Library, Source Physical File, Member, Record and Record Format

It is very important to understand the above jargons. All terms are related to each other in a following hierarchy.

Record & Record Format:

          The data in a file is called Record. it should be in some specific format and that format is called Record Format.

For example: On a page of paper, you have following data.

All the above detail/ data on the page is record.

Whole page is written in a pre-defined rules and that rules are specified in a template or format as mention below.

Example of Record Format.

If I want to code the above format as PF then I may code as following:

R       PFLETTERR                                       

                    SALUTATION      15A             TEXT('SALUTATION')    

                    BLNK_LINE1       80A             TEXT('BLANK LINE 1')  

                    DETAILS             500A           TEXT('DETAILS')       

                    BLNK_LINE2       80A             TEXT('BLANK LINE2')    

                    THANKS             15A             TEXT('THANKING YOU')  

                    BLNK_LINE3       80A             TEXT('BLANK LINE3')   

                    REGRADS          15A             TEXT('YOURS SINCERELY')

                    NAME                  30A             TEXT('NAME')          

Now a proper Example of Record Format & Records

Record Format – PF1R

PF1

In PF1R image:

• it is restricted that each record (that means each line of data) will have only two columns.
• It is restricting or telling us that any data (even blanks) in the 1^st col: will be consider as CUSTOMER ID and anything in 2^nd col: will be COUSTOMER NAME

In PF1 image:

• PF1 has 3 lines of data that means it has 3 Records
• It is a two column PF just as described by its format (PF1R).
• First col: has ID and 2^nd col: has Name.

Member:

          Member is the collection of record(s). it contains line of data in a proper

In the above PF1 example.

• ·        PF1 is a Member
• ·        It has 3 Records
• ·        Record Format PF1R is for all the records in the Member PF

Source Physical File:

            Source physical file is a file which contains the sources of different types of objects. 

• ·         It is the collection of file member(s).
• ·         There can be up to 32767 members
• ·        Used CRTSRCPF command to create library

·          

Library:

Library is a collection of files. Read more about Library (Here) 

• ·        Used CRTLIB command to create library

A Simple Loop Program

Here it is a simple program that print counting upto 10. it is a one of the basic programs but still it has so many advance topics and techniques. let us see the full coding first.

0001.00 DCOUNTER          S              2P 0                                                               
0002.00 D                                                                                                   
0003.00 C                   FOR       COUNTER = 1 TO 10                                                     
0004.00 C     COUNTER       DSPLY                                                                           
0005.00 C                   ENDFOR                                                                          
0006.00 C                   SETON                                            LR                              

Now, Let us parse the program line by line

0001.00 DCOUNTER          S              2P 0                                             
It is the very first line of the program.
0001.00 = line number
D = shows that it is Data Specification (RPGLE program is consists of specification such as H, F, D, I, C, . . . ). D-spec is used to declare variables
counter = variable name
S = it shows that variable is data structure (DS), single(S), constant(C)...
2 = variable length
P = data type ( few data type are character(A), Packed Decimal(P), zoned(S). 0 is showing that there is NO decimal Place

0002.00 D      (blank line)

0003.00 C                   FOR       COUNTER = 1 TO 10

C = indicate that following line is Calculation (C) Specification related. every calculation, looping, branching, program-calling is done here in C-Spec.
this line tells the compiler that a 'for-loop' has to be execute from 1 to 10.

0004.00 C     COUNTER       DSPLY
it display the value of 'counter' variable

0005.00 C                   ENDFOR      
this line complete the for loop and every thing between 'FOR' and 'ENDFOR' is part/ body of for loop. 

FOR-LOOP Syntax

FOR
.
.
.
.
ENDFOR 

0006.00 C                   SETON                                            LR        
it set on the last record(LR) indicator. which tells the compiler that end now.
A very importantand must have line in the RPG PGM. Without having this line compiler will generate following error while compiling the PGM and PGM will not compile.

 Msg id  Sv Number Seq     Message text                                               *RNF7023 40      0         The Compiler cannot determine how the program can end.        

Images

         

AS/400 Library

A library (*LIB) on the AS/400 is an object that is used as a system directory to keep track of other objects. 

OR

In AS/400 a library is an object that can contain other objects (executable objects, source files, etc.).

Library is used to find other OS/400 objects in the database. To find an OS/400 object you need the name of the library and the name of the object.  

The AS/400 identifies objects by their qualified name, which takes the form of LIBRARY/OBJECT.  

Some important Points:

• The AS/400 library is organized as a single-level hierarchy.
• An object can exist in only one library.
• Two or more objects can have the same name but they must be different types of objects.
• A library cannot reference other libraries except for the library called QSYS. This is the only library that can access other libraries.

Certain types of the AS/400 object (database file, storage areas and executable program objects) can be compiled, copied, and stored into/from many different libraries concurrently, with the Library List hierarchy determining which instance of the object to use during execution of any application that utilizes that object name. 

Generally speaking all libraries created by IBM for use by the operating system begin with the letter 'Q'.

Some IBM Standard Libraries:

QSYS -          System Parent Library
QSYS2 -        System Library for CPI's
QHLPSYS -  Online Documentation Library for Users
QTCP -          TCP Connectivity Utilities
QAFP -          Advanced Function Printing
QGPL -         General Purpose Library
QTEMP -      Job specific temporary Library (deleted when the job ends)


References:

• http://en.wikipedia.org/wiki/AS/400_library
• http://pic.dhe.ibm.com/infocenter/iseries/v7r1m0/index.jsp?topic=%2Frbam6%2Frbam6objects.htm

Predefined values and default library / directory locations for AS/400 Object Types

Objects can stored in libraries and integrated file system’s directories.

Some objects stored only in a specific Default library.

Some type of object allow the user to specify the library name at the time of object creation. If library name is not provided by the user then object will be created in current library *CURLIB by default.

One can change the current library by using the command CHGCURLIB

In case there is no current library in effect at the time of object creation then QGPL library will be used.

The other types of objects, identified by N/A (not applicable) in the Default user library column, cannot be stored in libraries or directories.

With the exception of the Dump System Object (DMPSYSOBJ) command, you cannot specify the object type in the format shown in the hexadecimal format column with commands.

  

Value	Object type	Default user library or directory
*ALRTBL	Alert table	*CURLIB
*AUTL	Authorization list	QSYS
*BLKSF	Block special file	Current directory
*BNDDIR	Binding directory	*CURLIB
*CFGL	Configuration list	QSYS
*CHRSF	Character special file	Current directory
*CHTFMT	Chart format	*CURLIB
*CLD	C/400 locale description	*CURLIB
*CLS	Class	*CURLIB
*CMD	Command	*CURLIB
*CNNL	Connection list	QSYS
*COSD	Class-of-service description	QSYS
*CRG	Cluster resource group	QUSRSYS
*CRQD	Change request description	*CURLIB
*CSI	Communications side information	*CURLIB
*CSPMAP	Cross-system product map	*CURLIB
*CSPTBL	Cross-system product table	*CURLIB
*CTLD	Controller description	QSYS
*DDIR	Distributed file directory	N/A
*DEVD	Device description	QSYS
*DIR	Directory	Current directory
*DOC	Document	QDOC
*DSTMF	Distributed stream file	N/A
*DTAARA	Data area	*CURLIB
*DTADCT	Data dictionary	library with same name as data dictionary
*DTAQ	Data queue	*CURLIB
*EDTD	Edit description	QSYS
*EXITRG	Exit registration	QUSRSYS
*FCT	Forms control table	*CURLIB
*FIFO	First-in-first-out special file	Current directory
*FILE	File	*CURLIB
*FLR	Folder	QDOC
*FNTRSC	Font resources	*CURLIB
*FNTTBL	Font mapping table	*CURLIB
*FORMDF	Form definition	*CURLIB
*FTR	Filter	*CURLIB
*GSS	Graphics symbol set	*CURLIB
*IGCDCT	Double-byte character set (DBCS) conversion dictionary	*CURLIB
*IGCSRT	Double-byte character set (DBCS) sort table	*CURLIB
*IGCTBL	Double-byte character set (DBCS) font table	QSYS
*IMGCLG	Image Catalog	QUSRSYS
*IPXD	Internetwork packet exchange description	QSYS
*JOBD	Job description	*CURLIB
*JOBQ	Job queue	*CURLIB
*JOBSCD	Job schedule	*CURLIB
*JRN	Journal	*CURLIB
*JRNRCV	Journal receiver	*CURLIB
*LIB	Library	QSYS
*LIND	Line description	QSYS
*LOCALE	Locale	*CURLIB
*MEDDFN	Media definition	*CURLIB
*MENU	Menu description	*CURLIB
*MGTCOL	Management collection	NA, or QPFRDATA if library specified using QYPSCSCA API
*MODD	Mode description	QSYS
*MODULE	Compiler unit	*CURLIB
*MSGF	Message file	*CURLIB
*MSGQ	Message queue	*CURLIB
*M36	AS/400® Advanced 36 machine	*CURLIB
*M36CFG	AS/400 Advanced 36 machine configuration	*CURLIB
*NODGRP	Node group	*CURLIB
*NODL	Node list	*CURLIB
*NTBD	NetBIOS description	QSYS
*NWID	Network interface description	QSYS
*NWSCFG	Network server configuration	QUSRSYS
*NWSD	Network server description	QSYS
*OUTQ	Output queue	*CURLIB
*OVL	Overlay	*CURLIB
*PAGDFN	Page definition	*CURLIB
*PAGSEG	Page segment	*CURLIB
*PDFMAP	Portable Document Format map	*CURLIB
*PDG	Print Descriptor Group	*CURLIB
*PGM	Program	*CURLIB
*PNLGRP	Panel group definition	*CURLIB
*PRDAVL	Product availability	QSYS
*PRDDFN	Product definition	QSYS
*PRDLOD	Product load	QSYS
*PSFCFG	Print Services Facility™ configuration	*CURLIB
*QMFORM	Query management form	*CURLIB
*QMQRY	Query management query	*CURLIB
*QRYDFN	Query definition	QGPL
*RCT	Reference code translate table	QGPL
*SBSD	Subsystem description	*CURLIB
*SCHIDX	Search index	QGPL
*SOCKET	Local socket	N/A
*SPADCT	Spelling aid dictionary	QGPL
*SQLPKG	Structured Query Language package	*CURLIB
*SQLUDT	User-defined SQL type	*CURLIB
*SQLXSR	SQL XML schema repository	*CURLIB
*SRVPGM	Service program	*CURLIB
*SSND	Session description	QGPL
*STMF	Bytestream file	Current directory
*SVRSTG	Server storage space	QUSRSYS
*SYMLNK	Symbolic link	Current directory
*S36	System/36 machine description	QGPL
*TBL	Table	*CURLIB
*TIMZON	Time zone description	QSYS
*USRIDX	User index	*CURLIB
*USRPRF	User profile	QSYS
*USRQ	User queue	*CURLIB
*USRSPC	User space	*CURLIB
*VLDL	Validation list	*CURLIB
*WSCST	Workstation user customization object	*CURLIB