04
Mon, Nov
5 New Articles

Free-Format RPG: Printing Without O-Specs or an Externally Defined Printer File

RPG
Typography
  • Smaller Small Medium Big Bigger
  • Default Helvetica Segoe Georgia Times

IBM has made just about everything in free-format RPG truly free-format…except O-specs. But you can print without needing an externally defined printer file.

Instead of adding free-format support for O-specs, IBM expects you to use an externally defined printer file, which can do everything O-specs can. But recently, I wanted to print a simple report and didn't want to create a separate printer file. I remembered reading somewhere about writing to a program describer printer file from a data structure. It turns out to be easy in free-form RPG, with code like this:

    dcl-ds line len(132) end-ds;

    write QPRINT line;

Building the Print Line

But how do you populate the data structure? Google helped me find the original article running around in my memory. It was written by Cletus the Codeslinger way back in 2004. His solution was to create "columns" of data in a data structure. Armed with that suggestion, I tried a test program:

**free

ctl-opt option(*srcstmt) actgrp(*new) main(Prt);

dcl-f   QCUSTCDT Disk extfile('QIWS/QCUSTCDT');

dcl-f   QPRINT printer(132);

dcl-proc Prt;

    dcl-ds line len(132) inz qualified;

        custname    char(20);

        *n          char(1);

        custinit    char(10);

        *n          char(3);

        cusnum      char(6);

    end-ds;

    read QCUSTCDT;

    dow (not %eof(QCUSTCDT));

        line.cusnum = %char(CUSNUM);

        line.custname = LSTNAM;

        line.custinit = INIT;

        write QPRINT line;

        read QCUSTCDT;

    enddo;

    return;

end-proc;

And sure enough, I got a nicely spaced report from file QIWS/QCUSTCDT data:

Free-Format RPG: Printing Without O-Specs or an Externally Defined Printer File - Figure 1

Figure 1: This report looks the way I hoped it would.

As Cletus pointed out, moving columns around or adding more space between them is remarkably easy by simply redefining the data structure. (This is way easier in a GUI editor than in SEU. So a quick plug for VS Code and the Code for IBM i extension.)

What About Headings?

With data structures, headings are also easy. I inserted these additional lines to define and populate a data structure for the heading:

    dcl-ds head likeds(line);

    head.custname = 'Name';

    head.custinit = 'Initials';

    head.cusnum = 'Number';

    write QPRINT head;

Running the new program, I now have column headings:

Free-Format RPG: Printing Without O-Specs or an Externally Defined Printer File - Figure 2 

Figure 2: Now I have headings too.

So now I had an easy way to print my simple report.

What About Top and Bottom Margins?

But when the report went to more than one page, I was printing on all 66 lines on the page. I needed a way to skip to, for example, line 6 to produce a top margin, and some way to determine whether I was near the bottom of the page before skipping to create a bottom margin.

Bottom of the page is easy: just code an overflow indicator (oflind):

dcl-f   QPRINT printer(132) oflind(*in99);

But when the overflow indicator turns on, how do you get back to the top of the page?

Cletus, of course, knew how to handle new pages: It was right there at the end of his article. Unfortunately, I didn't read that far.

So, in my infinite wisdom, when overflow turned on, I just printed enough blank lines to fill out the current page, and then I printed enough blank lines to produce a suitable top margin. And I had a functional report. But…

What About Overprinting?

Some people like to underscore headings and totals. I was stuck again, since my approach couldn't allow that. Frankly, overprinting was overkill for my simple report, but I'd come this far, so why stop now?

First Character Forms Control (FCFC) came to mind, and Google helped out again. If you are not familiar with FCFC, the first character of the print line controls the spacing. This Wiki article gives a decent overview of FCFC. There's an IBM document here.

I created my own program describe print file with this command:

CRTPRTF FILE(MYPRT) CTLCHAR(*FCFC) CHLVAL((1 (3)))

That means FCFC is in effect, and top of the page is on line 3, controlled by channel 1. Prompt the command and read the help for the CHLVAL parameter. (You can get the same setup with an OVRPRTF command to QPRINT if you don't want an additional print file.)

