to be on the i, but I didn’t want to create something from scratch when I can leverage a Linux or Unix tool that is already created.”

Caleb Shingledecker: Exploring PASE

For examples, Shingledecker picked Ghostscript and curl, two open source applications that accomplished what he needed.

Ghostscript is PostScript and PDF interpreting software. Shingledecker uses it to convert PDF documents and other output formats to PCL, which he drops into an output queue and sends to a printer. Ghostscript also has the capability to convert PDFs into almost any image format you can think of. It is distributed and licensed by Artifex Software. It’s available for Unix, Linux, Windows, and Mac.

Curl is used in command lines or scripts to transfer data with URL syntax. It compiles and runs under a variety of operating systems. The curl computer software project also includes libcurl, a free client-side URL transfer library.

“I’ve used curl to do a CL program that gets to a Web server somewhere else on the network and pull out just one file. It avoids writing a more complex application to do that. This is just a quick Qshell call. A simple CL program can use Qshell to fire off a program in PASE, compared to running something externally that requires a new application for the external server in addition to writing an application on i that calls out to it.”

Shingledecker describes Ghostscript and curl as tools in his toolbox. There are certain tools and features and functions that can be run in one environment but not others, he says. Access to a variety of tools puts developers in a better position to have the right tool for the job regardless of the platform. In certain situations, the functionality of the software is either enhanced or diminished by the server chosen to run the software.

Compared to running PASE with the OS/400 V5R2 and V5R3 or the i5/OS V5R4 iterations of the operating system, better tools and enhanced features have been added since the OS was renamed IBM i at the 6.1 release and the upgrades have continued through 7.1 and 7.2.

In the latest IBM i Technology Refresh–TR3 for i 7.2 and TR11 for i 7.1–there’s the GNU Compiler Collection compiler and open source tool kit, or GCC, that should boost open source development on i.

“Most of the (open source) components leverage C or C++ and are compiled under GCC. This compiler on IBM i allows that compiled code to work on IBM i pretty much unchanged,” according to Tim Rowe, IBM i business architect for application development and systems management. Prior to this GCC compiler, the lone option was the PASE-based XLT compiler.

Rowe is one of several IBM i executives who are speaking up for open source alternatives for IBM i. Tech conferences are including sessions on open source, subject matter experts are making the rounds at local user group meetings, and COMMON is hosting an IBM i Forum on open source languages in December.

You don’t hear a lot about people with IBM i skills built on top of Linux skills, but that was the progression for Shingledecker. So when he bumped into the PASE environment, it was not foreign territory. PASE allowed him to leverage his Linux knowledge and his knowledge of IBM i. Undoubtedly this gives him an advantage when shopping around for applications based in those environments but useful in an IBM i environment.

Shingledecker will be the guest speaker at the QUSER local user group meeting Tuesday in Minneapolis.

“The key is open source becoming more popular in the IBM i community,” Shingledecker says. “A lot of that technology can be downloaded with source code and compiled on IBM i and run in PASE. Doing things in the PASE environment lets people access cutting edge stuff. Lots of people don’t think the IBM i can run the latest greatest open source technology. But really it can.”

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