RPG-ILE (RPG-IV) free tutorials and code AS/400, AS400

RPG III/RPG400, iSeries, IBM AS400, OS/400, RPG IV/RPG-ILE

For all AS/400
RPG programmers

ILE-RPG AS400 free tutorials, utilities, iSeries - IBM AS/400 - ILE RPG IV free tutorials, utilities, code, and tips including an IBM ILE-RPG reference manual with sample code plus Free Format, Op Codes, Modules, and Sub Procedures (Subprocedures) and more.

RPG - AS/400 - Utilities, Code, Demos, ...

( click on Topic to view tutorial-code )

Category	Topic	Subject
Description

CLP - OS/400	CLP intro	CLP introductory tutorial
CLP intro tutorial with code - COMMAND LANGUAGE (SYSTEM) programming

code - full programs	RPG Sub Files	sample subfile program
sample subfile program: ile-rpg, dspf, pf, lf, and a small data set

Miscellaneous	QSECOFR notes 1994	notes taken while QSECOFR
notes taken while QSECOFR on a network of 3 AS/400\'s on subjects including object authority, job logs, WRKSYSVAL, terminals, inactivity, outq\'s & printers, profiles, routing tables, etc. . .

Miscellaneous	QSYS Commands List	QSYS (AS/400) Commands List
All the AS/400 QSYS commands, with short descriptions, including PWRDWNSYS etc. which you may not have authority to see or use.

Miscellaneous	RPG-ILE ref. code	RPG-ILE reference file for code
Reference file for code syntax used seldom enough to be forgotten; array overlays, SORTA, date formats, tables, multi-occur-DS\'s, SDS, plus.

tests & quizes	Certification	IBM sample RPG Cert. test
IBM had/has an on-line sample sertifiication test for RPG (ILE +) sr. programmer analysts along with a general list of things an RPG - AS/400 programmer should know.

tests & quizes	ILE-RPG; RPG-IV (4)	39 question quiz of RPG
quiz offered in 2007 to co's and agencies for technical testing of their RPG programmer job applicants and etc.

utility	Display File Format	Display Format of PF and all LFs
it combines the information of several as400 file description comands and displays it all in a more compact, readable, manner.

utility	LDA Local Data Area	LDA - Edit your Local Data Area
a simple CLP and DSPF to edit your Local Data Area - you can expand or contract it for how much you need

utility	object listing	object listing sorted by a date
object listing sorted by last used date and restricted by object size and or a date range

utility	printouts to files	copy multiple printouts to a file
a CMD, CLP, and RPG for copying multiple printouts to a file with the option of having the printouts deleted (y/n) afterward

utility	RPG ILE indented	indented source code listing
source code utility to print indented columnized RPG (III and ILE) source

a blog: differences in RPG-III(RPG400) and RPG-ILE(RPG-IV)

As almost everywhere, it is hard to find free RPG utilities, code, tips, and tutorials. Most everything comes with a price tag - and RPG info. is more expensive than most others.
I have found a few free sources and have shared the best of them here.

A reality in the computer business is that things have been changing faster than in almost any other market -- and it is unfortunate that when IBM realized they would have to make the AS/400 communicate easily with the internet (or continue to loose business at an even more alarming rate) their infamous response to all the RPG programmers out there was a double page ad suggesting that RPG programmers could get jobs flipping burgers. The AS/400 was then and now being sold as "a Java Machine".

By, or soon after, the year 2000, jobs for RPG programmers had virtually disappeared in the US. (ex: about 2 RPG jobs vs. 80 to 100 java jobs here in south Florida)

For those still working in RPG it becomes ever more dificult to find information. What I have and can find, I offer to you freely here (see links below). If you can learn Java on the AS/400 that should help. If you have, and have any experiences and or Java code to share, please share it here also.

