Cobol Complete Reference

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IBMMAINFRAMES.comIBMMAINFRAMES.com

With

DEXTRA UniversityDEXTRA UniversityPresents

COBOL – Complete ReferenceCOBOL – Complete Reference

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IntroductioIntroduction to n to

COBOL COBOL

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COBOLCOBOL COBOL is an acronym which stands for

Common Business Oriented Language. The name indicates the target area of COBOL applications. COBOL is used for developing business, typically file-

oriented, applications. It is not designed for writing systems programs. You would

not develop an operating system or a compiler using COBOL. COBOL is one of the oldest computer languages in use (it was

developed around the end of the 1950s). As a result it has some idiosyncrasies which programmers may find irritating.

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COBOL COBOL idiosyncrasiesidiosyncrasies One of the design goals was to make the language as

English-like as possible. As a consequence– the COBOL reserved word list is quite extensive and contains

hundreds of entries.

– COBOL uses structural concepts normally associated with English prose such as section, paragraph, sentence and so on. As a result COBOL programs tend to be verbose.

Some implementations require the program text to adhere to certain, archaic, formatting restrictions.

Although modern COBOL has introduced many of the constructs required to write well structured programs it also still retains elements which, if used, make it difficult, and in some cases impossible, to write good programs.

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The COBOL Meta language - Syntax The COBOL Meta language - Syntax NotationNotation

Words in uppercase are reserved words.– When underlined they must be present when the operation of

which they are a part is used.– When they are not underlined the used for readability only and are

optional. If used they must be spelt correctly. Words in mixed case represent names which will be devised

by the programmer. When material is enclosed in braces { } a choice must be

made from the options within the braces. Material is enclosed in square brackets [ ] indicates that the

material is an option which may be included or omitted as required.

The ellipsis symbol ‘...’ indicates that the preceding syntax element may be repeated at the programmer’s discretion.

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ProgramProgramProgramProgram

Divisions

Section(s)

Paragraph(s)

Sentence(s)

Statement(s)

Structure of COBOL programs.

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The Four The Four Divisions.Divisions.

DIVISIONS are used to identify the principal components of the program text. There are four DIVISIONS in all.

IDENTIFICATION DIVISION.

ENVIRONMENT DIVISION.

DATA DIVISION.

PROCEDURE DIVISION.

Although some of the divisions may be omitted the sequence in which the DIVISIONS are specified is fixed and must follow the pattern shown above.

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Functions of the four Functions of the four divisions.divisions.

The IDENTIFICATION DIVISION is used to supply information about the program to the programmer and to the compiler.

The ENVIRONMENT DIVISION describes to the compiler the environment in which the program will run.

As the name suggests, the DATA DIVISION is used to provide the descriptions of most of the data to be processed by the program.

The PROCEDURE DIVISION contains the description of the algorithm which will manipulate the data previously described. Like other languages COBOL provides a means for specifying sequence, selection and iteration constructs.

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COBOL Program Text Structure COBOL Program Text Structure

Data Descriptions

Algorithm Description

IDENTIFICATION DIVISION.IDENTIFICATION DIVISION.

DATA DIVISION.DATA DIVISION.

PROCEDURE DIVISION.PROCEDURE DIVISION.

Program Details

NNOTEOTEThe keyword DIVISION and a ‘full-stop’ is used in every case.

NNOTEOTEThe keyword DIVISION and a ‘full-stop’ is used in every case.

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IDENTIFICATION IDENTIFICATION DIVISION.DIVISION.

The purpose of the IDENTIFICATION DIVISION is to provide information about the program to the programmer and to the compiler.

Most of the entries in the IDENTIFICATION DIVISION are directed at the programmer and are treated by the compiler as comments.

An exception to this is the PROGRAM-ID clause. Every COBOL program must have a PROGRAM-ID. It is used to enable the compiler to identify the program.

There are several other informational paragraphs in the IDENTIFICATION DIVISION but we will ignore them for the moment.

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The IDENTIFICATION DIVISION Syntax.The IDENTIFICATION DIVISION Syntax.

The IDENTIFICATION DIVISION has the following structureIDENTIFICATION DIVISION.PROGRAM-ID. NameOfProgram.[AUTHOR. YourName.]

The keywords IDENTIFICATION DIVISION represent the division header and signal the commencement of the program text.

The paragraph name PROGRAM-ID is a keyword. It must be specified immediately after the division header.

The program name can be up to 30 characters long.

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The IDENTIFICATION DIVISION Syntax.The IDENTIFICATION DIVISION Syntax. The IDENTIFICATION DIVISION has the following

structureIDENTIFICATION DIVISION.PROGRAM-ID. NameOfProgram.[AUTHOR. YourName.]

The keywords IDENTIFICATION DIVISION represent the division header and signal the commencement of the program text.

The paragraph name PROGRAM-ID is a keyword. It must be specified immediately after the division header.

The program name can be up to 30 characters long.

$ SET SOURCEFORMAT"FREE"IDENTIFICATION DIVISION.PROGRAM-ID. SequenceProgram.AUTHOR. Michael Coughlan.

$ SET SOURCEFORMAT"FREE"IDENTIFICATION DIVISION.PROGRAM-ID. SequenceProgram.AUTHOR. Michael Coughlan.

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The DATA DIVISION.The DATA DIVISION.

The DATA DIVISION is used to describe most of the data that a program processes.

The DATA DIVISION is divided into two main sections;– FILE SECTION.– WORKING-STORAGE SECTION.

The FILE SECTION is used to describe most of the data that is sent to, or comes from, the computer’s peripherals.

The WORKING-STORAGE SECTION is used to describe the general variables used in the program.

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The DATA DIVISION has the following structure

DATA DIVISION SyntaxDATA DIVISION Syntax

DATA DIVISION.FILE SECTION. File Section entries.WORKING-STORAGE SECTION. WS entries.

$ SET SOURCEFORMAT"FREE"IDENTIFICATION DIVISION.PROGRAM-ID. Sequence-Program.AUTHOR. Michael Coughlan.

DATA DIVISION.WORKING-STORAGE SECTION.01 Num1 PIC 9 VALUE ZEROS.01 Num2 PIC 9 VALUE ZEROS.01 Result PIC 99 VALUE ZEROS.

$ SET SOURCEFORMAT"FREE"IDENTIFICATION DIVISION.PROGRAM-ID. Sequence-Program.AUTHOR. Michael Coughlan.


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The PROCEDURE The PROCEDURE DIVISION.DIVISION.

The PROCEDURE DIVISION is where all the data described in the DATA DIVISION is processed and produced. It is here that the programmer describes his algorithm.

The PROCEDURE DIVISION is hierarchical in structure and consists of Sections, Paragraphs, Sentences and Statements.

Only the Section is optional. There must be at least one paragraph, sentence and statement in the PROCEDURE DIVISION.

In the PROCEDURE DIVISION paragraph and section names are chosen by the programmer. The names used should reflect the processing being done in the paragraph or section.

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SectionSectionss

A section is a block of code made up of one or more paragraphs.

A section begins with the section name and ends where the next section name is encountered or where the program text ends.

A section name consists of a name devised by the programmer or defined by the language followed by the word SECTION followed by a full stop.

– SelectUlsterRecords SECTION.– FILE SECTION.

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ParagraphParagraphss

Each section consists of one or more paragraphs. A paragraph is a block of code made up of one or

more sentences. A paragraph begins with the paragraph name and

ends with the next paragraph or section name or the end of the program text.

The paragraph name consists of a name devised by the programmer or defined by the language followed by a full stop.

– PrintFinalTotals.– PROGRAM-ID.

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Sentences and Sentences and Statements.Statements.

A paragraph consists of one or more sentences. A sentence consists of one or more statements and is

terminated by a full stop.– MOVE .21 TO VatRate

COMPUTE VatAmount = ProductCost * VatRate.– DISPLAY "Enter name " WITH NO ADVANCING

ACCEPT StudentNameDISPLAY "Name entered was " StudentName.

A statement consists of a COBOL verb and an operand or operands.

– SUBTRACT Tax FROM GrossPay GIVING NetPay– READ StudentFile

AT END SET EndOfFile TO TRUEEND-READ

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A Full COBOL program.A Full COBOL program.IDENTIFICATION DIVISION.PROGRAM-ID. SequenceProgram.AUTHOR. Michael Coughlan.


PROCEDURE DIVISION.CalculateResult. ACCEPT Num1. ACCEPT Num2. MULTIPLY Num1 BY Num2 GIVING

Result. DISPLAY "Result is = ", Result. STOP RUN.

IDENTIFICATION DIVISION.PROGRAM-ID. SequenceProgram.AUTHOR. Michael Coughlan.


PROCEDURE DIVISION.CalculateResult. ACCEPT Num1. ACCEPT Num2. MULTIPLY Num1 BY Num2 GIVING

Result. DISPLAY "Result is = ", Result. STOP RUN.

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The minimum COBOL program.The minimum COBOL program.

IDENTIFICATION DIVISION.PROGRAM-ID. SmallestProgram.

PROCEDURE DIVISION.DisplayPrompt. DISPLAY "I did it". STOP RUN.

IDENTIFICATION DIVISION.PROGRAM-ID. SmallestProgram.

PROCEDURE DIVISION.DisplayPrompt. DISPLAY "I did it". STOP RUN.

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COBOL COBOL Basics 1 Basics 1

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COBOL coding COBOL coding rulesrules

Almost all COBOL compilers treat a line of COBOL code as if it contained two distinct areas. These are known as;

Area A and Area B When a COBOL compiler recognizes these two areas, all

division, section, paragraph names, FD entries and 01 level numbers must start in Area A. All other sentences must start in Area B.

Area A is four characters wide and is followed by Area B.

In Microfocus COBOL the compiler directive$ SET SOURCEFORMAT"FREE" frees us from all formatting restrictions.

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COBOL coding rulesCOBOL coding rules

$ SET SOURCEFORMAT"FREE"IDENTIFICATION DIVISION.PROGRAM-ID. ProgramFragment.* This is a comment. It starts* with an asterisk in column 1

$ SET SOURCEFORMAT"FREE"IDENTIFICATION DIVISION.PROGRAM-ID. ProgramFragment.* This is a comment. It starts* with an asterisk in column 1

Almost all COBOL compilers treat a line of COBOL code as if it contained two distinct areas. These are known as;

Area A and Area B

When a COBOL compiler recognizes these two areas, all division, section, paragraph names, FD entries and 01 level numbers must start in Area A. All other sentences must start in Area B.

Area A is four characters wide and is followed by Area B.

In Microfocus COBOL the compiler directive$ SET SOURCEFORMAT"FREE" frees us from all formatting restrictions.

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Name Name Construction.Construction.

All user defined names, such as data names, paragraph names, section names and mnemonic names, must adhere to the following rules;

– They must contain at least one character and not more than 30 characters.

– They must contain at least one alphabetic character and they must not begin or end with a hyphen.

– They must be contructed from the characters A to Z, the number 0 to 9 and the hyphen.e.g. TotalPay, Gross-Pay, PrintReportHeadings, Customer10-Rec

All data-names should describe the data they contain. All paragraph and section names should describe the function of

the paragraph or section.

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Describing DATA.Describing DATA.

ŒVariables.Literals.ŽFigurative Constants.

Unlike other programming languages, COBOL does not support user defined constants.

There are basically three kinds of data used in COBOL programs;

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Data-Names / Data-Names / VariablesVariables

A variable is a named location in memory into which a program can put data and from which it can retrieve data.

A data-name or identifier is the name used to identify the area of memory reserved for the variable.

Variables must be described in terms of their type and size.

Every variable used in a COBOL program must have a description in the DATA DIVISION.

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StudentName

Using VariablesUsing Variables

MOVE "JOHN" TO StudentName.DISPLAY "My name is ", StudentName.

01 StudentName01 StudentName PIC X(6) VALUE PIC X(6) VALUE SPACESSPACES..

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StudentName

MOVE "JOHN" TO StudentName.MOVE "JOHN" TO StudentName.DISPLAY "My name is ", StudentName.

01 StudentName PIC X(6) VALUE SPACES.

J O H N

Using Using VariablesVariables

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StudentName

MOVE "JOHN" TO StudentName.DISPLAY "My name is ", StudentName.DISPLAY "My name is ", StudentName.

01 StudentName PIC X(6) VALUE SPACES.

My name is JOHN

Using Using VariablesVariables

J O H NJ O H N

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COBOL Data TypesCOBOL Data Types COBOL is not a “typed” language and the distinction

between some of the data types available in the language is a little blurred.

For the time being we will focus on just two data types,– numeric– text or string

Data type is important because it determines the operations which are valid on the type.

COBOL is not as rigorous in the application of typing rules as other languages.

For example, some COBOL “numeric” data items may, from time to time, have values which are not “numeric”!

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Quick Review of “Data Typing”Quick Review of “Data Typing” In “typed” languages simply specifying the type of a data item

provides quite a lot of information about it.

The type usually determines the range of values the data item can store.

– For instance a CARDINAL item can store values between 0..65,535 and an INTEGER between -32,768..32,767

From the type of the item the compiler can establish how much memory to set aside for storing its values.

If the type is “REAL” the number of decimal places is allowed to vary dynamically with each calculation but the amount of the memory used to store a real number is fixed.

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COBOL data description.COBOL data description.

Because COBOL is not typed it employs a different mechanism for describing the characteristics of the data items in the program.

COBOL uses what could be described as a “declaration by example” strategy.

In effect, the programmer provides the system with an example, or template, or PICTURE of what the data item looks like.

From the “picture” the system derives the information necessary to allocate it.

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COBOL ‘PICTURE’ Clause COBOL ‘PICTURE’ Clause symbolssymbols

To create the required ‘picture’ the programmer uses a set of symbols.

The following symbols are used frequently in picture clauses;

– 9 (the digit nine) is used to indicate the occurrence of a digit at the corresponding position in the picture.

– X (the character X) is used to indicate the occurrence of any character from the character set at the corresponding position in the picture

– V (the character V) is used to indicate position of the decimal point in a numeric value! It is often referred to as the “assumed decimal point” character.

– S (the character S) indicates the presence of a sign and can only appear at the beginning of a picture.

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COBOL ‘PICTURE’ COBOL ‘PICTURE’ ClausesClauses

Some examples– PICTURE 999 a three digit (+ive only) integer– PICTURE S999 a three digit (+ive/-ive) integer– PICTURE XXXX a four character text item or string– PICTURE 99V99 a +ive ‘real’ in the range 0 to 99.99– PICTURE S9V9 a +ive/-ive ‘real’ in the range ?

If you wish you can use the abbreviation PIC.

Numeric values can have a maximum of 18 (eighteen) digits (i.e. 9’s).

The limit on string values is usually system-dependent.

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Abbreviating recurring symbolsAbbreviating recurring symbols

Recurring symbols can be specified using a ‘repeat’ factor inside round brackets

– PIC 9(6) is equivalent to PICTURE 999999– PIC 9(6)V99 is equivalent to PIC 999999V99– PICTURE X(10) is equivalent to PIC

XXXXXXXXXX– PIC S9(4)V9(4) is equivalent to PIC

S9999V9999– PIC 9(18) is equivalent to PIC

999999999999999999

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Declaring DATA in COBOLDeclaring DATA in COBOL In COBOL a variable declaration consists of a line containing

the following items;ŒA level number. A data-name or identifier.ŽA PICTURE clause.

We can give a starting value to variables by means of an extension to the picture clause called the value clause.

DATA DIVISION.WORKING-STORAGE SECTION.01 Num1 PIC 999 VALUE ZEROS.01 VatRate PIC V99 VALUE .18.01 StudentName PIC X(10)VALUE SPACES.

Num1 VatRate StudentNameNum1 VatRate StudentName

000000 .18.18

DDATAATA

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COBOL Literals.COBOL Literals.

String/Alphanumeric literals are enclosed in quotes and may consists of alphanumeric characters

e.g. "Michael Ryan", "-123", "123.45"

Numeric literals may consist of numerals, the decimal point and the plus or minus sign. Numeric literals are not enclosed in quotes.

e.g. 123, 123.45, -256, +2987

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Figurative Figurative ConstantsConstants

COBOL provides its own, special constants called Figurative Constants.

SPACE or SPACESSPACE or SPACES =

ZERO or ZEROS or ZEROSZERO or ZEROS or ZEROS = 0

QUOTE or QUOTESQUOTE or QUOTES = "

HIGH-VALUE or HIGH-VALUESHIGH-VALUE or HIGH-VALUES = Max Value

LOW-VALUE or LOW-VALUESLOW-VALUE or LOW-VALUES = Min Value

ALL ALL literalliteral = Fill With Literal

SPACE or SPACESSPACE or SPACES =

ZERO or ZEROS or ZEROSZERO or ZEROS or ZEROS = 0

QUOTE or QUOTESQUOTE or QUOTES = "

HIGH-VALUE or HIGH-VALUESHIGH-VALUE or HIGH-VALUES = Max Value

LOW-VALUE or LOW-VALUESLOW-VALUE or LOW-VALUES = Min Value

ALL ALL literalliteral = Fill With Literal

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Figurative Constants - ExamplesFigurative Constants - Examples01 GrossPay PIC 9(5)V99 VALUE 13.5.

MOVE TO GrossPay.

01 GrossPay PIC 9(5)V99 VALUE 13.5.

MOVE TO GrossPay.ZEROZEROSZEROES

01 StudentName PIC X(10) VALUE "MIKE".

MOVE ALL "-" TO StudentName.



StudentName

M I K E M I K E

GrossPay

0 0 0 1 3 5 0

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Figurative Constants - ExamplesFigurative Constants - Examples


MOVE TO GrossPay.


MOVE TO GrossPay.ZEROZEROSZEROES





StudentName

- - - - - - - - - -- - - - - - - - - -

GrossPay

0 0 0 0 0 0 0

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Editing, Checking, Compiling, Editing, Checking, Compiling, RunningRunning

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PROCO MenusPROCO MenusPROCO 1 - Menu

F1=help F2=edit F3=check F4=animate F5=compile F6=run F7=library F8=build

F10=directory

PROCO 1 - MenuF1=help F2=edit F3=check F4=animate F5=compile F6=run F7=library F8=build

F10=directory

PROCO 2 - Alt MenuF1=help F2=screens F7=link F10=CoWriter

PROCO 3 - Ctrl MenuF1=help F3=update-menu F4=UseUpdatedMenu F5=batch-files F7=OS-command F8=config

F10=user-menu



F10=user-menu

EDIT 1 -MenuF1=help F2=COBOL F3=InsertLine

F4=DeleteLine F5=RepeatLine F6=RestoreLine F7=RetypeChar F8=RestoreChar

F9=WordLeft F10=WordRight




EDIT 2 - Alt MenuF1=help F2=library F3=load-file F4=save-

file F5=split-line F6=join-line F7=print F8=calculate F9=untype-word-left

F10=DeleteWord

EDIT 3 - Ctrl MenuF1=help F2=find F3=block F4=clear F5=margins F6=draw/forms F7=tags

F8=WordWrap F9=window F10=scroll <-/-> (move in window) Home/End (of text) PgUp/PgDn



F10=DeleteWord



COBOL menuF1=help F2=check/animate F3=cmd-file

F7=locate-previous F8=locate-next F9=locate-current



Checker MenuF1=help F2=check/anim F3=pause

F4=list F6=lang F7=ref F9/F10=directives



Animate-MenuF1=help F2=view F3=align F4=exchange F5=where F6=look-up F9/F10=word-</>

Escape Animate Step Wch Go Zoom nx-If Prfm Rst Brk Env Qury Find Locate Txt Do



ALT key

CTRL key

ALT key

CTRL key

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COBOL COBOL BasicsBasics

2 2

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H E N N E S S Y R M 9 2 3 0 1 6 5 L M 5 1 0 5 5 0 F

Group Group Items/RecordsItems/Records

StudentDetails

WORKING-STORAGE SECTION.01 StudentDetails PIC X(26).

WORKING-STORAGE SECTION.01 StudentDetails PIC X(26).

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H E N N E S S Y R M 9 2 3 0 1 6 5 L M 5 1 0 5 5 0 F

StudentDetails

StudentName StudentId CourseCode Grant Gender

Group Items/RecordsGroup Items/Records

WORKING-STORAGE SECTION.01 StudentDetails.

0202 StudentNameStudentName PIC X(10).PIC X(10).0202 StudentIdStudentId PIC 9(7).PIC 9(7).0202 CourseCodeCourseCode PIC X(4).PIC X(4).0202 GrantGrant PIC 9(4).PIC 9(4).0202 GenderGender PIC X.PIC X.


0202 StudentNameStudentName PIC X(10).PIC X(10).0202 StudentIdStudentId PIC 9(7).PIC 9(7).0202 CourseCodeCourseCode PIC X(4).PIC X(4).0202 GrantGrant PIC 9(4).PIC 9(4).0202 GenderGender PIC X.PIC X.

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H E N N E S S Y R M 9 2 3 0 1 6 5 L M 5 1 0 5 5 0 F

StudentDetails

Surname Initials


0202 StudentName.StudentName.03 Surname03 Surname PIC X(8).PIC X(8).03 Initials03 Initials PIC XX.PIC XX.

0202 StudentIdStudentId PIC 9(7).PIC 9(7).0202 CourseCodeCourseCode PIC X(4).PIC X(4).0202 GrantGrant PIC 9(4).PIC 9(4).0202 GenderGender PIC X.PIC X.


0202 StudentName.StudentName.03 Surname03 Surname PIC X(8).PIC X(8).03 Initials03 Initials PIC XX.PIC XX.

0202 StudentIdStudentId PIC 9(7).PIC 9(7).0202 CourseCodeCourseCode PIC X(4).PIC X(4).0202 GrantGrant PIC 9(4).PIC 9(4).0202 GenderGender PIC X.PIC X.

StudentName StudentId CourseCode Grant Gender

Group Items/RecordsGroup Items/Records

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LEVEL Numbers express DATA LEVEL Numbers express DATA hierarchyhierarchy

In COBOL, level numbers are used to decompose a structure into it’s constituent parts.

In this hierarchical structure the higher the level number, the lower the item is in the hierarchy. At the lowest level the data is completely atomic.

The level numbers 01 through 49 are general level numbers but there are also special level numbers such as 66, 77 and 88.

In a hierarchical data description what is important is the relationship of the level numbers to one another, not the actual level numbers used.

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LEVEL Numbers express DATA LEVEL Numbers express DATA hierarchyhierarchy

In COBOL, level numbers are used to decompose a structure into it’s constituent parts.

In this hierarchical structure the higher the level number, the lower the item is in the hierarchy. At the lowest level the data is completely atomic.

The level numbers 01 through 49 are general level numbers but there are also special level numbers such as 66, 77 and 88.

In a hierarchical data description what is important is the relationship of the level numbers to one another, not the actual level numbers used.

01 StudentDetails.02 StudentName.

03 Surname PIC X(8).03 Initials PIC XX.

02 StudentId PIC 9(7).02 CourseCode PIC X(4).02 Grant PIC 9(4).02 Gender PIC X.










=

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Group and elementary items.Group and elementary items.

In COBOL the term “group item” is used to describe a data item which has been further subdivided.

– A Group item is declared using a level number and a data name. It cannot have a picture clause.

– Where a group item is the highest item in a data hierarchy it is referred to as a record and uses the level number 01.

The term “elementary item” is used to describe data items which are atomic; that is, not further subdivided.

An elementary item declaration consists of; a level number, a data name picture clause.

An elementary item must have a picture clause. Every group or elementary item declaration must be followed by a

full stop.

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PICTUREs for Group ItemsPICTUREs for Group Items

Picture clauses are NOT specified for ‘group’ data items because the size a group item is the sum of the sizes of its subordinate, elementary items and its type is always assumed to be PIC X.

The type of a group items is always assumed to be PIC X because group items may have several different data items and types subordinate to them.

An X picture is the only one which could support such collections.

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Assignment in COBOLAssignment in COBOL In “strongly typed” languages like Modula-2, Pascal or

ADA the assignment operation is simple because assignment is only allowed between data items with compatible types.

The simplicity of assignment in these languages is achieved at the “cost” of having a large number of data types.

In COBOL there are basically only three data types, Alphabetic (PIC A) Alphanumeric (PIC X) Numeric (PIC 9)

But this simplicity is achieved only at the cost of having a very complex assignment statement.

In COBOL assignment is achieved using the MOVE verb.

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The MOVE VerbThe MOVE Verb

The MOVE copies data from the source identifier or literal to one or more destination identifiers.

The source and destination identifiers can be group or elementary data items.

When the destination item is alphanumeric or alphabetic (PIC X or A) data is copied into the destination area from left to right with space filling or truncation on the right.

When data is MOVEd into an item the contents of the item are completely replaced. If the source data is too small to fill the destination item entirely the remaining area is zero or space filled.

MOVE TO ...Identifier

LiteralIdentifier

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MOVE “RYAN” TO Surname.MOVE “FITZPATRICK” TO Surname.MOVE “RYAN” TO Surname.MOVE “FITZPATRICK” TO Surname.

01 Surname PIC X(8).

MOVE-ing MOVE-ing DataData

C O U G H L A N

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R Y A N

MOVE “RYAN” TO Surname.MOVE “RYAN” TO Surname.MOVE “FITZPATRICK” TO Surname.MOVE “RYAN” TO Surname.MOVE “RYAN” TO Surname.MOVE “FITZPATRICK” TO Surname.


MOVEing MOVEing DataData

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MOVE “RYAN” TO Surname.MOVE “FITZPATRICK” TO Surname.MOVE “FITZPATRICK” TO Surname.MOVE “RYAN” TO Surname.MOVE “FITZPATRICK” TO Surname.MOVE “FITZPATRICK” TO Surname.


MOVEing DataMOVEing Data

F I T Z P A T R I C K

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MOVEing to a numeric item.MOVEing to a numeric item.

When the destination item is numeric, or edited numeric, then data is aligned along the decimal point with zero filling or truncation as necessary.

When the decimal point is not explicitly specified in either the source or destination items, the item is treated as if it had an assumed decimal point immediately after its rightmost character.

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MOVE ZEROS TO GrossPay.

MOVE 12.4 TO GrossPay.



01 GrossPay PIC 9(4)V99.

0 0 0 0 0 0

0 0 1 2 4 0

0 1 2 3 4 5 6

1 2 3 4 5 7 5 7

GrossPay

GrossPay

GrossPay

GrossPay

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MOVE 1234 TO CountyPop.

MOVE 12.4 TO CountyPop.

MOVE 154 TO Price.

MOVE 3552.75 TO Price.

01 CountyPop PIC 999.01 Price PIC 999V99.

1 2 3 4

0 1 2 4

1 5 4 0 0

3 5 5 2 7 5

Price

CountyPop

CountyPop

Price

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Legal MOVEsLegal MOVEsCertain combinations of sending and receiving data types are not permitted (even by COBOL).

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The DISPLAY VerbThe DISPLAY Verb

From time to time it may be useful to display messages and data values on the screen.

A simple DISPLAY statement can be used to achieve this.

A single DISPLAY can be used to display several data items or literals or any combination of these.

The WITH NO ADVANCING clause suppresses the carriage return/line feed.

DISPLAY Identifier

Literal

Identifier

Literal ...

UPON WITH NO ADVANCING

Mnemonic - Name

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The ACCEPT The ACCEPT verbverb

Format 1. ACCEPT Identifier FROM Mnemonic - name

Format 2. ACCEPT Identifier FROM

DATE

DAY

DAY - OF - WEEK

TIME

01 CurrentDate01 CurrentDate PIC 9(6).PIC 9(6).* YYMMDD

01 DayOfYear01 DayOfYear PIC 9(5).PIC 9(5).* YYDDD

01 Day0fWeek01 Day0fWeek PIC 9.PIC 9.* D (1=Monday)

01 CurrentTime 01 CurrentTime PIC 9(8).PIC 9(8).* HHMMSSss s = S/100

01 CurrentDate01 CurrentDate PIC 9(6).PIC 9(6).* YYMMDD

01 DayOfYear01 DayOfYear PIC 9(5).PIC 9(5).* YYDDD

01 Day0fWeek01 Day0fWeek PIC 9.PIC 9.* D (1=Monday)

01 CurrentTime 01 CurrentTime PIC 9(8).PIC 9(8).* HHMMSSss s = S/100

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PROCEDURE DIVISION.Begin. DISPLAY "Enter student details using template below". DISPLAY "NNNNNNNNNNSSSSSSSCCCCGGGGS ". ACCEPT StudentDetails. ACCEPT CurrentDate FROM DATE. ACCEPT DayOfYear FROM DAY. ACCEPT CurrentTime FROM TIME. DISPLAY "Name is ", Initials SPACE Surname. DISPLAY "Date is " CurrentDay SPACE CurrentMonth SPACE CurrentYear. DISPLAY "Today is day " YearDay " of the year". DISPLAY "The time is " CurrentHour ":" CurrentMinute. STOP RUN.

PROCEDURE DIVISION.Begin. DISPLAY "Enter student details using template below". DISPLAY "NNNNNNNNNNSSSSSSSCCCCGGGGS ". ACCEPT StudentDetails. ACCEPT CurrentDate FROM DATE. ACCEPT DayOfYear FROM DAY. ACCEPT CurrentTime FROM TIME. DISPLAY "Name is ", Initials SPACE Surname. DISPLAY "Date is " CurrentDay SPACE CurrentMonth SPACE CurrentYear. DISPLAY "Today is day " YearDay " of the year". DISPLAY "The time is " CurrentHour ":" CurrentMinute. STOP RUN.

$ SET SOURCEFORMAT"FREE"IDENTIFICATION DIVISION.PROGRAM-ID. AcceptAndDisplay.AUTHOR. Michael Coughlan.

DATA DIVISION.WORKING-STORAGE SECTION.01 StudentDetails. 02 StudentName. 03 Surname PIC X(8). 03 Initials PIC XX. 02 StudentId PIC 9(7). 02 CourseCode PIC X(4). 02 Grant PIC 9(4). 02 Gender PIC X.

01 CurrentDate. 02 CurrentYear PIC 99. 02 CurrentMonth PIC 99. 02 CurrentDay PIC 99.

01 DayOfYear. 02 FILLER PIC 99. 02 YearDay PIC 9(3).

01 CurrentTime. 02 CurrentHour PIC 99. 02 CurrentMinute PIC 99. 02 FILLER PIC 9(4).

$ SET SOURCEFORMAT"FREE"IDENTIFICATION DIVISION.PROGRAM-ID. AcceptAndDisplay.AUTHOR. Michael Coughlan.

DATA DIVISION.WORKING-STORAGE SECTION.01 StudentDetails. 02 StudentName. 03 Surname PIC X(8). 03 Initials PIC XX. 02 StudentId PIC 9(7). 02 CourseCode PIC X(4). 02 Grant PIC 9(4). 02 Gender PIC X.

01 CurrentDate. 02 CurrentYear PIC 99. 02 CurrentMonth PIC 99. 02 CurrentDay PIC 99.

01 DayOfYear. 02 FILLER PIC 99. 02 YearDay PIC 9(3).

01 CurrentTime. 02 CurrentHour PIC 99. 02 CurrentMinute PIC 99. 02 FILLER PIC 9(4).

Enter student details using template belowNNNNNNNNNNSSSSSSSCCCCGGGGSCOUGHLANMS9476532LM511245MName is MS COUGHLANDate is 24 01 94Today is day 024 of the yearThe time is 22:23

Enter student details using template belowNNNNNNNNNNSSSSSSSCCCCGGGGSCOUGHLANMS9476532LM511245MName is MS COUGHLANDate is 24 01 94Today is day 024 of the yearThe time is 22:23

Run of Accept and Display programRun of Accept and Display program

63

ALGORITALGORITHMS HMS

64

IDENTIFICATION DIVISION.PROGRAM-ID. FragmentAFragmentA.AUTHOR. Michael Coughlan.


PROCEDURE DIVISION.Calc-ResultCalc-Result. ACCEPT Num1. MULTIPLY Num1 BY Num2 GIVING Result. ACCEPT Num2. DISPLAY "Result is = ", Result. STOP RUN.

Num1 Num2 ResultNum1 Num2 Result

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DATA

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IDENTIFICATION DIVISION.PROGRAM-ID. FragmentA.AUTHOR. Michael Coughlan.


PROCEDURE DIVISION.Calc-Result. ACCEPT Num1ACCEPT Num1. MULTIPLY Num1 BY Num2 GIVING Result. ACCEPT Num2. DISPLAY "Result is = ", Result. STOP RUN.


99 00 0000

DATA

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PROCEDURE DIVISION.Calc-Result. ACCEPT Num1. MULTIPLY Num1 BY Num2 GIVING ResultMULTIPLY Num1 BY Num2 GIVING Result. ACCEPT Num2. DISPLAY "Result is = ", Result. STOP RUN.


99 00 0000

DATA

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PROCEDURE DIVISION.Calc-Result. ACCEPT Num1. MULTIPLY Num1 BY Num2 GIVING Result. ACCEPT Num2ACCEPT Num2. DISPLAY "Result is = ", Result. STOP RUN.


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DATA

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PROCEDURE DIVISION.Calc-Result. ACCEPT Num1. MULTIPLY Num1 BY Num2 GIVING Result. ACCEPT Num2. DISPLAY "Result is = ", ResultDISPLAY "Result is = ", Result. STOP RUN.


99 55 0000

DATA

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Sequence.

Selection.

Iteration.

Programs are written using three Programs are written using three main programming constructsmain programming constructs.

70

Num1 Num2 Result OperatorNum1 Num2 Result Operator

IDENTIFICATION DIVISION.PROGRAM-ID. Selection-ProgramSelection-Program.AUTHOR. Michael Coughlan.

DATA DIVISION.DATA DIVISION.WORKING-STORAGE SECTION.01 Num1 PIC 9 VALUE ZEROS.01 Num2 PIC 9 VALUE ZEROS.01 Result PIC 99 VALUE ZEROS.01 Operator PIC X VALUE SPACE.

PROCEDURE DIVISION.CalculatorCalculator. ACCEPT Num1. ACCEPT Num2. ACCEPT Operator IF Operator = "+" THEN ADD Num1, Num2 GIVING Result END-IF IF Operator = "*" THEN MULTIPLY Num1 BY Num2 GIVING Result END-IF. DISPLAY "Result is = ", Result. STOP RUN.

00 00 0000

DATA

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71

IDENTIFICATION DIVISION.PROGRAM-ID. Selection-Program.AUTHOR. Michael Coughlan.

DATA DIVISION.WORKING-STORAGE SECTION.01 Num1 PIC 9 VALUE ZEROS.01 Num2 PIC 9 VALUE ZEROS.01 Result PIC 99 VALUE ZEROS.01 Operator PIC X VALUE SPACE.

PROCEDURE DIVISION.Calculator. ACCEPT Num1ACCEPT Num1. ACCEPT Num2. ACCEPT Operator IF Operator = "+" THEN ADD Num1, Num2 GIVING Result END-IF IF Operator = "*" THEN MULTIPLY Num1 BY Num2 GIVING Result END-IF. DISPLAY "Result is = ", Result. STOP RUN.


77 00 0000

DATA

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PROCEDURE DIVISION.Calculator. ACCEPT Num1. ACCEPT Num2ACCEPT Num2. ACCEPT Operator IF Operator = "+" THEN ADD Num1, Num2 GIVING Result END-IF IF Operator = "*" THEN MULTIPLY Num1 BY Num2 GIVING Result END-IF. DISPLAY "Result is = ", Result. STOP RUN.


77 33 0000

DATA

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PROCEDURE DIVISION.Calculator. ACCEPT Num1. ACCEPT Num2. ACCEPT OperatorACCEPT Operator IF Operator = "+" THEN ADD Num1, Num2 GIVING Result END-IF IF Operator = "*" THEN MULTIPLY Num1 BY Num2 GIVING Result END-IF. DISPLAY "Result is = ", Result. STOP RUN.


77 33 0000

DATA

++

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PROCEDURE DIVISION.Calculator. ACCEPT Num1. ACCEPT Num2. ACCEPT Operator IF Operator = "+" THENIF Operator = "+" THEN ADD Num1, Num2 GIVING Result END-IFEND-IF IF Operator = "*" THEN MULTIPLY Num1 BY Num2 GIVING Result END-IF. DISPLAY "Result is = ", Result. STOP RUN.


77 33 0000

DATA

++

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PROCEDURE DIVISION.Calculator. ACCEPT Num1. ACCEPT Num2. ACCEPT Operator IF Operator = "+" THEN ADD Num1, Num2 GIVING ResultADD Num1, Num2 GIVING Result END-IF IF Operator = "*" THEN MULTIPLY Num1 BY Num2 GIVING Result END-IF. DISPLAY "Result is = ", Result. STOP RUN.


77 33 1010

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++

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PROCEDURE DIVISION.Calculator. ACCEPT Num1. ACCEPT Num2. ACCEPT Operator IF Operator = "+" THEN ADD Num1, Num2 GIVING Result END-IF IF Operator = "*" THENIF Operator = "*" THEN MULTIPLY Num1 BY Num2 GIVING Result END-IFEND-IF. DISPLAY "Result is = ", Result. STOP RUN.


77 33 1010

DATA

++

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PROCEDURE DIVISION.Calculator. ACCEPT Num1. ACCEPT Num2. ACCEPT Operator IF Operator = "+" THEN ADD Num1, Num2 GIVING Result END-IF IF Operator = "*" THEN MULTIPLY Num1 BY Num2 GIVING Result END-IF. DISPLAY "Result is = ", ResultDISPLAY "Result is = ", Result. STOP RUN.


77 33 1010

DATA

++

78

IDENTIFICATION DIVISION.PROGRAM-ID. Iteration-ProgramIteration-Program.AUTHOR. Michael Coughlan.

DATA DIVISIONDATA DIVISION.WORKING-STORAGE SECTION.01 Num1 PIC 9 VALUE ZEROS.01 Num2 PIC 9 VALUE ZEROS.01 Result PIC 99 VALUE ZEROS.01 Operator PIC X VALUE SPACE.

PROCEDURE DIVISION.Calculator. PERFORM 5 TIMES ACCEPT Num1 ACCEPT Num2 ACCEPT Operator IF Operator = "+" THEN ADD Num1, Num2 GIVING Result END-IF IF Operator = "*" THEN MULTIPLY Num1 BY Num2 GIVING Result END-IF DISPLAY "Result is = ", Result END-PERFORM. STOP RUN.

DATANum1 Num2 Result OperatorNum1 Num2 Result Operator

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Ex2: ITERATION PROGRAMEx2: ITERATION PROGRAM

79

IDENTIFICATION DIVISION.PROGRAM-ID. Iteration-Program.AUTHOR. Michael Coughlan.


PROCEDURE DIVISION.Calculator. PERFORM 5 TIMESPERFORM 5 TIMES ACCEPT Num1 ACCEPT Num2 ACCEPT Operator IF Operator = "+" THEN ADD Num1, Num2 GIVING Result END-IF IF Operator = "*" THEN MULTIPLY Num1 BY Num2 GIVING Result END-IF DISPLAY "Result is = ", Result END-PERFORMEND-PERFORM. STOP RUN.


00 00 0000

DATA

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PROCEDURE DIVISION.Calculator. PERFORM 5 TIMES ACCEPT Num1ACCEPT Num1 ACCEPT Num2 ACCEPT Operator IF Operator = "+" THEN ADD Num1, Num2 GIVING Result END-IF IF Operator = "*" THEN MULTIPLY Num1 BY Num2 GIVING Result END-IF DISPLAY "Result is = ", Result END-PERFORM. STOP RUN.


55 00 0000

DATA

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PROCEDURE DIVISION.Calculator. PERFORM 5 TIMES ACCEPT Num1 ACCEPT Num2ACCEPT Num2 ACCEPT Operator IF Operator = "+" THEN ADD Num1, Num2 GIVING Result END-IF IF Operator = "*" THEN MULTIPLY Num1 BY Num2 GIVING Result END-IF DISPLAY "Result is = ", Result END-PERFORM. STOP RUN.


55 33 0000

DATA

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PROCEDURE DIVISION.Calculator. PERFORM 5 TIMES ACCEPT Num1 ACCEPT Num2 ACCEPT OperatorACCEPT Operator IF Operator = "+" THEN ADD Num1, Num2 GIVING Result END-IF IF Operator = "*" THEN MULTIPLY Num1 BY Num2 GIVING Result END-IF DISPLAY "Result is = ", Result END-PERFORM. STOP RUN.


55 33 0000

DATA

**

83



PROCEDURE DIVISION.Calculator. PERFORM 5 TIMES ACCEPT Num1 ACCEPT Num2 ACCEPT Operator IF Operator = "+" THENIF Operator = "+" THEN ADD Num1, Num2 GIVING Result END-IFEND-IF IF Operator = "*" THEN MULTIPLY Num1 BY Num2 GIVING Result END-IF DISPLAY "Result is = ", Result END-PERFORM. STOP RUN.


55 33 0000

DATA

**

84



PROCEDURE DIVISION.Calculator. PERFORM 5 TIMES ACCEPT Num1 ACCEPT Num2 ACCEPT Operator IF Operator = "+" THEN ADD Num1, Num2 GIVING Result END-IF IF Operator = "*" THENIF Operator = "*" THEN MULTIPLY Num1 BY Num2 GIVING Result END-IFEND-IF DISPLAY "Result is = ", Result END-PERFORM. STOP RUN.


55 33 0000

DATA

**

85



PROCEDURE DIVISION.Calculator. PERFORM 5 TIMES ACCEPT Num1 ACCEPT Num2 ACCEPT Operator IF Operator = "+" THEN ADD Num1, Num2 GIVING Result END-IF IF Operator = "*" THEN MULTIPLY Num1 BY Num2 GIVING ResultMULTIPLY Num1 BY Num2 GIVING Result END-IF DISPLAY "Result is = ", Result END-PERFORM. STOP RUN.


55 33 1515

DATA

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86



PROCEDURE DIVISION.Calculator. PERFORM 5 TIMES ACCEPT Num1 ACCEPT Num2 ACCEPT Operator IF Operator = "+" THEN ADD Num1, Num2 GIVING Result END-IF IF Operator = "*" THEN MULTIPLY Num1 BY Num2 GIVING Result END-IF DISPLAY "Result is = ", ResultDISPLAY "Result is = ", Result END-PERFORM. STOP RUN.


55 33 1515

DATA

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General General IntroductionIntroductionAlgorithmsAlgorithms

90

Let’s write a programLet’s write a program

A program is a collection of statements written in a language the computer understands.

A computer executes program statements one after another in sequence until it reaches the end of the program unless some statement in the program alters the order of execution.

Let’s write a program to accept two numbers from the user, multiply them together and display the result on the screen.

We’ll write the program in COBOL.

What COBOL program statements will we need to do the job?

91

Program StatementsProgram Statements

We need a statement to take in the first number and store it in a named memory location.– ACCEPT Num1.

We need a statement to take in the second number and store it in a named memory location.– ACCEPT Num2.

We need a statement to multiply the two numbers together and store the result in a named location.– MULTIPLY Num1 BY Num2 GIVING Result.

We need a statement to display the result on the screen.– DISPLAY "Result is = ", Result.

92

IDENTIFICATION DIVISION.PROGRAM-ID. FragmentAFragmentA.AUTHOR. Michael Coughlan.


PROCEDURE DIVISION.Calc-ResultCalc-Result. ACCEPT Num1. MULTIPLY Num1 BY Num2 GIVING Result. ACCEPT Num2. DISPLAY "Result is = ", Result. STOP RUN.


00 00 0000

DATA

93



PROCEDURE DIVISION.Calc-Result. ACCEPT Num1ACCEPT Num1. MULTIPLY Num1 BY Num2 GIVING Result. ACCEPT Num2. DISPLAY "Result is = ", Result. STOP RUN.


99 00 0000

DATA

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PROCEDURE DIVISION.Calc-Result. ACCEPT Num1. MULTIPLY Num1 BY Num2 GIVING ResultMULTIPLY Num1 BY Num2 GIVING Result. ACCEPT Num2. DISPLAY "Result is = ", Result. STOP RUN.


99 00 0000

DATA

95



PROCEDURE DIVISION.Calc-Result. ACCEPT Num1. MULTIPLY Num1 BY Num2 GIVING Result. ACCEPT Num2ACCEPT Num2. DISPLAY "Result is = ", Result. STOP RUN.


00 55 0000

DATA

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PROCEDURE DIVISION.Calc-Result. ACCEPT Num1. MULTIPLY Num1 BY Num2 GIVING Result. ACCEPT Num2. DISPLAY "Result is = ", ResultDISPLAY "Result is = ", Result. STOP RUN.


99 55 0000

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Oh No!!Oh No!!We got the We got the

wrong wrong answer.answer.Let’s try Let’s try again.again.

97

IDENTIFICATION DIVISION.PROGRAM-ID. FragmentBFragmentB.AUTHOR. Michael Coughlan.


PROCEDURE DIVISION.Calc-ResultCalc-Result. ACCEPT Num1. ACCEPT Num2. DISPLAY "Result is = ", Result. MULTIPLY Num1 BY Num2 GIVING Result. STOP RUN.


00 00 0000

DATA

98

IDENTIFICATION DIVISION.PROGRAM-ID. FragmentB.AUTHOR. Michael Coughlan.


PROCEDURE DIVISION.Calc-Result. ACCEPT Num1.ACCEPT Num1. ACCEPT Num2. DISPLAY "Result is = ", Result. MULTIPLY Num1 BY Num2 GIVING Result. STOP RUN.


99 00 0000

DATA

99



PROCEDURE DIVISION.Calc-Result. ACCEPT Num1. ACCEPT Num2ACCEPT Num2. DISPLAY "Result is = ", Result. MULTIPLY Num1 BY Num2 GIVING Result. STOP RUN.


99 55 0000

DATA

100



PROCEDURE DIVISION.Calc-Result. ACCEPT Num1. ACCEPT Num2. DISPLAY "Result is = ", ResultDISPLAY "Result is = ", Result. MULTIPLY Num1 BY Num2 GIVING Result. STOP RUN.


99 55 0000

DATA

Oh No!!Oh No!!We got the We got the

wrong answer wrong answer again.again.

Let’s have one Let’s have one more try.more try.

101



PROCEDURE DIVISION.Calc-Result. ACCEPT Num1. ACCEPT Num2. DISPLAY "Result is = ", Result. MULTIPLY Num1 BY Num2 GIVING ResultMULTIPLY Num1 BY Num2 GIVING Result. STOP RUN.


99 55 4545

DATA

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IDENTIFICATION DIVISION.PROGRAM-ID. Sequence-ProgramSequence-Program.AUTHOR. Michael Coughlan.


PROCEDURE DIVISION.Calc-ResultCalc-Result. ACCEPT Num1. ACCEPT Num2. MULTIPLY Num1 BY Num2 GIVING Result. DISPLAY "Result is = ", Result. STOP RUN.

00 00 0000

DATA

103

IDENTIFICATION DIVISION.PROGRAM-ID. Sequence-Program.AUTHOR. Michael Coughlan.


PROCEDURE DIVISION.Calc-Result. ACCEPT Num1ACCEPT Num1. ACCEPT Num2. MULTIPLY Num1 BY Num2 GIVING Result. DISPLAY "Result is = ", Result. STOP RUN.

9 0 00

Num1 Num2 Result

DATA

104



PROCEDURE DIVISION.Calc-Result. ACCEPT Num1. ACCEPT Num2ACCEPT Num2. MULTIPLY Num1 BY Num2 GIVING Result. DISPLAY "Result is = ", Result. STOP RUN.

9 5 00

Num1 Num2 Result

DATA

105



PROCEDURE DIVISION.Calc-Result. ACCEPT Num1. ACCEPT Num2. MULTIPLY Num1 BY Num2 GIVING ResultMULTIPLY Num1 BY Num2 GIVING Result. DISPLAY "Result is = ", Result. STOP RUN.

9 5 45

Num1 Num2 Result

DATA

106



PROCEDURE DIVISION.Calc-Result. ACCEPT Num1. ACCEPT Num2. MULTIPLY Num1 BY Num2 GIVING Result. DISPLAY "Result is = ", ResultDISPLAY "Result is = ", Result. STOP RUN.

9 5 45

Num1 Num2 Result

DATA

Right .. At last!!Right .. At last!!

It’s not enough to It’s not enough to know what know what

statements we need. statements we need. We must make sure We must make sure

the computer the computer executes them in the executes them in the

right order.right order.

107

Sequence.

Selection.

Iteration.

Programs are written using three Programs are written using three main programming constructsmain programming constructs.

108


IDENTIFICATION DIVISION.PROGRAM-ID. Selection-ProgramSelection-Program.AUTHOR. Michael Coughlan.


PROCEDURE DIVISION.CalculatorCalculator. ACCEPT Num1. ACCEPT Num2. ACCEPT Operator IF Operator = "+" THEN ADD Num1, Num2 GIVING Result END-IF IF Operator = "*" THEN MULTIPLY Num1 BY Num2 GIVING Result END-IF. DISPLAY "Result is = ", Result. STOP RUN.

00 00 0000

DATA

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PROCEDURE DIVISION.Calculator. ACCEPT Num1ACCEPT Num1. ACCEPT Num2. ACCEPT Operator IF Operator = "+" THEN ADD Num1, Num2 GIVING Result END-IF IF Operator = "*" THEN MULTIPLY Num1 BY Num2 GIVING Result END-IF. DISPLAY "Result is = ", Result. STOP RUN.


77 00 0000

DATA

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PROCEDURE DIVISION.Calculator. ACCEPT Num1. ACCEPT Num2ACCEPT Num2. ACCEPT Operator IF Operator = "+" THEN ADD Num1, Num2 GIVING Result END-IF IF Operator = "*" THEN MULTIPLY Num1 BY Num2 GIVING Result END-IF. DISPLAY "Result is = ", Result. STOP RUN.


77 33 0000

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111



PROCEDURE DIVISION.Calculator. ACCEPT Num1. ACCEPT Num2. ACCEPT OperatorACCEPT Operator IF Operator = "+" THEN ADD Num1, Num2 GIVING Result END-IF IF Operator = "*" THEN MULTIPLY Num1 BY Num2 GIVING Result END-IF. DISPLAY "Result is = ", Result. STOP RUN.


77 33 0000

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112



PROCEDURE DIVISION.Calculator. ACCEPT Num1. ACCEPT Num2. ACCEPT Operator IF Operator = "+" THENIF Operator = "+" THEN ADD Num1, Num2 GIVING Result END-IFEND-IF IF Operator = "*" THEN MULTIPLY Num1 BY Num2 GIVING Result END-IF. DISPLAY "Result is = ", Result. STOP RUN.


77 33 0000

DATA

++

113



PROCEDURE DIVISION.Calculator. ACCEPT Num1. ACCEPT Num2. ACCEPT Operator IF Operator = "+" THEN ADD Num1, Num2 GIVING ResultADD Num1, Num2 GIVING Result END-IF IF Operator = "*" THEN MULTIPLY Num1 BY Num2 GIVING Result END-IF. DISPLAY "Result is = ", Result. STOP RUN.


77 33 1010

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++

114



PROCEDURE DIVISION.Calculator. ACCEPT Num1. ACCEPT Num2. ACCEPT Operator IF Operator = "+" THEN ADD Num1, Num2 GIVING Result END-IF IF Operator = "*" THENIF Operator = "*" THEN MULTIPLY Num1 BY Num2 GIVING Result END-IFEND-IF. DISPLAY "Result is = ", Result. STOP RUN.


77 33 1010

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++

115



PROCEDURE DIVISION.Calculator. ACCEPT Num1. ACCEPT Num2. ACCEPT Operator IF Operator = "+" THEN ADD Num1, Num2 GIVING Result END-IF IF Operator = "*" THEN MULTIPLY Num1 BY Num2 GIVING Result END-IF. DISPLAY "Result is = ", ResultDISPLAY "Result is = ", Result. STOP RUN.


77 33 1010

DATA

++

116

IDENTIFICATION DIVISION.PROGRAM-ID. Iteration-ProgramIteration-Program.AUTHOR. Michael Coughlan.

DATA DIVISIONDATA DIVISION.WORKING-STORAGE SECTION.01 Num1 PIC 9 VALUE ZEROS.01 Num2 PIC 9 VALUE ZEROS.01 Result PIC 99 VALUE ZEROS.01 Operator PIC X VALUE SPACE.

PROCEDURE DIVISION.Calculator. PERFORM 5 TIMES ACCEPT Num1 ACCEPT Num2 ACCEPT Operator IF Operator = "+" THEN ADD Num1, Num2 GIVING Result END-IF IF Operator = "*" THEN MULTIPLY Num1 BY Num2 GIVING Result END-IF DISPLAY "Result is = ", Result END-PERFORM. STOP RUN.


00 00 0000

DATA

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117



PROCEDURE DIVISION.Calculator. PERFORM 5 TIMESPERFORM 5 TIMES ACCEPT Num1 ACCEPT Num2 ACCEPT Operator IF Operator = "+" THEN ADD Num1, Num2 GIVING Result END-IF IF Operator = "*" THEN MULTIPLY Num1 BY Num2 GIVING Result END-IF DISPLAY "Result is = ", Result END-PERFORMEND-PERFORM. STOP RUN.


00 00 0000

DATA

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PROCEDURE DIVISION.Calculator. PERFORM 5 TIMES ACCEPT Num1 ACCEPT Num2 ACCEPT OperatorACCEPT Operator IF Operator = "+" THEN ADD Num1, Num2 GIVING Result END-IF IF Operator = "*" THEN MULTIPLY Num1 BY Num2 GIVING Result END-IF DISPLAY "Result is = ", Result END-PERFORM. STOP RUN.


55 33 0000

DATA

**

121



PROCEDURE DIVISION.Calculator. PERFORM 5 TIMES ACCEPT Num1 ACCEPT Num2 ACCEPT Operator IF Operator = "+" THENIF Operator = "+" THEN ADD Num1, Num2 GIVING Result END-IFEND-IF IF Operator = "*" THEN MULTIPLY Num1 BY Num2 GIVING Result END-IF DISPLAY "Result is = ", Result END-PERFORM. STOP RUN.


55 33 0000

DATA

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122



PROCEDURE DIVISION.Calculator. PERFORM 5 TIMES ACCEPT Num1 ACCEPT Num2 ACCEPT Operator IF Operator = "+" THEN ADD Num1, Num2 GIVING Result END-IF IF Operator = "*" THENIF Operator = "*" THEN MULTIPLY Num1 BY Num2 GIVING Result END-IFEND-IF DISPLAY "Result is = ", Result END-PERFORM. STOP RUN.


55 33 0000

DATA

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123



PROCEDURE DIVISION.Calculator. PERFORM 5 TIMES ACCEPT Num1 ACCEPT Num2 ACCEPT Operator IF Operator = "+" THEN ADD Num1, Num2 GIVING Result END-IF IF Operator = "*" THEN MULTIPLY Num1 BY Num2 GIVING ResultMULTIPLY Num1 BY Num2 GIVING Result END-IF DISPLAY "Result is = ", Result END-PERFORM. STOP RUN.


55 33 1515

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124



PROCEDURE DIVISION.Calculator. PERFORM 5 TIMES ACCEPT Num1 ACCEPT Num2 ACCEPT Operator IF Operator = "+" THEN ADD Num1, Num2 GIVING Result END-IF IF Operator = "*" THEN MULTIPLY Num1 BY Num2 GIVING Result END-IF DISPLAY "Result is = ", ResultDISPLAY "Result is = ", Result END-PERFORM. STOP RUN.


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127

Arithmetic Arithmetic and and

Edited Edited PicturesPictures

128

Arithmetic Verb Arithmetic Verb TemplateTemplate

Most COBOL arithmetic verbs conform to the template above. For example;

ADD Takings TO CashTotal.ADD Males TO Females GIVING TotalStudents. SUBTRACT Tax FROM GrossPay.SUBTRACT Tax FROM GrossPay GIVING NetPay.DIVIDE Total BY Members GIVING MemberAverage.DIVIDE Members INTO Total GIVING MemberAverage.MULTIPLY 10 BY Magnitude.MULTIPLY Members BY Subs GIVING TotalSubs.

The exceptions are the COMPUTE and the DIVIDE with REMAINDER.

VERB Identifier

Literal

TO

FROM

BY

INTO

Identifier

Identifier GIVING Identifier ROUNDED

ON SIZE ERROR StatementBlock END - VERB

129

The ROUNDED optionThe ROUNDED option

Receiving Field Actual Result Truncated Result Rounded Result

PIC 9(3)V9. 123.25

PIC 9(3). 123.25

123.2 123.3

123 123

The ROUNDED option takes effect when, after decimal The ROUNDED option takes effect when, after decimal point alignment, the result calculated must be truncated on point alignment, the result calculated must be truncated on the right hand side. the right hand side.

The option adds 1 to the receiving item when the leftmost The option adds 1 to the receiving item when the leftmost truncated digit has an absolute value of 5 or greater.truncated digit has an absolute value of 5 or greater.

130

A size error condition exists when, after decimal point A size error condition exists when, after decimal point alignment, the result is truncated on either the alignment, the result is truncated on either the leftleft or the or the rightright hand side.hand side.

If an arithmetic statement has a rounded phrase then a size If an arithmetic statement has a rounded phrase then a size error only occurs if there is truncation on the error only occurs if there is truncation on the leftleft hand side hand side (most significant digits).(most significant digits).

Receiving Field Actual Result SIZE ERROR

PIC 9(3)V9. 245.96

PIC 9(3)V9. 1245.9

PIC 9(3). 124

PIC 9(3). 1246

PIC 9(3)V9 Not Rounded 124.45

PIC 9(3)V9 Rounded 124.45

PIC 9(3)V9 Rounded 3124.45

The ON SIZE ERROR optionThe ON SIZE ERROR option

Yes

Yes

No

Yes

Yes

No

Yes

131

ADD ExamplesADD Examples

ADD Cash TO Total.BeforeBefore 3 1000AfterAfter

ADD Cash, 20 TO Total, Wage.Before Before 3 1000 100AfterAfter

ADD Cash, Total GIVING Result.BeforeBefore 3 1000 0015AfterAfter

ADD Males TO Females GIVING TotalStudents.Before Before 1500 0625 1234AfterAfter

ADD Cash TO Total.BeforeBefore 3 1000AfterAfter

ADD Cash, 20 TO Total, Wage.Before Before 3 1000 100AfterAfter

ADD Cash, Total GIVING Result.BeforeBefore 3 1000 0015AfterAfter

ADD Males TO Females GIVING TotalStudents.Before Before 1500 0625 1234AfterAfter

3 1003

3 1023 123

3 1000 1003

1500 0625 2125

132

SUBTRACT ExamplesSUBTRACT Examples

SUBTRACT Tax FROM GrossPay, Total.Before Before 120 4000 9120 AfterAfter

SUBTRACT Tax, 80 FROM Total.Before Before 100 480AfterAfter

SUBTRACT Tax FROM GrossPay GIVING NetPay.BeforeBefore 750 1000 0012AfterAfter

SUBTRACT Tax FROM GrossPay, Total.Before Before 120 4000 9120 AfterAfter

SUBTRACT Tax, 80 FROM Total.Before Before 100 480AfterAfter

SUBTRACT Tax FROM GrossPay GIVING NetPay.BeforeBefore 750 1000 0012AfterAfter

120 3880 9000

100 300

750 1000 0250

133

MULTIPLY and DIVIDE MULTIPLY and DIVIDE ExamplesExamples

MULTIPLY Subs BY Members GIVING TotalSubs ON SIZE ERROR DISPLAY "TotalSubs too small" END-MULTIPLY. Subs Members TotalSubsSubs Members TotalSubs

BeforeBefore 15.50 100 0123.45AfterAfter

MULTIPLY 10 BY Magnitude, Size.

BeforeBefore 355 125AfterAfter

DIVIDE Total BY Members GIVING Average ROUNDED.BeforeBefore 9234.55 100 1234.56AfterAfter

MULTIPLY Subs BY Members GIVING TotalSubs ON SIZE ERROR DISPLAY "TotalSubs too small" END-MULTIPLY. Subs Members TotalSubsSubs Members TotalSubs

BeforeBefore 15.50 100 0123.45AfterAfter

MULTIPLY 10 BY Magnitude, Size.

BeforeBefore 355 125AfterAfter

DIVIDE Total BY Members GIVING Average ROUNDED.BeforeBefore 9234.55 100 1234.56AfterAfter

15.50 100 1550.00

3550 1250

9234.55 100 92.35

134

The Divide ExceptionThe Divide Exception

DIVIDE INTO GIVING Identifier [ ROUNDED ] REMAINDER Identifier

ON SIZE ERROR

NOT ON SIZE ERROR StatementBlock END - DIVIDE

DIVIDE BY GIVING Identifier [ ROUNDED ] REMAINDER Identifier

ON SIZE ERROR

NOT ON SIZE ERROR StatementBlock END - DIVIDE

Identifier

Literal

Identifier

Literal

Identifier

Literal

Identifier

Literal

DIVIDE 201 BY 10 GIVING Quotient REMAINDER Remain.Before Before 209 424AfterAfter

DIVIDE 201 BY 10 GIVING Quotient REMAINDER Remain.Before Before 209 424AfterAfter

020 001

135

Compute IrishPrice = SterlingPrice / Rate * 100.Before Before 1000.50 156.25 87 AfterAfter

Compute IrishPrice = SterlingPrice / Rate * 100.Before Before 1000.50 156.25 87 AfterAfter 179.59 156.25 87

The COMPUTEThe COMPUTE COMPUTE Identifier [ ROUNDED ] . . . = ArithmeticExpression

ON SIZE ERROR

NOT ON SIZE ERROR StatementBlock END - COMPUTE

Precedence Rules.Precedence Rules.1.1. **** = POWER NN

2.2. ** = MULTIPLY x// = DIVIDE ÷

3.3. ++ = ADD +-- = SUBTRACT -

Precedence Rules.Precedence Rules.1.1. **** = POWER NN

2.2. ** = MULTIPLY x// = DIVIDE ÷

3.3. ++ = ADD +-- = SUBTRACT -

136

Edited Pictures.Edited Pictures.

Edited Pictures are PICTURE clauses which format data intended for output to screen or printer.

To enable the data items to be formatted in a particular style COBOL provides additional picture symbols supplementing the basic 9, X, A, V and S symbols.

The additional symbols are referred to as “Edit Symbols” and PICTURE clauses which include edit symbols are called “Edited Pictures”.

The term edit is used because the edit symbols have the effect of changing, or editing, the data inserted into the edited item.

Edited items can not be used as operands in a computation but they may be used as the result or destination of a computation (i.e. to the right of the word GIVING).

137

Editing TypesEditing Types

COBOL provides two basic types of editingŒ Insertion Editing - which modifies a value by including additional items. Suppression and Replacement Editing -

which suppresses and replaces leading zeros.

Each type has sub-categoriesInsertion editing

Simple InsertionSpecial InsertionFixed InsertionFloating Insertion

Suppression and ReplacementZero suppression and replacement with spacesZero suppression and replacement with asterisks

138

Editing SymbolsEditing Symbols

, B 0 / Simple Insertion

. Special Insertion

+ - CR DB $ Fixed Insertion

+ - S Floating Insertion

Z * Suppression and Replacement

, B 0 / Simple Insertion

. Special Insertion

+ - CR DB $ Fixed Insertion

+ - S Floating Insertion

Z * Suppression and Replacement

Edit Symbol Editing TypeEdit Symbol Editing Type

139

Simple Insertion.Simple Insertion.

Sending Sending Receiving Receiving

Picture Data Picture ResultPicture Data Picture Result

PIC 999999 123456 PIC 999,999

PIC 9(6) 000078 PIC 9(3),9(3)

PIC 9(6) 000078 PIC ZZZ,ZZZ

PIC 9(6) 000178 PIC ***,***

PIC 9(6) 002178 PIC ***,***

PIC 9(6) 120183 PIC 99B99B99

PIC 9(6) 120183 PIC 99/99/99

PIC 9(6) 001245 PIC 990099



PIC 999999 123456 PIC 999,999

PIC 9(6) 000078 PIC 9(3),9(3)

PIC 9(6) 000078 PIC ZZZ,ZZZ

PIC 9(6) 000178 PIC ***,***

PIC 9(6) 002178 PIC ***,***

PIC 9(6) 120183 PIC 99B99B99

PIC 9(6) 120183 PIC 99/99/99

PIC 9(6) 001245 PIC 990099

123,456000,07878****178**2,178

12018312/01/83 120045

140

Special Special Insertion.Insertion.



PIC 999V99 12345 PIC 999.99

PIC 999V99 02345 PIC 999.9

PIC 999V99 51234 PIC 99.99

PIC 999 456 PIC 999.99



PIC 999V99 12345 PIC 999.99

PIC 999V99 02345 PIC 999.9

PIC 999V99 51234 PIC 99.99

PIC 999 456 PIC 999.99

123.45

023.4

12.34

456.00

141

Fixed Insertion - Plus and Minus.Fixed Insertion - Plus and Minus.



PIC S999 -123 PIC -999

PIC S999 -123 PIC 999-

PIC S999 +123 PIC -999

PIC S9(5) +12345 PIC +9(5)

PIC S9(3) -123 PIC +9(3)

PIC S9(3) -123 PIC 999+



PIC S999 -123 PIC -999

PIC S999 -123 PIC 999-

PIC S999 +123 PIC -999

PIC S9(5) +12345 PIC +9(5)

PIC S9(3) -123 PIC +9(3)

PIC S9(3) -123 PIC 999+

-123123-123

+12345-123123-

142

Fixed Insertion - Credit, Debit, $Fixed Insertion - Credit, Debit, $



PIC S9(4) +1234 PIC 9(4)CR

PIC S9(4) -1234 PIC 9(4)CR

PIC S9(4) +1234 PIC 9(4)DB

PIC S9(4) -1234 PIC 9(4)DB

PIC 9(4) 1234 PIC $99999

PIC 9(4) 0000 PIC $ZZZZZ



PIC S9(4) +1234 PIC 9(4)CR

PIC S9(4) -1234 PIC 9(4)CR

PIC S9(4) +1234 PIC 9(4)DB

PIC S9(4) -1234 PIC 9(4)DB

PIC 9(4) 1234 PIC $99999

PIC 9(4) 0000 PIC $ZZZZZ

12341234CR12231234DB

$01234$

143

Floating Floating Insertion.Insertion.



PIC 9(4) 0000 PIC $$,$$9.99

PIC 9(4) 0080 PIC $$,$$9.00

PIC 9(4) 0128 PIC $$,$$9.99

PIC 9(5) 57397 PIC $$,$$9

PIC S9(4) - 0005 PIC ++++9

PIC S9(4) +0080 PIC ++++9

PIC S9(4) - 0080 PIC - - - - 9

PIC S9(5) +71234 PIC - - - - 9



PIC 9(4) 0000 PIC $$,$$9.99

PIC 9(4) 0080 PIC $$,$$9.00

PIC 9(4) 0128 PIC $$,$$9.99

PIC 9(5) 57397 PIC $$,$$9

PIC S9(4) - 0005 PIC ++++9

PIC S9(4) +0080 PIC ++++9

PIC S9(4) - 0080 PIC - - - - 9

PIC S9(5) +71234 PIC - - - - 9

$0.00 $80.00 $128.00$7,397

-5 +80 -80 ž1234

144

Suppression and Suppression and ReplacementReplacement



PIC 9(5) 12345 PIC ZZ,999

PIC 9(5) 01234 PIC ZZ,999

PIC 9(5) 00123 PIC ZZ,999

PIC 9(5) 00012 PIC ZZ,999

PIC 9(5) 05678 PIC **,**9

PIC 9(5) 00567 PIC **,**9

PIC 9(5) 00000 PIC **,***



PIC 9(5) 12345 PIC ZZ,999

PIC 9(5) 01234 PIC ZZ,999

PIC 9(5) 00123 PIC ZZ,999

PIC 9(5) 00012 PIC ZZ,999

PIC 9(5) 05678 PIC **,**9

PIC 9(5) 00567 PIC **,**9

PIC 9(5) 00000 PIC **,***

12,3451,234123012*5,678***567******

145

The The USAUSAGE GE

clausclause e

146

USAGE IS DISPLAYUSAGE IS DISPLAY

The USAGE clause specifies the format of numeric data items in the computer storage.

When no USAGE clause is explicitly declared, USAGE IS DISPLAY is assumed.

When numeric items have a USAGE of DISPLAY they are held as ASCII characters !!

SYSTEMSYSTEM CHARCHAR HEXHEX DEC DEC 88 44 22 11 88 44 22 11

ASCIIASCII "A" "A" 41 41 65 65 00 11 00 00 00 00 00 11

EBCDICEBCDIC "A" "A" C1 C1 193 193 11 11 00 00 00 00 00 11

147

Arithmetic when USAGE IS Arithmetic when USAGE IS DISPLAYDISPLAY

88 44 22 11 88 44 22 11 HEX CHARHEX CHAR

Num1 PIC 9 VALUE 4.Num1 PIC 9 VALUE 4. 00 00 11 11 00 11 00 00 41 41 "4""4"


Num3 PIC 9.Num3 PIC 9. 00 00 00 00 00 00 00 00 0 0 nulnul

ADD Num1,Num2 GIVING Num3.ADD Num1,Num2 GIVING Num3.

148

Arithmetic when USAGE IS Arithmetic when USAGE IS DISPLAYDISPLAY

88 44 22 11 88 44 22 11 HEX CHARHEX CHAR



Num3 PIC 9.Num3 PIC 9. 00 11 11 00 00 11 00 11 65 65 "e""e"

ADD Num1,Num2 GIVING Num3.ADD Num1,Num2 GIVING Num3.

149

Why use the USAGE Why use the USAGE clause?clause?

The USAGE clause is used for purposes of optimisation - both speed and storage.

The USAGE clause controls the way data items (normally numeric) are stored in memory.

150

USAGE SyntaxUSAGE Syntax

01 Num1 PIC 9(5)V99 USAGE IS COMP.

01 Num2 PIC 99 USAGE IS PACKED-DECIMAL.

01 IdxItem USAGE IS INDEX.

01 GroupItems COMP. 02 Item1 PIC 999. 02 Item2 PIC 9(4)V99. 02 New1 PIC S9(5) COMP SYNC.

151

USAGE IS COMPUSAGE IS COMP

Number of DigitsNumber of Digits Storage Required.Storage Required.

11 TOTO 44 1 WORD (2 Bytes)1 WORD (2 Bytes)

55 TOTO 99 1 LONGWORD (4 Bytes)1 LONGWORD (4 Bytes)

1010 TOTO 1818 1 QUADWORD (8 Bytes)1 QUADWORD (8 Bytes)

01 TotalCount PIC 9(7) USAGE IS COMP.01 TotalCount PIC 9(7) USAGE IS COMP.

Takes 4 bytes (1 LONGWORD) of storage.Takes 4 bytes (1 LONGWORD) of storage.

COMP items are held in memory as pure binary two's complement numbers.

152

COMP - Storage COMP - Storage RequirementsRequirements

2 Bytes can represent any 4 digit number.2 Bytes can represent any 4 digit number.

32768 16384 8192 4096 2048 1024 512 256 128 64 32 16 8 4 2 1

Max. number = Max. number = ++ or or - - 32767 32767 PIC 9999 PIC 9999

4 Bytes can represent any 9 digit number4 Bytes can represent any 9 digit number

Max. number = Max. number = ++ or or - - 2, 147,483,647 2, 147,483,647 PIC 999 999 999 PIC 999 999 999

153

USAGE IS PACKED-USAGE IS PACKED-DECIMALDECIMAL

Data items declared as PACKED-DECIMAL are held in binary-coded-decimal (BCD) form.

Instead of representing the value as one single binary number, each digit is held in binary form in a nibble (half a byte).

PIC S9 PIC S9(2) PIC S9(3) VALUE +5 VALUE -32 VALUE +262

5 +5 + 0 3 2 -0 3 2 - 2 6 2 +2 6 2 +

154

01 ThreeBytes01 ThreeBytes PIC XXX VALUE "DOG".PIC XXX VALUE "DOG".01 TwoBytes01 TwoBytes PIC 9(4) COMP.PIC 9(4) COMP.

D O G D O G NumberNumber

The SYNCHRONIZED The SYNCHRONIZED ClauseClause

The SYNCHRONIZED clause explicitly aligns COMP and INDEX data items along their natural WORD boundaries.

If there is no SYNCHRONIZED clause the data items are aligned on byte boundaries.

This clause is used to optimise speed of processing - but it does so at the expense of storage.

Word1 Word2 Word3

155

01 ThreeBytes01 ThreeBytes PIC XXX VALUE "DOG".PIC XXX VALUE "DOG".01 TwoBytes01 TwoBytes PIC 9(4) COMP PIC 9(4) COMP SYNCSYNC..

D O G D O G NumberNumber


COMP SYNC (1 TO 4 Digits) = 2 Byte boundaryCOMP SYNC (5 TO 9 Digits) = 4 Byte boundaryCOMP SYNC (10 TO 18 Digits) = 8 Byte boundary INDEX = 4 Byte boundary

Word1 Word2 Word3

156

01 FiveBytes01 FiveBytes PIC XXX VALUE "FROGS".PIC XXX VALUE "FROGS".01 FourBytes01 FourBytes PIC S9(5) COMP.PIC S9(5) COMP.

F R O G S F R O G S NumberNumberNumberNumber



Word1 Word2 Word3 Word4 Word5 Word6

157

01 FiveBytes01 FiveBytes PIC XXX VALUE "FROGS".PIC XXX VALUE "FROGS".01 FourBytes01 FourBytes PIC S9(5) COMP PIC S9(5) COMP SYNCSYNC..

F R O G S F R O G S NumberNumberNumberNumber



Word1 Word2 Word3 Word4 Word5 Word6

Aligns along a 4 byte boundary

Aligns along a 4 byte boundary

158

ConditioConditions. ns.

159

IF IF Syntax.Syntax.

IF Condition THEN StatementBlock

NEXT SENTENCE

ELSE StatementBlock

NEXT SENTENCE END - IF

Simple Conditions– Relation Conditions– Class Conditions– Sign Conditions

Complex ConditionsCondition Names

Simple Conditions– Relation Conditions– Class Conditions– Sign Conditions

Complex ConditionsCondition Names

CCONDITION ONDITION TTYPESYPES

160

Relation ConditionsRelation Conditions

Identifier

Literal

ArithmeticExpression

Identifier

Literal

ArithmeticExpression

IS

NOT GREATER THAN

NOT >

NOT LESS THAN

NOT <

NOT EQUAL TO

NOT =

GREATER THAN OR EQUAL TO

>=

LESS THAN OR EQUAL TO

<=

161

Class Class Conditions.Conditions.

Although COBOL data items are not ‘typed’ they do fall into some broad categories, or classes, such a numeric or alphanumeric, etc.

A Class Condition determines whether the value of data item is a member of one these classes.

Identifier IS [NOT]

NUMERIC

ALPHABETIC

ALPHABETIC - LOWER

ALPHABETIC - UPPER

UserDefinedClassName

162

Sign Sign ConditionsConditions

The sign condition determines whether or not the value of an arithmetic expression is less than, greater than or equal to zero.

Sign conditions are just another way of writing some of the Relational conditions.

ArithExp IS [NOT]

POSITIVE

NEGATIVE

ZERO

163

Complex conditions.Complex conditions.

Programs often require conditions which are more complex than single value testing or determining a data class.

Like all other programming languages COBOL allows simple conditions to be combined using OR and AND to form composite conditions.

Like other conditions, a complex condition evaluates to true or false.

A complex condition is an expression which is evaluated from left to right unless the order of evaluation is changed by the precedence rules or bracketing.

Condition AND

OR Condition

164

Just like arithmetic expressions, complex conditions Just like arithmetic expressions, complex conditions are evaluated using precedence rules and the order of are evaluated using precedence rules and the order of evaluation may be changed by bracketing.evaluation may be changed by bracketing.

ExamplesExamplesIF Row > 0 IF Row > 0 ANDAND Row < 26 THEN Row < 26 THEN

DISPLAY “On Screen”DISPLAY “On Screen”END-IFEND-IF

IF VarA > VarC IF VarA > VarC OROR VarC = VarD VarC = VarD OROR VarA VarA NOTNOT = VarF = VarF DISPLAY “Done”DISPLAY “Done”

END-IFEND-IF

( ) ( )

( ) ( ) ( )

Complex conditions have precedence rules Complex conditions have precedence rules too.too.

Precedence Rules.Precedence Rules.1.1. NOTNOT = **

2.2. ANDAND = * or /

3.3. OROR = + or -

Precedence Rules.Precedence Rules.1.1. NOTNOT = **

2.2. ANDAND = * or /

3.3. OROR = + or -

165

Implied Implied Subjects.Subjects.

When a data item is involved in a relation condition with each of a number of other items it can be tedious to have to repeat the data item for each condition. For example,

IF TotalAmt > 10000 AND TotalAmt < 50000 THENIF Grade = “A” OR Grade = “B+” OR GRADE = “B” THENIF VarA > VarB AND VarA > VarC AND VarA > VarD

DISPLAY “VarA is the Greatest”END-IF

In these situations COBOL provides an abbreviation mechanism called implied subjects.

The statements above may be re-written using implied subjects as;

IF TotalAmt > 10000 AND < 50000 THENIF Grade=“A” OR “B+” OR “B” THENIF VarA > VarB AND VarC AND VarD

DISPLAY “VarA is the Greatest”END-IF

Implied SubjectsImplied SubjectsTotalAmt Grade = VarA >

Implied SubjectsImplied SubjectsTotalAmt Grade = VarA >

166

Nested IFsNested IFs

IF ( VarA < 10 ) AND ( VarB NOT > VarC ) THENIF VarG = 14 THEN

DISPLAY “First”ELSE

DISPLAY “Second”END-IF

ELSEDISPLAY “Third”

END-IF

IF ( VarA < 10 ) AND ( VarB NOT > VarC ) THENIF VarG = 14 THEN

DISPLAY “First”ELSE

DISPLAY “Second”END-IF

ELSEDISPLAY “Third”

END-IF

VarAVarA VarBVarB VarCVarC VarGVarG DISPLAYDISPLAY

3 4 15 14 3 4 15 15 3 4 3 14 13 4 15 14

VarAVarA VarBVarB VarCVarC VarGVarG DISPLAYDISPLAY

3 4 15 14 3 4 15 15 3 4 3 14 13 4 15 14

167

Condition Names.Condition Names.

Wherever a condition can occur, such as in an IF statement or an EVALUATE or a PERFORM..UNTIL, a CONDITION NAME (Level 88) may be used.

A Condition Name is essentially a BOOLEAN variable which is either TRUE or FALSE.

Example.IF StudentRecord = HIGH-VALUES THEN Action

The statement above may be replaced by the one below. The condition name EndOfStudentFile may be used instead of the condition StudentRecord = HIGH-VALUES.

IF EndOfStudentFile THEN Action

168

Defining Condition Defining Condition Names.Names.

Condition Names are defined in the DATA DIVISION using the special level number 88.

They are always associated with a data item and are defined immediately after the definition of the data item.

A condition name takes the value TRUE or FALSE depending on the value in its associated data item.

A Condition Name may be associated with ANY data item whether it is a group or an elementary item.

The VALUE clause is used to identify the values which make the Condition Name TRUE.

88 ConditionName VALUE

VALUES

Literal

LowValue THROUGH

THRU HighValue

169

01 CityCode PIC 9 VALUE 5.88 Dublin VALUE 1.88 Limerick VALUE 2.88 Cork VALUE 3.88 Galway VALUE 4.88 Sligo VALUE 5.88 Waterford VALUE 6.88 UniversityCity VALUE 1 THRU 4.


IF Limerick DISPLAY "Hey, we're home."END-IFIF UniversityCity PERFORM CalcRentSurchargeEND-IF


Dublin FALSE Limerick FALSECork FALSEGalway FALSESligo TRUEWaterford FALSEUniversityCity FALSE

City CodeCity Code

55

170





Dublin FALSE Limerick TRUECork FALSEGalway FALSESligo FALSEWaterford FALSEUniversityCity TRUE

City CodeCity Code

22

171





Dublin FALSE Limerick FALSECork FALSEGalway FALSESligo FALSEWaterford TRUEUniversityCity FALSE

City CodeCity Code

66

172

01 InputChar PIC X.88 Vowel VALUE "A","E","I","O","U".88 Consonant VALUE "B" THRU "D", "F","G","H"

"J" THRU "N", "P" THRU "T""V" THRU "Z".

88 Digit VALUE "0" THRU "9".88 LowerCase VALUE "a" THRU "z".88 ValidChar VALUE "A" THRU "Z","0" THRU "9".




IF ValidChar DISPLAY "Input OK."END-IFIF LowerCase

DISPLAY "Not Upper Case"END-IFIF Vowel Display "Vowel entered."END-IF



Vowel TRUEConsonant FALSEDigit FALSELowerCase FALSEValidChar TRUE

Input CharInput Char

EE

173











Vowel FALSEConsonant FALSEDigit TRUELowerCase FALSEValidChar TRUE


44

174











Vowel FALSEConsonant FALSEDigit FALSELowerCase TRUEValidChar FALSE


gg

175

01 EndOfFileFlag PIC 9 VALUE 0.88 EndOfFile VALUE 1.


READ InFileAT END MOVE 1 TO EndOfFileFlag

END-READPERFORM UNTIL EndOfFile

StatementsREAD InFile

AT END MOVE 1 TO EndOfFileFlagEND-READ

END-PERFORM




AT END MOVE 1 TO EndOfFileFlagEND-READ

END-PERFORM

EndOfFile

EndOfFileFlagEndOfFileFlag

00

176






AT END MOVE 1 TO EndOfFileFlagAT END MOVE 1 TO EndOfFileFlagEND-READ

END-PERFORM




AT END MOVE 1 TO EndOfFileFlagAT END MOVE 1 TO EndOfFileFlagEND-READ

END-PERFORM

EndOfFileFlagEndOfFileFlag

11

EndOfFile

177

Using the SET Using the SET verb.verb.

01 FILLER PIC 9 VALUE 0.88 EndOfFile VALUE 1.88 NotEndOfFile VALUE 0.


READ InFileAT END SET EndOfFile TO TRUE




END-PERFORMSet NotEndOfFile TO TRUE.






EndOfFile 1NotEndOfFile 0

FILLERFILLER

00

178







AT END SET EndOfFile TO TRUEAT END SET EndOfFile TO TRUEEND-READ





AT END SET EndOfFile TO TRUEAT END SET EndOfFile TO TRUEEND-READ



FILLERFILLER

11

179















FILLERFILLER

00

180

PROCEDURE DIVISION.Begin. OPEN INPUT StudentFile READ StudentFile AT END SET EndOfFile TO TRUE END-READ PERFORM UNTIL EndOfFile DISPLAY StudentId SPACE StudentName SPACE CourseCode READ StudentFile AT END SET EndOfFile TO TRUE END-READ END-PERFORM CLOSE StudentFile STOP RUN.

PROCEDURE DIVISION.Begin. OPEN INPUT StudentFile READ StudentFile AT END SET EndOfFile TO TRUE END-READ PERFORM UNTIL EndOfFile DISPLAY StudentId SPACE StudentName SPACE CourseCode READ StudentFile AT END SET EndOfFile TO TRUE END-READ END-PERFORM CLOSE StudentFile STOP RUN.

FD StudentFile.01 StudentDetails. 88 EndOfFile VALUE HIGH-VALUES. 02 StudentId PIC 9(7). 02 StudentName. 03 Surname PIC X(8). 03 Initials PIC XX. 02 DateOfBirth. 03 YOBirth PIC 9(2). 03 MOBirth PIC 9(2). 03 DOBirth PIC 9(2). 02 CourseCode PIC X(4). 02 Grant PIC 9(4). 02 Gender PIC X.

FD StudentFile.01 StudentDetails. 88 EndOfFile VALUE HIGH-VALUES. 02 StudentId PIC 9(7). 02 StudentName. 03 Surname PIC X(8). 03 Initials PIC XX. 02 DateOfBirth. 03 YOBirth PIC 9(2). 03 MOBirth PIC 9(2). 03 DOBirth PIC 9(2). 02 CourseCode PIC X(4). 02 Grant PIC 9(4). 02 Gender PIC X.

181

The The EvaluateEvaluate

EVALUATE

Identifier

Literal

CondExpression

ArithExpression

TRUE

FALSE

WHEN

ANY

Condition

TRUE

FALSE

NOT

Identifier

Literal

ArithExpression

THRU

THROUGH

Identifier

Literal

ArithExpression

StatementBlock

WHEN OTHER StatementBlock

END - EVALUATE

182

W I L L I A M S W I L L I A M S

EVALUATE TRUE PositionWHEN L-Arrow 2 THRU 10 PERFORM MoveLeftWHEN R-Arrow 1 THRU 9 PERFORM MoveRightWHEN L-Arrow 1 MOVE 10 TO PositionWHEN R-Arrow 10 MOVE 1 TO PositionWHEN DeleteKey 1 PERFORM CantDeleteWHEN Character ANY PERFORM InsertCharWHEN OTHER PERFORM DisplayErrorMessage

END-EVALUATE

1 2 3 4 5 6 7 8 9 10

183

Decision Table Decision Table Implementation.Implementation.

EVALUATE Gender TRUE TRUEWHEN "M" Age<20 ANY MOVE 5 TO BonusWHEN "F" Age<20 ANY MOVE 10 TO BonusWHEN "M" Age>19 AND <41 Service<10 MOVE 12 TO BonusWHEN "F" Age>19 AND <41 Service<10 MOVE 13 TO BonusWHEN "M" Age>40 Service<10 MOVE 20 TO BonusWHEN "F" Age>40 Service<10 MOVE 15 TO Bonus

: : : : : : : : : :

WHEN "F" ANY Service>20 MOVE 25 TO BonusEND-EVALUATE

GenderGender M F M F M F M F Age Age <20 <20 20-40 20-40 40> 40> 20-40 20-40 etcServiceService Any Any <10 <10 <10 <10 10-20 10-20 etc% Bonus% Bonus 5 10 12 13 20 15 14 23

184

DesignDesigninging

PrograProgramsms

185

COBOLCOBOL

COBOL is an acronym standing for Common Business Oriented Language.

COBOL programs are (mostly) written for the vertical market.

COBOL programs tend to be long lived.

Because of this longevity ease of program maintenance is an important consideration.

Why is program maintenance important?

186

Cost of a system over its entire Cost of a system over its entire life.life.

Maintenance Costs are only as low as this because many systems become so unmaintainable early in their lives that they have to be SCRAPPED !! :- B. Boehm

Maintenance67%

Testing15%Coding

7%

Analysisand

Design 9%

Zelkowitz ACM 1978

p202

187

Program Program Maintenance.Maintenance.

Program maintenance is an umbrella term that covers;

Œ Changing the program to fix bugs that appear in the system.

Changing the program to reflect changes in the environment.

ŽChanging the program to reflect changes in the users perception of the requirements.

Changing the program to include extensions to the user requirements (i.e. new requirements).

What do these all have in common?

CHANGING THE PROGRAM.

188

How should write your How should write your programs?programs?

You should write your programs with the expectation that they will have to be changed.

This means that you should;

write programs that are easy to read.

write programs that are easy to understand.

write programs that are easy to change.

You should write your programs as you would like them written if you had to maintain them.

189

Efficiency vs Efficiency vs Clarity.Clarity.

Many programmers are overly concerned about making their programs as efficient as possible (in terms of the speed of execution or the amount of memory used).

But the proper concern of a programmer, and particularly a COBOL programmer, is not this kind of efficiency, it is clarity.

As a rule 70% of the work of the program will be done in 10% of the code.

It is therefore a pointless exercise to try to optimize the whole program, especially if this has to be done at the expense of clarity.

Write your program as clearly as possible and then, if its too slow, identify the 10% of the code where the work is being done and optimize it.

190

When shouldn’t we design our When shouldn’t we design our programs?programs?

We shouldn’t design our programs, when we want to create programs that do not work.

We shouldn’t design when we want to produce programs that do not solve the problem specified.

When we want to create programs that;get the wrong inputs,or perform the wrong transformations on themor produce the wrong outputs

then we shouldn’t bother to design our programs.

But if we want to create programs that work, we cannot avoid design.

The only question is; will it be a good design or a bad design

191

Producing a Good Producing a Good Design.Design.

The first step to producing a good design is to design consciously.

Subconscious design means that design is done while constructing the program. This never leads to good results.

Conscious design starts by separating the design task from the task of program construction.

Design, consists of devising a solution to the problem specified.

Construction, consists of taking the design and encoding the solution using a particular programming language.

192

Why separate design from Why separate design from construction?construction?

Separating program design from program construction makes both tasks easier.

Designing before construction, allows us to plan our solution to the problem - instead of stumbling from one incorrect solution to another.

Good program structure results from planing and design. It is unlikely to result from ad hoc tinkering.

Designing helps us to get an overview of the problem and to think about the solution without getting bogged down by the details of construction.

It helps us to iron out problems with the specification and to discover any bugs in our solution before we commit it to code (see next slide).

Design allows us to develop portable solutions

193

Relative cost of fixing a bug.Relative cost of fixing a bug.

In ProductionIn Productionx82x82

In In ConstructionConstruction

x20x20

194

Design Notations.Design Notations.

A number of notations have been suggested to assist the programmer with the task of program design.

Some notations are textual and others graphical.

Some notations can actually assist in the design process.

While others merely articulate the design.

195

Flowcharts as design tools.Flowcharts as design tools.

196

Structured Flowcharts as design Structured Flowcharts as design tools.tools.

197

Structured English.Structured English.

For each transaction record do the followingIF the record is a receipt then

add 1 to the ReceiptsCountadd the Amount to the Balance

otherwiseadd 1 to the PaymentsCountsubtract the Amount from the

BalanceEndIFadd 1 to the RecordCountWrite the Balance to the CustomerFile

When the file has been processed Output the ReceiptsCount

the PaymentsCountand the RecordCount

For each transaction record do the followingIF the record is a receipt then

add 1 to the ReceiptsCountadd the Amount to the Balance

otherwiseadd 1 to the PaymentsCountsubtract the Amount from the

BalanceEndIFadd 1 to the RecordCountWrite the Balance to the CustomerFile

When the file has been processed Output the ReceiptsCount

the PaymentsCountand the RecordCount

198

The Jackson Method.The Jackson Method.

199

Warnier-Orr Warnier-Orr Diagrams.Diagrams.

UpdateCustomerBalance

OpenFiles

ProcessRecords

RecordType ?

ProcessReceipt

ProcessPayment

WriteNewBalance

PrintTotals

CloseFiles

200

IntroductionIntroductionto to

Diagrammatic Diagrammatic Stepwise Stepwise

RefinementRefinement

201

DIAGRAMMATIC STEPWISE REFINEMENT (DSR).DIAGRAMMATIC STEPWISE REFINEMENT (DSR).

an approach to program design based onan approach to program design based on

The Program Structure Diagrams used in the Jackson Method (JSP)

Wirth's Stepwise Refinement approach to program design.

202

Steps in the DSR Steps in the DSR approachapproach

1. Define the problem completely.

2. Work out what needs to be done to solve the problem.

3. Using Stepwise Refinement, design a Program Structure Diagram (PSD) to represent your solution to the problem.

4. Write out the Executable Operations needed to produce the output from the input.

5. Assign the Executable Operations to the appropriate places in the PSD.

6. Insert the Iteration and Selection conditions.

7. Test your solution using test data.

8. Translate the populated PSD into code.

203

Stepwise RefinementStepwise Refinement

Is an approach to program design which involves breaking a task into sub-tasks.

Each sub-task is in turn broken into further sub-tasks.

This process continues until the sub-tasks are so simple that their implementation is straight forward.

204

Sequence

Selection

Iteration

Program Structure Program Structure DiagramsDiagrams

Program Structure Diagrams (PSDs) are used to Program Structure Diagrams (PSDs) are used to represent the hierarchy of tasks and sub-tasks represent the hierarchy of tasks and sub-tasks created by Stepwise Refinement. created by Stepwise Refinement.

They are drawn using the three classic constructs They are drawn using the three classic constructs of Structured Programming.of Structured Programming.

205

PRINTPRINTREPORTREPORT

Sequence PSDSequence PSD


HEADINGSHEADINGS


BODYBODY

PRINTPRINTREPORTREPORTFOOTINGFOOTING

206

ADD TOADD TOFEMALESFEMALES

ADD TOADD TOMALESMALES

Selection PSDSelection PSD

COUNTCOUNTSTUDENTSTUDENT

oo

207

Selection with Null partSelection with Null part

COUNTCOUNTSTUDENTSTUDENT

ADD TOADD TOLM51 COUNTLM51 COUNT

ADD TOADD TOLM60 COUNTLM60 COUNT

oo

208

Iteration PSDIteration PSD

PROCESSPROCESSACCOUNTACCOUNT

PROCESSPROCESSACCOUNTSACCOUNTS

**

209

PROCESSPROCESSACCOUNTACCOUNT

Iteration PSD - Explicit Repeat Iteration PSD - Explicit Repeat LoopLoop

PROCESSPROCESSREMAININGREMAININGACCOUNTSACCOUNTS

**

PROCESSPROCESSACCOUNTSACCOUNTS

PROCESSPROCESSFIRST FIRST

ACCOUNTACCOUNT

210

PROCESSPROCESSCOUNTYCOUNTYRECORDRECORD


PRINTPRINTCOUNTRYCOUNTRY

BODYBODY

PRINTPRINTCOUNTYCOUNTYTOTALSTOTALS

INITIALIZEINITIALIZECOUNTYCOUNTYTOTALSTOTALS

**

Print-Country-Body is an iteration of three components. This is equivalent to ;

an iteration of one component which is in turn a sequence of three.

211

PROCESSPROCESSCOUNTYCOUNTYRECORDRECORD


PRINTPRINTCOUNTRYCOUNTRY

BODYBODY

PRINTPRINTCOUNTYCOUNTYTOTALSTOTALS

INITIALIZEINITIALIZECOUNTYCOUNTYTOTALSTOTALS

**

PRINTPRINTCOUNTYCOUNTYREPORTREPORT

212

Payroll Proof Totals Program Payroll Proof Totals Program SpecificationSpecification

Write a program to produce proof totals for a weekly payroll. The payroll file consists of records with the following format:-

COL 1 Record-Type PIC 9.1 = Regular2 = Overtime3 = Bonus

COLS 2-6 Employee-Number PIC 9(5).COLS 7-11 Earnings PIC 9(3)V99.

(in pounds and pence)

The print layout should be as follows:

PAYROLL PROOF TOTALS

Regular Earnings : 25$2,111.23

Overtime Earnings : 2$21.50

Bonus Earnings : 6$123.45

PAYROLL PROOF TOTALS

Regular Earnings : 25$2,111.23

Overtime Earnings : 2$21.50

Bonus Earnings : 6$123.45

213

Applying DSR to the Payroll Proof Totals ProgramApplying DSR to the Payroll Proof Totals Program

1. Define the problem completely2. Work out what needs to be done to solve the

problem.3. Using Stepwise Refinement design a Program

Structure Diagram (PSD) to represent your solution to the problem.

214

PrintPrintProof TotalsProof Totals

ReportReport

215


ReportReport

PrintPrintProofProofTotalsTotals

ProcessProcessPayrollPayroll

RecordsRecords

216


ReportReport


**


RecordsRecords

Process AProcess APayrollPayrollRecordRecord

217


ReportReport

oo


**


RecordsRecords


Add To Add To OvertimeOvertime

Add To Add To RegularRegular

Add ToAdd ToBonusBonus

218


ReportReport

oo


**


RecordsRecords





PrintPrintReportReport

HeadingsHeadings

PrintPrintRegular Regular TotalsTotals

PrintPrintOvertimeOvertime

TotalsTotals

PrintPrintBonusBonusTotalsTotals

219

1. OPEN OUTPUT Print-File.2. CLOSE Print-File.3. WRITE Print-Line FROM Heading-Line AFTER ADVANCING PAGE.4. WRITE Print-Line FROM Regular-Line AFTER ADVANCING 1 LINE.5. WRITE Print-Line FROM Overtime-Line AFTER ADVANCING 1 LINE.6. WRITE Print-Line FROM Bonus-Line AFTER ADVANCING 1 LINE.7. MOVE Regular-Total TO Print-Reg-Total.8. MOVE Overtime-Total TO Print-Overtime-Total.9. MOVE Bonus-Total TO Print-Bonus-Total.10. MOVE Regular-Count TO Print-Reg-Count.11. MOVE Overtime-Count TO Print-Over-Count.12. MOVE Bonus-Count TO Print-Bonus-Count.13. ADD Earnings TO Regular-Total.14. ADD Earnings TO Overtime-Total.15. ADD Earnings TO Bonus-Total.16. ADD 1 TO Regular-Count.17. ADD 1 TO Overtime-Count.18. ADD 1 TO Bonus-Count.19. READ Payroll-File

AT END SET End-of-File TO TRUEEND-READ.

20. OPEN INPUT Payroll-File.21. CLOSE Payroll-File.

1. OPEN OUTPUT Print-File.2. CLOSE Print-File.3. WRITE Print-Line FROM Heading-Line AFTER ADVANCING PAGE.4. WRITE Print-Line FROM Regular-Line AFTER ADVANCING 1 LINE.5. WRITE Print-Line FROM Overtime-Line AFTER ADVANCING 1 LINE.6. WRITE Print-Line FROM Bonus-Line AFTER ADVANCING 1 LINE.7. MOVE Regular-Total TO Print-Reg-Total.8. MOVE Overtime-Total TO Print-Overtime-Total.9. MOVE Bonus-Total TO Print-Bonus-Total.10. MOVE Regular-Count TO Print-Reg-Count.11. MOVE Overtime-Count TO Print-Over-Count.12. MOVE Bonus-Count TO Print-Bonus-Count.13. ADD Earnings TO Regular-Total.14. ADD Earnings TO Overtime-Total.15. ADD Earnings TO Bonus-Total.16. ADD 1 TO Regular-Count.17. ADD 1 TO Overtime-Count.18. ADD 1 TO Bonus-Count.19. READ Payroll-File



4.4. Write out the Executable Operations needed to Write out the Executable Operations needed to produce the produce the outputoutput from the from the input input..

220

5.5. Assign the Executable Operations to the Assign the Executable Operations to the appropriate places in the PSD.appropriate places in the PSD.

AlgorithmFor all Executable Operations.

– Get an Executable Operation.– Ask "To what component/components must I attach this

operation to get the program to work?".– If there are already operations attached to a target component

then a further question must be asked ; "Where, in relation to the existing operations, does this operation go?".

221


ReportReport

oo


**


RecordsRecords






HeadingsHeadings



TotalsTotals


1. OPEN OUTPUT Print-File.2. CLOSE Print-File.

222


ReportReport

oo


**


RecordsRecords






HeadingsHeadings



TotalsTotals


11 22

1. OPEN OUTPUT Print-File.2. CLOSE Print-File.3. WRITE Print-Line FROM Heading-Line ... 4. WRITE Print-Line FROM Regular-Line ... 5. WRITE Print-Line FROM Overtime-Line ... 6. WRITE Print-Line FROM Bonus-Line ...

223


ReportReport

oo


**


RecordsRecords






HeadingsHeadings



TotalsTotals


1 2

3. WRITE Print-Line FROM Heading-Line ... 4. WRITE Print-Line FROM Regular-Line ... 5. WRITE Print-Line FROM Overtime-Line ... 6. WRITE Print-Line FROM Bonus-Line ...7. MOVE Regular-Total TO Print-Reg-Total.8. MOVE Overtime-Total TO Print-Overtime-Total.9. MOVE Bonus-Total TO Print-Bonus-Total.

33 44 6655

224


ReportReport

oo


**


RecordsRecords






HeadingsHeadings



TotalsTotals


1 2

7. MOVE Regular-Total TO Print-Reg-Total.8. MOVE Overtime-Total TO Print-Overtime-Total.9. MOVE Bonus-Total TO Print-Bonus-Total.10. MOVE Regular-Count TO Print-Reg-Count.11. MOVE Overtime-Count TO Print-Over-Count.12. MOVE Bonus-Count TO Print-Bonus-Count.

3 77,4 99,688,5

225


ReportReport

oo


**


RecordsRecords






HeadingsHeadings



TotalsTotals


1 2

10. MOVE Regular-Count TO Print-Reg-Count.11. MOVE Overtime-Count TO Print-Over-Count.12. MOVE Bonus-Count TO Print-Bonus-Count.13. ADD Earnings TO Regular-Total.14. ADD Earnings TO Overtime-Total.15. ADD Earnings TO Bonus-Total.16. ADD 1 TO Regular-Count.17. ADD 1 TO Overtime-Count.18. ADD 1 TO Bonus-Count.

7,1010,4 1212,9,61111,8,53

226


ReportReport

oo


**


RecordsRecords






HeadingsHeadings



TotalsTotals


1 2

13. ADD Earnings TO Regular-Total.14. ADD Earnings TO Overtime-Total.15. ADD Earnings TO Bonus-Total.16. ADD 1 TO Regular-Count.17. ADD 1 TO Overtime-Count.18. ADD 1 TO Bonus-Count.19. READ Payroll-File


14,1714,17 15,1815,18

7,10,4 12,9,611,8,53

227


ReportReport

oo


**


RecordsRecords






HeadingsHeadings



TotalsTotals


1,1919 2

19. READ Payroll-FileAT END SET End-of-File TO TRUE

END-READ.

13,16 14,17 15,18

7,10,4 12,9,611,8,53

228


ReportReport

oo


**


RecordsRecords






HeadingsHeadings



TotalsTotals


1,19 2

19. READ Payroll-FileAT END SET End-of-File TO TRUE

END-READ.20. OPEN INPUT Payroll-File.21. CLOSE Payroll-File.

13,16 14,17 15,18

1919

7,10,4 12,9,611,8,53

229


ReportReport

oo


**


RecordsRecords






HeadingsHeadings



TotalsTotals



1,2020,19 2,2121

19

13,16 14,17 15,18

3 7,10,4 12,9,611,8,5

230

6.6. Insert the Iteration and Selection Insert the Iteration and Selection conditions.conditions.

Go to each iteration component and ask;"What iteration statement must I use here to get the program to work correctly?". Write the Iteration statement, give it a number and insert its number into the diagram.

Go to each selection component and ask;" What selection statement must I use here to get the program to work correctly?". Write the Selection statement, give it a number and insert its number into the diagram.

231


ReportReport

oo



RecordsRecords






HeadingsHeadings



TotalsTotals


1,20,19 2,21

1. 1. PERFORM Process-Payroll-Records UNTIL End-of-File.

13,16 14,17 15,18

19

11

7,10,4 12,9,611,8,53

**

232


ReportReport


**


RecordsRecords






HeadingsHeadings



TotalsTotals


1,20,19 2,21


2.2. IF Regular-Rec PERFORM Add-to-RegularELSE

IF Overtime-Rec PERFORM Add-to-Overtime

ELSE PERFORM Add-to-BonusEND-IF

END-IF.

13,16 14,17 15,18

19

11

227,10,4 12,9,611,8,53

oo

Using IF...ELSEUsing IF...ELSE

233


ReportReport


**


RecordsRecords






HeadingsHeadings



TotalsTotals


1,20,19 2,21


2.2. EVALUATE TRUEWHEN Regular-Rec PERFORM Add-to-

RegularWHEN Overtime-Rec PERFORM Add-to-

OvertimeWHEN Bonus-Rec PERFORM Add-to-

BonusEND-EVALUATE.

13,16 14,17 15,18

19

11

227,10,4 12,9,611,8,53

oo

Using the EvaluateUsing the Evaluate

23411 12341234 050.25050.2511 12341234 050.25050.25


ReportReport


**


RecordsRecords






HeadingsHeadings



TotalsTotals


1,20,19 2,21

13,16 14,17 15,18

19

11

227,10,4 12,9,611,8,53

oo

7.7. Test the program using test Test the program using test data.data.

TypeType Emp-No Emp-No EarningsEarnings11 12341234 050.25050.2522 12341234 025.50025.5011 23452345 120.25120.2533 12341234 010.50010.50

Employee-RecEmployee-RecTypeType Emp-No Emp-No EarningsEarnings

000.00000.00 000000

000.00000.00 000000

000.00000.00 000000

23511 12341234 050.25050.2511 12341234 050.25050.25


ReportReport


**


RecordsRecords






HeadingsHeadings



TotalsTotals


1,20,19 2,21

13,16 14,17 15,18

19

11

227,10,4 12,9,611,8,53

oo




050.25050.25050.25050.25 001001001001

000.00000.00 000000

000.00000.00 000000

23622 12341234 025.50025.5022 12341234 025.50025.50


ReportReport


**


RecordsRecords






HeadingsHeadings



TotalsTotals


1,20,19 2,21

13,16 14,17 15,18

19

11

227,10,4 12,9,611,8,53

oo




050.25050.25 001001

000.00000.00 000000

000.00000.00 000000

23722 12341234 025.50025.5022 12341234 025.50025.50


ReportReport


**


RecordsRecords






HeadingsHeadings



TotalsTotals


1,20,19 2,21

13,16 14,17 15,18

19

11

227,10,4 12,9,611,8,53

oo




050.25050.25 001001

025.50025.50025.50025.50 001001001001

000.00000.00 000000

23811 23452345 120.25120.2511 23452345 120.25120.25


ReportReport


**


RecordsRecords






HeadingsHeadings



TotalsTotals


1,20,19 2,21

13,16 14,17 15,18

19

11

227,10,4 12,9,611,8,53

oo




050.25050.25 001001

025.50025.50 001001

000.00000.00 000000

23911 23452345 120.25120.2511 23452345 120.25120.25


ReportReport


**


RecordsRecords






HeadingsHeadings



TotalsTotals


1,20,19 2,21

13,16 14,17 15,18

19

11

227,10,4 12,9,611,8,53

oo




170.50170.50170.50170.50 002002002002

025.50025.50 001001

000.00000.00 000000

24033 12341234 010.50010.5033 12341234 010.50010.50


ReportReport


**


RecordsRecords






HeadingsHeadings



TotalsTotals


1,20,19 2,21

13,16 14,17 15,18

19

11

227,10,4 12,9,611,8,53

oo




170.50170.50 002002

025.50025.50 001001

000.00000.00 000000

24133 12341234 010.50010.5033 12341234 010.50010.50


ReportReport


**


RecordsRecords






HeadingsHeadings



TotalsTotals


1,20,19 2,21

13,16 14,17 15,18

19

11

227,10,4 12,9,611,8,53

oo




170.50170.50 002002

025.50025.50 001001

010.50010.50010.50010.50 001001001001

242


ReportReport


**


RecordsRecords






HeadingsHeadings



TotalsTotals


1,20,19 2,21

13,16 14,17 15,18

19

11

227,10,4 12,9,611,8,53

oo




170.50170.50 002002

025.50025.50 001001

010.50010.50 001001HIGH-VALUESHIGH-VALUESHIGH-VALUESHIGH-VALUES

243


ReportReport


**


RecordsRecords






HeadingsHeadings



TotalsTotals


1,20,19 2,21

13,16 14,17 15,18

19

11

227,10,4 12,9,611,8,53

oo




170.50170.50 002002

025.50025.50 001001


244


ReportReport


**


RecordsRecords






HeadingsHeadings



TotalsTotals


1,20,19 2,21

13,16 14,17 15,18

19

11

227,10,4 12,9,611,8,53

oo




170.50170.50 002002

025.50025.50 001001


245

8.8. Translate the populated PSD into COBOL codeTranslate the populated PSD into COBOL code

Start at the top of the diagram. At each parent component write the sequence of

executable operations, child components and iteration and selection conditions as statements in a paragraph.

Replace child components with PERFORMs of the component name.

At the top component, use the name as the name of the first paragraph and preceed it with the PROCEDURE DIVISION header. End the sequence with the STOP RUN statement.

246


ReportReport


**


RecordsRecords






HeadingsHeadings



TotalsTotals


1,20,19 2,21

13,16 14,17 15,18

19

11

227,10,4 12,9,611,8,53

oo

247


ReportReport


**


RecordsRecords






HeadingsHeadings



TotalsTotals


1,20,19 2,21

PROCEDURE DIVISION.PROCEDURE DIVISION.Print-Proof-Totals-Report.Print-Proof-Totals-Report.

OPEN INPUT Payroll-File.OPEN INPUT Payroll-File.OPEN Output Print-File.OPEN Output Print-File.Read Payroll-File ....Read Payroll-File ....PERFORM Process-Payroll-Records PERFORM Process-Payroll-Records

UNTIL End-Of-File.UNTIL End-Of-File.PERFORM Print-Proof-Totals.PERFORM Print-Proof-Totals.CLOSE Print-File.CLOSE Print-File.CLOSE Payroll-File.CLOSE Payroll-File.STOP RUN.STOP RUN.

13,16 14,17 15,18

19

11

227,10,4 12,9,611,8,53

oo

248


ReportReport


**


RecordsRecords






HeadingsHeadings



TotalsTotals


1,20,19 2,21

13,16 14,17 15,18

19

11

227,10,4 12,9,611,8,53

oo

Process-Payroll-Records. EVALUATE TRUE

WHEN Regular-Rec PERFORM Add-to-RegularWHEN Overtime-Rec PERFORM Add-to-OvertimeWHEN Bonus-Rec PERFORM Add-to-Bonus

END-EVALUATE. READ Payroll-File READ Payroll-File

AT END SET End-Of-File TO TRUE AT END SET End-Of-File TO TRUEEND-READ.END-READ.

249

Tables Tables and and

PERFORM..VARYINGPERFORM..VARYING

The program to calculate the total taxes paid for the country is easy to write.

BUT.What do we do if we want to calculate the taxes paid in each county?

TaxTotal

Variable = Named location in memory

PROCEDURE DIVISION.Begin. OPEN INPUT TaxFile READ TaxFile AT END SET EndOfTaxFile TO TRUE END-READ PERFORM UNTIL EndOfTaxFile ADD TaxPaid TO TaxTotal READ TaxFile AT END SET EndOfTaxFile TO TRUE END-READ END-PERFORM. DISPLAY "Total taxes are ", TaxTotal CLOSE TaxFile STOP RUN.

PAYENum CountyNum TaxPaid

PROCEDURE DIVISION.Begin. OPEN INPUT TaxFile READ TaxFile AT END SET EndOfTaxFile TO TRUE END-READ PERFORM SumCountyTaxes UNTIL EndOfTaxFile DISPLAY "County 1 total is ", County1TaxTotal : : : 24 Statements : : :: : : 24 Statements : : : DISPLAY "County 26 total is ", County26TaxTotal CLOSE TaxFile STOP RUN.SumCountyTaxes. IF CountyNum = 1 ADD TaxPaid TO County1TaxTotal END-IF : : : 24 Statements : : :: : : 24 Statements : : : IF CountyNum = 26 ADD TaxPaid TO County26TaxTotal END-IF READ TaxFile AT END SET EndOfTaxFile TO TRUE END-READ

County1TaxTotal

County2TaxTotal

County3TaxTotal

County4TaxTotal

County5TaxTotal

Tables/Tables/ArraysArrays

10

1 2 3 4 5 61 2 3 4 5 6

MOVE MOVE 1010 TO CountyTax( TO CountyTax(55))

ADD TaxPaid TO CountyTax(CountyNum)ADD TaxPaid TO CountyTax(CountyNum)

ADD TaxPaid TO CountyTax(CountyNum + 2)ADD TaxPaid TO CountyTax(CountyNum + 2)

A table is a contiguous sequence of memory locations called elements elements, , which all have the same namesame name, and are uniquely identified by that name and by their positionposition in the sequence.


CountyTax


55

1 2 3 4 5 61 2 3 4 5 6

MOVE 10 TO CountyTax(5)MOVE 10 TO CountyTax(5)

ADD ADD TaxPaidTaxPaid TO CountyTax( TO CountyTax(CountyNumCountyNum))

ADD TaxPaid TO CountyTax(CountyNum + 2)ADD TaxPaid TO CountyTax(CountyNum + 2)



1010

55 2

CountyTax

5555


1 2 3 4 5 61 2 3 4 5 6

MOVE 10 TO CountyTax(5)MOVE 10 TO CountyTax(5)

ADD TaxPaid TO CountyTax(CountyNum)ADD TaxPaid TO CountyTax(CountyNum)

ADD ADD TaxPaidTaxPaid TO CountyTax( TO CountyTax(CountyNum + 2CountyNum + 2))



1010

55 2

55

CountyTax

55555555


1 2 3 4 5 61 2 3 4 5 6

MOVE 10 TO CountyTax(MOVE 10 TO CountyTax(55))

ADD TaxPaid TO CountyTax(ADD TaxPaid TO CountyTax(CountyNumCountyNum))

ADD TaxPaid TO CountyTax(ADD TaxPaid TO CountyTax(CountyNum + 2CountyNum + 2))



1010The position index is called a subscript.

Subscript

CountyTax

PROCEDURE DIVISION.Begin. OPEN INPUT TaxFile READ TaxFile AT END SET EndOfTaxFile TO TRUE END-READ PERFORM UNTIL EndOfTaxFile ADD TaxPaid TO CountyTax(CountyNum) READ TaxFile AT END SET EndOfTaxFile TO TRUE END-READ END-PERFORM. PERFORM VARYING Idx FROM 1 BY 1 UNTIL Idx GREATER THAN 26 DISPLAY "County ", CountyNum " tax total is " CountyTax(Idx) END-PERFORM CLOSE TaxFile STOP RUN.

Subscript

1 2 3 4 5 61 2 3 4 5 6

CountyTax

TaxRecord.PAYENum CountyName TaxPaid

1 2 3 4 5 61 2 3 4 5 6

CountyTax

IF CountyName = "CARLOW" ADD TaxPaid TO CountyTax(1) END-IF IF CountyName = "CAVAN" ADD TaxPaid TO CountyTax(2) END-IF : : : : : : : : : : : : : : : : : : : : 24 TIMES24 TIMES

A-89432 CLARE 7894.55

1 2 3 4 5 61 2 3 4 5 6

CountyTax

A-89432 CLARE 7894.55

TaxRecord.PAYENum CountyName TaxPaid Idx

1 2 3 4 5 61 2 3 4 5 6

CORKCORKCAVANCAVAN DONEGALDONEGALCARLOWCARLOW CLARECLARE DUBLINDUBLIN

County

PERFORM VARYING Idx FROM 1 BY 1 UNTIL County(Idx) = CountyName END-PERFORM ADD TaxPaid TO CountyTax(Idx)

11

500.50 125.75 1000.00 745.55 345.23 123.45500.50 125.75 1000.00 745.55 345.23 123.45

1 2 3 4 5 61 2 3 4 5 6

CountyTax

A-89432 CLARE 7894.55


1 2 3 4 5 61 2 3 4 5 6


County


22

500.50 125.75 1000.00 745.55 345.23 123.45500.50 125.75 1000.00 745.55 345.23 123.45

1 2 3 4 5 61 2 3 4 5 6

CountyTax

A-89432 CLARE 7894.55


1 2 3 4 5 61 2 3 4 5 6


County


33

500.50 125.75 1000.00 745.55 345.23 123.45500.50 125.75 1000.00 745.55 345.23 123.45

1 2 3 4 5 61 2 3 4 5 6

CountyTax

A-89432 CLARE 7894.55


1 2 3 4 5 61 2 3 4 5 6


County


33

500.50 125.75 500.50 125.75 8894.558894.55 745.55 345.23 123.45 745.55 345.23 123.45

262

1 2 3 4 5 61 2 3 4 5 6

TaxTotalsCountyTax

Declaring Declaring Tables.Tables.

000000 000000 000000 000000 000000 000000

01 TaxTotals.01 TaxTotals. 02 CountyTax PIC 9(10)V99 02 CountyTax PIC 9(10)V99 OCCURS 26 TIMES. OCCURS 26 TIMES.

oror 02 CountyTax OCCURS 26 TIMES 02 CountyTax OCCURS 26 TIMES

PIC 9(10)V99. PIC 9(10)V99.

e.g. e.g. MOVE ZEROS TO TaxTotals.MOVE ZEROS TO TaxTotals.

MOVE 20 TO CountyTax(5).MOVE 20 TO CountyTax(5).

Group Items as Group Items as Elements.Elements.

1 2 3 1 2 3 4 4 5 6 5 6

TaxTotals

CountyTax PayerCount

CountyTaxDetails

01 TaxTotals.01 TaxTotals. 02 CountyTaxDetails OCCURS 26 TIMES. 02 CountyTaxDetails OCCURS 26 TIMES. 03 CountyTax PIC 9(10)V99. 03 CountyTax PIC 9(10)V99. 03 PayerCount PIC 9(7). 03 PayerCount PIC 9(7).

e.g. MOVE 25 TO PayerCount(2).e.g. MOVE 25 TO PayerCount(2). MOVE 67 TO CountyTax(5). MOVE 67 TO CountyTax(5). MOVE ZEROS TO CountyTaxDetails(3). MOVE ZEROS TO CountyTaxDetails(3).

25 67

000000 000000

264

PERFORM..VARYING PERFORM..VARYING SyntaxSyntax

PERFORM 1stProc THRU

THROUGH EndProc WITH TEST

BEFORE

AFTER

VARYING Identifer1

IndexName1 FROM

BY Identifier3

Literal UNTIL Condition1

AFTER Identifier4

IndexName3 FROM

BY Identifier6

Literal UNTIL Condition2

Identifier

IndexName

Literal

Identifier

IndexName

Literal

2

2

5

4

StatementBlock END - PERFORM

PERFORM VARYING Idx1 FROM 1 BY 1 UNTIL Idx1 EQUAL TO 3 DISPLAY Idx1END-PERFORM.

Idx1 = 3

Loop Body

True

Move 1 to Idx1Move 1 to Idx1

Next Statement

Inc Idx1

False

Idx1

11


Loop Body

True

Move 1 to Idx1

Next Statement

Inc Idx1

False

Idx1

11

Idx1 = 3

11


Loop BodyLoop Body

True

Move 1 to Idx1

Next Statement

Inc Idx1

False

Idx1

11

Idx1 = 3

11


Loop Body

True

Move 1 to Idx1

Next Statement

Inc Idx1Inc Idx1

False

Idx1

22

Idx1 = 3

11


Loop Body

True

Move 1 to Idx1

Next Statement

Inc Idx1

False

Idx1

22

Idx1 = 3

1122


Loop BodyLoop Body

True

Move 1 to Idx1

Next Statement

Inc Idx1

False

Idx1

22

Idx1 = 3

1122


Loop Body

True

Move 1 to Idx1

Next Statement

Inc Idx1Inc Idx1

False

Idx1

33

Idx1 = 3

1122


Loop Body

True

Move 1 to Idx1

Next Statement

Inc Idx1

False

Idx1

33

Next Statement

Exit value = 3

Idx1 = 3

T Idx1 Idx2T Idx1 Idx2

PERFORM IterationCount VARYING Idx1 FROM 1 BY 2 UNTIL Idx1 EQUAL TO 5 AFTER Idx2 FROM 6 BY -1 UNTIL Idx2 LESS THAN 4

IterationCountIterationCount

Y

Next Statement

Dec Idx2

N

1 1 6

2 1 5

3 1 4

4 3 6

5 3 5

6 3 4

x = 5 = 6

Move 1 to Idx1Move 6 to Idx2

Y

NMove 6 to Idx2

Inc Idx1

Idx1 = 5

Idx2 < 4

274

Advanced Advanced Tables.Tables.

01 JeansTable.01 JeansTable.

One Dimension One Dimension Table.Table.


11 2 2 33 4 4

01 JeansTable.01 JeansTable. 02 Province OCCURS 4 TIMES.02 Province OCCURS 4 TIMES. 03 SalesValue PIC 9(8)V99. 03 SalesValue PIC 9(8)V99. 03 NumSold PIC 9(7). 03 NumSold PIC 9(7).


11 2 2 33 4 4

01 JeansTable.01 JeansTable. 02 Province OCCURS 4 TIMES.02 Province OCCURS 4 TIMES. 03 SalesValue PIC 9(8)V99. 03 SalesValue PIC 9(8)V99. 03 NumSold PIC 9(7). 03 NumSold PIC 9(7).

ProvinceProvinceSalesValue NumSoldSalesValue NumSold

12346.99 309

Two Dimension Two Dimension Table.Table.

11 2 2 33 4 4

01 JeansTable.01 JeansTable. 02 Province OCCURS 4 TIMES.02 Province OCCURS 4 TIMES.

Two Dimension Two Dimension Table.Table.

11 2 2 33 4 4

01 JeansTable.01 JeansTable. 02 Province OCCURS 4 TIMES.02 Province OCCURS 4 TIMES. 03 Gender OCCURS 2 TIMES.03 Gender OCCURS 2 TIMES. 04 SalesValue PIC 9(8)V99. 04 SalesValue PIC 9(8)V99. 04 NumSold PIC 9(7). 04 NumSold PIC 9(7).

1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2

Three Dimension Three Dimension Table.Table.

11 2 2 33 4 4

01 JeansTable.01 JeansTable. 02 Province OCCURS 4 TIMES.02 Province OCCURS 4 TIMES.


11 2 2 33 4 4

01 JeansTable.01 JeansTable. 02 Province OCCURS 4 TIMES.02 Province OCCURS 4 TIMES. 03 Gender OCCURS 2 TIMES.03 Gender OCCURS 2 TIMES.

1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2


11 2 2 33 4 4

01 JeansTable.01 JeansTable. 02 Province OCCURS 4 TIMES.02 Province OCCURS 4 TIMES. 03 Gender OCCURS 2 TIMES.03 Gender OCCURS 2 TIMES. 04 Colour OCCURS 3 TIMES.04 Colour OCCURS 3 TIMES.

1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3


11 2 2 33 4 4

01 JeansTable.01 JeansTable. 02 Province OCCURS 4 TIMES.02 Province OCCURS 4 TIMES. 03 Gender OCCURS 2 TIMES.03 Gender OCCURS 2 TIMES. 04 Colour OCCURS 3 TIMES.04 Colour OCCURS 3 TIMES. 05 SalesValue PIC 9(8)V99. 05 SalesValue PIC 9(8)V99. 05 NumSold PIC 9(7). 05 NumSold PIC 9(7).

1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3

ColourColourSalesValue NumSoldSalesValue NumSold

12346.99 309

Record Record Elements.Elements.

01 JeansTable.01 JeansTable. 02 Province OCCURS 4 TIMES.02 Province OCCURS 4 TIMES. 03 ProviceTotal PIC 9(8).03 ProviceTotal PIC 9(8). 03 Gender OCCURS 2 TIMES. 03 Gender OCCURS 2 TIMES. 04 Colour OCCURS 3 TIMES.04 Colour OCCURS 3 TIMES. 05 SalesValue PIC 9(8)V99. 05 SalesValue PIC 9(8)V99. 05 NumSold PIC 9(7). 05 NumSold PIC 9(7).

1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3

1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2

11 2 2 33 4 4

The Redefines The Redefines Clause.Clause.

01 Rates.01 Rates. 02 10Rate02 10Rate PIC 99V999.PIC 99V999. 02 100Rate 02 100Rate REDEFINESREDEFINES 10Rate10Rate PIC 999V99.PIC 999V99. 02 1000Rate 02 1000Rate REDEFINESREDEFINES 10Rate10Rate PIC 9999V9.PIC 9999V9.

1 2 3 4 5 1 2 3 4 5

RatesRates

..

The Redefines Clause.The Redefines Clause.

01 Rates.01 Rates. 02 10Rate02 10Rate PIC 99V999.PIC 99V999. 02 100Rate02 100Rate REDEFINESREDEFINES 10Rate10Rate PIC 999V99.PIC 999V99. 02 1000Rate 02 1000Rate REDEFINESREDEFINES 10Rate10Rate PIC 9999V9.PIC 9999V9.

1 2 3 4 5 1 2 3 4 5

RatesRates

..

The Redefines The Redefines Clause.Clause.

01 Rates.01 Rates. 02 10Rate 02 10Rate PIC 99V999.PIC 99V999. 02 100Rate 02 100Rate REDEFINESREDEFINES 10Rate10Rate PIC 999V99.PIC 999V99. 02 1000Rate02 1000Rate REDEFINESREDEFINES 10Rate10Rate PIC 9999V9.PIC 9999V9.

1 2 3 4 5 1 2 3 4 5

RatesRates

..

The Redefines Clause.The Redefines Clause.

01 HoldDate.01 HoldDate. 02 EuroDate. 02 EuroDate. 03 EuroDay PIC 99. 03 EuroDay PIC 99. 03 EuroMonth PIC 99. 03 EuroMonth PIC 99. 03 EuroYear PIC 9(4). 03 EuroYear PIC 9(4). 02 USDate REDEFINES EuroDate. 02 USDate REDEFINES EuroDate. 03 USMonth PIC 99. 03 USMonth PIC 99. 03 USDay PIC 99. 03 USDay PIC 99. 03 USYear PIC 9(4). 03 USYear PIC 9(4).

11 06 1983 11 06 1983

EuroDateEuroDateEuroDay EuroMonth EuroYearEuroDay EuroMonth EuroYear

USDay USMonth USYear USDay USMonth USYear USDateUSDate

HoldDateHoldDate

Creating Pre-filled Creating Pre-filled TablesTables

01 LetterTable.01 LetterTable. 02 TableValues. 02 TableValues.


A B C D E F G H I J K L A B C D E F G H I J K L

01 LetterTable.01 LetterTable. 02 TableValues. 02 TableValues. 03 FILLER PIC X(13) 03 FILLER PIC X(13) VALUE " VALUE "ABCDEFGHIJKLMABCDEFGHIJKLM".". 03 FILLER PIC X(13) 03 FILLER PIC X(13) VALUE " VALUE "NOPQRSTUVWXYZNOPQRSTUVWXYZ".".



01 LetterTable.01 LetterTable. 02 TableValues. 02 TableValues. 03 FILLER PIC X(13) 03 FILLER PIC X(13) VALUE " VALUE "ABCDEFGHIJKLMABCDEFGHIJKLM".". 03 FILLER PIC X(13) 03 FILLER PIC X(13) VALUE " VALUE "NOPQRSTUVWXYZNOPQRSTUVWXYZ".".

02 FILLER REDEFINES TableValues.02 FILLER REDEFINES TableValues. 03 Letter PIC X OCCURS 26 TIMES. 03 Letter PIC X OCCURS 26 TIMES.

Two Dimension Table of Two Dimension Table of Values.Values.

01 BonusTable.01 BonusTable. 02 BonusValues. 02 BonusValues. 03 FILLER PIC X(24) 03 FILLER PIC X(24) VALUE " VALUE "507590758595354365406085507590758595354365406085".".

50 75 90 75 85 95 35 43 65 40 60 8550 75 90 75 85 95 35 43 65 40 60 85


11 2 2 33 4 4

01 BonusTable.01 BonusTable. 02 BonusValues. 02 BonusValues. 03 FILLER PIC X(24) 03 FILLER PIC X(24) VALUE " VALUE "507590758595354365406085507590758595354365406085".". 02 FILLER REDEFINES BonusValues. 02 FILLER REDEFINES BonusValues. 03 Province OCCURS 4 TIMES. 03 Province OCCURS 4 TIMES.

50 75 90 75 85 95 35 43 65 40 60 8550 75 90 75 85 95 35 43 65 40 60 85


11 2 2 33 4 4

01 BonusTable.01 BonusTable. 02 BonusValues. 02 BonusValues. 03 FILLER PIC X(24) 03 FILLER PIC X(24) VALUE " VALUE "507590758595354365406085507590758595354365406085".". 02 FILLER REDEFINES BonusValues. 02 FILLER REDEFINES BonusValues. 03 Province OCCURS 4 TIMES. 03 Province OCCURS 4 TIMES. 04 Bonus OCCURS 3 TIMES PIC 99.04 Bonus OCCURS 3 TIMES PIC 99.

1 2 3 1 2 3 1 2 3 1 2 31 2 3 1 2 3 1 2 3 1 2 3

50 75 90 75 85 95 35 43 65 40 60 8550 75 90 75 85 95 35 43 65 40 60 85

295

COBOL 85 Table COBOL 85 Table Changes.Changes.

Creating pre-filled tables without the REDEFINES clause.

01 DayTable VALUE "MonTueWedThrFriSatSun".02 Day OCCURS 7 TIMES PIC X(3).

Initializing Tables with values.

01 TaxTable.02 County OCCURS 32 TIMES. 03 CountyTax PIC 9(5) VALUE ZEROS. 03 CountyName PIC X(12) VALUE SPACES.

The The PERFORMPERFORM

297

The PERFORM The PERFORM VerbVerb

Iteration is an important programming construct. We use iteration when we need to repeat the same instructions over and over again.

Most programming languages have several iteration keywords (e.g. WHILE, FOR, REPEAT) which facilitate the creation different ‘types’ of iteration structure.

COBOL only has one iteration construct; PERFORM.

But the PERFORM has several variations.

Each variation is equivalent to one of the iteration ‘types’ available in other languages.

This lecture concentrates on three of the PERFORM formats. The PERFORM..VARYING, the COBOL equivalent of the FOR , will be introduced later.

298

Paragraphs :- RevisitedParagraphs :- Revisited

A Paragraph is a block of code to which we have given a name.

A Paragraph Name is a programmer defined name formed using the standard rules for programmer defined names (A-Z, 0-9, -).

A Paragraph Name is ALWAYS terminated with a ‘full-stop’.

Any number of statements and sentences may be included in a paragraph, and the last one (at least) must be terminated with a ‘full-stop’.

The scope of a paragraph is delimited by the occurrence of another paragraph name or the end of the program text.

299

ProcessRecord. DISPLAY StudentRecord READ StudentFile

AT END MOVE HIGH-VALUES TO StudentRecord END-READ.

ProduceOutput. DISPLAY “Here is a message”.

Paragraph ExampleParagraph Example

NOTENOTE

The scope of ‘ProcessRecord’ is delimited by the occurrence the paragraph name ‘ProduceOutput’.

NOTENOTE

The scope of ‘ProcessRecord’ is delimited by the occurrence the paragraph name ‘ProduceOutput’.

300

Format 1 Syntax.Format 1 Syntax.

This is the only type of PERFORM that is not an iteration construct.

It instructs the computer to transfer control to an out-of-line block of code.

When the end of the block is reached, control reverts to the statement (not the sentence) immediately following the PERFORM.

1stProc and EndProc are the names of Paragraphs or Sections.

The PERFORM..THRU instructs the computer to treat the Paragraphs or Sections from 1stProc TO EndProc as a single block of code.


THROUGH EndProc

PROCEDURE DIVISION.TopLevel.TopLevel. DISPLAY "In TopLevel. Starting to run program"DISPLAY "In TopLevel. Starting to run program" PERFORM OneLevelDown DISPLAY "Back in TopLevel.". STOP RUN.

TwoLevelsDown. DISPLAY ">>>>>>>> Now in TwoLevelsDown."

OneLevelDown. DISPLAY ">>>> Now in OneLevelDown" PERFORM TwoLevelsDown DISPLAY ">>>> Back in OneLevelDown".

PROCEDURE DIVISION.TopLevel.TopLevel. DISPLAY "In TopLevel. Starting to run program"DISPLAY "In TopLevel. Starting to run program" PERFORM OneLevelDown DISPLAY "Back in TopLevel.". STOP RUN.



Run of PerformFormat1

In TopLevel. Starting to run program>>>> Now in OneLevelDown>>>>>>>> Now in TwoLevelsDown.>>>> Back in OneLevelDownBack in TopLevel.


Format 1 Format 1 Example.Example.

PROCEDURE DIVISION.TopLevel.TopLevel. DISPLAY "In TopLevel. Starting to run program" PERFORM OneLevelDownPERFORM OneLevelDown DISPLAY "Back in TopLevel.". STOP RUN.



PROCEDURE DIVISION.TopLevel.TopLevel. DISPLAY "In TopLevel. Starting to run program" PERFORM OneLevelDownPERFORM OneLevelDown DISPLAY "Back in TopLevel.". STOP RUN.







PROCEDURE DIVISION.TopLevel. DISPLAY "In TopLevel. Starting to run program" PERFORM OneLevelDown DISPLAY "Back in TopLevel.". STOP RUN.


OneLevelDown.OneLevelDown. DISPLAY ">>>> Now in OneLevelDown"DISPLAY ">>>> Now in OneLevelDown" PERFORM TwoLevelsDown DISPLAY ">>>> Back in OneLevelDown".



OneLevelDown.OneLevelDown. DISPLAY ">>>> Now in OneLevelDown"DISPLAY ">>>> Now in OneLevelDown" PERFORM TwoLevelsDown DISPLAY ">>>> Back in OneLevelDown".







OneLevelDown.OneLevelDown. DISPLAY ">>>> Now in OneLevelDown" PERFORM TwoLevelsDownPERFORM TwoLevelsDown DISPLAY ">>>> Back in OneLevelDown".



OneLevelDown.OneLevelDown. DISPLAY ">>>> Now in OneLevelDown" PERFORM TwoLevelsDownPERFORM TwoLevelsDown DISPLAY ">>>> Back in OneLevelDown".






TwoLevelsDown.TwoLevelsDown. DISPLAY ">>>>>>>> Now in TwoLevelsDown."DISPLAY ">>>>>>>> Now in TwoLevelsDown."



TwoLevelsDown.TwoLevelsDown. DISPLAY ">>>>>>>> Now in TwoLevelsDown."DISPLAY ">>>>>>>> Now in TwoLevelsDown."








OneLevelDown.OneLevelDown. DISPLAY ">>>> Now in OneLevelDown" PERFORM TwoLevelsDown DISPLAY ">>>> Back in OneLevelDown".DISPLAY ">>>> Back in OneLevelDown".



OneLevelDown.OneLevelDown. DISPLAY ">>>> Now in OneLevelDown" PERFORM TwoLevelsDown DISPLAY ">>>> Back in OneLevelDown".DISPLAY ">>>> Back in OneLevelDown".





PROCEDURE DIVISION.TopLevel.TopLevel. DISPLAY "In TopLevel. Starting to run program" PERFORM OneLevelDown DISPLAY "Back in TopLevel.".DISPLAY "Back in TopLevel.". STOP RUN.



PROCEDURE DIVISION.TopLevel.TopLevel. DISPLAY "In TopLevel. Starting to run program" PERFORM OneLevelDown DISPLAY "Back in TopLevel.".DISPLAY "Back in TopLevel.". STOP RUN.







PROCEDURE DIVISION.Begin. PERFORM SumSales STOP RUN.

SumSales. Statements Statements

IF NoErrorFound Statements Statements

IF NoErrorFound Statements Statements Statements

END-IF END-IF.

PROCEDURE DIVISION.Begin. PERFORM SumSales STOP RUN.

SumSales. Statements Statements

IF NoErrorFound Statements Statements

IF NoErrorFound Statements Statements Statements

END-IF END-IF.

Why use the PERFORM Why use the PERFORM Thru?Thru?

Go To and PERFORM Go To and PERFORM THRUTHRU

PROCEDURE DIVISIONBegin. PERFORM SumSales THRU SumSalesExit STOP RUN.

SumSales. Statements Statements IF ErrorFound GO TO SumSalesExit END-IF Statements Statements Statements IF ErrorFound GO TO SumSalesExit END-IF Statements

SumSalesExit. EXIT.

PROCEDURE DIVISIONBegin. PERFORM SumSales THRU SumSalesExit STOP RUN.

SumSales. Statements Statements IF ErrorFound GO TO SumSalesExit END-IF Statements Statements Statements IF ErrorFound GO TO SumSalesExit END-IF Statements

SumSalesExit. EXIT.

Format 2 - SyntaxFormat 2 - Syntax


THROUGH EndProc

RepeatCount TIMES


PROCEDURE DIVISION.Begin.

DisplayName.


DisplayName.

StatementsPERFORM DisplayName 4 TIMESStatementsSTOP RUN.

DISPLAY “Tom Ryan”.

$ SET SOURCEFORMAT"FREE"IDENTIFICATION DIVISION.PROGRAM-ID. PerformExample2.AUTHOR. Michael Coughlan.

DATA DIVISION.WORKING-STORAGE SECTION.01 NumofTimes PIC 9 VALUE 5.

PROCEDURE DIVISION.Begin. DISPLAY "Starting to run program" PERFORM 3 TIMES DISPLAY ">>>>This is an in line Perform" END-PERFORM DISPLAY "Finished in line Perform" PERFORM OutOfLineEG NumOfTimes TIMES DISPLAY "Back in Begin. About to Stop". STOP RUN.

OutOfLineEG. DISPLAY ">>>> This is an out of line Perform".

$ SET SOURCEFORMAT"FREE"IDENTIFICATION DIVISION.PROGRAM-ID. PerformExample2.AUTHOR. Michael Coughlan.

DATA DIVISION.WORKING-STORAGE SECTION.01 NumofTimes PIC 9 VALUE 5.

PROCEDURE DIVISION.Begin. DISPLAY "Starting to run program" PERFORM 3 TIMES DISPLAY ">>>>This is an in line Perform" END-PERFORM DISPLAY "Finished in line Perform" PERFORM OutOfLineEG NumOfTimes TIMES DISPLAY "Back in Begin. About to Stop". STOP RUN.

OutOfLineEG. DISPLAY ">>>> This is an out of line Perform".

Format 2 Format 2 ExampleExample

Starting to run program>>>>This is an in line Perform>>>>This is an in line Perform>>>>This is an in line PerformFinished in line Perform>>>> This is an out of line Perform>>>> This is an out of line Perform>>>> This is an out of line Perform>>>> This is an out of line Perform>>>> This is an out of line PerformBack in Begin. About to Stop

Starting to run program>>>>This is an in line Perform>>>>This is an in line Perform>>>>This is an in line PerformFinished in line Perform>>>> This is an out of line Perform>>>> This is an out of line Perform>>>> This is an out of line Perform>>>> This is an out of line Perform>>>> This is an out of line PerformBack in Begin. About to Stop

Run of PerformExample2

312

Format 3 SyntaxFormat 3 Syntax

This format is used where the WHILE or REPEAT constructs are used in other languages.

If the WITH TEST BEFORE phrase is used the PERFORM behaves like a WHILE loop and the condition is tested before the loop body is entered.

If the WITH TEST AFTER phrase is used the PERFORM behaves like a REPEAT loop and the condition is tested after the loop body is entered.

The WITH TEST BEFORE phrase is the default and so is rarely explicitly stated.


THROUGH EndProc WITH TEST

BEFORE

AFTER

UNTIL Condition


313

test

Loop Body

False

True

PERFORM WITHTEST AFTER =REPEAT ... UNTIL

PERFORM WITHTEST AFTER =REPEAT ... UNTIL

Next Statement

test

Loop Body

False

True

PERFORM WITHTEST BEFORE =WHILE ... DO

PERFORM WITHTEST BEFORE =WHILE ... DO

Next Statement

314

Sequential File Sequential File ProcessingProcessing

In general terms, the WHILE loop is an ideal construct for processing sequences of data items whose length is not predefined.

Such sequences of values are often called “streams”.

Because the ‘length’ of the stream is unknown we have to be careful how we manage the detection of the end of the stream.

A useful way for solving this problem uses a strategy known as “read ahead”.

315

The READ The READ AheadAhead

With the “read ahead” strategy we always try to stay one data item ahead of the processing.

The general format of the “read ahead” algorithm is as follows;Attempt to READ first data itemWHILE NOT EndOfStream Process data item Attempt to READ next data itemENDWHILE

Use this to process any stream of data.

316

Reading a Sequential Reading a Sequential FileFile

Algorithm TemplateREAD StudentRecordsREAD StudentRecords

AT END MOVE HIGH-VALUES TO StudentRecordAT END MOVE HIGH-VALUES TO StudentRecordEND-READEND-READPERFORM UNTIL StudentRecord = HIGH-VALUESPERFORM UNTIL StudentRecord = HIGH-VALUES

DISPLAY StudentRecordDISPLAY StudentRecordREAD StudentRecordsREAD StudentRecords

AT END MOVE HIGH-VALUES TO AT END MOVE HIGH-VALUES TO StudentRecordStudentRecord END-READEND-READEND-PERFORMEND-PERFORM

This is an example of an algorithm which is capable of processing any sequential file; ordered or unordered!

PROCEDURE DIVISION.Begin. OPEN INPUT StudentFile

READ StudentFile AT END MOVE HIGH-VALUES TO StudentDetails END-READ PERFORM UNTIL StudentDetails = HIGH-VALUES DISPLAY StudentId SPACE StudentName SPACE CourseCode READ StudentFile AT END MOVE HIGH-VALUES TO StudentDetails END-READ END-PERFORM

CLOSE StudentFile STOP RUN.

PROCEDURE DIVISION.Begin. OPEN INPUT StudentFile

READ StudentFile AT END MOVE HIGH-VALUES TO StudentDetails END-READ PERFORM UNTIL StudentDetails = HIGH-VALUES DISPLAY StudentId SPACE StudentName SPACE CourseCode READ StudentFile AT END MOVE HIGH-VALUES TO StudentDetails END-READ END-PERFORM

CLOSE StudentFile STOP RUN.

9456789 COUGHLANMS LM51

9367892 RYAN TG LM60

9368934 WILSON HR LM61




RUN OF SeqRead

Searching Tables.Searching Tables.



01 LetterTable. 02 TableValues. 03 FILLER PIC X(13) VALUE "ABCDEFGHIJKLMABCDEFGHIJKLM". 03 FILLER PIC X(13) VALUE "NOPQRSTUVWXYZNOPQRSTUVWXYZ".








