12
Tue, Nov
6 New Articles
  1. You are here:  
  2. Home
  3. Programming
  4. RPG
  5. Tips and Techniques: Checking for F3/F12 from an IBM Command

Tips and Techniques: Checking for F3/F12 from an IBM Command

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

I don't know how many times I've needed to end a CL program because a user, who just called the CL program to run a Query/400 routine, pressed the F3 or F12 key to exit without running the query. My CL had no way of knowing if the user pressed F3 to exit the Query prompt.

Likewise, I have a utility that allows users to run the WRKSPLF CL command after entering some criteria. If the user presses Enter or F12 to return, I want the system to perform one task; if the user presses F3, I want the system to do something else. But how?

You might think it would be impractical do something like this or require access to some mystical DSM API set. As it turns out, the solution was there all along; the Retrieve Job Information API (QUSRJOBI) actually returns two on/off-style flags that indicate whether F3 or F12 was pressed on an IBM-supplied screen.

Using this API to check for F3 or F12 isn't difficult, but it is somewhat stealthy. The location of the information is buried in the middle of some API data structure that contains other information that you just don't need when testing for F3 or F12.

You can either call the API directly or use the handy wrapper command that I've provided here. The wrapper allows you to use the RTVEXITKEY command to check for F3 or F12 by retrieving the values into CL variables. The command definition source for RTVEXITKEY and two command processing programs (you get to choose one) are listed below.

Here's the command definition source for RTVEXITKEY:

RTVEXITKEY: CMD        PROMPT('Retrieve F3/F12 Status')
   /* Command processing program is RTVEXITKEY *CLP  */
             PARM       KWD(RTNF3) TYPE(*CHAR) LEN(1) RTNVAL(*YES) +
                          PROMPT('CL var for F3 key        (1)')

             PARM       KWD(RTNF12) TYPE(*CHAR) LEN(1) RTNVAL(*YES) +
                          PROMPT('CL var for F12 key       (1)')

To use this command, compile it with the following options:

CRTCMD CMD(RTVEXITKEY) PGM(RTVEXITKEY) +          

         ALLOW(*IPGM *BPGM *IMOD *BMOD)

You have two choices for the program to call when this command is run. You can use either the CL example listed below or the RPG IV program listed after the CL (but not both!). The advantage of the CL is that it is quick and easy; the advantage of the RPG IV is that that you have more options and better control. For example, with the RPG IV version, you may specify the RTNF3 parameter, the RTNF12 parameter, or both; with the CL version, you must specify both return parameters.

Here's the CL version of the command processing program for RTVEXITKEY:

RTVEXITKEY:  PGM        PARM(&F3 &F12)

             DCL        VAR(&JOB) TYPE(*CHAR) LEN(26) VALUE('*')
             DCL        VAR(&INTJOBID) TYPE(*CHAR) LEN(16) VALUE(' ')
             DCL        VAR(&JOBINFO) TYPE(*CHAR) LEN(350)
             DCL        VAR(&F3LOC) TYPE(*DEC) LEN(5 0) VALUE(103)
             DCL        VAR(&F12LOC) TYPE(*DEC) LEN(5 0) VALUE(104)
             DCL        VAR(&F12) TYPE(*CHAR) LEN(1)
             DCL        VAR(&F3) TYPE(*CHAR) LEN(1)
             DCL        VAR(&RTNLEN) TYPE(*CHAR) LEN(4) +
                          VALUE(X'00000000')

             CHGVAR     VAR(%BIN(&RTNLEN)) VALUE(350)

             CALL       PGM(QUSRJOBI) PARM(&JOBINFO &RTNLEN +
                             'JOBI0600' &JOB &INTJOBID)

             CHGVAR     VAR(&F3) VALUE(%SST(&JOBINFO &F3LOC 1))
             CHGVAR     VAR(&F12) VALUE(%SST(&JOBINFO &F12LOC 1))

 ENDPGM:     ENDPGM

Here's the RPG IV version of the command processing program for RTVEXITKEY:

     H DFTACTGRP(*NO) ACTGRP(*CALLER)
      **************************************************************
      **
      **  RTVEXITKEY - Return the status of the F3 & F12 keys
      **               Use this program as the CPP for the
      **               RtvExitKey command to retrieve whether or
      **               not the end-user pressed F3 or F12 to
      **               leave a system display. For example, if
      **               RUNQRY was being used, this program can
      **               return an indication as to whether F3 or
      **               F12 was used to leave RUNQRY, thus not
      **               actually running the query itself.
      **
      **************************************************************

      **  Prototype for this program.
     D RtvExitKey      PR
     D  RtnF3                         1A
     D  RtnF12                        1A   OPTIONS(*NOPASS)

      **  Entry PList for this program.
     D RtvExitKey      PI
     D  RtnF3                         1A
     D  RtnF12                        1A   OPTIONS(*NOPASS)


      **  Standard API Error Data Structure
     D QUSEC           DS                  Inz
     D  dsLen                        10I 0 Inz(%size(QUSEC))
     D  nErrRtnLen                   10I 0
     D  CPFMSGID                      7A
     D  szReserved1                   1A

      **  Prototype for Retrieve Job Info API
     D QUSRJOBI        PR                  EXTPGM('QUSRJOBI')
     D  rtnBuffer                 32765A   OPTIONS(*VARSIZE)
     D  nLenRtnbuffer                10I 0 Const
     D  Format                        8A   Const
     D  Job                          26A   Const
     D  IntJob                       16A   Const
     D  api_error                          Like(QUSEC)

      **  Return DS for returned job information
     D JobInfo         DS
     D   F3                           1A   Overlay(JobInfo:103)
     D   F12                          1A   Overlay(JobInfo:104)

      **  Call the Retrieve Job Information API
     C                   CALLP     QUSRJOBI(JOBINFO: %size(jobInfo) :
     C                                  'JOBI0600': '*': ' ':QUSEC)

      **  Did it work?
     C                   if        nErrRtnLen = 0
      **  If we need to return the status of F12, do it.
     C                   if        %Parms >= 1
     C                   eval      RtnF3 = F3
      **  If we need to return the status of F3, do it.
     C                   if        %Parms >= 2
     C                   eval      RtnF12 = F12
     C                   endif
     C                   endif
     C                   endif

      **  ENDPGM:
     C                   eval      *INLR = *ON
     C                   return

The following example illustrates how to use this command:

 TESTFKEY:   PGM
             DCL        VAR(&F3) TYPE(*CHAR) LEN(1)
             DCL        VAR(&F12) TYPE(*CHAR) LEN(1)

 SPLF:       WRKSPLF

             RTVEXITKEY  RTNF3(&F3)
             IF          (&F3 = '1') DO
              /*  user pressed F3 to exit WrkSplf  */
             ENDDO

 ENDPGM:     ENDPGM

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.

BOB COZZI

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.

MC Press books written by Robert Cozzi available now on the MC Press Bookstore.

RPG TnT RPG TnT
Get this jam-packed resource of quick, easy-to-implement RPG tips!
List Price $65.00

Now On Sale

The Modern RPG IV Language The Modern RPG IV Language
 Cozzi on everything RPG! What more could you want?
List Price $99.95

Now On Sale
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: