RPG IV

1
RPG IV

• Getting Started - Chapter 2

2
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

3
Specifications in RPG IV

• Different specifications for different purposes
• File Description Specifications
• Input Specifications
• Definition Specifications
• Calculation Specifications
• Output Specifications

4
File Description Specifications

• File Name
• File Type
• File Designation
• File Format
• Record Length
• Device

5
Input Specifications

• Record Identification Entries
• File Name
• Sequence
• Field Description Entries
• Field Location
• Decimal Positions
• Field Name

6
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

7
Pseudocode for Program
8
Calculation Specifications

• Except
• Read
• Dow
• Enddo
• Eval
• Return

9
Internal Documentation

• Comment lines
• in position 7

10
Completed Program - F I

• ..1........2........3........4........5....
  ....6........7........8
• F
  
• F This program produces a weekly sales report.
  The report data comes
• F directly from input file SalesMast.
  
• F Author J. Yaeger Date Written
  12/10/94
• F
  
• ..1........2........3........4........5....
  ....6........7........8
• FilenameIP FRlen Device
• FSalesMast IF F 63 DISK
• FQPRINT O F 132 PRINTER
• ..1........2........3........4........5....
  ....6........7........8
• IilenameSq
• ISalesMast NS
• I FromToDcField
  
• I 1 4
  0SlspNumber
• I 5 34
  SlspName
• I 35 50
  ItemNumber
• I 51 56
  0DateOfSale
• I 57 63 2Price

11
Completed Program - C Spec

• ..1........2........3........4........5....
  ....6........7........8
• C Factor1Opcode(E)Factor2Result
  LenDcHiLoEq
• C EXCEPT Headings
• C READ SalesMast
  
• C DOW NOT EOF
• C EXCEPT Detail
• C READ SalesMast
  
• C ENDDO
• C EVAL INLR ON
• C RETURN

12
Completed Program - O Headings Spec

• ..1........2........3........4........5....
  ....6........7........8
• OilenameD ExceptnameBASbSa
• OQPRINT E Headings 2 2
• ..1........2........3........4........5....
  ....6........7........8
• O FieldY End
  Constant/Editword
• O 8
  'PAGE'
• O PAGE 13
• O 50
  'WEEKLY SALES REPORT'
• O 64
  'DATE'
• O UDATE Y 73
• O E Headings 1
• O 7
  'SLSPSN.'
• O 48
  'DATE OF'
• O 77
  'SALE'
• O E Headings 2
• O 3
  'NO.'
• O 21
  'NAME'
• O 46
  'SALE'
• O 61
  'ITEM SOLD'

13
Completed Program - O Detail Spec

• ..1........2........3........4........5....
  ....6........7........8
• OilenameD ExceptnameBASbSa
• O E Detail 1
• ..1........2........3........4........5....
  ....6........7........8
• O FieldY End
  Constant/Editword
• O SlspNumber 4
• O SlspName 37
• O DateOfSale Y 48
• O ItemNumber 67
• O Price 1 79

14
Edit Codes
15
Edit Words
16
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.

17
Points to Remember (cont)

• 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.

18
Points to Remember (cont)

• It generally is customary to edit numeric values
  that are printed.
• Comment lines, signaled by an in position 7 of
  a specification line, can appear anywhere within
  a program.