Searching a Searching a TableTable

01 LetterTable. 02 TableValues. 03 FILLER PIC X(13) VALUE "ABCDEFGHIJKLM". 03 FILLER PIC X(13) VALUE "NOPQRSTUVWXYZ". 02 FILLER REDEFINES TableValues. 03 Letter PIC X OCCURS 26 TIMES.

01 LetterTable. 02 TableValues. 03 FILLER PIC X(13) VALUE "ABCDEFGHIJKLM". 03 FILLER PIC X(13) VALUE "NOPQRSTUVWXYZ". 02 FILLER REDEFINES TableValues. 03 Letter PIC X OCCURS 26 TIMES.

PERFORM VARYING Idx FROM 1 BY 1 UNTIL LetterIn EQUAL TO Letter(Idx)END-PERFORM.DISPLAY LetterIn, "is in position ", Idx.

PERFORM VARYING Idx FROM 1 BY 1 UNTIL LetterIn EQUAL TO Letter(Idx)END-PERFORM.DISPLAY LetterIn, "is in position ", Idx.

A B C D E F G H I J K L A B C D E F G H I J K L 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 12

322

Search Search SyntaxSyntax

323

SET SET SyntaxSyntax

Searching a Searching a TableTable

01 LetterTable. 02 TableValues. 03 FILLER PIC X(13) VALUE "ABCDEFGHIJKLM". 03 FILLER PIC X(13) VALUE "NOPQRSTUVWXYZ". 02 FILLER REDEFINES TableValues. 03 Letter PIC X OCCURS 26 TIMES INDEXED BY LetterIdx.

SET LetterIdx TO 1.SEARCH Letter AT END DISPLAY "Letter not found!" WHEN Letter(LetterIdx) = LetterIn DISPLAY LetterIn, "is in position ", IdxEND-SEARCH.

01 LetterTable. 02 TableValues. 03 FILLER PIC X(13) VALUE "ABCDEFGHIJKLM". 03 FILLER PIC X(13) VALUE "NOPQRSTUVWXYZ". 02 FILLER REDEFINES TableValues. 03 Letter PIC X OCCURS 26 TIMES INDEXED BY LetterIdx.

SET LetterIdx TO 1.SEARCH Letter AT END DISPLAY "Letter not found!" WHEN Letter(LetterIdx) = LetterIn DISPLAY LetterIn, "is in position ", IdxEND-SEARCH.


Searching a Two Dimension Searching a Two Dimension Table.Table.

1 2 3 4 1 2 3 4

1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 1 2 3 41 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 1 2 3 4

01 TimeTable. 02 Day OCCURS 5 TIMES INDEXED BY DayIdx. 03 Hours OCCURS 8 TIMES INDEXED BY HourIdx. 04 Item PIC X(10). 04 Location PIC X(10).

SET DayIdx TO 0.PERFORM UNTIL MeetingFound OR DayIdx > 5 SET DayIdx UP BY 1 SET HourIdx TO 1 SEARCH Hours WHEN MeetingType = Item(DayIdx, HourIdx) SET MeetingFound TO TRUE DISPLAY MeetingType " on " DayIdx " at " HourIdx END-SEARCHEND-PERFORM.

Search All Search All Syntax.Syntax.

Using the Search Using the Search AllAll

01 LetterTable. 02 TableValues. 03 FILLER PIC X(13) VALUE "ABCDEFGHIJKLM". 03 FILLER PIC X(13) VALUE "NOPQRSTUVWXYZ". 02 FILLER REDEFINES TableValues. 03 Letter PIC X OCCURS 26 TIMES ASCENDING KEY IS Letter INDEXED BY LetterIdx.

SEARCH ALL Letter WHEN Letter(LetterIdx) = LetterIn DISPLAY LetterIn, "is in position ", IdxEND-SEARCH.

01 LetterTable. 02 TableValues. 03 FILLER PIC X(13) VALUE "ABCDEFGHIJKLM". 03 FILLER PIC X(13) VALUE "NOPQRSTUVWXYZ". 02 FILLER REDEFINES TableValues. 03 Letter PIC X OCCURS 26 TIMES ASCENDING KEY IS Letter INDEXED BY LetterIdx.

SEARCH ALL Letter WHEN Letter(LetterIdx) = LetterIn DISPLAY LetterIn, "is in position ", IdxEND-SEARCH.


How the Search All How the Search All works.works.

A B C D E F G H I J K L A B C D E F G H I J K L MM N O P Q R S T U V W X Y Z N O P Q R S T U V W X Y Z

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26

ALGORITHM.ALGORITHM.Middle = (Lower + Upper) / 2CASE TRUE WHEN Letter(Middle) < "Q" THEN Lower = Middle + 1 WHEN Letter(Middle) > "Q" THEN Upper = Middle -1 WHEN Letter(Middle) = "Q" THEN SET ItemFound TO TRUE WHEN Lower > Upper THEN ItemNotInTable TO TRUE

11

LowerLower

2626

UpperUpper

1313 MM

MiddleMiddle

==

Letter(Middle)Letter(Middle)


A B C D E F G H I J K L M N O P Q R S T U V W X Y ZN O P Q R S T U V W X Y Z

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26


1414

LowerLower

2626

UpperUpper

1313 MM

MiddleMiddle

==



A B C D E F G H I J K L M N O P Q R S N O P Q R S TT U V W X Y ZU V W X Y Z

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26


1414

LowerLower

2626

UpperUpper

2020 TT

MiddleMiddle

==



A B C D E F G H I J K L M N O P Q R S N O P Q R S T U V W X Y Z

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26


1414

LowerLower

1919

UpperUpper

2020 TT

MiddleMiddle

==


How the Search All works.How the Search All works.

A B C D E F G H I J K L M N O N O PP Q R S Q R S T U V W X Y Z

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26


1414

LowerLower

1919

UpperUpper

1616 PP

MiddleMiddle

==



A B C D E F G H I J K L M N O P Q R S Q R S T U V W X Y Z

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26


1717

LowerLower

1919

UpperUpper

1616 PP

MiddleMiddle

==



A B C D E F G H I J K L M N O P Q Q RR S S T U V W X Y Z

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26


1717

LowerLower

1919

UpperUpper

1818 RR

MiddleMiddle

==



A B C D E F G H I J K L M N O P Q Q R S R S T U V W X Y Z

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26


1717

LowerLower

1717

UpperUpper

1818 RR

MiddleMiddle

==



A B C D E F G H I J K L M N O P QQ R S T U V W X Y Z

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26


1717

LowerLower

1717

UpperUpper

1818 QQ

MiddleMiddle

==



A B C D E F G H I J K L M N O P QQ R S T U V W X Y Z

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26


1717

LowerLower

1717

UpperUpper

1818 QQ

MiddleMiddle

==


Search All Search All Example.Example.

01 StateTable. 02 StateValues. 03 FILLER PIC X(20) VALUE ?????????????? Post Codes and NamesPost Codes and Names 03 FILLER PIC X(20) VALUE ?????????????? 02 FILLER REDEFINES StateValues. 03 States OCCURS 50 TIMES ASCENDING KEY IS StateName INDEXED BY StateIdx. 04 PostCode PIC X(6). 04 StateName PIC X(14).

SEARCH ALL States AT END DISPLAY "State not found" WHEN StateName(StateIdx) = InputName MOVE PostCode(StateIdx) TO PrintPostCodeEND-SEARCH.

01 StateTable. 02 StateValues. 03 FILLER PIC X(20) VALUE ?????????????? Post Codes and NamesPost Codes and Names 03 FILLER PIC X(20) VALUE ?????????????? 02 FILLER REDEFINES StateValues. 03 States OCCURS 50 TIMES ASCENDING KEY IS StateName INDEXED BY StateIdx. 04 PostCode PIC X(6). 04 StateName PIC X(14).

SEARCH ALL States AT END DISPLAY "State not found" WHEN StateName(StateIdx) = InputName MOVE PostCode(StateIdx) TO PrintPostCodeEND-SEARCH.

INSPEINSPECT CT

340

INSPECT Syntax - Format INSPECT Syntax - Format 11

INSPECT FullName TALLYING UnstrPtr FOR LEADING SPACES.

INSPECT SourceLine TALLYING ECount FOR ALL "e" AFTER INITIAL "start"

BEFORE INITIAL "end".

INSPECT Example 1INSPECT Example 1

READ TextFile AT END SET EndOfFile TO TRUEEND-READPERFORM UNTIL EndOfFile PERFORM VARYING idx FROM 1 BY 1 UNTIL idx > 26 INSPECT TextLine TALLYING LetterCount(idx) FOR ALL Letter(idx) END-PERFORM READ TextFile AT END SET EndOfFile TO TRUE END-READEND-PERFORMPERFORM VARYING idx FROM 1 BY 1 UNTIL idx > 26 DISPLAY "Letter " Letter(idx) " occurs " LetterCount(idx) " times" END-PERFORM

342

How the INSPECT works.How the INSPECT works.

The INSPECT scans the Source String from left to right counting and/or replacing characters under the control of the TALLYING, REPLACING or CONVERTING phrases.

The behaviour of the INSPECT is modified by using the LEADING, FIRST, BEFORE and AFTER phrases.

An ALL, LEADING, CHARACTERS, FIRST or CONVERTING phrase may only be followed by one BEFORE and one AFTER phrase.

343

Modifying Modifying PhrasesPhrases

LEADINGThe LEADING phrase causes counting/replacement of all Compare$il characters from the first valid one encountered to the first invalid one.

FIRSTThe FIRST phrase causes only the first valid character to be replaced.

BEFOREThe BEFORE phrase designates as valid those characters to the left of the delimiter associated with it.

AFTERThe AFTER phrase designates as valid those characters to the right of the delimiter associated with it.

344

INSPECT Syntax - Format INSPECT Syntax - Format 22

PERFORM VARYING idx FROM 1 BY 1 UNTIL idx > 10

INSPECT TextLine REPLACING SwearWord(idx) BY "*#@!"

END-PERFORM

INSPECT StringData REPLACING ALL "FF" BY "GG" AFTER INITIAL "AA" BEFORE INITIAL "QQ".

FF FF FF FF AA FF FF FF FF FF QQ FF FF FF ZZ

StringDataStringData


INSPECT Example INSPECT Example 22

INSPECT StringData REPLACING ALL "FF" BY "GG" AFTER INITIAL "AA" BEFORE INITIAL "QQ".

FF FF FF FF AA GG GG GG GG GG QQ FF FF FF ZZ



INSPECT StringData REPLACING LEADING "FF" BY "GG" AFTER INITIAL "AA" BEFORE INITIAL "ZZ".




INSPECT StringData REPLACING LEADING "FF" BY "GG" AFTER INITIAL "AA" BEFORE INITIAL "ZZ".

FF FF FF FF AA GG GG GG GG GG QQ FF FF FF ZZ



INSPECT StringData REPLACING ALL "FF" BY "GG" AFTER INITIAL "AA" BEFORE INITIAL "ZZ".




INSPECT StringData REPLACING ALL "FF" BY "GG" AFTER INITIAL "AA" BEFORE INITIAL "ZZ".

FF FF FF FF AA GG GG GG GG GG QQ GG GG GG ZZ



INSPECT StringData REPLACING FIRST "FF" BY "GG" AFTER INITIAL "AA" BEFORE INITIAL "QQ".




INSPECT StringData REPLACING FIRST "FF" BY "GG" AFTER INITIAL "AA" BEFORE INITIAL "QQ".

FF FF FF FF AA GG FF FF FF FF QQ FF FF FF ZZ





INSPECT StringData REPLACING ALL "FFFFFFFF" BY "FROGFROG" AFTER INITIAL "AA" BEFORE INITIAL "QQ".


FF FF FF FF AA FF RR OO GG FF QQ FF FF FF ZZ


INSPECT StringData REPLACING ALL "FFFFFFFF" BY "FROGFROG" AFTER INITIAL "AA" BEFORE INITIAL "QQ".

355

INSPECT Syntax - Format 3INSPECT Syntax - Format 3

356

INSPECT Syntax - Format 4INSPECT Syntax - Format 4

INSPECT TextLine CONVERTING "0123456789" TO "5298317046" AFTER INITIAL "codeon" BEFORE INITIAL "codeoff".


INSPECT StringData CONVERTING "FXTDFXTD" TO "zyabzyab".

PP XX PP FF PP DD PP TT PP PP FF XX TT DD PP



INSPECT StringData CONVERTING "FXTDFXTD" TO "zyabzyab".

PP yy PP zz PP bb PP aa PP PP zz yy aa bb PP



INSPECT StringData REPLACING "FXTDFXTD" BY "zyabzyab".

PP XX PP FF PP DD PP TT PP PP FF XX TT DD PP



INSPECT StringData REPLACING "FXTDFXTD" BY "zyabzyab".

PP XX PP FF PP DD PP TT PP PP zz yy aa bb PP



PP xx PP ff PP dd PP TT PP PP ff xx TT dd PP


INSPECT StringData REPLACING ALL "xx" BY "yy" "dd" BY "zz" "ff" BY "ss".


INSPECT StringData REPLACING ALL "XX" BY "yy" "DD" BY "zz" "FF" BY "ss".

PP yy PP ss PP zz PP TT PP PP ss yy TT zz PP



INSPECT CustAddress CONVERTING "abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz" TO "ABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJKLMNOPQRSTUVWXYZ".

01 AlphaChars. 02 AlphaLower PIC X(26) VALUE "abcdefghijklmnopqrstuvwxyz". 02 AlphaUpper PIC X(26) VALUE "ABCDEFGHIJKLMNOPQRSTUVWXYZ".

INSPECT CustAddress CONVERTING AlphaLowerAlphaLower TO AlphaUpperAlphaUpper.INSPECT CustAddress CONVERTING AlphaUpperAlphaUpper TO AlphaLowerAlphaLower.


01 RussianPay PIC $$$,$$$,$$9.99.

MOVE 12345.67 TO RussianPay.INSPECT RussianPay REPLACING ALL "$"$" BY "RR".DISPLAY RussianPay " roubles".

RussianPayRussianPay


01 RussianPay PIC $$$,$$$,$$9.99.

MOVE 12345.67 TO RussianPay.MOVE 12345.67 TO RussianPay.INSPECT RussianPay REPLACING ALL "$"$" BY "RR".DISPLAY RussianPay " roubles".

$12,345.67$12,345.67RussianPayRussianPay


01 RussianPay PIC $$$,$$$,$$9.99.

MOVE 12345.67 TO RussianPay.INSPECT RussianPay REPLACING ALL "$$"" BY "RR".DISPLAY RussianPay " roubles".

RR12,345.6712,345.67RussianPayRussianPay


01 RussianPay PIC $$$,$$$,$$9.99.

MOVE 12345.67 TO RussianPay.INSPECT RussianPay REPLACING ALL "$"$" BY "RR".DISPLAY RussianPay " roubles".

RR12,345.6712,345.67RussianPayRussianPay

R12,345.67 roublesR12,345.67 roubles

STRISTRING NG

STRING Syntax.STRING Syntax.

STRING Ident1, Ident2, "10" DELIMITED BY SIZE

INTO DestStringEND-STRING.

STRING Ident1 DELIMITED BY SIZE Ident2 DELIMITED BY SPACES Ident3 DELIMITED BY "Frogs" INTO Ident4 WITH POINTER StrPtrEND-STRING.

How the STRING How the STRING WorksWorks

The STRING moves characters from the source string into the destination string from left to right. But no space filling occurs.

When there are a number of source strings, characters are moved from the leftmost source string first.

When a WITH POINTER phrase is used its value determines the starting character position for insertion into the destination string.

The ON OVERFLOW clause executes if there are still valid characters left in the source strings but the destination string is full.

STRING Example STRING Example 11

01 DayStr PIC XX. 55

01 MonthStr PIC X(9). J U N EJ U N E

01 YearStr PIC X(4). 1 9 9 41 9 9 401 DateStr PIC X(15) VALUE ALL "-".

- - - - - - - - - - - - - - -- - - - - - - - - - - - - - -

STRING DayStr DELIMITED BY SPACES ", " DELIMITED BY SIZE MonthStr DELIMITED BY SPACES ", " DELIMITED BY SIZE YearStr DELIMITED BY SIZE INTO DateStrEND-STRING.





55 - - - - - - - - - - - - - - - - - - - - - - - - - - - -

STRING DayStr DELIMITED BY SPACESDayStr DELIMITED BY SPACES ", " DELIMITED BY SIZE MonthStr DELIMITED BY SPACES ", " DELIMITED BY SIZE YearStr DELIMITED BY SIZE INTO DateStrEND-STRING.

STRING Example 1STRING Example 1




55 , , - - - - - - - - - - - - - - - - - - - - - - - - - -

STRING DayStr DELIMITED BY SPACES ", " DELIMITED BY SIZE", " DELIMITED BY SIZE MonthStr DELIMITED BY SPACES ", " DELIMITED BY SIZE YearStr DELIMITED BY SIZE INTO DateStrEND-STRING.





5 , J U N E 5 , J U N E - - - - - - - - -- - - - - - - - -

STRING DayStr DELIMITED BY SPACES ", " DELIMITED BY SIZE MonthStr DELIMITED BY SPACESMonthStr DELIMITED BY SPACES ", " DELIMITED BY SIZE YearStr DELIMITED BY SIZE INTO DateStrEND-STRING.





5 , J U N E , 5 , J U N E , - - - - - - - -- - - - - - - -

STRING DayStr DELIMITED BY SPACES ", " DELIMITED BY SIZE MonthStr DELIMITED BY SPACES ", " DELIMITED BY SIZE", " DELIMITED BY SIZE YearStr DELIMITED BY SIZE INTO DateStrEND-STRING.





5 , J U N E , 1 9 9 4 5 , J U N E , 1 9 9 4 - - - -- - - -

STRING DayStr DELIMITED BY SPACES ", " DELIMITED BY SIZE MonthStr DELIMITED BY SPACES ", " DELIMITED BY SIZE YearStr DELIMITED BY SIZEYearStr DELIMITED BY SIZE INTO DateStrEND-STRING.


01 StrPtr PIC 99.

01 DayStr PIC XX. 5 5



- - - - - - - - - - - - - - -- - - - - - - - - - - - - - -

MOVE 1 TO StrPtrSTRING DayStr DELIMITED BY SPACES "," DELIMITED BY SIZE INTO DateStr WITH POINTER StrPtrEND-STRING.STRING MonthStr DELIMITED BY SPACES "," DELIMITED BY SIZE INTO DateStr WITH POINTER StrPtrEND-STRING.STRING YearStr DELIMITED BY SIZE INTO DateStr WITH POINTER StrPtrEND-STRING.


01 StrPtr PIC 99.




5 , 5 , - - - - - - - - - - - - -- - - - - - - - - - - - -



01 StrPtr PIC 99.




5 , J U N E , 5 , J U N E , - - - - - - - -- - - - - - - -



01 StrPtr PIC 99.




5 , J U N E , 1 9 9 4 5 , J U N E , 1 9 9 4 - - - -- - - -


01 StringFields. 02 Field1 PIC X(18) VALUE "Where does this go". 02 Field2 PIC X(30) VALUE "This is the destination string". 02 Field3 PIC X(15) VALUE "Here is another".

01 StrPointers. 02 StrPtr PIC 99. 02 NewPtr PIC 9.

STRING Field1 DELIMITED BY SPACES INTO Field2END-STRING.DISPLAY Field2.


This is the destination stringThis is the destination string



STRING Field1 DELIMITED BY SPACES INTO Field2END-STRING.DISPLAY Field2.


WhereWhereis the destination stringis the destination string



STRING Field1 DELIMITED BY SIZE INTO Field2END-STRING.DISPLAY Field2.





STRING Field1 DELIMITED BY SIZE INTO Field2END-STRING.DISPLAY Field2.


Where does this goWhere does this goation stringation string



MOVE 6 TO StrPtr.STRING Field1, Field3 DELIMITED BY SPACE INTO Field2 WITH POINTER StrPtr ON OVERFLOW DISPLAY "String Error" NOT ON OVERFLOW DISPLAY Field2END-STRING.





MOVE 6 TO StrPtr.STRING Field1, Field3 DELIMITED BY SPACE INTO Field2 WITH POINTER StrPtr ON OVERFLOW DISPLAY "String Error" NOT ON OVERFLOW DISPLAY Field2END-STRING.


This This WhereHereWhereHerestination stringstination string



STRING Field1, Field2, Field3 DELIMITED BY SPACES INTO Field4END-STRING.DISPLAY Field4




STRING Field1, Field2, Field3 DELIMITED BY SPACES INTO Field4END-STRING.DISPLAY Field4


WhereThisHereWhereThisHere



MOVE 4 TO NewPtr.STRING Field1 DELIMITED BY "this" Field3 DELIMITED BY SPACE "END" DELIMITED BY SIZE INTO Field2END-STRING.





MOVE 4 TO NewPtr.STRING Field1 DELIMITED BY "this" Field3 DELIMITED BY SPACE "END" DELIMITED BY SIZE INTO Field2END-STRING.


Where does HereENDWhere does HereENDation stringation string



MOVE 4 TO NewPtr.STRING Field1 DELIMITED BY "this" Field3 DELIMITED BY SPACE "Tom" DELIMITED BY SIZE INTO Field2 WITH POINTER NewPtr ON OVERFLOW DISPLAY "String Error" NOT ON OVERFLOW DISPLAY Field2END-STRING.





MOVE 4 TO NewPtr.STRING Field1 DELIMITED BY "this" Field3 DELIMITED BY SPACE "Tom" DELIMITED BY SIZE INTO Field2 WITH POINTER NewPtr ON OVERFLOW DISPLAY "String Error" NOT ON OVERFLOW DISPLAY Field2END-STRING.


ThiThiWhere Where he destination stringhe destination string

UNSTRUNSTRING ING

UNSTRING Syntax.UNSTRING Syntax.

UNSTRING FullName DELIMITED BY ALL SPACES INTO FirstName, SecondName, SurnameEND-UNSTRING

UNSTRING CustAddress DELIMITED BY "," INTO AdrLine(1), AdrLine(2), AdrLine(3), AdrLine(4), AdrLine(5), AdrLine(6) TALLYING IN AdrLinesUsedEND-UNSTRING.

395

How the UNSTRING How the UNSTRING worksworks

The UNSTRING copies characters from the Source String to the Destination String until a Delimiter is encountered in the Source String or the Destination String is full.

When either of these things happen the next Destination String becomes the receiving area and characters are copied into it until it too is full or another Delimiter is encountered in the Source String.

Characters are copied from the Source String to the Destination Strings according to the rules for Alphanumeric moves. There is space filling.

396

UNSTRING UNSTRING TerminationTermination

The UNSTRING statement terminates when:-

All the characters in the Source String have been examinedOR

All the Destination Strings have been processed

OR

Some error condition is encountered.

397

UNSTRING UNSTRING clauses.clauses.

ON OVERFLOW.The ON OVERFLOW is activated if :-

– The Unstring pointer (Pointer#i) is not pointing to a character position within the SourceString when the UNSTRING executes.

– All the Destination Strings have been processed but there are still valid unexamined characters in the Source String.

COUNT IN The COUNT IN clause is associated with a particular Destination String and holds a count of the number of characters passed to the Destination String.

TALLYING INOnly one TALLYING clause can be used with each UNSTRING. It holds a count of the number of Destination Strings affected by the UNSTRING operation.

398

The UNSTRING clauses 2.The UNSTRING clauses 2.

WITH POINTERThe Pointer#i holds the position of the next non-delimiter character to be examined in the Source String.

Pointer#i must be large enough to hold a value one greater than the size of the Source String.

DELIMITER INA DELIMITER IN clause is associated with a particular Destination String. HoldDelim$i holds the Delimiter that was encountered in the Source String.

ALLWhen the ALL phrase is used, contiguous delimiters are treated as if only one delimiter had been encountered.

UNSTRING Example 1UNSTRING Example 1

01 DayStr PIC XX.

01 MonthStr PIC XX.

01 YearStr PIC XX.

01 DateStr PIC X(8). 1 9 - 0 5 - 8 01 9 - 0 5 - 8 0

ACCEPT DateStr.UNSTRING DateStr INTO DayStr, MonthStr, YearStr ON OVERFLOW DISPLAY "Chars Left"END-UNSTRING.


01 DayStr PIC XX. 1 91 9

01 MonthStr PIC XX.

01 YearStr PIC XX.

01 DateStr PIC X(8). 1 91 9 - 0 5 - 8 0 - 0 5 - 8 0




01 MonthStr PIC XX. - 0- 0

01 YearStr PIC XX.

01 DateStr PIC X(8). 1 9 1 9 - 0- 0 5 - 8 0 5 - 8 0





01 YearStr PIC XX. 5 -5 -

01 DateStr PIC X(8). 1 9 - 0 1 9 - 0 5 -5 - 8 0 8 0





01 YearStr PIC XX. 5 -5 -

01 DateStr PIC X(8). 1 9 - 0 5 - 8 01 9 - 0 5 - 8 0


Chars LeftChars Left Chars LeftChars Left


01 DayStr PIC XX.

01 MonthStr PIC XX.

01 YearStr PIC XX. 01 DateStr PIC X(8).

1 9 s t o p 0 5 s t o p 8 01 9 s t o p 0 5 s t o p 8 0

ACCEPT DateStr.UNSTRING DateStr DELIMITED BY "stop" INTO DayStr, MonthStr, YearStr ON OVERFLOW DISPLAY "Chars Left"END-UNSTRING.



01 MonthStr PIC XX.


1 91 9 s t o ps t o p 0 5 s t o p 8 0 0 5 s t o p 8 0




01 MonthStr PIC XX. 0 50 5


1 9 s t o p 1 9 s t o p 0 50 5 s t o ps t o p 8 0 8 0





01 YearStr PIC XX. 8 08 001 DateStr PIC X(8).

1 9 s t o p 0 5 s t o p 1 9 s t o p 0 5 s t o p 8 08 0




01 MonthStr PIC XX.

01 YearStr PIC XX.

01 DateStr PIC X(8). 1 91 9 -- 0 5 / 8 0 0 5 / 8 0

ACCEPT DateStr.UNSTRING DateStr DELIMITED BY "/" OR "-" INTO DayStr DELIMITER IN Hold1 MonthStr DELIMITER IN Hold2 YearStrEND-UNSTRING.DISPLAY DayStr SPACE MonthStr SPACE YearStr.DISPLAY Hold1 SPACE Hold2




01 YearStr PIC XX.

01 DateStr PIC X(8). 1 9 - 1 9 - 0 50 5 // 8 0 8 0





01 YearStr PIC XX. 8 08 0

01 DateStr PIC X(8). 1 9 - 0 5 / 1 9 - 0 5 / 8 08 0






01 DateStr PIC X(8). 1 9 - 0 5 / 8 01 9 - 0 5 / 8 0


19 05 8019 05 80- /- /19 05 8019 05 80- /- /


01 DayStr PIC XX.

01 MonthStr PIC XX.

01 YearStr PIC XX.

01 DateStr PIC X(8). 1 9 - 0 5 / 8 01 9 - 0 5 / 8 0

ACCEPT DateStr.UNSTRING DateStr DELIMITED BY "/" OR "-" INTO DayStr DELIMITER IN Hold1 MonthStr DELIMITER IN Hold1 YearStrEND-UNSTRING.DISPLAY DayStr SPACE MonthStr SPACE YearStr.DISPLAY Hold1





01 DateStr PIC X(8). 1 9 - 0 5 / 8 01 9 - 0 5 / 8 0

ACCEPT DateStr.UNSTRING DateStr DELIMITED BY "/" OR "-" INTO DayStr DELIMITER IN Hold1 MonthStr DELIMITER IN Hold1 YearStrEND-UNSTRING.DISPLAY DayStr SPACE MonthStr SPACE YearStr.DISPLAY Hold1

19 05 8019 05 80//19 05 8019 05 80//


01 DayStr PIC XX.

01 MonthStr PIC XX.

01 YearStr PIC XX.

01 DateStr PIC X(11). 1 5 - - - 0 7 - - 9 41 5 - - - 0 7 - - 9 4

ACCEPT DateStr.UNSTRING DateStr DELIMITED BY ALL "-" INTO DayStr, MonthStr, YearStr ON OVERFLOW DISPLAY "Chars Left"END-UNSTRING.





01 DateStr PIC X(11). 1 51 5 - - -- - - 0 70 7 - -- - 9 49 4

ACCEPT DateStr.UNSTRING DateStr DELIMITED BY ALL "-" INTO DayStr, MonthStr, YearStr ON OVERFLOW DISPLAY "Chars Left"END-UNSTRING.


01 DayStr PIC XX.

01 MonthStr PIC XX.

01 YearStr PIC XX.

01 DateStr PIC X(11). 1 5 - - - 0 7 - - 9 41 5 - - - 0 7 - - 9 4

ACCEPT DateStr.UNSTRING DateStr DELIMITED BY "-" INTO DayStr, MonthStr, YearStr ON OVERFLOW DISPLAY "Chars Left"END-UNSTRING.



01 MonthStr PIC XX.

01 YearStr PIC XX.

01 DateStr PIC X(11). 1 51 5 - - - - - 0 7 - - 9 4- 0 7 - - 9 4

ACCEPT DateStr.UNSTRING DateStr DELIMITED BY "-" INTO DayStr, MonthStr, YearStr ON OVERFLOW DISPLAY "Chars Left"END-UNSTRING.

Chars LeftChars LeftChars LeftChars Left

UNSTRING Example 7UNSTRING Example 701 OldName PIC X(80).

01 TempName. 02 NameInitial PIC X. 02 FILLER PIC X(15).

01 NewName PIC X(30).

01 Pointers. 02 StrPtr PIC 99 VALUE 1. 02 UnstrPtr PIC 99 VALUE 1. 88 NameProcessed VALUE 81.

PROCEDURE DIVISION.ProcessName. ACCEPT OldName. PERFORM UNTIL NameProcessed UNSTRING OldName DELIMITED BY ALL SPACES INTO TempName WITH POINTER UnstrPtr END-UNSTRING Display TempName END-PERFORM STOP RUN.

Tim John RobertsTim John Roberts






TimTimTimTim

TimTim John Roberts John Roberts

T imT im






JohnJohnJohnJohn

Tim Tim JohnJohn Roberts Roberts

J ohnJ ohn






RobertsRobertsRobertsRoberts

Tim John Tim John RobertsRoberts

R obertsR oberts


OldName

TempName

NewName

PROCEDURE DIVISION.ProcessName. ACCEPT OldName. UNSTRING OldName DELIMITED BY ALL SPACES INTO TempName WITH POINTER UnstrPtr END-UNSTRING PERFORM UNTIL NameProcessed STRING NameInitial "." DELIMITED BY SIZE INTO NewName WITH POINTER StrPtr END-STRING UNSTRING OldName DELIMITED BY ALL SPACES INTO TempName WITH POINTER UnstrPtr END-UNSTRING END-PERFORM STRING SPACE TempName DELIMITED BY SIZE INTO NewName WITH POINTER StrPtr END-STRING STOP RUN.



OldName

TempName

NewName


TimTim John Roberts John Roberts

T imT im


OldName

TempName

NewName



TT im im

T .T .


OldName

TempName

NewName


Tim Tim JohnJohn Roberts Roberts

J ohnJ ohn

T .T .


OldName

TempName

NewName



J J ohnohn

T . T . J .J .


OldName

TempName

NewName


Tim John Tim John RobertsRoberts

R obertsR oberts

T . J .T . J .

UNSTRING Example UNSTRING Example 88

OldName

TempName

NewName



R obertsR oberts

T . J . T . J . RobertsRoberts

IntroductioIntroductionn

to to Sequential Sequential

FilesFiles

430

COBOL's COBOL's forteforte

COBOL is generally used in situations where the volume of data to be processed is large.

These systems are sometimes referred to as “data intensive” systems.

Generally, large volumes of data arise not because the data is inherently voluminous but because the same items of information have been recorded about a great many instances of the same object.

431

Files, Records, Files, Records, Fields.Fields.

We use the term FIELD to describe an item of information we are recording about an object

(e.g. StudentName, DateOfBirth, CourseCode).

We use the term RECORD to describe the collection of fields which record information about an object

(e.g. a StudentRecord is a collection of fields recording information about a student).

We use the term FILE to describe a collection of one or more occurrences (instances) of a record type (template).

It is important to distinguish between the record occurrence (i.e. the values of a record) and the record type (i.e. the structure of the record). Every record in a file has a different value but the same structure.

432

Files, Records, Files, Records, Fields.Fields.

StudId StudName DateOfBirthStudId StudName DateOfBirth9723456 COUGHLAN 100919619724567 RYAN 311219769534118 COFFEY 230619649423458 O'BRIEN 031119799312876 SMITH 12121976

StudId StudName DateOfBirthStudId StudName DateOfBirth9723456 COUGHLAN 100919619724567 RYAN 311219769534118 COFFEY 230619649423458 O'BRIEN 031119799312876 SMITH 12121976

STUDENTS.DATSTUDENTS.DAT

DATA DIVISION.FILE SECTION.FD StudentFile.01 StudentDetails. 02 StudId PIC 9(7). 02 StudName PIC X(8). 02 DateOfBirth PIC X(8).

DATA DIVISION.FILE SECTION.FD StudentFile.01 StudentDetails. 02 StudId PIC 9(7). 02 StudName PIC X(8). 02 DateOfBirth PIC X(8).

occurrencesoccurrences

Record Type Record Type (Template)(Template)(Structure)(Structure)

433

How files are How files are processed.processed.

Files are repositories of data that reside on backing storage (hard disk or magnetic tape).

A file may consist of hundreds of thousands or even millions of records.

Suppose we want to keep information about all the TV license holders in the country. Suppose each record is about 150 characters/bytes long. If we estimate the number of licenses at 1 million this gives us a size for the file of 150 X 1,000,000 = 150 megabytes.

If we want to process a file of this size we cannot do it by loading the whole file into the computer’s memory at once.

Files are processed by reading them into the computer’s memory one record at a time.

434

Record Record BuffersBuffers

To process a file records are read from the file into the computer’s memory one record at a time.

The computer uses the programmers description of the record (i.e. the record template) to set aside sufficient memory to store one instance of the record.

Memory allocated for storing a record is usually called a “record buffer”

The record buffer is the only connection between the program and the records in the file.

435

Record Record BuffersBuffers

IDENTIFICATION DIVISION.etc.ENVIRONMENT DIVISION.etc.DATA DIVISION.FILE SECTION.

ProgramProgram

RecordBufferRecordBuffer DeclarationDeclaration

STUDENTS.DAT

DISK Record Instance

436

Implications of Implications of ‘Buffers’‘Buffers’

If your program processes more than one file you will have to describe a record buffer for each file.

To process all the records in an INPUT file each record instance must be copied (read) from the file into the record buffer when required.

To create an OUTPUT file containing data records each record must be placed in the record buffer and then transferred (written) to the file.

To transfer a record from an input file to an output file we will have to

– read the record into the input record buffer– transfer it to the output record buffer– write the data to the output file from the output record buffer

Creating a Student Creating a Student RecordRecord

01 StudentDetails.

Student Id. 02 StudentId PIC 9(7).

Student Name. 02 StudentName.

Surname 03 Surname PIC X(8).

Initials 03 Initials PIC XX. Date of Birth 02 DaateOfBirth.

Year of Birth 03 YOBirth PIC 99.

Month of Birth 03 MOBirth PIC 99.

Day of Birth 03 DOBirth PIC 99. Course Code 02 CourseCode PIC X(4).

Value of grant 02 Grant PIC 9(4).

Gender 02 Gender PIC X.

01 StudentDetails.

Student Id. 02 StudentId PIC 9(7).

Student Name. 02 StudentName.

Surname 03 Surname PIC X(8).

Initials 03 Initials PIC XX. Date of Birth 02 DaateOfBirth.

Year of Birth 03 YOBirth PIC 99.

Month of Birth 03 MOBirth PIC 99.

Day of Birth 03 DOBirth PIC 99. Course Code 02 CourseCode PIC X(4).

Value of grant 02 Grant PIC 9(4).

Gender 02 Gender PIC X.

Student Details.Student Details.

438

Describing the record buffer in COBOLDescribing the record buffer in COBOL

The record type/template/buffer of every file used in a program must be described in the FILE SECTION by means of an FD (file description) entry.

The FD entry consists of the letters FD and an internal file name.

DATA DIVISION.FILE SECTION.FD StudentFile.01 StudentDetails. 02 StudentId PIC 9(7). 02 StudentName. 03 Surname PIC X(8). 03 Initials PIC XX. 02 DateOfBirth. 03 YOBirth PIC 9(2). 03 MOBirth PIC 9(2). 03 DOBirth PIC 9(2). 02 CourseCode PIC X(4). 02 Grant PIC 9(4). 02 Gender PIC X.


439

STUDENTS.DAT

The Select and Assign The Select and Assign Clause.Clause.

The internal file name used in the FD entry is connected to an external file (on disk or tape) by means of the Select and Assign clause.

ENVIRONMENT DIVISION.INPUT-OUTPUT SECTION.FILE-CONTROL. SELECT StudentFile ASSIGN TO “STUDENTS.DAT”.


ENVIRONMENT DIVISION.INPUT-OUTPUT SECTION.FILE-CONTROL. SELECT StudentFile ASSIGN TO “STUDENTS.DAT”.


DISK

440

Select and Assign Select and Assign Syntax.Syntax.

LINE SEQUENTIAL means each record is followed by the carriage return and line feed characters.

RECORD SEQUENTIAL means that the file consists of a stream of bytes. Only the fact that we know the size of each record allows us to retrieve them.

SELECT FileName ASSIGN TO ExternalFileReference

[ORGANIZATION IS LINE

RECORD SEQUENTIAL].

441

COBOL file handling COBOL file handling VerbsVerbs

OPENBefore your program can access the data in an input file or place data in an output file you must make the file available to the program by OPENing it.

READThe READ copies a record occurrence/instance from the file and places it in the record buffer.

WRITE The WRITE copies the record it finds in the record buffer to the file.

CLOSEYou must ensure that (before terminating) your program closes all the files it has opened. Failure to do so may result in data not being written to the file or users being prevented from accessing the file.

442

OPEN and CLOSE verb OPEN and CLOSE verb syntaxsyntax

When you open a file you have to indicate to the system what how you want to use it (e.g. INPUT, OUTPUT, EXTEND) so that the system can manage the file correctly.

Opening a file does not transfer any data to the record buffer, it simply provides access.

OPEN InternalFileName ...

INPUT

OUTPUT

EXTEND

443

The READ verb The READ verb

Once the system has opened a file and made it available to the program it is the programmers responsibility to process it correctly.

Remember, the file record buffer is our only connection with the file and it is only able to store a single record at a time.

To process all the records in the file we have to transfer them, one record at a time, from the file to the buffer.

COBOL provides the READ verb for this purpose.

444

READ verb READ verb syntaxsyntax

The InternalFilename specified must be a file that has been OPENed for INPUT.

The NEXT RECORD clause is optional and generally not used.

Using INTO Identifier clause causes the data to be read into the record buffer and then copied from there to the specified Identifier in one operation.

– When this option is used there will be two copies of the data. It is the equivalent of a READ followed by a MOVE.

READ InternalFilename NEXT RECORD

INTO Identifier

AT END StatementBlock

END - READ

445

PERFORM UNTIL StudentRecord = HIGH-VALUES READ StudentRecords AT END MOVE HIGH-VALUES TO StudentRecord END-READEND-PERFORM.

FF rr aa nn kk CC uu rr tt aa ii nn99 33 33 44 55 66 77 LL MM 00 55 11

StudentID StudentName Course.

StudentRecord

FF rr aa nn kk CC uu rr tt aa ii nn99 33 33 44 55 66 77 LL MM 00 55 11T h o m a s H e a l y9 3 8 3 7 1 5 L M 0 6 8T o n y O ‘ B r i a n9 3 4 7 2 9 2 L M 0 5 1B i l l y D o w n e s9 3 7 8 8 1 1 L M 0 2 1

EOF

How the READ How the READ worksworks

446

TT hh oo mm aa ss HH ee aa ll yy 99 33 88 33 77 11 55 LL MM 00 66 88


StudentRecord

F r a n k C u r t a i n9 3 3 4 5 6 7 L M 0 5 1

TT hh oo mm aa ss HH ee aa ll yy99 33 88 33 77 11 55 LL MM 00 66 88T o n y O ‘ B r i a n9 3 4 7 2 9 2 L M 0 5 1B i l l y D o w n e s9 3 7 8 8 1 1 L M 0 2 1

EOF



447

TT oo nn yy OO ‘‘ BB rr ii aa nn 99 33 44 77 22 99 22 LL MM 00 55 11


StudentRecord

F r a n k C u r t a i n9 3 3 4 5 6 7 L M 0 5 1T h o m a s H e a l y9 3 8 3 7 1 5 L M 0 6 8TT oo nn yy OO ‘‘ BB rr ii aa nn99 33 44 77 22 99 22 LL MM 00 55 11B i l l y D o w n e s9 3 7 8 8 1 1 L M 0 2 1

EOF



448

BB ii ll ll yy DD oo ww nn ee ss 99 33 77 88 88 11 11 LL MM 00 22 11


StudentRecord

F r a n k C u r t a i n9 3 3 4 5 6 7 L M 0 5 1T h o m a s H e a l y9 3 8 3 7 1 5 L M 0 6 8T o n y O ‘ B r i a n9 3 4 7 2 9 2 L M 0 5 1

BB ii ll ll yy DD oo ww nn ee ss99 33 77 88 88 11 11 LL MM 00 22 11

EOF



449


StudentRecord

F r a n k C u r t a i n9 3 3 4 5 6 7 L M 0 5 1T h o m a s H e a l y9 3 8 3 7 1 5 L M 0 6 8T o n y O ‘ B r i a n9 3 4 7 2 9 2 L M 0 5 1B i l l y D o w n e s9 3 7 8 8 1 1 L M 0 2 1

EOF

HIGH-VALUES



450

WRITE WRITE Syntax.Syntax.

To WRITE data to a file move the data to the record buffer (declared in the FD entry) and then WRITE the contents of record buffer to the file.

WRITE

ADVANCING

AdvanceNum

MnemonicName

PAGE

RecordName FROM Identifier

BEFORE

AFTER

LINE

LINES



StudentRecord


EOF

How the WRITE How the WRITE worksworks

OPEN OUTPUT StudentFile. MOVE "9334567Frank Curtain LM051" TO StudentDetails. WRITE StudentDetails. MOVE "9383715Thomas Healy LM068" TO StudentDetails. WRITE StudentDetails. CLOSE StudentFile. STOP RUN.


Students.Dat

TT hh oo mm aa ss HH ee aa ll yy 99 33 88 33 77 11 55 LL MM 00 66 88


StudentRecord

F r a n k C u r t a i n9 3 3 4 5 6 7 L M 0 5 1

TT hh oo mm aa ss HH ee aa ll yy99 33 88 33 77 11 55 LL MM 00 66 88

EOF

How the WRITE How the WRITE worksworks



Students.Dat

$ SET SOURCEFORMAT"FREE"IDENTIFICATION DIVISION.PROGRAM-ID. SeqWrite.AUTHOR. Michael Coughlan.

ENVIRONMENT DIVISION.INPUT-OUTPUT SECTION.FILE-CONTROL. SELECT StudentFile ASSIGN TO "STUDENTS.DAT"

ORGANIZATION IS LINE SEQUENTIAL.


PROCEDURE DIVISION.Begin. OPEN OUTPUT StudentFile. DISPLAY "Enter student details using template below. Enter no data to end.". PERFORM GetStudentDetails. PERFORM UNTIL StudentDetails = SPACES WRITE StudentDetails PERFORM GetStudentDetails END-PERFORM. CLOSE StudentFile. STOP RUN.

GetStudentDetails. DISPLAY "NNNNNNNSSSSSSSSIIYYMMDDCCCCGGGGS". ACCEPT StudentDetails.





PROCEDURE DIVISION.Begin. OPEN OUTPUT StudentFile. DISPLAY "Enter student details using template below. Enter no data to end.". PERFORM GetStudentDetails. PERFORM UNTIL StudentDetails = SPACES WRITE StudentDetails PERFORM GetStudentDetails END-PERFORM. CLOSE StudentFile. STOP RUN.

GetStudentDetails. DISPLAY "NNNNNNNSSSSSSSSIIYYMMDDCCCCGGGGS". ACCEPT StudentDetails.

$ SET SOURCEFORMAT"FREE"IDENTIFICATION DIVISION.PROGRAM-ID. SeqRead.AUTHOR. Michael Coughlan.

ENVIRONMENT DIVISION.INPUT-OUTPUT SECTION.FILE-CONTROL. SELECT StudentFile ASSIGN TO “STUDENTS.DAT”



PROCEDURE DIVISION.Begin. OPEN INPUT StudentFile READ StudentFile AT END MOVE HIGH-VALUES TO StudentDetails END-READ PERFORM UNTIL StudentDetails = HIGH-VALUES DISPLAY StudentId SPACE StudentName SPACE CourseCode READ StudentFile AT END MOVE HIGH-VALUES TO StudentDetails END-READ END-PERFORM CLOSE StudentFile STOP RUN.


ENVIRONMENT DIVISION.INPUT-OUTPUT SECTION.FILE-CONTROL. SELECT StudentFile ASSIGN TO “STUDENTS.DAT”




ProcesProcessingsing

SequenSequentialtial

Files Files


OPEN OUTPUT StudentFileDISPLAY "Enter student details using template below. Press CR to end.". PERFORM GetStudentDetailsPERFORM UNTIL StudentDetails = SPACES

WRITE StudentDetailsPERFORM GetStudentDetails

END-PERFORMCLOSE StudentFileSTOP RUN.

GetStudentDetails.DISPLAY "NNNNNNNSSSSSSSSIIYYMMDDCCCCGGGGS".ACCEPT StudentDetails.


OPEN OUTPUT StudentFileDISPLAY "Enter student details using template below. Press CR to end.". PERFORM GetStudentDetailsPERFORM UNTIL StudentDetails = SPACES

WRITE StudentDetailsPERFORM GetStudentDetails

END-PERFORMCLOSE StudentFileSTOP RUN.

GetStudentDetails.DISPLAY "NNNNNNNSSSSSSSSIIYYMMDDCCCCGGGGS".ACCEPT StudentDetails.

Enter student details using template below. Press CR to end.NNNNNNNSSSSSSSSIIYYMMDDCCCCGGGGS9456789COUGHLANMS580812LM510598MNNNNNNNSSSSSSSSIIYYMMDDCCCCGGGGS9367892RYAN TG521210LM601222FNNNNNNNSSSSSSSSIIYYMMDDCCCCGGGGS9368934WILSON HR520323LM610786MNNNNNNNSSSSSSSSIIYYMMDDCCCCGGGGSCarriageReturn

Enter student details using template below. Press CR to end.NNNNNNNSSSSSSSSIIYYMMDDCCCCGGGGS9456789COUGHLANMS580812LM510598MNNNNNNNSSSSSSSSIIYYMMDDCCCCGGGGS9367892RYAN TG521210LM601222FNNNNNNNSSSSSSSSIIYYMMDDCCCCGGGGS9368934WILSON HR520323LM610786MNNNNNNNSSSSSSSSIIYYMMDDCCCCGGGGSCarriageReturn

Run of SeqWrite $ SET SOURCEFORMAT"FREE"IDENTIFICATION DIVISION.PROGRAM-ID. SeqWrite.AUTHOR. Michael Coughlan.
























RUN OF SeqRead

458

Organization and Organization and AccessAccess

Two important characteristics of files are– DATA ORGANIZATIONDATA ORGANIZATION– METHOD OF ACCESSMETHOD OF ACCESS

Data organization refers to the way the records of the file are organized on the backing storage device.COBOL recognizes three main file organizations;

– Sequential - Records organized serially. – Relative - Relative record number based organization.– Indexed - Index based organization.

The method of access refers to the way in which records are accessed. – A file with an organization of Indexed or Relative may

still have its records accessed sequentially. – But records in a file with an organization of Sequential can not be accessed

directly.

459

Sequential Sequential OrganizationOrganization

The simplest COBOL file organization is Sequential.

In a Sequential file the records are arranged serially, one after another, like cards in a dealing shoe.

In a Sequential file the only way to access any particular record is to; Start at the first record and read all the succeeding records until you find the one you want or reach the end of the file.

Sequential files may be OrderedOrdered

orUnorderedUnordered (these should be called Serial files)

The ordering of the records in a file has a significant impact on the way in which it is processed and the processing that can be done on it.

460

Ordered and Unordered Ordered and Unordered FilesFiles

RecordA

RecordB

RecordG

RecordH

RecordK

RecordM

RecordN

RecordA

RecordB

RecordG

RecordH

RecordK

RecordM

RecordN

Ordered File

RecordM

RecordH

RecordB

RecordN

RecordA

RecordK

RecordG

RecordM

RecordH

RecordB

RecordN

RecordA

RecordK

RecordG

Unordered File

In an ordered file the records are sequenced on some field in the record.

RecordF

RecordP

RecordW

RecordF

RecordP

RecordW

TransactionFile

RecordM

RecordH

RecordB

RecordN

RecordA

RecordK

RecordG

RecordM

RecordH

RecordB

RecordN

RecordA

RecordK

RecordG

Unordered FilePROGRAM

PROGRAMFILE SECTION.

PROCEDURE DIVISION.

OPEN EXTEND UF.

OPEN INPUT TF.

READ TF.

MOVE TFRec TO UFRec.

WRITE UFRec.

FILE SECTION.

PROCEDURE DIVISION.

OPEN EXTEND UF.

OPEN INPUT TF.

READ TF.


WRITE UFRec.

TFRecTFRec

UFRecUFRec

Adding records to unordered Adding records to unordered filesfiles

RecordFRecordF

RecordP

RecordW

RecordFRecordF

RecordP

RecordW

TransactionFile

RecordM

RecordH

RecordB

RecordN

RecordA

RecordK

RecordG

RecordFRecordF

RecordM

RecordH

RecordB

RecordN

RecordA

RecordK

RecordG

RecordFRecordF

Unordered FilePROGRAM

PROGRAMFILE SECTION.

PROCEDURE DIVISION.

OPEN EXTEND UF.

OPEN INPUT TF.

READ TF.


WRITE UFRec.

FILE SECTION.

PROCEDURE DIVISION.

OPEN EXTEND UF.

OPEN INPUT TF.

READ TF.


WRITE UFRec.

RecordFRecordF

RecordFRecordF


RecordFRecordF

RecordPRecordP

RecordWRecordW

RecordFRecordF

RecordPRecordP

RecordWRecordW

TransactionFile

RecordM

RecordH

RecordB

RecordN

RecordA

RecordK

RecordG

RecordFRecordF

RecordPRecordP

RecordWRecordW

RecordM

RecordH

RecordB

RecordN

RecordA

RecordK

RecordG

RecordFRecordF

RecordPRecordP

RecordWRecordW

Unordered File

RESULTRESULT


464

Problems with Unordered Sequential Problems with Unordered Sequential FilesFiles

It is easy to add records to an unordered Sequential file.

But it is not really possible to delete records from an unordered Sequential file.

And it is not feasible to update records in an unordered Sequential file

465

Records in a Sequential file can not be deleted or updated “in situ”.

The only way to delete Sequential file records is to create a new file which does not contain them.

The only way to update records in a Sequential File is to create a new file which contains the updated records.

Because both these operations rely on record matching they do not work for unordered Sequential files.

Why?

Problems with Unordered Sequential FilesProblems with Unordered Sequential Files

Deleting records from unordered Deleting records from unordered files?files?

RecordBRecordB

RecordM

RecordK

RecordBRecordB

RecordM

RecordK

Transaction File

RecordMRecordM

RecordH

RecordB

RecordN

RecordA

RecordK

RecordMRecordM

RecordH

RecordB

RecordN

RecordA

RecordK

Unordered File

New File

Delete UFDelete UFRecord?Record?

RecordMRecordMRecordMRecordM

NONO

RecordBRecordB

RecordM

RecordK

RecordBRecordB

RecordM

RecordK

Transaction File

RecordM

RecordHRecordH

RecordB

RecordN

RecordA

RecordK

RecordM

RecordHRecordH

RecordB

RecordN

RecordA

RecordK

Unordered File

New File


RecordM

RecordHRecordH

RecordM

RecordHRecordHNONO


RecordBRecordB

RecordM

RecordK

RecordBRecordB

RecordM

RecordK

Transaction File

RecordM

RecordH

RecordBRecordB

RecordN

RecordA

RecordK

RecordM

RecordH

RecordBRecordB

RecordN

RecordA

RecordK

Unordered File

New File


RecordM

RecordH

RecordM

RecordHYESYES


RecordB

RecordMRecordM

RecordK

RecordB

RecordMRecordM

RecordK

Transaction File

RecordM

RecordH

RecordB

RecordNRecordN

RecordA

RecordK

RecordM

RecordH

RecordB

RecordNRecordN

RecordA

RecordK

Unordered File

New File


RecordM

RecordH

RecordNRecordN

RecordM

RecordH

RecordNRecordN

NONO

But wait...We should have deleted RecordM. Too late. It’s already been written to the new file.


RecordB

RecordK

RecordM

RecordB

RecordK

RecordM

Transaction File

RecordA

RecordB

RecordG

RecordH

RecordK

RecordM

RecordN

RecordA

RecordB

RecordG

RecordH

RecordK

RecordM

RecordN

Ordered File

New FilePROGRAM

FILE SECTION.

PROCEDURE DIVISION.OPEN INPUT TF.OPEN INPUT OFOPEN OUTPUT NF.READ TF.READ OF.IF TFKey NOT = OFKeyMOVE OFRec TO NFRecWRITE NFRecREAD OF

ELSEREAD TFREAD OF

END-IF.

FILE SECTION.


ELSEREAD TFREAD OF

END-IF.

TFRecTFRec

OFRecOFRec

NFRecNFRec

Deleting records from an ordered Deleting records from an ordered filefile

RecordBRecordB

RecordK

RecordM

RecordBRecordB

RecordK

RecordM

Transaction File

RecordARecordA

RecordB

RecordG

RecordH

RecordK

RecordM

RecordN

RecordARecordA

RecordB

RecordG

RecordH

RecordK

RecordM

RecordN

Ordered File

New FilePROGRAM

RecordARecordARecordARecordAFILE SECTION.

PROCEDURE DIVISION.OPEN INPUT TF.OPEN INPUT OFOPEN OUTPUT NF.READ TF.READ OF.IF TFRec NOT = OFRecMOVE OFRec TO NFRecWRITE NFRecREAD OF

ELSEREAD TFREAD OF

END-IF.

FILE SECTION.

PROCEDURE DIVISION.OPEN INPUT TF.OPEN INPUT OFOPEN OUTPUT NF.READ TF.READ OF.IF TFRec NOT = OFRecMOVE OFRec TO NFRecWRITE NFRecREAD OF

ELSEREAD TFREAD OF

END-IF.

RecordBRecordB

RecordARecordA

RecordARecordA


Problem !!How can we

recognize which record we want

to delete?

By its Key Field

RecordB

RecordK

RecordM

RecordB

RecordK

RecordM

Transaction File

RecordA

RecordBRecordB

RecordG

RecordH

RecordK

RecordM

RecordN

RecordA

RecordBRecordB

RecordG

RecordH

RecordK

RecordM

RecordN

Ordered File

New FilePROGRAM

FILE SECTION.


ELSEREAD TFREAD OF

END-IF.

FILE SECTION.


ELSEREAD TFREAD OF

END-IF.

RecordBRecordB

RecordBRecordB

RecordARecordA


RecordARecordA

RecordB

RecordKRecordK

RecordM

RecordB

RecordKRecordK

RecordM

Transaction File

RecordA

RecordB

RecordGRecordG

RecordH

RecordK

RecordM

RecordN

RecordA

RecordB

RecordGRecordG

RecordH

RecordK

RecordM

RecordN

Ordered File

New FilePROGRAM

RecordA

RecordGRecordG

RecordA

RecordGRecordG

FILE SECTION.


ELSEREAD TFREAD OF

END-IF.

FILE SECTION.


ELSEREAD TFREAD OF

END-IF.

RecordKRecordK

RecordGRecordG

RecordGRecordG


RecordBRecordB

RecordKRecordK

RecordMRecordM

RecordBRecordB

RecordKRecordK

RecordMRecordM

Transaction File

RecordARecordA

RecordBRecordB

RecordGRecordG

RecordHRecordH

RecordKRecordK

RecordMRecordM

RecordNRecordN

RecordARecordA

RecordBRecordB

RecordGRecordG

RecordHRecordH

RecordKRecordK

RecordMRecordM

RecordNRecordN

Ordered File

New File

RESULTRESULT

RecordARecordA

RecordGRecordG

RecordHRecordH

RecordNRecordN

RecordARecordA

RecordGRecordG

RecordHRecordH

RecordNRecordN


RecordB

RecordH

RecordK

RecordB

RecordH

RecordK

Transaction File

RecordA

RecordB

RecordG

RecordH

RecordK

RecordM

RecordN

RecordA

RecordB

RecordG

RecordH

RecordK

RecordM

RecordN

Ordered File

New FilePROGRAM

FILE SECTION.

PROCEDURE DIVISION.OPEN INPUT TF.OPEN INPUT OFOPEN OUTPUT NF.READ TF.READ OF.IF TFKey = OFKeyUpdate OFRec with TFRecMOVE OFRec+ TO NFRecWRITE NFRecREAD TFREAD OF

ELSEMOVE OFRec TO NFRecWRITE NFRec

READ OFEND-IF.

FILE SECTION.



READ OFEND-IF.

TFRecTFRec

OFRecOFRec

NFRecNFRec

Updating records in an ordered Updating records in an ordered filefile

RecordBRecordB

RecordH

RecordK

RecordBRecordB

RecordH

RecordK

Transaction File

RecordARecordA

RecordB

RecordG

RecordH

RecordK

RecordM

RecordN

RecordARecordA

RecordB

RecordG

RecordH

RecordK

RecordM

RecordN

Ordered File

New FilePROGRAM




READ OFEND-IF.

FILE SECTION.



READ OFEND-IF.

RecordBRecordB

RecordARecordA

RecordARecordA


RecordB

RecordH

RecordK

RecordB

RecordH

RecordK

Transaction File

RecordA

RecordBRecordB

RecordG

RecordH

RecordK

RecordM

RecordN

RecordA

RecordBRecordB

RecordG

RecordH

RecordK

RecordM

RecordN

Ordered File

New FilePROGRAM

RecordA

RecordB+RecordB+

RecordA

RecordB+RecordB+

FILE SECTION.



READ OFEND-IF.

FILE SECTION.



READ OFEND-IF.

RecordBRecordB

RecordBRecordB

RecordB+RecordB+


RecordB

RecordHRecordH

RecordK

RecordB

RecordHRecordH

RecordK

Transaction File

RecordA

RecordB

RecordGRecordG

RecordH

RecordK

RecordM

RecordN

RecordA

RecordB

RecordGRecordG

RecordH

RecordK

RecordM

RecordN

Ordered File

New FilePROGRAM

RecordA

RecordB+

RecordGRecordG

RecordA

RecordB+

RecordGRecordG

FILE SECTION.



READ OFEND-IF.

FILE SECTION.



READ OFEND-IF.

RecordHRecordH

RecordGRecordG

RecordGRecordG


RecordC

RecordF

RecordP

RecordC

RecordF

RecordP

Transaction File

RecordA

RecordB

RecordG

RecordH

RecordK

RecordM

RecordN

RecordA

RecordB

RecordG

RecordH

RecordK

RecordM

RecordN

Ordered File

New FilePROGRAM

FILE SECTION.

PROCEDURE DIVISION.OPEN INPUT TF.OPEN INPUT OFOPEN OUTPUT NF.READ TF.READ OF.IF TFKey < OFKeyMOVE TFRec TO NFRecWRITE NFRecREAD TF


READ OFEND-IF.

FILE SECTION.



READ OFEND-IF.

TFRecTFRec

OFRecOFRec

NFRecNFRec

Inserting records into an ordered Inserting records into an ordered filefile

RecordCRecordC

RecordF

RecordP

RecordCRecordC

RecordF

RecordP

Transaction File

RecordARecordA

RecordB

RecordG

RecordH

RecordK

RecordM

RecordN

RecordARecordA

RecordB

RecordG

RecordH

RecordK

RecordM

RecordN

Ordered File

New FilePROGRAM



ELSEMOVE OFRec TO NFRecWRITE NFRecREAD OF

END-IF.

FILE SECTION.



END-IF.

RecordCRecordC

RecordARecordA

RecordARecordA


RecordC

RecordF

RecordP

RecordC

RecordF

RecordP

Transaction File

RecordA

RecordBRecordB

RecordG

RecordH

RecordK

RecordM

RecordN

RecordA

RecordBRecordB

RecordG

RecordH

RecordK

RecordM

RecordN

Ordered File

New FilePROGRAM

RecordA

RecordBRecordB

RecordA

RecordBRecordB

FILE SECTION.



END-IF.

FILE SECTION.



END-IF.

RecordCRecordC

RecordBRecordB

RecordBRecordB


RecordC

RecordF

RecordP

RecordC

RecordF

RecordP

Transaction File

RecordA

RecordB

RecordGRecordG

RecordH

RecordK

RecordM

RecordN

RecordA

RecordB

RecordGRecordG

RecordH

RecordK

RecordM

RecordN

Ordered File

New FilePROGRAM

RecordA

RecordB

RecordCRecordC

RecordA

RecordB

RecordCRecordC

FILE SECTION.



END-IF.

FILE SECTION.



END-IF.

RecordCRecordC

RecordGRecordG

RecordCRecordC


RecordC

RecordFRecordF

RecordP

RecordC

RecordFRecordF

RecordP

Transaction File

RecordA

RecordB

RecordG

RecordH

RecordK

RecordM

RecordN

RecordA

RecordB

RecordG

RecordH

RecordK

RecordM

RecordN

Ordered File

New FilePROGRAM

RecordA

RecordB

RecordC

RecordFRecordF

RecordA

RecordB

RecordC

RecordFRecordF

FILE SECTION.



END-IF.

FILE SECTION.



END-IF.

RecordFRecordF

RecordGRecordG

RecordFRecordF


RecordC

RecordF

RecordPRecordP

RecordC

RecordF

RecordPRecordP

Transaction File

RecordA

RecordB

RecordG

RecordH

RecordK

RecordM

RecordN

RecordA

RecordB

RecordG

RecordH

RecordK

RecordM

RecordN

Ordered File

New FilePROGRAM

RecordA

RecordB

RecordC

RecordF

RecordGRecordG

RecordA

RecordB

RecordC

RecordF

RecordGRecordG

FILE SECTION.



END-IF.

FILE SECTION.



END-IF.

RecordPRecordP

RecordGRecordG

RecordGRecordG


485

AdvancAdvanceded

SequeSequentialntial

Files 1.Files 1.

486

Single Record Type Single Record Type FilesFiles

In a file which contains only one record type (the kind we have examined so far) the record structure is described as part of the file FD using an 01 level number.

The record description creates a ‘buffer’ capable of storing one record instance at a time.

Each time a record is read from the file it overwrites the previous contents of the buffer.

The record buffer is the only connection between the file and the program.

487

Multiple Record Type Multiple Record Type FilesFiles

Quite often a single file will contain more than one type of record.

For instance, some of the terminal exercises required that your program apply a file of transaction records to the StudentsFile.

For simplicity, the Transaction file in these exercises contained one record type only; either Insertion or Update or Deletion.

In a real environment, transactions of this sort would normally be collected together into one single transaction file.

488

Implications of a multiple record transaction Implications of a multiple record transaction file.file.

Gathering all the transactions into a single file implies that the file will contain different record types (i.e. records with different structures).

The different record structures may give rise to records which are also of different lengths.

For example an insertion transaction will contain all the fields that

appear in the StudentFile record (32 characters).

a deletion transaction will contain only the StudentId (7 characters).

an update transaction used to record course changes might contain the StudentId, the OldCourseCode and the NewCourseCode (15 characters).

489

Describing multiple record Describing multiple record filesfiles

To describe these different record types we have to use more than one record description in the file's FD.

Because record descriptions always begin with level 01 we provide a 01 level for each record type in the file.

What is not obvious from this description is that COBOL continues to create just a single ‘record buffer’ for the file!

And this ‘record buffer’ is only able to store a single record at a time!

DATA DIVISION.FILE SECTION.FD TransactionFile.01 InsertionRec. 02 StudentId PIC 9(7). 02 StudentName. 03 Surname PIC X(8). 03 Initials PIC XX. 02 DateOfBirth. 03 YOBirth PIC 9(2). 03 MOBirth PIC 9(2). 03 DOBirth PIC 9(2). 02 CourseCode PIC X(4). 02 Grant PIC 9(4). 02 Gender PIC X.

01 DeleteRec. 02 StudentId PIC 9(7).

01 UpdateRec. 02 StudentId PIC 9(7). 02 OldCourseCode PIC X(4). 02 NewCourseCode PIC X(4).

Multiple record descriptions - One record Multiple record descriptions - One record bufferbuffer

Multiple record descriptions in a file are IMPLICITLY redefinitions of the single record buffer.

9 2 3 0 1 6 5 H E N N E S S Y R M 7 1 0 9 1 5 L M 5 1 0 5 5 0 F

TransactionFile BufferTransactionFile Buffer


InsertionRecInsertionRecStudentId StudentName DateOfBirth CourseCode Grant Gender InsertionRecInsertionRecStudentId StudentName DateOfBirth CourseCode Grant Gender

9 2 3 0 1 6 5 H E N N E S S Y R M 7 1 0 9 1 5 L M 5 1 0 5 5 0 F




StudentId

DeletionRecDeletionRec StudentId

DeletionRecDeletionRec

9 2 3 0 1 6 5 H E N N E S S Y R M 7 1 0 9 1 5 L M 5 1 0 5 5 0 F




StudentId



StudentId OldCourseCode NewCourseCode

UpdateRecUpdateRec StudentId OldCourseCode NewCourseCode

UpdateRecUpdateRec

9 2 3 0 1 6 5 H E N N E S S Y R M 7 1 0 9 1 5 L M 5 1 0 5 5 0 F


All these record descriptions are valid at the same time.

But only one description makes sense for the values in the buffer.

How can we tell which description to use? InsertionRecInsertionRecStudentId StudentName DateOfBirth CourseCode Grant Gender InsertionRecInsertionRecStudentId StudentName DateOfBirth CourseCode Grant Gender

StudentId



StudentId OldCourseCode NewCourseCode

UpdateRecUpdateRec StudentId OldCourseCode NewCourseCode

UpdateRecUpdateRec

9 2 3 0 1 6 5 H E N N E S S Y R M 7 1 0 9 1 5 L M 5 1 0 5 5 0 F


496

The Transaction Type The Transaction Type CodeCode

Generally we cannot reliably establish the type of record READ into the buffer by examining its contents.

To allow us to distinguish between the record types, a special data item is inserted into each transaction which identifies the transaction type.

This data item is usually the first data item in the transaction record and one character in size, but it does not have to be.

Transaction types can be identified using a number, a letter or other character.

The Revised FD.The Revised FD. TransCode occurs in all the

record descriptions. How can we refer to the one

in DeleteRec? MOVE TransCode OF

DeleteRec TO TCode. But TransCode really only

needs to be defined in one record.

Since all the records map on to the same area of storage the TransCode defined for the InsertionRec can be used no matter which record type is actually in the buffer .

DATA DIVISION.FILE SECTION.FD TransactionFile.01 InsertionRec. 02 TransCode PIC X. 02 StudentId PIC 9(7). 02 StudentName. 03 Surname PIC X(8). 03 Initials PIC XX. 02 DateOfBirth. 03 YOBirth PIC 9(2). 03 MOBirth PIC 9(2). 03 DOBirth PIC 9(2). 02 CourseCode PIC X(4). 02 Grant PIC 9(4). 02 Gender PIC X.

01 DeleteRec. 02 TransCode PIC X. 02 StudentId PIC 9(7).

01 UpdateRec. 02 TransCode PIC X. 02 StudentId PIC 9(7). 02 OldCourseCode PIC X(4). 02 NewCourseCode PIC X(4).

The Final The Final FD.FD.

DATA DIVISION.FILE SECTION.FD TransactionFile.01 InsertionRec. 88 EndOfTransFile VALUE HIGH-VALUES. 02 TransCode PIC X. 88 Insertion VALUE "I". 88 Deletion VALUE "D". 88 Update VALUE "U". 02 StudentId PIC 9(7). 02 StudentName. 03 Surname PIC X(8). 03 Initials PIC XX. 02 DateOfBirth. 03 YOBirth PIC 9(2). 03 MOBirth PIC 9(2). 03 DOBirth PIC 9(2). 02 CourseCode PIC X(4). 02 Grant PIC 9(4). 02 Gender PIC X.

01 DeleteRec. 02 FILLER PIC X(8).

01 UpdateRec. 02 FILLER PIC X(8). 02 OldCourseCode PIC X(4). 02 NewCourseCode PIC X(4).

TransCode and StudentId have the same description and are in the same location in all three records.

So they are defined only in the InsertionRec.

In the other records the area occupied by these two items is defined using FILLER.

What happens when we display the OldCourseCode? What happens if we now read an Update record into

the buffer?

InsertionRecInsertionRecTransCode StudentId StudentName DateOfBirth CourseCode Grant Gender InsertionRecInsertionRecTransCode StudentId StudentName DateOfBirth CourseCode Grant Gender

FILLER

DeletionRecDeletionRec FILLER


FILLER OldCourseCode NewCourseCode

UpdateRecUpdateRecFILLER OldCourseCode NewCourseCode

UpdateRecUpdateRec

I 9 2 3 0 1 6 5 H E N N E S S Y R M 7 1 0 9 1 5 L M 5 1 0 5 5 0 F


When a record smaller than the size of the largest record is read into the buffer any data that is not explicitly overwritten is left intact.

What happens when we display StudentName and DateOfBirth?

InsertionRecInsertionRecTransCode StudentId StudentName DateOfBirth CourseCode Grant Gender InsertionRecInsertionRecTransCode StudentId StudentName DateOfBirth CourseCode Grant Gender

FILLER

DeletionRecDeletionRec FILLER


FILLER OldCourseCode NewCourseCode

UpdateRecUpdateRec FILLER OldCourseCode NewCourseCode

UpdateRecUpdateRec

U 9 3 1 5 6 8 2 L M 6 1 L M 5 1 R M 7 1 0 9 1 5 L M 5 1 0 5 5 0 F


501

Printing a Printing a Report.Report.

A report is made up of groups of printed lines of different types.

What types of line are required for the Student Details Report?

A program is required which will print a report.A program is required which will print a report.