Alternately, get a domain name, and pay the $10 a month for a web site you can build and experiment with yourself. ( see my hints on domain names and on web site design. Also, www.web-page-hosting-review.com and www.web-hosting-reviews.org and www.100best-domain-names.com are good sources for comparisons and recomendations. )

(All links will open in their own window)

Link	Description
RPG - iSeries AS/400 Links
www.theRPGsource.com	free examples of rpg-free (format) source code
www.as400pro.com/servlet/sql.viewCats?Type=T	AS/400 PRO web site lots of free information on all areas of as400 and os400 programming: CLP, ile-RPG, Visual-Age, java, operations, Apache, PHP, and more
lab400.com/RI_pages.asp?idno=4139	free AS400 info on subProcedures, service programs, web design, WebFacing without WebSphere, html, javaScript, and more. You have to sign up with them first but ...
www.iseriestools.com/	Free AS/400 utiities
www.code400.com	Code samples and forum for the AS400, Iseries, I5 whatever they call it today.
64.233.179.104/search?q=cache: sxbRnWQaHsIJ:as400bks.rochester.ibm.com/ html/as400/v4r5/ic2924/info/ java/rzaid/java400.pdf&hl=en	intro to AS/400 JAVA including info on installing the java licensed pgm in case it is not already; qshell; mapping a network drive; creating a directory; compiling; & other resources
www.itjungle.com/fhg/fhg021104-story01.html	a good description and discussion of activation groups (new, caller, named).
groups.google.com/groups? hl=en& group=comp.sys.ibm.as400.misc	Google has an extensive Q&A - over 116,000 (searchable) AS/400 postings.
www.texas400.com/tutas400toc.html	introductory AS/400 tutorial -- on Commands; lib.lists; PDM; queries; PF's and LF's; SDA; RLU; Debugging RPG ILE with STRDBG; a complete maint. pgm. in ILE & RPG3
www.texas400.com/basicas400tips.html	about 28 basic as/400 tips from programming to administration. Also see FAVORITE Tips and Techniques; Basic AS/400 Skills; their favorite AS/400 Links; some RPG Source Code; and an introductory AS/400 Tutorial
www.itjungle.com/fhg/fhgindex.html	all the back-issue articles from the Midrange Programmer, OS/400 Edition and Midrange Guru, OS/400 Edition magazines
www.freeas400software.com/	links to AS/400 software - tools, Utilities, - even a few games
www.taatool.com/document/category.htm	TAATOOLS free AS/400 utilities IBM made available to all RPG programmers - written by IBM'ers
www-922.ibm.com/boatcgi/start	developing web aps on the AS400 with RPG behind the html(s) - from "a non-profit site" but you have to register.

View all Utilities,
Code-Samples,
Demos, Tutorials
outside the AS/400

RPG ILE BOOKS

I have seen pdf formatted IBM (RPG-ILE) manuals where you could only see (or download) one item at a time. here is IBM's reference manuals source where you can see and download the whole book in either html or pdf format; (#3. below is the best)
One drawback, in the html book (#1), the "internal" links to the topics in the table of contents (and elsewhere) pointed to another copy of the book on IBM's web site instead of internally as it should. I have stopped that and the chapters now point to their respective locations. The worst of it is that virtually all the code is based on goto's - RPGII programming! Worthess. The ILE-RPG Sample-1 SUBF-Program below it is greatly enhanced over the original and is structured.

(7 meg)

1. WebSphere Development Studio ILE RPG Reference V5R3 . (pdf)

( this includes sample code written in RPG-Free format )

( The RPG compiler for Windows ) (5.4 meg)

2. VisualAge RPG Language Reference V5R3 (pdf)

(includes built in functions, a lot of sample code, some in /free-format)

( unfortunately, a number of examples still use rt-hand indicators and
spagetti spinning infinite loops, goto's, leave's, etc. )

a Redbook

3. Who Knew You Could Do That with RPG IV?
^{A Sorcerer's Guide to System Access and More
(5.5megs)}

4. Neat features discovered about the D spec!

5. An old RPG III (RPG400) Users Guide, V5R3

For more downloadable IBM books, see

IBM Public Library, Boulder, Colorado

look under: Site Map, Programming, Languages, RPG.

_{Thanks to a friend, Ken Killian,
for items 3. and 4. and the 1st 2 code images below.}

THE 3 BASIC PROGRAMMING CONSTRUCTS
1. SEQUENCE	consecutive
2. BRANCH	if - else
3. LOOP	do while
The basics of structured programming: All code stays within the 3 constructs, therefore 1. there are no goto's, jumps, exits, iterates, etc. 2. all loops terminate at the bottom. (the condition may be expressed at the top) 3. there are no infinite loops.

just 1 affirmation, from a David Michael Zokaites:
"The most basic practice, for those programming in procedural languages, is to avoid the infamous goto statement; well structured and designed programs simply have little need for it. "Spaghetti code," riddled with gotos, is notoriously difficult to decipher."

RPG Free

note: there are 2 errors of omission here. One (10a) has been "fixed" the other
(a single character) has not. Can you spot it? (Hint, the editor has highlighted it.)

For everyone, these opcodes may be of significance in the above program:
Option(*Srcstmt:*Nodebugio)
Bnddir('QC2LE')
DftActGrp(*No)

a before and after example:
RPG ILE Free sample#2

Data Queues

The Dou(DOuntil) loop is not structured _{(what is the simplist/correct way to re-write it?)

Remember, there is always the initial read followed by the loop.

"WS_REG" & "Register_Vendor" are two "DUMMY"
functions/subprocedure. They are NOT DEFINED}

^{The following program receives a customer number as an input

parameter and returns the name and address as output parameters.}

     F*
     FARMstF1   UF   E             Disk    Rename(ARMST:RARMST)

     D*-----          =--    ---    ---  = ---------------------------
     D pCusNo          S              6p 0
     D pName           S             30a
     D pAddr1          S             30a
     D pAddr2          S             30a
     D pCity           S             25a
     D pState          S              2a
     D pZip            S             10a
     D*-----          =--    ---    ---  = ---------------------------

     C* -==------------- ========= ------------- ============== ---- :++--==   *
     C     *entry        plist
     C                   parm                    pCusNo
     C                   parm                    pName
     C                   parm                    pAddr1
     C                   parm                    pAddr2
     C                   parm                    pCity
     C                   parm                    pState
     C                   parm                    pZip

     C     pCusNo        chain     ARMstF1

     C                   if        %found
     C                   eval      pName  = ARNm01
     C                   eval      pAddr1 = ARAd01
     C                   eval      pAddr2 = ARAd02
     C                   eval      pCity  = ARCy01
     C                   eval      pState = ARSt01
     C                   eval      pZip   = ARZp15
     C                   endif
       
     C                   eval      *InLR = *On
     C* -==------------- ========= ------------- ============== ---- :++--==   *

The same program using free calculations:

     F*-------- := - -  ---      - ------- ---------------------------
     FARMstF1   UF   E             Disk    Rename(ARMST:RARMST)

      /copy cust_pr
     D**      D E F I N I T I O N S
     D* The PI "procedure interface" describes the *ENTRY parameters
      *                            only the pCusNo comes in, it and the  
      *                            rest are passed on to the next pgm.
     D getCustInf      PI
     D  pCusNo                        6p 0   const
     D  pName                        30a
     D  pAddr1                       30a
     D  pAddr2                       30a
     D  pCity                        25a
     D  pState                        2a
     D  pZip                         10a
     D*-----          =--    ---    ---  = ---------------------------
      /free
        // get the record:
        chain pCusNo ARMstF1;

        if %found;
           pName  = ARNm01;
           pAddr1 = ARAd01;
           pAddr2 = ARAd02;
           pCity  = ARCy01;
           pState = ARSt01;
           pZip   = ARZp15;
        endif;
       
        // RPG makes use of switches.  One switch "LR" stands for 
        // "last record".  This ends program execution.
        *InLR = *On;
      /end-free

free-format RPG:

     F...
     D...
     C* --------------------------------------
      /FREE

         var01 = var2 + var 3;

         dou  msgInf.bytRet >= msgInf.bytAvl;
            //... call the API
            QMHRTVM(msgInf: memSize: i_format: i_msgID: i_qMsgF:
              i_rplData: %len(i_rplData): rplVars: rtnCtrlChr: errCode);

            //... get more memory
            if  memSize < msgInf.bytAvl;
                memSize = msgInf.bytAvl;
                pMsgInf = %realloc(pMsgInf: memSize);
            else;
                o_msg = f_newMsg(cMsg_ID_OK);
            endif;

         enddo;

      /END-FREE
     C*
     C*
     o* -----------------------
     O*
     O*
     o* -----------------------
      * (subprocedure) b = begining
     P procedurename   b
     D SubProc         PI
     C*
     C*
      /FREE
     ...etc.
      /END-FREE
     P procedurename   e
     C* -------------------------------------

MOVEing numeric to string:
the MOVEL etc. is not needed.

           %SubSt(CurrInv:1:6) = %Char(InvNo);
           alpha5 = digits(num5);

%SubSt replaces the dropped MOVEL operation

Notes:
(sub)Procedures follow the O-specs, if you have any. Since most RPG programs these days don't have O-specs, subprocedures usually follow the C-specs.

A program with a subprocedure will not run in the default activation group, so include an H-spec to force it to run in a named activation group. ex: QILE

     H dftactgrp(*no) actgrp('QILE')
     F*-------- := - -  ---      - -------

Returning a Value: Here's another thing subprocedures can do that subroutines can't: A subprocedure can return a value in the same way that a built-in function returns a value. This means that you can reference a subprocedure name in such operations as EVAL, IF, and DOx. Like:

     C                   eval      PWStateTax =
     C                                CalcStateTax
     C                                  (PWGross:
     C                                   PWNbrPer:
     C                                   PWMarStat:
     C                                   PWNbrDep)
      * where CalcStateTax is a sub-procedure

subprocedures support recursion. That is, a subprocedure can call itself.

However: Don't start converting subroutines to subprocedures. You may benefit from converting subroutines that carry out common tasks or tend to break and need a lot of fixing; but otherwise, don't.

There is one big advantage to the old subroutines worth mentioning. Subroutines are accessed faster than subprocedures. In a fast processing read loop of a file, the simple subrouting may be noticeably faster and performance may be an issue.

           PGM
           DCL     &msgid   *CHAR 7
           DCL     &msgf    *CHAR 10
           DCL     &msgflib *CHAR 10
           DCL     &msgdta  *CHAR 100
           MONMSG  CPF0000 EXEC(GOTO ERROR)
          .
          .    (Include normal processing here)
          .
           RETURN     /* Normal end of program */

   /* ---------------------------------------- */
   ERROR:  RCVMSG     MSGTYPE(*LAST)         +
                      MSGDTA(&msgdta)        +
                      MSGID(&msgid)          +
                      MSGF(&msgf)            +
                      SNDMSGFLIB(&msgflib)

           MONMSG     CPF0000  /* Just in case */

           SNDPGMMSG  MSGID(&msgid)          +
                      MSGF(&msgflib/&msgf)   +
                      MSGDTA(&msgdta)        +
                      MSGTYPE(*ESCAPE)

           MONMSG     CPF0000  /* Just in case */

           ENDPGM

"However, many programs have special error-handling requirements, and should be accommodated whenever possible."

Binding ( or Linking )

In Windows, MS introduced the ".dll" or Dynamic Link Library, where each .dll file contains one or more object modules that were "linked" to create a single loadable .dll file that can be (dynamically) loaded (on demand) into memory, if and when needed.

In OS/400, they call these a "service program" (*SRVPGM).

The CRTPGM command is used to combine one or more *MODULEs into a *PGM, while CRTSRVPGM is used to combine one or more *MODULEs into a *SRVPGM. Both of these commands, are part of the "binder" or linker of OS/400.

UPDPGM can be used to replace one or more *MODULEs in a *PGM (perhaps with a newer, "fixed" version). Similarly, UPDSRVPGM can replace *MODULEs in a *SRVPGM.

All of these functions were provided by a single utilty program of IBM's venerable mainframe OS/360, OS/VS, MVS thru OS/390, and it is called the "Linkage Editor".

So, CRTPGM, CRTSRVPGM, UPDPGM and UPDSRVPGM are all a part of the ILE "binder" in OS/400.

CRTBNDRPG - option 14=Compile in PDM

Activation Groups

Previous articles discussed creating programs out of modules, which is a two-step process: In RPG, this would include CRTRPGMOD (Create RPG Module) and then CRTPGM (Create Program). I use this approach exclusively, but for single-module programs, these steps can be consolidated into one command: CRTBNDRPG (Create Bound RPG Program). In PDM, this is the old stand by option 14, and the result is a *PGM object: The interim *MODULE object is not created. The reason why I mention this approach now is that this is typically the first run-in that new RPG IV programmers have with activation groups.

If you prompt 14 in PDM, you will see an option for Default Activation Group, with a default of *YES. If you try to create a program with DFTACTGRP(*YES), that program can't use any ILE features: no procedures (not even internal), no service programs, no binding directories. This sort of program is considered OPM even if it is written in RPG IV. As a result, you frequently see examples that include an H-spec of DFTACTGRP(*NO). This allows the program to compile with all of those ILE goodies because now, by virtue of being created with something other than the DAG, it is an ILE program.

From "What You Should Know About Activation Groups" by Joel Cochran at IT Jungle.

Binding Directories, A Way of Life

The first thing you should be aware of when building RPG IV applications with multiple modules (source members) is the binding directory. Binding directories contain lists of either modules or service program objects. The AS/400 binder uses these objects to compile RPG IV programs.

A binding contains only a list of the modules or service programs, not the actual objects. So as new versions or fixes or introduced, the latest object is used by the compilers. Another wonderful byproduct of binding directories is that you don't have to specify a long list of module names for the program your compiling.

While you can create your own binding directories, which is something I do for each application I create, you can also take advantage of a binding directory that is provided with all AS/400 systems. That binding directory name is QC2LE.

QC2LE Binding Directory

There is a special binding directory on your AS/400 named QC2LE. It contains a list of modules and service programs needed for the C language runtime environment.

The C language has several interesting methods for evoking a procedure call, fortunately one of these methods allows the procedure to be called via a pointer to a procedure. Consequently, the functions for the C runtime library are stored in service programs. This is where the binding directory comes in. IBM provides with OS/400, the QC2LE binding directory. In this binding directory is a list of all the modules and service programs that make up the C runtime library.

In many ways, the IBM AS/400-iSeries has not lived up to the adoration some,
mostly those who have not paid attention to the alternatives, have given it.

Routerless Clients for the AS/400

"AS/400 Technology Showcase" (magazine) pg.43

"as the internet takes hold of the communications world, its underlying protocol layer, TCP/IP, has become widespread and the requirement for a router has been eliminated (the SNA protocol subset of Logical Unit 6.2 - LU6.2).
... the router is a complex, slow, and resource-hungry component, TCP/IP eliminates the need of the router layer. Gone are the 40 or so seconds waiting for the APPC router to establish its connection with the as400. Gone are the mysterious connection points that make it nearly imposslible to determine where the fault lies. The router was eight miles of bumpy, gravel road, and now its gone. finished. Done with. We've got TCP/IP now and we aren't going back. Do you have a connection to the AS400? Just ping it and find out.

IBM has often blazed its own technological trail while failing to notice the clearly marked and highly traveled path paralleling its course to an identical destination. Thus IBM encoded characters in EBCDIC instead of ASCII, invented the propriatary microchannel bus when the industry was crying for non-propriatary bus standards, clung to the OS/2 operating system long after the world had clearly embraced Windows, and promoted token ring topology over the simpler and less expensive Ethernet.

- Jerome Draper, specialist in connecting the AS400 to pc's lan's Macs and to the internet.

Ask a Question; report an error (thanks)

For all AS/400 RPG programmers