I made the line length 133 in the RPG to account for the extra control character on the front, and then I did a little coding. First, I defined the FCFC control characters as constants with more meaningful names:

    dcl-c TOP '1';       // Skip to top of page & print

    dcl-c S1  ' ';       // Space 1 line & print

    dcl-c S2  '0';       // Space 2 lines & print

    dcl-c S3  '-';       // Space 3 lines & print

    dcl-c S0  '+';       // Space 0, overprint

Then I defined a data structure "line" for a 133-character line. The first character of the line is the FCFC. I included a 6-character left margin and a field "text" for any situations where I might want to print unstructured text. I overlaid "text" with the column definitions, just two in this case since this is a demo program that prints an increasing number and a timestamp.

    dcl-ds line len(133) inz qualified;

        fcfc     char(1);

        *n       char(6);        // left margin

        text     Char(125);      // Ad-hoc text

        num      char(6)    overlay(text:*next);

        *n       char(6)    overlay(text:*next);

        ts       char(26)   overlay(text:*next);

    end-ds;

Next I defined three heading lines, like the “line” data structure, and populated them, setting the FCFC values and the heading text.

    dcl-ds   head1 likeds(line);

    dcl-ds   head2 likeds(line);

    dcl-ds   head3 likeds(line);

    head1.fcfc = TOP;

    head1.text = 'Sample Report Using Concocted Data';

    head2.fcfc = S2;

    head2.num = 'Number';

    head2.ts = 'Time Stamp';

    head3.fcfc = S0;

    head3.num = *all'_';

    head3.ts = *all'_';

    *in99 = *on;    // First page is always skip

Then a simple loop to write the report and handle overflow:

    for k = 1 to 70;

        if (*in99 = *on);

            *in99 = *off;

            write MYPRT head1;

            write MYPRT head2;

            write MYPRT head3;

        endif;

        evalr line.num = %trim(%char(k));

        line.ts = %char(%timestamp());

        line.fcfc = S1;

        write MYPRT line;

    endfor;

    line.fcfc = S3;

    line.text = '*** End of Report ***';

    write MYPRT line;

And now I have a program that generates a report like this:

Free-Format RPG: Printing Without O-Specs or an Externally Defined Printer File - Figure 3

Free-Format RPG: Printing Without O-Specs or an Externally Defined Printer File - Figure 4

Figures 3 and 4: Now this two-page report looks really good.

The Cletus Approach to Headings

My solution turned out to be different from the one Cletus used. He used the PRTCTL parameter on the printer F-spec. The PRTCTL parameter defines a data structure that specifies spacing and skipping for each a line. Like this:

dcl-f   QPRINT printer(132) oflind(*in99) prtctl(pCtl);

dcl-ds  pCtl len(15) qualified inz;

    sp_b4    char(3);   // Space before

    sp_aft   char(3);   // Space after

    sk_b4    char(3);   // Skip to line num before

    sk_aft   char(3);   // Skip to line num after

    linenum  char(3);

This approach gives you a bit more control, and you can do more skipping and spacing before and after like you can do in O-specs. You don't have to create your own FCFC printer file or override QPRINT. I modified my FCFC test program to use this approach, and it came out about 20 lines longer, but that just might be my coding style. For simple reports, I think FCFC printing is easier and quite straightforward.

You can find IBM PRTCTL documentation here.

Conclusion

Maybe report writing is on the wane, being replaced by spreadsheet downloads or JSON micro services accessed from your browser, but if you still need to print from free-format RPG and don't want to create an externally defined print file, you now have two easy alternative options. (And on a side note, qualified data structures in RPG are extremely useful.)

The code for my two test programs can be downloaded from this site. They can also be found in my GitHub repository.

What Next?

Since I was into this, and I also occasionally wish I could print from a CLP program, I'm in the process of writing a general printing program that can be called either from RPG or with a CL command.

 

Sam Lennon

Sam Lennon is an analyst, developer, consultant and IBM i geek. He started his programming career in 360 assembly language on IBM mainframes, but moved to the AS400 platform in 1991 and has been an AS400/iSeries/i5/IBM i advocate ever since.

BLOG COMMENTS POWERED BY DISQUS

LATEST COMMENTS

Support MC Press Online

$

Book Reviews

Resource Center

  • SB Profound WC 5536 Have you been wondering about Node.js? Our free Node.js Webinar Series takes you from total beginner to creating a fully-functional IBM i Node.js business application. You can find Part 1 here. In Part 2 of our free Node.js Webinar Series, Brian May teaches you the different tooling options available for writing code, debugging, and using Git for version control. Brian will briefly discuss the different tools available, and demonstrate his preferred setup for Node development on IBM i or any platform. Attend this webinar to learn:

  • SB Profound WP 5539More than ever, there is a demand for IT to deliver innovation. Your IBM i has been an essential part of your business operations for years. However, your organization may struggle to maintain the current system and implement new projects. The thousands of customers we've worked with and surveyed state that expectations regarding the digital footprint and vision of the company are not aligned with the current IT environment.

  • SB HelpSystems ROBOT Generic IBM announced the E1080 servers using the latest Power10 processor in September 2021. The most powerful processor from IBM to date, Power10 is designed to handle the demands of doing business in today’s high-tech atmosphere, including running cloud applications, supporting big data, and managing AI workloads. But what does Power10 mean for your data center? In this recorded webinar, IBMers Dan Sundt and Dylan Boday join IBM Power Champion Tom Huntington for a discussion on why Power10 technology is the right strategic investment if you run IBM i, AIX, or Linux. In this action-packed hour, Tom will share trends from the IBM i and AIX user communities while Dan and Dylan dive into the tech specs for key hardware, including:

  • Magic MarkTRY the one package that solves all your document design and printing challenges on all your platforms. Produce bar code labels, electronic forms, ad hoc reports, and RFID tags – without programming! MarkMagic is the only document design and print solution that combines report writing, WYSIWYG label and forms design, and conditional printing in one integrated product. Make sure your data survives when catastrophe hits. Request your trial now!  Request Now.

  • SB HelpSystems ROBOT GenericForms of ransomware has been around for over 30 years, and with more and more organizations suffering attacks each year, it continues to endure. What has made ransomware such a durable threat and what is the best way to combat it? In order to prevent ransomware, organizations must first understand how it works.

  • SB HelpSystems ROBOT GenericIT security is a top priority for businesses around the world, but most IBM i pros don’t know where to begin—and most cybersecurity experts don’t know IBM i. In this session, Robin Tatam explores the business impact of lax IBM i security, the top vulnerabilities putting IBM i at risk, and the steps you can take to protect your organization. If you’re looking to avoid unexpected downtime or corrupted data, you don’t want to miss this session.

  • SB HelpSystems ROBOT GenericCan you trust all of your users all of the time? A typical end user receives 16 malicious emails each month, but only 17 percent of these phishing campaigns are reported to IT. Once an attack is underway, most organizations won’t discover the breach until six months later. A staggering amount of damage can occur in that time. Despite these risks, 93 percent of organizations are leaving their IBM i systems vulnerable to cybercrime. In this on-demand webinar, IBM i security experts Robin Tatam and Sandi Moore will reveal:

  • FORTRA Disaster protection is vital to every business. Yet, it often consists of patched together procedures that are prone to error. From automatic backups to data encryption to media management, Robot automates the routine (yet often complex) tasks of iSeries backup and recovery, saving you time and money and making the process safer and more reliable. Automate your backups with the Robot Backup and Recovery Solution. Key features include:

  • FORTRAManaging messages on your IBM i can be more than a full-time job if you have to do it manually. Messages need a response and resources must be monitored—often over multiple systems and across platforms. How can you be sure you won’t miss important system events? Automate your message center with the Robot Message Management Solution. Key features include:

  • FORTRAThe thought of printing, distributing, and storing iSeries reports manually may reduce you to tears. Paper and labor costs associated with report generation can spiral out of control. Mountains of paper threaten to swamp your files. Robot automates report bursting, distribution, bundling, and archiving, and offers secure, selective online report viewing. Manage your reports with the Robot Report Management Solution. Key features include:

  • FORTRAFor over 30 years, Robot has been a leader in systems management for IBM i. With batch job creation and scheduling at its core, the Robot Job Scheduling Solution reduces the opportunity for human error and helps you maintain service levels, automating even the biggest, most complex runbooks. Manage your job schedule with the Robot Job Scheduling Solution. Key features include:

  • LANSA Business users want new applications now. Market and regulatory pressures require faster application updates and delivery into production. Your IBM i developers may be approaching retirement, and you see no sure way to fill their positions with experienced developers. In addition, you may be caught between maintaining your existing applications and the uncertainty of moving to something new.

  • LANSAWhen it comes to creating your business applications, there are hundreds of coding platforms and programming languages to choose from. These options range from very complex traditional programming languages to Low-Code platforms where sometimes no traditional coding experience is needed. Download our whitepaper, The Power of Writing Code in a Low-Code Solution, and:

  • LANSASupply Chain is becoming increasingly complex and unpredictable. From raw materials for manufacturing to food supply chains, the journey from source to production to delivery to consumers is marred with inefficiencies, manual processes, shortages, recalls, counterfeits, and scandals. In this webinar, we discuss how:

  • The MC Resource Centers bring you the widest selection of white papers, trial software, and on-demand webcasts for you to choose from. >> Review the list of White Papers, Trial Software or On-Demand Webcast at the MC Press Resource Center. >> Add the items to yru Cart and complet he checkout process and submit

  • Profound Logic Have you been wondering about Node.js? Our free Node.js Webinar Series takes you from total beginner to creating a fully-functional IBM i Node.js business application.

  • SB Profound WC 5536Join us for this hour-long webcast that will explore:

  • Fortra IT managers hoping to find new IBM i talent are discovering that the pool of experienced RPG programmers and operators or administrators with intimate knowledge of the operating system and the applications that run on it is small. This begs the question: How will you manage the platform that supports such a big part of your business? This guide offers strategies and software suggestions to help you plan IT staffing and resources and smooth the transition after your AS/400 talent retires. Read on to learn: