1. Getting Started Chapter 2 Presentation © Copyright 2002, Bryan Meyers
4/21/2017
Getting Started
Chapter 2
Presentation © Copyright 2002, Bryan Meyers

2. Objectives Describe the RPG Specification forms
4/21/2017
Objectives
Describe the RPG Specification forms
Create a simple read/write RPG program
Explain how to include comment lines in a program
Explain how to do output editing to control the appearance of a report
Programming in RPG IV
Third Edition

3. Specifications in RPG IV
4/21/2017
Specifications in RPG IV
Different specifications for different purposes
File Description Specifications
Describe files used by program
Definition Specifications
Describe working variables, structures
Input Specifications
Describe input fields in files
Calculation Specifications
Processing instructions
Output Specifications
Describe program output (reports, files, etc.)
Programming in RPG IV
Third Edition

4. File Description Specifications
4/21/2017
File Description Specifications
File Name
File Type
File Designation
File Format
Record Length
Device *
FFilename++IPEASFRlen+LKlen+AIDevice+.Keywords
FSalesMast IF F DISK
FQPRINT O F PRINTER
Programming in RPG IV
Third Edition

5. Input Specifications Record Identification Entries
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Input Specifications
Record Identification Entries
File Name
Sequence
Field Description Entries
Field Location
Decimal Positions
Field Name *
IFilename++SqNORiPos1+NCCPos2+NCCPos3+NCC
I Fmt+SPFrom+To+++DcField L1M1FrP1MnZr......
ISalesMast NS
I SlspNumber
I SlspName
I ItemNumber
I DateOfSale
I Price
Programming in RPG IV
Third Edition

6. Output Specifications
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Output Specifications
Record Identification Entries
File Name
Type
Exception Name
Space and Skip Entries
Field Description Entries
Field Name
Constants
End Position in Output Record
Edit Codes *
OFilename++DF..N01N02N03Excnam++++B++A++Sb+Sa
O N01N02N03Field YB.End++PConstant/editword/DTformat++
OQPRINT E Headings
O ‘PAGE ’
O PAGE
O ‘WEEKLY SALES REPORT ’
O ‘DATE ’
O *DATE Y
Programming in RPG IV
Third Edition

7. Pseudocode for Program
4/21/2017
Pseudocode for Program
WRITE report headings
READ a record
WHILE there are more records
WRITE a detail line
READ the next record
ENDWHILE
END Program
Programming in RPG IV
Third Edition

8. Calculation Specifications
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Calculation Specifications
Except
Read
Dow
Enddo
Eval
Return *
/FREE
EXCEPT Headings;
READ SalesMast;
DOW NOT %EOF;
EXCEPT Detail;
ENDDO;
EVAL *INLR =*ON;
RETURN;
/END-FREE
Programming in RPG IV
Third Edition

9. Fixed-Format C-Specifications
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Fixed-Format C-Specifications
Before Version 5, compiler did not support free-format calculations
Fixed-format C spec required *
CL0N01Factor Opcode(E)+Factor Result Len++D+HiLoEq....
CL0N01Factor Opcode(E)+Extended-factor
C EXCEPT Headings
C READ SalesMast
C DOW NOT %EOF
C EXCEPT Detail
C ENDDO
C EVAL *INLR =*ON
C RETURN
Programming in RPG IV
Third Edition

10. Internal Documentation
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Internal Documentation
Comment lines begin with //
Starting at Version 5
Free format specifications
Comment can make up entire line or a portion of the line, after the code
// can be anywhere from 8-80
Fixed format specifications
Comment must make up entire line
// Can be anywhere from 7-80
Fixed format also supports comments that start with * in column 7
Used exclusively before Version 5
Blank lines are also allowed
Programming in RPG IV
Third Edition

11. Completed Program - F & I
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Completed Program - F & I *
// ***********************************************************************
// This program produces a weekly sales report. The report data comes
// directly from input file SalesMast.
// Author: J.Yaeger Date Written: 12/10/1994.
// Date Modified: 12/20/2001.
FSalesMast IF F DISK
FQPRINT O F PRINTER
ISalesMast NS
I SlspNumber
I SlspName
I ItemNumber
I DateOfSale
I Price
Programming in RPG IV
Third Edition

12. Completed Program - C Spec
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Completed Program - C Spec *
/FREE
EXCEPT Headings;
READ SalesMast;
DOW NOT %EOF;
EXCEPT Detail;
ENDDO;
EVAL *INLR =*ON;
RETURN;
/END-FREE *
C EXCEPT Headings
C READ SalesMast
C DOW NOT %EOF
C EXCEPT Detail
C ENDDO
C EVAL *INLR =*ON
C RETURN
(Before V5)
Programming in RPG IV
Third Edition

13. Completed Program - O Spec
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Completed Program - O Spec *
OQPRINT E Headings
O 'PAGE'
O PAGE
O 'WEEKLY SALES REPORT'
O 'DATE'
O *DATE Y
O E Headings
O 'SLSPSN.'
O 'DATE OF'
O 'SALE'
O E Headings
O 'NO.'
O 'NAME'
O 'SALE'
O 'ITEM SOLD'
O 'PRICE'
Programming in RPG IV
Third Edition

14. Completed Program - O Spec
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Completed Program - O Spec *
O E Detail
O SlspNumber
O SlspName
O DateOfSale Y
O ItemNumber
O Price
Programming in RPG IV
Third Edition

15. Edit Codes Commas Print Zero No Sign CR Right - Floating - Yes 1 A J N
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Edit Codes
Commas
Print Zero
No Sign CR
Right -
Floating -
Yes 1 A J N No 2 B K O 3 C L P 4 D M Q
Programming in RPG IV
Third Edition

16. Edit Words Value Edit Word Prints 999999999 ‘bbb-bb-bbbb’ 999-99-9999
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Edit Words
Value
Edit Word
Prints
‘bbb-bb-bbbb’
‘bbb&bb&bbbb’
‘0(bbb)bbb-bbbb’
(123)
00012^14
‘bbb$0.bb’
$12.14
‘$bbbb0.bb’ $
05612^14
‘$bb,bb0.bb’
$ 5,612.14
Programming in RPG IV
Third Edition

17. 4/21/2017
Points to Remember
RPG programs are written as fixed form specifications
Different specification forms convey different kinds of information to the RPG compiler
File specifications contain descriptions of all files used within a program
Programming in RPG IV
Third Edition

18. 4/21/2017
Points to Remember
Input specifications provide detail information about each program described input file used by a program
Calculation specifications center on operations, or processing steps, to be accomplished by the computer
Output specifications provide details about each program-described output file
Programming in RPG IV
Third Edition

19. 4/21/2017
Points to Remember
It generally is customary to edit numeric values that are printed
Comment lines, which begin with //, can appear almost anywhere within a program
Programming in RPG IV
Third Edition