The report, called the Student Details Report, will The report, called the Student Details Report, will be based on the file Students.Dat.be based on the file Students.Dat.

The report will show the Name, StudentId, Gender The report will show the Name, StudentId, Gender and CourseCode of each student in the file.and CourseCode of each student in the file.

502

Report Print Report Print Lines.Lines.

Page Heading.

– UL Student Details Report

Page Footing.

– Page : PageNum

Column Headings.

– Student Id. Student Name Gender Course

Student Detail Line.

– StudentId. StudentName Gender CourseCode

Report Footing.

– *** End of Student Details Report ***

Describing Print Describing Print Lines.Lines.

01 PageHeading. 02 FILLER PIC X(7) VALUE SPACES. 02 FILLER PIC X(25) VALUE "UL Student Details Report".

01 PageFooting. 02 FILLER PIC X(19) VALUE SPACES. 02 FILLER PIC X(7) VALUE "Page : ". 02 FILLER PIC 99.

01 ColumnHeadings PIC X(36) VALUE " StudentId StudentName Gender Course".

01 StudentDetailLine. 02 PrnStudId PIC BB9(7). 02 PrnStudName PIC BBX(10). 02 PrnGender PIC BBBBX. 02 PrnCourse PIC BBBBX(4).

01 ReportFooting PIC X(38) VALUE "*** End of Student Details Report ***".

The Print Lines are all different record types!

504

The File The File BufferBuffer

All data coming from, or going to, the peripherals must pass through a file buffer declared in the File Section.

The file buffer is associated with the physical device by means of a Select and Assign clause.

In previous lectures we saw that the file bufferis represented by a record description (01 level).

But the different types of line that must appear on our report are declared as different record types.

How can we declare these different record types in the File Section?

ENVIRONMENT DIVISION.INPUT-OUTPUT SECTION.FILE-CONTROL. SELECT Printer ASSIGN TO “LPT1”.

DATA DIVISION.FILE SECTION.FD Printer.01 PrintLine. ????????????????

505

No No VALUEVALUE clause in the clause in the FILE SECTIONFILE SECTION..

Defining a file buffer which is used by different record types is easy (as we have seen).

But !! These record types all map on to the same area of storage and

print line records cannot share the same area of storage. Why? Because most of the print line record values are

assigned using the VALUE clause and these values are assigned as soon as the program starts.

To prevent us trying to use the VALUE clause to assign values to a File buffer COBOL has a rule which states that;

In the FILE SECTION, the VALUE clause must be used in condition-name entries only (i.e. it cannot be used to give an initial value to an item).

506

A A SolutionSolution

We define the print records in the WORKING-

STORAGE SECTION. We create a file buffer in the FILE SECTION

which is the size of the largest print record. We print a line by moving the appropriate print

record to the file buffer and then WRITEing the contents of the file buffer to the device.

We get round the problem as follows;We get round the problem as follows;

ENVIRONMENT DIVISION.INPUT-OUTPUT SECTION.FILE-CONTROL. SELECT ReportFile ASSIGN TO “STUDENTS.RPT”.

DATA DIVISION.FILE SECTION.FD ReportFile.01 PrintLine PIC X(38).

WORKING-STORAGE SECTION.01 PageHeading. 02 FILLER PIC X(7) VALUE SPACES. 02 FILLER PIC X(25) VALUE "UL Student Details Report".

01 PageFooting. 02 FILLER PIC X(19) VALUE SPACES. 02 FILLER PIC X(7) VALUE "Page : ". 02 FILLER PIC 99.

01 ColumnHeadings PIC X(36) VALUE " StudentId StudentName Gender Course".

01 StudentDetailLine. 02 PrnStudId PIC BB9(7). 02 PrnStudName PIC BBX(10). 02 PrnGender PIC BBBBX. 02 PrnCourse PIC BBBBX(4).

01 ReportFooting PIC X(38) VALUE "*** End of Student Details Report ***".

STUDENTS.RPT

DISK

508

WRITE Syntax WRITE Syntax revisited.revisited.

When we are writing to a printer or a print file we use a form of the WRITE command different from that we use when writing to a sequential file.

ENVIRONMENT DIVISION. INPUT-OUTPUT SECTION. FILE-CONTROL. SELECT ReportFile ASSIGN TO "STUDENTS.RPT" ORGANIZATION IS LINE SEQUENTIAL.

DATA DIVISION. FILE SECTION. FD ReportFile. 01 PrintLine PIC X(40).

WORKING-STORAGE SECTION. 01 HeadingLine PIC X(21) VALUE " Record Count Report".

01 StudentTotalLine. 02 FILLER PIC X(17) VALUE "Total Students = ". 02 PrnStudentCount PIC Z,ZZ9.

01 MaleTotalLine. 02 FILLER PIC X(17) VALUE "Total Males = ". 02 PrnMaleCount PIC Z,ZZ9.

01 FemaleTotalLine. 02 FILLER PIC X(17) VALUE "Total Females = ". 02 PrnFemaleCount PIC Z,ZZ9.

MOVE StudentCount TO PrnStudentCountMOVE MaleCount TO PrnMaleCountMOVE FemaleCount TO PrnFemaleCountWRITE PrintLine FROM HeadingLine AFTER ADVANCING PAGEWRITE PrintLine FROM StudentTotalLine AFTER ADVANCING 2 LINESWRITE PrintLine FROM MaleTotalLine AFTER ADVANCING 2 LINESWRITE PrintLine FROM FemaleTotalLine AFTER ADVANCING 2 LINES.

STUDENTS.RPT

DISK

510

SortSortandandMerMergege

511

The StudentFile is a sequential file sequenced upon ascending StudentId.

Write a program to display the number of students taking each course. How?

DATA DIVISION.DATA DIVISION.FILE SECTION.FILE SECTION.FD StudentFile.FD StudentFile.01 StudentDetails.01 StudentDetails. 02 StudentId PIC 9(7). 02 StudentId PIC 9(7). 02 StudentName. 02 StudentName. 03 Surname PIC X(8). 03 Surname PIC X(8). 03 Initials PIC XX. 03 Initials PIC XX. 02 DateOfBirth. 02 DateOfBirth. 03 YOBirth PIC 9(2). 03 YOBirth PIC 9(2). 03 MOBirth PIC 9(2). 03 MOBirth PIC 9(2). 03 DOBirth PIC 9(2). 03 DOBirth PIC 9(2). 02 CourseCode PIC X(4). 02 CourseCode PIC X(4). 02 Grant PIC 9(4). 02 Grant PIC 9(4). 02 Gender PIC X. 02 Gender PIC X.

Simplified Sort Simplified Sort Syntax.Syntax.

The WorkFileName identifies a temporary work file that the SORT process uses for the sort. It is defined in the FILE SECTION using an SD entry.

Each SortKeyIdentifier identifies a field in the record of the work file upon which the file will be sequenced.

When more than one SortKeyIdentifier is specified, the keys decrease in significance from left to right (leftmost key is most significant, rightmost is least significant).

InFileName and OutFileName, are the names of the input and output files. These files are automatically opened by the SORT. When the SORT executes they must not be already open.

FD SalesFile.01 SalesRec. 02 FILLER PIC X(10).

SD WorkFile.01 WorkRec. 02 WSalesmanNum PIC 9(5). 02 FILLER PIC X(5).

FD SortedSalesFile.01 SortedSalesRec. 02 SalesmanNum PIC 9(5). 02 ItemType PIC X. 02 QtySold PIC 9(4).

PROCEDURE DIVISION.Begin. SORT WorkFile ON ASCENDING KEY WSalesmanNum USING SalesFile GIVING SortedSalesFile.

OPEN INPUT SortedSalesFile.

Sort Sort Example.Example.

ENVIRONMENT DIVISION.INPUT-OUTPUT SECTION.FILE-CONTROL. SELECT WorkFile ASSIGN TO "WORK.TMP".

SD WorkFile.01 WorkRecord. 02 ProvinceCode PIC 9. 02 SalesmanCode PIC 9(5). 02 FILLER PIC X(19).

PROCEDURE DIVISION.Begin. SORT WorkFile ON ASCENDING KEY ProvinceCode DESCENDING KEY SalesmanCode USING UnsortedSales GIVING SortedSales.

OPEN INPUT SortedSales.


SD WorkFile.01 WorkRecord. 02 ProvinceCode PIC 9. 02 SalesmanCode PIC 9(5). 02 FILLER PIC X(19).

PROCEDURE DIVISION.Begin. SORT WorkFile ON ASCENDING KEY ProvinceCode DESCENDING KEY SalesmanCode USING UnsortedSales GIVING SortedSales.


SORTSORTProcessProcess

WorkFileWorkFile

How the SORT works.How the SORT works.

SORT WorkFile ON ASCENDING KEY WSalesmanNum USING SalesFile GIVING SortedSalesFile.

SalesFileSalesFile SortedSalesFileSortedSalesFile

UnsortedRecords

SortedRecords


How the INPUT PROCEDURE How the INPUT PROCEDURE works.works.

SORT WorkFile ON ASCENDING KEY WSalesmanNum INPUT PROCEDURE IS SelectHatSales GIVING SortedSalesFile.

WorkFileWorkFile

SalesFileSalesFile SortedSalesFileSortedSalesFile

SortedRecords

SelectHatSalesSelectHatSales

UnsortedHat

Records

UnsortedRecords

517

OPEN INPUT InFileNameREAD InFileName RECORDPERFORM UNTIL Condition RELEASE SDWorkRec READ InFileName RECORDEND-PERFORMCLOSE InFile

OPEN INPUT InFileNameREAD InFileName RECORDPERFORM UNTIL Condition RELEASE SDWorkRec READ InFileName RECORDEND-PERFORMCLOSE InFile

INPUT PROCEDURE INPUT PROCEDURE TemplateTemplate

FD SalesFile.01 SalesRec. 88 EndOfSales VALUE HIGH-VALUES. 02 FILLER PIC 9(5). 02 FILLER PIC X. 88 HatRecord VALUE "H". 02 FILLER PIC X(4).SD WorkFile.01 WorkRec. 02 WSalesmanNum PIC 9(5). 02 FILLER PIC X(5).FD SortedSalesFile.01 SortedSalesRec. 02 SalesmanNum PIC 9(5). 02 ItemType PIC X. 02 QtySold PIC 9(4).PROCEDURE DIVISION.Begin. SORT WorkFile ON ASCENDING KEY WSalesmanNum INPUT PROCEDURE IS SelectHatSales GIVING SortedSalesFile.

FD SalesFile.01 SalesRec. 88 EndOfSales VALUE HIGH-VALUES. 02 FILLER PIC 9(5). 02 FILLER PIC X. 88 HatRecord VALUE "H". 02 FILLER PIC X(4).SD WorkFile.01 WorkRec. 02 WSalesmanNum PIC 9(5). 02 FILLER PIC X(5).FD SortedSalesFile.01 SortedSalesRec. 02 SalesmanNum PIC 9(5). 02 ItemType PIC X. 02 QtySold PIC 9(4).PROCEDURE DIVISION.Begin. SORT WorkFile ON ASCENDING KEY WSalesmanNum INPUT PROCEDURE IS SelectHatSales GIVING SortedSalesFile.

INPUT PROCEDURE - ExampleINPUT PROCEDURE - Example

New Version New Version

SelectHatSales. OPEN INPUT SalesFile

READ SalesFile AT END SET EndOfSales TO TRUE END-READ PERFORM UNTIL EndOfSales IF HatRecord RELEASE WorkRec FROM SalesRec END-IF READ SalesFile AT END SET EndOfSales TO TRUE END-READ END-PERFORM

CLOSE SalesFile.

SelectHatSales. OPEN INPUT SalesFile

READ SalesFile AT END SET EndOfSales TO TRUE END-READ PERFORM UNTIL EndOfSales IF HatRecord RELEASE WorkRec FROM SalesRec END-IF READ SalesFile AT END SET EndOfSales TO TRUE END-READ END-PERFORM

CLOSE SalesFile.

Old Version Old Version SelectHatSales SECTION.BeginHatSales. OPEN INPUT SalesFile READ SalesFile AT END SET EndOfSales TO TRUE END-READ PERFORM GetHatSales UNTIL EndOfSales CLOSE SalesFile GO TO SelectHatSalesExit.

GetHatSales. IF HatRecord RELEASE WorkRec FROM SalesRec END-IF READ SalesFile AT END SET EndOfSales TO TRUE END-READ.

SelectHatSalesExit EXIT.

SelectHatSales SECTION.BeginHatSales. OPEN INPUT SalesFile READ SalesFile AT END SET EndOfSales TO TRUE END-READ PERFORM GetHatSales UNTIL EndOfSales CLOSE SalesFile GO TO SelectHatSalesExit.

GetHatSales. IF HatRecord RELEASE WorkRec FROM SalesRec END-IF READ SalesFile AT END SET EndOfSales TO TRUE END-READ.

SelectHatSalesExit EXIT.


SD WorkFile.01 WorkRecord. 88 EndOfWorkFile VALUE HIGH-VALUES. 02 ProvinceCode PIC 9. 88 ProvinceIsUlster VALUE 4. 02 SalesmanCode PIC 9(5). 02 FILLER PIC X(19).FD UnsortedSales.01 FILLER PIC X(25).FD SortedSales.01 SortedRec. 88 EndOfSalesFile VALUE HIGH-VALUES. 02 ProvinceCode PIC 9. 02 SalesmanCode PIC 9(5). 02 ItemCode PIC 9(7). 02 ItemCost PIC 9(3)V99. 02 QtySold PIC 9(7).


SD WorkFile.01 WorkRecord. 88 EndOfWorkFile VALUE HIGH-VALUES. 02 ProvinceCode PIC 9. 88 ProvinceIsUlster VALUE 4. 02 SalesmanCode PIC 9(5). 02 FILLER PIC X(19).FD UnsortedSales.01 FILLER PIC X(25).FD SortedSales.01 SortedRec. 88 EndOfSalesFile VALUE HIGH-VALUES. 02 ProvinceCode PIC 9. 02 SalesmanCode PIC 9(5). 02 ItemCode PIC 9(7). 02 ItemCost PIC 9(3)V99. 02 QtySold PIC 9(7).

PROCEDURE DIVISION.Begin. SORT WorkFile ON ASCENDING KEY ProvinceCode SalesmanCode INPUT PROCEDURE IS SelectUlsterRecs GIVING SortedSales.


SelectUlsterRecs. OPEN INPUT UnsortedSales READ UnsortedSales INTO WorkRec AT END SET EndOfSalesFile TO TRUE END-READ

PERFORM UNTIL EndOfSalesFile IF ProvinceIsUlster RELEASE WorkRec END-IF READ UnsortedSales INTO WorkRec AT END SET EndOfSalesFile TO TRUE END-READ END-PERFORM

CLOSE UnsortedSales

PROCEDURE DIVISION.Begin. SORT WorkFile ON ASCENDING KEY ProvinceCode SalesmanCode INPUT PROCEDURE IS SelectUlsterRecs GIVING SortedSales.


SelectUlsterRecs. OPEN INPUT UnsortedSales READ UnsortedSales INTO WorkRec AT END SET EndOfSalesFile TO TRUE END-READ

PERFORM UNTIL EndOfSalesFile IF ProvinceIsUlster RELEASE WorkRec END-IF READ UnsortedSales INTO WorkRec AT END SET EndOfSalesFile TO TRUE END-READ END-PERFORM

CLOSE UnsortedSales

Full Sort Full Sort Syntax.Syntax.

ProcedureName is the name of a section or paragraph.

SummariseSalesSummariseSales


WorkFileWorkFile

How the OUTPUT PROCEDURE How the OUTPUT PROCEDURE works.works.

SORT WorkFile ON ASCENDING KEY WSalesmanNum USING SalesFile OUTPUT PROCEDURE IS SummariseSales.

SalesFileSalesFile SalesSummaryFileSalesSummaryFile

UnsortedRecords

SalesmanSummary

RecordSortedRecords

OPEN OUTPUT OutFileRETURN SDWorkFile RECORDPERFORM UNTIL Condition WRITE OutRec RETURN SDWorkFile RECORDEND-PERFORMCLOSE OutFile

OUTPUT PROCEDURE OUTPUT PROCEDURE TemplateTemplate

FD SalesFile.01 SalesRec PIC X(10).SD WorkFile.01 WorkRec. 88 EndOfWorkFile VALUE HIGH-VALUES. 02 WSalesmanNum PIC 9(5). 02 FILLER PIC X. 02 WQtySold PIC X(4).FD SalesSummaryFile.01 SummaryRec. 02 SalesmanNum PIC 9(5). 02 TotalQtySold PIC 9(6).PROCEDURE DIVISION.Begin. SORT WorkFile ON ASCENDING KEY WSalesmanNum USING SalesFile OUTPUT PROCEDURE IS SummariseSales. OPEN INPUT SalesSummaryFile. PERFORM PrintSummaryReport.`

FD SalesFile.01 SalesRec PIC X(10).SD WorkFile.01 WorkRec. 88 EndOfWorkFile VALUE HIGH-VALUES. 02 WSalesmanNum PIC 9(5). 02 FILLER PIC X. 02 WQtySold PIC X(4).FD SalesSummaryFile.01 SummaryRec. 02 SalesmanNum PIC 9(5). 02 TotalQtySold PIC 9(6).PROCEDURE DIVISION.Begin. SORT WorkFile ON ASCENDING KEY WSalesmanNum USING SalesFile OUTPUT PROCEDURE IS SummariseSales. OPEN INPUT SalesSummaryFile. PERFORM PrintSummaryReport.`

Output PROCEDURE - ExampleOutput PROCEDURE - Example

SummariseSales. OPEN OUTPUT SalesSummaryFile RETURN WorkFile AT END SET EndOfWorkFile TO TRUE END-RETURN PERFORM UNTIL EndOfWorkFile MOVE WSalesmanNum TO SalesmanNum MOVE ZEROS TO TotalQtySold PERFORM UNTIL WSalesManNum NOT = SalesmanNum OR EndOfWorkFile ADD WQtySold TO TotalQtySold RETURN WorkFile AT END SET EndOfWorkFile TO TRUE END-RETURN END-PERFORM WRITE SummaryRec END-PERFORM CLOSE SalesSummaryFile.

SummariseSales. OPEN OUTPUT SalesSummaryFile RETURN WorkFile AT END SET EndOfWorkFile TO TRUE END-RETURN PERFORM UNTIL EndOfWorkFile MOVE WSalesmanNum TO SalesmanNum MOVE ZEROS TO TotalQtySold PERFORM UNTIL WSalesManNum NOT = SalesmanNum OR EndOfWorkFile ADD WQtySold TO TotalQtySold RETURN WorkFile AT END SET EndOfWorkFile TO TRUE END-RETURN END-PERFORM WRITE SummaryRec END-PERFORM CLOSE SalesSummaryFile.

528

RELEASE and RETURN RELEASE and RETURN SyntaxSyntax

Write

Read

Feeding the SORT from the Feeding the SORT from the keyboard.keyboard.

SORT WorkFile ON ASCENDING KEY WStudentId INPUT PROCEDURE IS GetStudentDetails GIVING StudentFile.

WorkFileWorkFile

StudentFileStudentFile

SortedStudentRecords


GetStudentDetailsGetStudentDetails

UnsortedStudentRecords

8965125COUGHLAN

ENVIRONMENT DIVISION.INPUT-OUTPUT SECTION.FILE-CONTROL. SELECT StudentFile ASSIGN TO "SORTSTUD.DAT"

ORGANIZATION IS LINE SEQUENTIAL. SELECT WorkFile ASSIGN TO "WORK.TMP".DATA DIVISION.FILE SECTION.FD StudentFile.01 StudentDetails PIC X(32).SD WorkFile.01 WorkRec. 02 WStudentId PIC 9(7). 02 FILLER PIC X(25).PROCEDURE DIVISION.Begin. SORT WorkFile ON ASCENDING KEY WStudentId INPUT PROCEDURE IS GetStudentDetails GIVING StudentFile. STOP RUN.GetStudentDetails. DISPLAY "Enter student details using template below." DISPLAY "Enter no data to end.". DISPLAY "NNNNNNNSSSSSSSSIIYYMMDDCCCCGGGGS". ACCEPT WorkRec. PERFORM UNTIL WorkRec = SPACES RELEASE WorkRec ACCEPT WorkRec END-PERFORM.

ENVIRONMENT DIVISION.INPUT-OUTPUT SECTION.FILE-CONTROL. SELECT StudentFile ASSIGN TO "SORTSTUD.DAT"

ORGANIZATION IS LINE SEQUENTIAL. SELECT WorkFile ASSIGN TO "WORK.TMP".DATA DIVISION.FILE SECTION.FD StudentFile.01 StudentDetails PIC X(32).SD WorkFile.01 WorkRec. 02 WStudentId PIC 9(7). 02 FILLER PIC X(25).PROCEDURE DIVISION.Begin. SORT WorkFile ON ASCENDING KEY WStudentId INPUT PROCEDURE IS GetStudentDetails GIVING StudentFile. STOP RUN.GetStudentDetails. DISPLAY "Enter student details using template below." DISPLAY "Enter no data to end.". DISPLAY "NNNNNNNSSSSSSSSIIYYMMDDCCCCGGGGS". ACCEPT WorkRec. PERFORM UNTIL WorkRec = SPACES RELEASE WorkRec ACCEPT WorkRec END-PERFORM.

531

MERGE MERGE Syntax.Syntax.

The Merge takes two or more identically sequenced files and combines them, according to the key values specified, to produce a combined file which is then output to an output file or OUTPUT PROCEDURE.

e.g.MERGE WorkFile ON ASCENDING KEY StudentId USING InsertionsFile, StudentFile GIVING NewStudentFile.

ENVIRONMENT DIVISION.INPUT-OUTPUT SECTION.FILE-CONTROL. SELECT StudentFile ASSIGN TO "STUDENTS.DAT" ORGANIZATION IS LINE SEQUENTIAL. SELECT InsertionsFile ASSIGN TO "TRANSINS.DAT" ORGANIZATION IS LINE SEQUENTIAL. SELECT NewStudentFile ASSIGN TO "STUDENTS.NEW" ORGANIZATION IS LINE SEQUENTIAL. SELECT WorkFile ASSIGN TO "WORK.TMP".

DATA DIVISION.FILE SECTION.FD StudentFile.01 StudentRec PIC X(32).FD InsertionsFile.01 InsertionRec PIC X(32).FD NewStudentFile.01 NewStudentRec PIC X(32).SD WorkFile.01 WorkRec. 02 WStudentId PIC 9(7). 02 FILLER PIC X(25).

PROCEDURE DIVISION.Begin. MERGE WorkFile ON ASCENDING KEY WStudentId USING InsertionsFile, StudentFile GIVING NewStudentFile. STOP RUN.

ENVIRONMENT DIVISION.INPUT-OUTPUT SECTION.FILE-CONTROL. SELECT StudentFile ASSIGN TO "STUDENTS.DAT" ORGANIZATION IS LINE SEQUENTIAL. SELECT InsertionsFile ASSIGN TO "TRANSINS.DAT" ORGANIZATION IS LINE SEQUENTIAL. SELECT NewStudentFile ASSIGN TO "STUDENTS.NEW" ORGANIZATION IS LINE SEQUENTIAL. SELECT WorkFile ASSIGN TO "WORK.TMP".

DATA DIVISION.FILE SECTION.FD StudentFile.01 StudentRec PIC X(32).FD InsertionsFile.01 InsertionRec PIC X(32).FD NewStudentFile.01 NewStudentRec PIC X(32).SD WorkFile.01 WorkRec. 02 WStudentId PIC 9(7). 02 FILLER PIC X(25).

PROCEDURE DIVISION.Begin. MERGE WorkFile ON ASCENDING KEY WStudentId USING InsertionsFile, StudentFile GIVING NewStudentFile. STOP RUN.

IntroductioIntroduction ton to

Direct Direct AccessAccessFiles.Files.

Sequential Files - Adding a Sequential Files - Adding a RecordRecord

Rec085Rec085Rec300Rec300Rec150Rec150Rec005Rec005Rec090Rec090Rec045Rec045Rec100Rec100Rec001Rec001Rec325Rec325

^Z^Z

OrderedOrdered

Rec001Rec001Rec005Rec005Rec045Rec045Rec090Rec090Rec100Rec100Rec150Rec150Rec300Rec300Rec325Rec325

^Z^Z

UnorderedUnordered

Sequential Files - Adding a Sequential Files - Adding a RecordRecord

Rec085Rec085Rec300Rec300Rec150Rec150Rec005Rec005Rec090Rec090Rec045Rec045Rec100Rec100Rec001Rec001Rec325Rec325Rec085Rec085

^Z^Z

New-OrderedNew-Ordered


^Z^Z

Extend-UnorderedExtend-Unordered

Sequential Files - Deleting a Sequential Files - Deleting a RecordRecord


^Z^Z

OrderedOrdered


^Z^Z

UnorderedUnordered

Sequential Files - Deleting a Sequential Files - Deleting a RecordRecord


^Z^Z


Rec001Rec001Rec005Rec005Rec045Rec045Rec090Rec090Rec100Rec100Rec300Rec300Rec325Rec325

^Z^Z

New-UnorderedNew-Unordered

Sequential Files - Amending a Sequential Files - Amending a RecordRecord


^Z^Z

OrderedOrdered


^Z^Z

UnorderedUnordered

Sequential Files - Amending a Sequential Files - Amending a RecordRecord


^Z^Z


Rec001Rec001Rec005Rec005Rec045Rec045 Rec090Rec090Rec100Rec100Rec150 Rec150 Rec300Rec300Rec325 Rec325

^Z^Z

New-UnorderedNew-Unordered

Relative Files – Relative Files – OrganizationOrganization

Rec001Rec001freefree

Rec003Rec003Rec004Rec004

freefreefreefree

Rec007 Rec007


freefreeRec328Rec328

1

2

3

4

5

6

7

325

326

327

328

Relative RecordNumber

Relative Files - Adding a Relative Files - Adding a RecordRecord



freefreefreefree

Rec007 Rec007



1

2

3

4

5

6

7

325

326

327

328


Rec327Rec327

Relative Files - Adding a Relative Files - Adding a RecordRecord



freefreefreefree

Rec007 Rec007

Rec325Rec325Rec326Rec326Rec327Rec327Rec328Rec328

1

2

3

4

5

6

7

325

326

327

328


Rec327Rec327

Relative Files - Deleting a Relative Files - Deleting a RecordRecord



freefreefreefree

Rec007 Rec007



1

2

3

4

5

6

7

325

326

327

328


Rec325Rec325

Relative Files - Deleting a Relative Files - Deleting a RecordRecord



freefreefreefree

Rec007 Rec007

deleted/freedeleted/freeRec326Rec326


1

2

3

4

5

6

7

325

326

327

328


Rec325Rec325

Relative Files - Amending a Relative Files - Amending a RecordRecord



freefreefreefree

Rec007 Rec007



1

2

3

4

5

6

7

325

326

327

328


Rec007Rec007

Relative Files - Amending a Relative Files - Amending a RecordRecord



freefreefreefree

Rec007 Rec007



1

2

3

4

5

6

7

325

326

327

328


Rec007Rec007

Indexed Files - Indexed Files - OrganizationOrganization

H R ZH R Z

L O RL O RC F HC F H T W ZT W Z

Mi Nf Ni Nt Oi Ot

Index Records

Data Records

Indexed Files - Reading Record Indexed Files - Reading Record NiNi

H H RR Z Z


Mi Nf Ni Nt Oi Ot

Index Records

Data Records


H R ZH R Z

L L OO R RC F HC F H T W ZT W Z

Mi Nf Ni Nt Oi Ot

Index Records

Data Records


H R ZH R Z


Mi Nf Ni Nt Oi Ot

Index Records

Data Records

551

Sequential Sequential Files.Files.

Slow - when the hit rate is low. Complicated to change (insert, delete,

amend)

Fast - when the hit rate is high. Most storage efficient. Simple organization. Recovers space from deleted records.

Disadvantages.Disadvantages.

Advantages.Advantages.

552

Relative Relative Files.Files.

Wasteful of storage if the file is only partially populated.

Cannot recover space from deleted records. Only a single, numeric key allowed. Keys must map on to the range of the Relative

Record numbers.

Fastest Direct Access organization. Very little storage overhead. Can be read sequentially.



553

Indexed Indexed Files.Files.

Slowest Direct Access organization. Especially slow when adding or deleting records. Not very storage efficient. Must store the Index

records, the alternate Index records, the data records and the alternate data records.

Can use multiple, alphanumeric keys. Can have duplicate alternate keys. Can be read sequentially on any of its keys. Can partially recover space from deleted records.



RelatiRelative ve

Files.Files.

Creating a Relative Creating a Relative FileFile

$ SET SOURCEFORMAT"FREE"IDENTIFICATION DIVISION.PROGRAM-ID. CreateRelativeFromSeq.* Creates a Relative file from a sequential file.ENVIRONMENT DIVISION.INPUT-OUTPUT SECTION.FILE-CONTROL. SELECT SupplierFile ASSIGN TO "SUPP.DAT" ORGANIZATION IS RELATIVE ACCESS MODE IS RANDOM RELATIVE KEY IS SupplierKey FILE STATUS IS SupplierStatus. SELECT SupplierFileSeq ASSIGN TO "INSUPP.DAT".

DATA DIVISION.FILE SECTION.FD SupplierFile.01 SupplierRecord. 02 SupplierCode PIC 99. 02 SupplierName PIC X(20). 02 SupplierAddress PIC X(60).

FD SupplierFileSeq.01 SupplierRecordSeq. 88 EndOfFile VALUE HIGH-VALUES. 02 SupplierCodeSeq PIC 99. 02 SupplierNameSeq PIC X(20). 02 SupplierAddressSeq PIC X(60).

WORKING-STORAGE SECTION.01 SupplierStatus PIC X(2).01 SupplierKey PIC 99.

$ SET SOURCEFORMAT"FREE"IDENTIFICATION DIVISION.PROGRAM-ID. CreateRelativeFromSeq.* Creates a Relative file from a sequential file.ENVIRONMENT DIVISION.INPUT-OUTPUT SECTION.FILE-CONTROL. SELECT SupplierFile ASSIGN TO "SUPP.DAT" ORGANIZATION IS RELATIVE ACCESS MODE IS RANDOM RELATIVE KEY IS SupplierKey FILE STATUS IS SupplierStatus. SELECT SupplierFileSeq ASSIGN TO "INSUPP.DAT".



WORKING-STORAGE SECTION.01 SupplierStatus PIC X(2).01 SupplierKey PIC 99.

$ SET SOURCEFORMAT"FREE"IDENTIFICATION DIVISION.PROGRAM-ID. CreateRelativeFromSeq.* Creates a Relative file from a sequential file.ENVIRONMENT DIVISION.INPUT-OUTPUT SECTION.FILE-CONTROL. SELECT SupplierFile ASSIGN TO "SUPP.DAT" ORGANIZATION IS RELATIVE ACCESS MODE IS RANDOM RELATIVE KEY IS SupplierKeySupplierKey FILE STATUS IS SupplierStatusSupplierStatus. SELECT SupplierFileSeq ASSIGN TO "INSUPP.DAT".



WORKING-STORAGE SECTION.01 SupplierStatusSupplierStatus PIC X(2).01 SupplierKeySupplierKey PIC 99.

$ SET SOURCEFORMAT"FREE"IDENTIFICATION DIVISION.PROGRAM-ID. CreateRelativeFromSeq.* Creates a Relative file from a sequential file.ENVIRONMENT DIVISION.INPUT-OUTPUT SECTION.FILE-CONTROL. SELECT SupplierFile ASSIGN TO "SUPP.DAT" ORGANIZATION IS RELATIVE ACCESS MODE IS RANDOM RELATIVE KEY IS SupplierKeySupplierKey FILE STATUS IS SupplierStatusSupplierStatus. SELECT SupplierFileSeq ASSIGN TO "INSUPP.DAT".



WORKING-STORAGE SECTION.01 SupplierStatusSupplierStatus PIC X(2).01 SupplierKeySupplierKey PIC 99.



PROCEDURE DIVISION.Begin. OPEN OUTPUT SupplierFile. OPEN INPUT SupplierFileSeq.

READ SupplierFileSeq AT END SET EndOfFile TO TRUE END-READ PERFORM UNTIL EndOfFile MOVE SupplierCodeSeq TO SupplierKey MOVE SupplierRecordSeq TO SupplierRecord WRITE SupplierRecord INVALID KEY DISPLAY "SUPP STATUS :-", SupplierStatus END-WRITE READ SupplierFileSeq AT END SET EndOfFile TO TRUE END-READ END-PERFORM.

CLOSE SupplierFile, SupplierFileSeq. STOP RUN.

PROCEDURE DIVISION.Begin. OPEN OUTPUT SupplierFile. OPEN INPUT SupplierFileSeq.

READ SupplierFileSeq AT END SET EndOfFile TO TRUE END-READ PERFORM UNTIL EndOfFile MOVE SupplierCodeSeq TO SupplierKey MOVE SupplierRecordSeq TO SupplierRecord WRITE SupplierRecord INVALID KEY DISPLAY "SUPP STATUS :-", SupplierStatus END-WRITE READ SupplierFileSeq AT END SET EndOfFile TO TRUE END-READ END-PERFORM.

CLOSE SupplierFile, SupplierFileSeq. STOP RUN.

Reading a Relative Reading a Relative File.File.

$ SET SOURCEFORMAT"FREE"IDENTIFICATION DIVISION.PROGRAM-ID. ReadRelative.* Reads a Relative file directly or in sequence

ENVIRONMENT DIVISION.INPUT-OUTPUT SECTION.FILE-CONTROL.SELECT SupplierFile ASSIGN TO "SUPP.DAT" ORGANIZATION IS RELATIVE ACCESS MODE IS DYNAMIC RELATIVE KEY IS SupplierKeySupplierKey FILE STATUS IS SupplierStatusSupplierStatus.

DATA DIVISION.FILE SECTION.FD SupplierFile.01 SupplierRecord. 88 EndOfFile VALUE HIGH-VALUES. 02 SupplierCode PIC 99. 02 SupplierName PIC X(20). 02 SupplierAddress PIC X(60).

WORKING-STORAGE SECTION.01 SupplierStatusSupplierStatus PIC X(2). 88 RecordFound VALUE "00".01 SupplierKey SupplierKey PIC 99.01 PrnSupplierRecord. 02 PrnSupplierCode PIC BB99. 02 PrnSupplierName PIC BBX(20). 02 PrnSupplierAddress PIC BBX(50).01 ReadType PIC 9. 88 DirectRead VALUE 1. 88 SequentialRead VALUE 2.

$ SET SOURCEFORMAT"FREE"IDENTIFICATION DIVISION.PROGRAM-ID. ReadRelative.* Reads a Relative file directly or in sequence

ENVIRONMENT DIVISION.INPUT-OUTPUT SECTION.FILE-CONTROL.SELECT SupplierFile ASSIGN TO "SUPP.DAT" ORGANIZATION IS RELATIVE ACCESS MODE IS DYNAMIC RELATIVE KEY IS SupplierKeySupplierKey FILE STATUS IS SupplierStatusSupplierStatus.

DATA DIVISION.FILE SECTION.FD SupplierFile.01 SupplierRecord. 88 EndOfFile VALUE HIGH-VALUES. 02 SupplierCode PIC 99. 02 SupplierName PIC X(20). 02 SupplierAddress PIC X(60).

WORKING-STORAGE SECTION.01 SupplierStatusSupplierStatus PIC X(2). 88 RecordFound VALUE "00".01 SupplierKey SupplierKey PIC 99.01 PrnSupplierRecord. 02 PrnSupplierCode PIC BB99. 02 PrnSupplierName PIC BBX(20). 02 PrnSupplierAddress PIC BBX(50).01 ReadType PIC 9. 88 DirectRead VALUE 1. 88 SequentialRead VALUE 2.


PROCEDURE DIVISION.BEGIN. OPEN INPUT SupplierFile. DISPLAY "Enter Read type (Direct=1, Seq=2)-> " WITH NO ADVANCING. ACCEPT ReadType. IF DirectRead DISPLAY "Enter supplier key (2 digits)-> " WITH NO ADVANCING ACCEPT SupplierKey READ SupplierFile INVALID KEY DISPLAY "SUPP STATUS :-", SupplierStatus END-READ PERFORM DisplayRecord END-IF IF SequentialRead READ SupplierFile NEXT RECORD AT END SET EndOfFile TO TRUE END-READ PERFORM UNTIL EndOfFile PERFORM DisplayRecord READ SupplierFile NEXT RECORD AT END SET EndOfFile TO TRUE END-READ END-PERFORM END-IF CLOSE SupplierFile. STOP RUN.

DisplayRecord. IF RecordFound MOVE SupplierCode TO PrnSupplierCode MOVE SupplierName TO PrnSupplierName MOVE SupplierAddress TO PrnSupplierAddress DISPLAY PrnSupplierRecord END-IF.

PROCEDURE DIVISION.BEGIN. OPEN INPUT SupplierFile. DISPLAY "Enter Read type (Direct=1, Seq=2)-> " WITH NO ADVANCING. ACCEPT ReadType. IF DirectRead DISPLAY "Enter supplier key (2 digits)-> " WITH NO ADVANCING ACCEPT SupplierKey READ SupplierFile INVALID KEY DISPLAY "SUPP STATUS :-", SupplierStatus END-READ PERFORM DisplayRecord END-IF IF SequentialRead READ SupplierFile NEXT RECORD AT END SET EndOfFile TO TRUE END-READ PERFORM UNTIL EndOfFile PERFORM DisplayRecord READ SupplierFile NEXT RECORD AT END SET EndOfFile TO TRUE END-READ END-PERFORM END-IF CLOSE SupplierFile. STOP RUN.

DisplayRecord. IF RecordFound MOVE SupplierCode TO PrnSupplierCode MOVE SupplierName TO PrnSupplierName MOVE SupplierAddress TO PrnSupplierAddress DISPLAY PrnSupplierRecord END-IF.


RUN OF REL-EG2.EXE USING SEQUENTIAL READINGEnter Read type (Direct=1, Seq=2)-> 2 01 VESTRON VIDEOS OVER THE SEA SOMEWHERE IN LONDON 02 EMI STUDIOS HOLLYWOOD, CALIFORNIA, USA 03 BBC WILDLIFE BUSH HOUSE, LONDON, ENGLAND 04 CBS STUDIOS HOLLYWOOD, CALIFORNIA, USA 05 YACHTING MONTHLY TREE HOUSE, LONDON, ENGLAND 06 VIRGIN VIDEOS IS THIS ONE ALSO LOCATED IN ENGLAND 07 CIC VIDEOS NEW YORK PLAZZA, NEW YORK, USA

RUN OF REL-EG2.EXE USING DIRECT READEnter Read type (Direct=1, Seq=2)-> 1Enter supplier key (2 digits)-> 05 05 YACHTING MONTHLY TREE HOUSE, LONDON, ENGLAND

RUN OF REL-EG2.EXE USING SEQUENTIAL READINGEnter Read type (Direct=1, Seq=2)-> 2 01 VESTRON VIDEOS OVER THE SEA SOMEWHERE IN LONDON 02 EMI STUDIOS HOLLYWOOD, CALIFORNIA, USA 03 BBC WILDLIFE BUSH HOUSE, LONDON, ENGLAND 04 CBS STUDIOS HOLLYWOOD, CALIFORNIA, USA 05 YACHTING MONTHLY TREE HOUSE, LONDON, ENGLAND 06 VIRGIN VIDEOS IS THIS ONE ALSO LOCATED IN ENGLAND 07 CIC VIDEOS NEW YORK PLAZZA, NEW YORK, USA

RUN OF REL-EG2.EXE USING DIRECT READEnter Read type (Direct=1, Seq=2)-> 1Enter supplier key (2 digits)-> 05 05 YACHTING MONTHLY TREE HOUSE, LONDON, ENGLAND

561

Select and Assign for Relative FilesSelect and Assign for Relative Files

562

FDs for Relative FDs for Relative FilesFiles

563

Relative File Verbs - Relative File Verbs - OPENOPEN

564

Relative File Verbs - Relative File Verbs - READREAD

565

Relative File Verbs - Write and RewriteRelative File Verbs - Write and Rewrite

566

Relative File Verbs - DELETERelative File Verbs - DELETE

567

Relative File Verbs - Relative File Verbs - STARTSTART

Error Handling Using Declaratives. Error Handling Using Declaratives.

PROCEDURE DIVISION.DECLARATIVES.SectionOne SECTION. USE clause for this section.ParOne1. ???????????????? ????????????????ParOne2. ???????????????? ????????????????

SectionTwo SECTION. USE clause for this section.ParTwo1. ???????????????? ????????????????ParTwo2. ???????????????? ????????????????END-DECLARATIVES.Main SECTION.Begin.

PROCEDURE DIVISION.DECLARATIVES.SectionOne SECTION. USE clause for this section.ParOne1. ???????????????? ????????????????ParOne2. ???????????????? ????????????????

SectionTwo SECTION. USE clause for this section.ParTwo1. ???????????????? ????????????????ParTwo2. ???????????????? ????????????????END-DECLARATIVES.Main SECTION.Begin.

Error Handling Using Declaratives. Error Handling Using Declaratives.

PROCEDURE DIVISION.DECLARATIVES.FileError SECTION. USE AFTER ERROR PROCEDURE ON RelativeFile.CheckFileStatus. EVALUATE TRUE WHEN RecordDoesNotExist DISPLAY "Record does not exist" WHEN RecordAlreadyExists DISPLAY "Record already exists" WHEN FileNotOpen OPEN I-O RelativeFile END-EVALUATE.END-DECLARATIVES.Main SECTION.Begin.

PROCEDURE DIVISION.DECLARATIVES.FileError SECTION. USE AFTER ERROR PROCEDURE ON RelativeFile.CheckFileStatus. EVALUATE TRUE WHEN RecordDoesNotExist DISPLAY "Record does not exist" WHEN RecordAlreadyExists DISPLAY "Record already exists" WHEN FileNotOpen OPEN I-O RelativeFile END-EVALUATE.END-DECLARATIVES.Main SECTION.Begin.

IndexIndexeded

Files.Files.

Creating an Indexed FileCreating an Indexed File

$ SET SOURCEFORMAT"FREE"IDENTIFICATION DIVISION.PROGRAM-ID. CreateIndexedFromSeq.* Creates an indexed file from a sequential file.

ENVIRONMENT DIVISION.INPUT-OUTPUT SECTION.FILE-CONTROL. SELECT VideoFile ASSIGN TO "VIDEO.DAT" ORGANIZATION IS INDEXED ACCESS MODE IS RANDOM RECORD KEY IS VideoCode ALTERNATE RECORD KEY IS VideoTitle WITH DUPLICATES FILE STATUS IS VideoStatus. SELECT SeqVideoFile ASSIGN TO "INVIDEO.DAT".

DATA DIVISION.FILE SECTION.FD VideoFile.01 VideoRecord. 02 VideoCode PIC 9(5). 02 VideoTitle PIC X(40). 02 VideoSupplierCode PIC 99.FD SeqVideoFile.01 SeqVideoRecord. 88 EndOfFile VALUE HIGH-VALUES. 02 SeqVideoCode PIC 9(5). 02 SeqVideoTitle PIC X(40). 02 SeqVideoSupplierCode PIC 99.

WORKING-STORAGE SECTION.01 VideoStatus PIC X(2).

$ SET SOURCEFORMAT"FREE"IDENTIFICATION DIVISION.PROGRAM-ID. CreateIndexedFromSeq.* Creates an indexed file from a sequential file.

ENVIRONMENT DIVISION.INPUT-OUTPUT SECTION.FILE-CONTROL. SELECT VideoFile ASSIGN TO "VIDEO.DAT" ORGANIZATION IS INDEXED ACCESS MODE IS RANDOM RECORD KEY IS VideoCode ALTERNATE RECORD KEY IS VideoTitle WITH DUPLICATES FILE STATUS IS VideoStatus. SELECT SeqVideoFile ASSIGN TO "INVIDEO.DAT".

DATA DIVISION.FILE SECTION.FD VideoFile.01 VideoRecord. 02 VideoCode PIC 9(5). 02 VideoTitle PIC X(40). 02 VideoSupplierCode PIC 99.FD SeqVideoFile.01 SeqVideoRecord. 88 EndOfFile VALUE HIGH-VALUES. 02 SeqVideoCode PIC 9(5). 02 SeqVideoTitle PIC X(40). 02 SeqVideoSupplierCode PIC 99.

WORKING-STORAGE SECTION.01 VideoStatus PIC X(2).

PROCEDURE DIVISION.Begin. OPEN INPUT SeqVideoFile. OPEN OUTPUT VideoFile.

READ SeqVideoFile AT END SET EndOfFile TO TRUE END-READ. PERFORM UNTIL EndOfFile WRITE VideoRecord FROM SeqVideoRecord INVALID KEY DISPLAY "VIDEO STATUS :- ", VideoStatus END-WRITE READ SeqVideoFile AT END SET EndOfFile TO TRUE END-READ END-PERFORM.

CLOSE VideoFile, SeqVideoFile. STOP RUN.

PROCEDURE DIVISION.Begin. OPEN INPUT SeqVideoFile. OPEN OUTPUT VideoFile.

READ SeqVideoFile AT END SET EndOfFile TO TRUE END-READ. PERFORM UNTIL EndOfFile WRITE VideoRecord FROM SeqVideoRecord INVALID KEY DISPLAY "VIDEO STATUS :- ", VideoStatus END-WRITE READ SeqVideoFile AT END SET EndOfFile TO TRUE END-READ END-PERFORM.

CLOSE VideoFile, SeqVideoFile. STOP RUN.

Creating an Indexed Creating an Indexed FileFile

Reading an Indexed File - Sequentially.Reading an Indexed File - Sequentially.

$ SET SOURCEFORMAT"FREE"IDENTIFICATION DIVISION.PROGRAM-ID. ReadingIndexedFile.* Sequential reading of an indexed file

ENVIRONMENT DIVISION.INPUT-OUTPUT SECTION.FILE-CONTROL. SELECT VideoFile ASSIGN TO "VIDEO.DAT" ORGANIZATION IS INDEXED ACCESS MODE IS DYNAMIC RECORD KEY IS VideoCode ALTERNATE RECORD KEY IS VideoTitle WITH DUPLICATES FILE STATUS IS VideoStatus.

DATA DIVISION.FILE SECTION.FD VideoFile01 VideoRecord. 88 EndOfFile VALUE HIGH-VALUE. 02 VideoCode PIC 9(5). 02 VideoTitle PIC X(40). 02 SupplierCode PIC 99.

WORKING-STORAGE SECTION.01 VideoStatus PIC X(2).01 RequiredSequence PIC 9. 88 VideoCodeSequence VALUE 1. 88 VideoTitleSequence VALUE 2.01 PrnVideoRecord. 02 PrnVideoCode PIC 9(5). 02 PrnVideoTitle PIC BBBBX(40). 02 PrnSupplierCode PIC BBBB99.

$ SET SOURCEFORMAT"FREE"IDENTIFICATION DIVISION.PROGRAM-ID. ReadingIndexedFile.* Sequential reading of an indexed file


DATA DIVISION.FILE SECTION.FD VideoFile01 VideoRecord. 88 EndOfFile VALUE HIGH-VALUE. 02 VideoCode PIC 9(5). 02 VideoTitle PIC X(40). 02 SupplierCode PIC 99.

WORKING-STORAGE SECTION.01 VideoStatus PIC X(2).01 RequiredSequence PIC 9. 88 VideoCodeSequence VALUE 1. 88 VideoTitleSequence VALUE 2.01 PrnVideoRecord. 02 PrnVideoCode PIC 9(5). 02 PrnVideoTitle PIC BBBBX(40). 02 PrnSupplierCode PIC BBBB99.


PROCEDURE DIVISION.Begin. OPEN INPUT VideoFile.

DISPLAY "Enter key : 1=VideoCode, 2=VideoTitle ->" WITH NO ADVANCING. ACCEPT RequiredSequence.

IF VideoTitleSequence MOVE SPACES TO VideoTitle START VideoFile KEY IS GREATER THAN VideoTitle INVALID KEY DISPLAY "VIDEO STATUS :- ", VideoStatus END-START END-IF

READ VideoFile NEXT RECORD AT END SET EndOfFile TO TRUE END-READ. PERFORM UNTIL EndOfFile MOVE VideoCode TO PrnVideoCode MOVE VideoTitle TO PrnVideoTitle MOVE SupplierCode TO PrnSupplierCode DISPLAY PrnVideoRecord READ VideoFile NEXT RECORD AT END SET EndOfFile TO TRUE END-READ END-PERFORM.

CLOSE VideoFile. STOP RUN.

PROCEDURE DIVISION.Begin. OPEN INPUT VideoFile.

DISPLAY "Enter key : 1=VideoCode, 2=VideoTitle ->" WITH NO ADVANCING. ACCEPT RequiredSequence.

IF VideoTitleSequence MOVE SPACES TO VideoTitle START VideoFile KEY IS GREATER THAN VideoTitle INVALID KEY DISPLAY "VIDEO STATUS :- ", VideoStatus END-START END-IF

READ VideoFile NEXT RECORD AT END SET EndOfFile TO TRUE END-READ. PERFORM UNTIL EndOfFile MOVE VideoCode TO PrnVideoCode MOVE VideoTitle TO PrnVideoTitle MOVE SupplierCode TO PrnSupplierCode DISPLAY PrnVideoRecord READ VideoFile NEXT RECORD AT END SET EndOfFile TO TRUE END-READ END-PERFORM.

CLOSE VideoFile. STOP RUN.


RUN OF INDEX-EG2.EXE USING VIDEOCODE KEYEnter key : 1=VideoCode, 2=VideoTitle ->100121 FLIGHT OF THE CONDOR, THE 0300333 PREDATOR 0200444 LIVING EARTH, THE 0301001 COMMANDO 0201100 ROBOCOP 0102001 LEOPARD HUNTS IN DARKNESS, A 0302121 DIRTY DANCING 0403031 COMPETENT CREW 0503032 YACHT MASTER 0504041 OPEN OCEAN SAILING 0504042 PRINCESS BRIDE, THE 0604444 LIFE ON EARTH 0305051 OVERBOARD 0106061 HOPE AND GLORY 0707071 AMONG THE WILD CHIMPANZEES 0308081 WHALE NATION 0309091 BESTSELLER 0710001 WICKED WALTZING 0411111 TERMINATOR, THE 0213301 MASSACRE AT MASAI MARA 0314032 KNOTTY PROBLEMS FOR SAILORS 0517001 ALIEN 0717002 ALIENS 0717041 GARFIELD TAKES A HIKE 0618001 SURVIVING THE STORM 0519444 PINOCCIO 02

RUN OF INDEX-EG2.EXE USING VIDEOCODE KEYEnter key : 1=VideoCode, 2=VideoTitle ->100121 FLIGHT OF THE CONDOR, THE 0300333 PREDATOR 0200444 LIVING EARTH, THE 0301001 COMMANDO 0201100 ROBOCOP 0102001 LEOPARD HUNTS IN DARKNESS, A 0302121 DIRTY DANCING 0403031 COMPETENT CREW 0503032 YACHT MASTER 0504041 OPEN OCEAN SAILING 0504042 PRINCESS BRIDE, THE 0604444 LIFE ON EARTH 0305051 OVERBOARD 0106061 HOPE AND GLORY 0707071 AMONG THE WILD CHIMPANZEES 0308081 WHALE NATION 0309091 BESTSELLER 0710001 WICKED WALTZING 0411111 TERMINATOR, THE 0213301 MASSACRE AT MASAI MARA 0314032 KNOTTY PROBLEMS FOR SAILORS 0517001 ALIEN 0717002 ALIENS 0717041 GARFIELD TAKES A HIKE 0618001 SURVIVING THE STORM 0519444 PINOCCIO 02

RUN OF INDEX-EG2 USING VIDEOTITLE KEYEnter key : 1=VideoCode, 2=VideoTitle ->2 17001 ALIEN 0717002 ALIENS 0707071 AMONG THE WILD CHIMPANZEES 0309091 BESTSELLER 0701001 COMMANDO 0203031 COMPETENT CREW 0502121 DIRTY DANCING 0400121 FLIGHT OF THE CONDOR, THE 0317041 GARFIELD TAKES A HIKE 0606061 HOPE AND GLORY 0714032 KNOTTY PROBLEMS FOR SAILORS 0502001 LEOPARD HUNTS IN DARKNESS, A 0304444 LIFE ON EARTH 0300444 LIVING EARTH, THE 0313301 MASSACRE AT MASAI MARA 0304041 OPEN OCEAN SAILING 0505051 OVERBOARD 0119444 PINOCCIO 0200333 PREDATOR 0204042 PRINCESS BRIDE, THE 0601100 ROBOCOP 0118001 SURVIVING THE STORM 0511111 TERMINATOR, THE 0208081 WHALE NATION 0310001 WICKED WALTZING 0403032 YACHT MASTER 05

RUN OF INDEX-EG2 USING VIDEOTITLE KEYEnter key : 1=VideoCode, 2=VideoTitle ->2 17001 ALIEN 0717002 ALIENS 0707071 AMONG THE WILD CHIMPANZEES 0309091 BESTSELLER 0701001 COMMANDO 0203031 COMPETENT CREW 0502121 DIRTY DANCING 0400121 FLIGHT OF THE CONDOR, THE 0317041 GARFIELD TAKES A HIKE 0606061 HOPE AND GLORY 0714032 KNOTTY PROBLEMS FOR SAILORS 0502001 LEOPARD HUNTS IN DARKNESS, A 0304444 LIFE ON EARTH 0300444 LIVING EARTH, THE 0313301 MASSACRE AT MASAI MARA 0304041 OPEN OCEAN SAILING 0505051 OVERBOARD 0119444 PINOCCIO 0200333 PREDATOR 0204042 PRINCESS BRIDE, THE 0601100 ROBOCOP 0118001 SURVIVING THE STORM 0511111 TERMINATOR, THE 0208081 WHALE NATION 0310001 WICKED WALTZING 0403032 YACHT MASTER 05

Reading an Indexed File - Directly.Reading an Indexed File - Directly.

IDENTIFICATION DIVISION.PROGRAM-ID. ReadingIndexedFile.* Illustrates direct read on an indexed file by any key


DATA DIVISION.FILE SECTION.FD VideoFile.01 VideoRecord. 02 VideoCode PIC 9(5). 02 VideoTitle PIC X(40). 02 SupplierCode PIC 99.

WORKING-STORAGE SECTION.01 VideoStatus PIC X(2). 88 RecordFound VALUE "00".01 RequiredKey PIC 9. 88 VideoCodeKey VALUE 1. 88 VideoTitleKey VALUE 2.01 PrnVideoRecord. 02 PrnVideoCode PIC 9(5). 02 PrnVideoTitle PIC BBBBX(40). 02 PrnSupplierCode PIC BBBB99.

IDENTIFICATION DIVISION.PROGRAM-ID. ReadingIndexedFile.* Illustrates direct read on an indexed file by any key


DATA DIVISION.FILE SECTION.FD VideoFile.01 VideoRecord. 02 VideoCode PIC 9(5). 02 VideoTitle PIC X(40). 02 SupplierCode PIC 99.

WORKING-STORAGE SECTION.01 VideoStatus PIC X(2). 88 RecordFound VALUE "00".01 RequiredKey PIC 9. 88 VideoCodeKey VALUE 1. 88 VideoTitleKey VALUE 2.01 PrnVideoRecord. 02 PrnVideoCode PIC 9(5). 02 PrnVideoTitle PIC BBBBX(40). 02 PrnSupplierCode PIC BBBB99.


PROCEDURE DIVISION.Begin. OPEN INPUT VideoFile. DISPLAY "Chose key VideoCode = 1, VideoTitle = 2 -> " WITH NO ADVANCING. ACCEPT RequiredKey. IF VideoCodeKey DISPLAY "Enter Video Code (5 digits) -> " WITH NO ADVANCING ACCEPT VideoCode READ VideoFile KEY IS VideoCode INVALID KEY DISPLAY "VIDEO STATUS :- ", VideoStatus END-READ END-IF IF VideoTitleKey DISPLAY "Enter Video Title (40 chars) -> " WITH NO ADVANCING ACCEPT VideoTitle READ VideoFile KEY IS VideoTitle INVALID KEY DISPLAY "VIDEO STATUS :- ", VideoStatus END-READ END-IF IF RecordFound MOVE VideoCode TO PrnVideoCode MOVE VideoTitle TO PrnVideoTitle MOVE SupplierCode TO PrnSupplierCode DISPLAY PrnVideoRecord END-IF. CLOSE VideoFile. STOP RUN.

PROCEDURE DIVISION.Begin. OPEN INPUT VideoFile. DISPLAY "Chose key VideoCode = 1, VideoTitle = 2 -> " WITH NO ADVANCING. ACCEPT RequiredKey. IF VideoCodeKey DISPLAY "Enter Video Code (5 digits) -> " WITH NO ADVANCING ACCEPT VideoCode READ VideoFile KEY IS VideoCode INVALID KEY DISPLAY "VIDEO STATUS :- ", VideoStatus END-READ END-IF IF VideoTitleKey DISPLAY "Enter Video Title (40 chars) -> " WITH NO ADVANCING ACCEPT VideoTitle READ VideoFile KEY IS VideoTitle INVALID KEY DISPLAY "VIDEO STATUS :- ", VideoStatus END-READ END-IF IF RecordFound MOVE VideoCode TO PrnVideoCode MOVE VideoTitle TO PrnVideoTitle MOVE SupplierCode TO PrnSupplierCode DISPLAY PrnVideoRecord END-IF. CLOSE VideoFile. STOP RUN.


RUN OF INDEX-EG3.EXE USING VIDEOCODEChose key VideoCode = 1, VideoTitle = 2 -> 1Enter Video Code (5 digits) -> 0212102121 DIRTY DANCING 04

RUN OF INDEX-EG3.EXE USING VIDEOCODEChose key VideoCode = 1, VideoTitle = 2 -> 1Enter Video Code (5 digits) -> 0505105051 OVERBOARD 01

RUN OF INDEX-EG3.EXE USING VIDEOTITLEChose key VideoCode = 1, VideoTitle = 2 -> 2Enter Video Title (40 chars) -> OVERBOARD05051 OVERBOARD 01

RUN OF INDEX-EG3.EXE USING VIDEOTITLEChose key VideoCode = 1, VideoTitle = 2 -> 2Enter Video Title (40 chars) -> DIRTY DANCING02121 DIRTY DANCING 04

RUN OF INDEX-EG3.EXE USING NON EXISTANT VIDEOCODEChose key VideoCode = 1, VideoTitle = 2 -> 1Enter Video Code (5 digits) -> 44444VIDEO STATUS :- 23

RUN OF INDEX-EG3.EXE USING VIDEOCODEChose key VideoCode = 1, VideoTitle = 2 -> 1Enter Video Code (5 digits) -> 0212102121 DIRTY DANCING 04

RUN OF INDEX-EG3.EXE USING VIDEOCODEChose key VideoCode = 1, VideoTitle = 2 -> 1Enter Video Code (5 digits) -> 0505105051 OVERBOARD 01

RUN OF INDEX-EG3.EXE USING VIDEOTITLEChose key VideoCode = 1, VideoTitle = 2 -> 2Enter Video Title (40 chars) -> OVERBOARD05051 OVERBOARD 01

RUN OF INDEX-EG3.EXE USING VIDEOTITLEChose key VideoCode = 1, VideoTitle = 2 -> 2Enter Video Title (40 chars) -> DIRTY DANCING02121 DIRTY DANCING 04

RUN OF INDEX-EG3.EXE USING NON EXISTANT VIDEOCODEChose key VideoCode = 1, VideoTitle = 2 -> 1Enter Video Code (5 digits) -> 44444VIDEO STATUS :- 23

579

Select and Assign for Indexed Select and Assign for Indexed FilesFiles

Indexed Files - Primary Indexed Files - Primary KeyKey

30 60 9930 60 99

40 50 6040 50 6010 20 3010 20 30 70 80 9970 80 99

41 43 44 45 46 49

Index Buckets

Level 1Level 1

Level 0Level 0

Level 2Level 2

Data BucketsData Buckets

Indexed Files - Alternate Indexed Files - Alternate KeyKey

H R ZH R Z


Mi Nf Ni Nt Oi Ot

Index Buckets

Level 1Level 1

Level 0Level 0

Level 2Level 2

Base BucketsBase Buckets

50 51 54 55 56 59 Ii Ef Bi Nt Jt At


Indexed Files - Alternate Indexed Files - Alternate KeyKey

H R ZH R Z


Mi Nf Ni Nt Oi Ot

Index Buckets

Level 1Level 1

Level 0Level 0

Level 2Level 2

Base BucketsBase Buckets

50 51 54 55 56 59 Ii Ef Bi Nt Jt At


Ot45

Nf65

Mi71

583

FDs for Indexed FDs for Indexed FilesFiles

584

Indexed File Verbs - Indexed File Verbs - OPENOPEN

585

Indexed File Verbs - Indexed File Verbs - READREAD

586

Indexed File Verbs - Write and Indexed File Verbs - Write and RewriteRewrite

587

Indexed File Verbs - Indexed File Verbs - DELETEDELETE

588

Indexed File Verbs - STARTIndexed File Verbs - START

The CALL The CALL VerbVerb

590

CALL CALL SyntaxSyntax

CALL CALL Example.Example.

IDENTIFICATION DIVISION.IDENTIFICATION DIVISION.PROGRAM-ID DateValidate IS INITIAL.PROGRAM-ID DateValidate IS INITIAL.DATA DIVISION.DATA DIVISION.WORKING-STORAGE SECTION.WORKING-STORAGE SECTION. ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?

LINKAGE SECTION.LINKAGE SECTION.01 DateParam PIC X(8).01 DateParam PIC X(8).01 DateResult PIC 9.01 DateResult PIC 9.

PROCEDURE DIVISION USING DateParam, DateResult.PROCEDURE DIVISION USING DateParam, DateResult.Begin. Begin. ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?? ? ? ? ? ? ? ? ? ? ? ? EXIT PROGRAM.EXIT PROGRAM.

??????.??????. ? ? ? ? ? ? ? ? ? ? ? ?? ? ? ? ? ? ? ? ? ? ? ?

CALL "DateValidate"CALL "DateValidate"USING BY CONTENT TempDateUSING BY CONTENT TempDateUSING BY REFERENCE DateCheckResult.USING BY REFERENCE DateCheckResult.

592

CALL CALL ParametersParameters

CALL "ProgramName" USING P1, P2, P3, P4.CALL "ProgramName" USING P1, P2, P3, P4.

PROCEDURE DIVISION USING P2, P4, P1, P3.PROCEDURE DIVISION USING P2, P4, P1, P3.

593

CALL CALL ParametersParameters

CALL "ProgramName" USING P1, P2, P3, P4.CALL "ProgramName" USING P1, P2, P3, P4.

PROCEDURE DIVISION USING P2, P4, P1, P3.PROCEDURE DIVISION USING P2, P4, P1, P3.

Positions Correspond - Not NamesPositions Correspond - Not Names

Parameter Passing MechanismsParameter Passing Mechanisms

CALL .. BYCALL .. BYREFERENCEREFERENCE

CALLedCALLedProgramProgram

Parameter Passing Parameter Passing MechanismsMechanisms



Address of Address of

Data ItemData Item

DirectionDirectionof Data Flowof Data Flow





Data ItemData Item

CALL .. BYCALL .. BYCONTENTCONTENT


Copy ofCopy ofData ItemData Item






Data ItemData Item

CALL .. BYCALL .. BYCONTENTCONTENT


Copy ofCopy ofData ItemData Item

Address of Address of CopyCopy

Data Data ItemItem



Avoiding “State Memory” - The IS INITIAL Avoiding “State Memory” - The IS INITIAL phrase.phrase.

$ SET SOURCEFORMAT"FREE"IDENTIFICATION DIVISION.PROGRAM-ID. Steadfast IS INITIALIS INITIAL.

DATA DIVISION.WORKING-STORAGE SECTION.01 RunningTotal PIC 9(7) VALUE 50.

LINKAGE SECTION.01 ParamValue PIC 99.

PROCEDURE DIVISION USING ParamValue.Begin. ADD ParamValue TO RunningTotal. DISPLAY "Total = ", RunningTotal. EXIT PROGRAM.

$ SET SOURCEFORMAT"FREE"IDENTIFICATION DIVISION.PROGRAM-ID. Steadfast IS INITIALIS INITIAL.




12

Total = 62

5

Total = 55

12

Total = 62

Avoiding “State Memory” - The IS INITIAL phrase.Avoiding “State Memory” - The IS INITIAL phrase.

$ SET SOURCEFORMAT"FREE"IDENTIFICATION DIVISION.PROGRAM-ID. Fickle.








12

Total = 62

5

Total = 67

12

Total = 79

The CANCEL The CANCEL command.command.









12

Total = 62

12

Total = 62

CALL "Fickle" USING BY CONTENT IncValue.CALL "Fickle" USING BY CONTENT IncValue.CANCELCANCEL "Fickle" "Fickle"CALL "Fickle" USING BY CONTENT IncValue.CALL "Fickle" USING BY CONTENT IncValue.

Contained Sub-Contained Sub-ProgramsPrograms

$ SET SOURCEFORMAT"FREE"IDENTIFICATION DIVISION.PROGRAM-ID. MainProgram. ? ? ? ? ? ? ? ? ?01 TableItem IS GLOBALIS GLOBAL.

PROCEDURE DIVISION. ? ? ? ? ? ? ? ? ? CALL PutToTable USING BY CONTENT DataItem ? ? ? ? ? ? ? ? ? CALL ReportFromTable. EXIT PROGRAM.

IDENTIFICATION DIVISION.PROGRAM-ID. PutToTable. ? ? ? ? ? ? ? ? ?END-PROGRAM PutToTable.

IDENTIFICATION DIVISION.PROGRAM-ID. ReportFromTable. ? ? ? ? ? ? ? ? ?END-PROGRAM ReportFromTable.END-PROGRAM MainProgram.























The COMMON PROGRAM PhraseThe COMMON PROGRAM Phrase

$ SET SOURCEFORMAT"FREE"IDENTIFICATION DIVISION.PROGRAM-ID. MainProgram. ? ? ? ? ? ? ? ? ?01 TableItem IS GLOBALIS GLOBAL.PROCEDURE DIVISION. ? ? ? ? ? ? ? ? ? EXIT PROGRAM.

IDENTIFICATION DIVISION.PROGRAM-ID. PutToTable. ? ? ? ? ? ? ? ? ? CALL ReportFromTable. ? ? ? ? ? ? ? ? ? END-PROGRAM PutToTable.

IDENTIFICATION DIVISION.PROGRAM-ID. ReportFromTable IS COMMON PROGRAM. ? ? ? ? ? ? ? ? ? CALL PutToTable USING ???? ? ? ? ? ? ? ? ? ? END-PROGRAM ReportFromTable.END-PROGRAM MainProgram.




The COMMON PROGRAM The COMMON PROGRAM PhrasePhrase







YESYES

The COMMON PROGRAM The COMMON PROGRAM PhrasePhrase







YESYES

NONO

Creating Abstract Data Creating Abstract Data Types?Types?

$ SET SOURCEFORMAT"FREE"IDENTIFICATION DIVISION.PROGRAM-ID. Stack.DATA DIVISION.WORKING-STORAGE SECTION.01 StackHolder IS GLOBAL. 02 StackItem OCCURS 20 TIMES PIC X(10).PROCEDURE DIVISION USING ????.Begin. EVALUATE TRUE WHEN PushStack CALL "Push" USING ??? WHEN PopStack CALL "Pop" USING ??? END-EVALUATE. EXIT PROGRAM.

IDENTIFICATION DIVISION.PROGRAM-ID. Push. ? ? ? ? ? ? ? ? ?END-PROGRAM Push.

IDENTIFICATION DIVISION.PROGRAM-ID. Pop. ? ? ? ? ? ? ? ? ?END-PROGRAM Pop.END-PROGRAM Stack.




StackStack

PushPush

PopPop

MainMain








StackStack

PushPush

PopPop

MainMain








StackStack

PushPush

PopPop

MainMain

610

The IS EXTERNAL The IS EXTERNAL phrase.phrase.

FD CommonFileArea IS EXTERNAL.

WORKING-STORAGE SECTION.01 SharedRec IS EXTERNAL. 02 PartA PIC X(4). 02 PartB PIC 9(5).



ProgramAProgramA

01 SharedRec etc01 SharedRec etc

ProgramDProgramDProgramCProgramC01 SharedRec etc01 SharedRec etc

ProgramBProgramB

SharedRecSharedRec

Mike12345Mike12345



ProgramAProgramA



ProgramBProgramB

SharedRecSharedRecPUTPUT

Mike12345Mike12345

Mike12345Mike12345



ProgramAProgramA



ProgramBProgramB

SharedRecSharedRecPUTPUT GETGET

Mike12345Mike12345

Mike12345Mike12345

Mike12345Mike12345

COPY COPY VerbVerb

615

The COPY VerbThe COPY Verb

The COPY verb is very different from other COBOL verbs.

While other COBOL statements are executed at run time the COPY is executed at compile time.

The COPY statement allows programs to include frequently used source code text from a copy file or copy library.

The COPY can include source code text without change or it can change the text as it is copied into the client program.

616

The COPY verb2The COPY verb2

The COPY verb is generally used when creating large software systems.

It allows item descriptions to be kept and updated centrally in a copy Library, often under the control of a copy librarian.

A copy library contains COBOL elements that can be reference using a textname.

Each client program which wants to use items described in the copy library uses the COPY verb to include the descriptions it requires.

When more than one copy library is used the OF or IN qualifier is used to indicate which library is being referenced.

617

Why use the COPY verb?Why use the COPY verb?

Using the COPY verb makes implementation simpler by reducing the amount of coding required and eliminating transcription errors.

Using the COPY verb makes some maintenance tasks easier and safer.

The text in the copy library is updated and the affected programs are recompiled.

Using copy libraries makes it more difficult for programmers to make ad hoc changes to file and record formats.

Changes generally have to be approved by the COPY librarian.

618

COPY formatCOPY format

COPY TextName

ExternalFileNameLiteral

OF

IN

LibraryName

LibraryNameLiteral

REPLACING

== PseudoText1 ==

Identifier1

Literal1

Word1

BY

== PseudoText2 ==

Identifier2

Literal2

Word2

Example COPY statements.

COPY "CopyFile2.CBL" REPLACING XYZ BY 120.

COPY Copyfile3 IN "EXLIB".

COPY "CopyFile3.CBL" IN "EXLIB".TextName



LibraryNameLiteral

LibraryNameLiteral

619

How the COPY worksHow the COPY works

If the REPLACING phrase is not used then the compiler simply copies the text into the client program without change.

If the COPY does use the REPLACING phrase then the text is copied and each properly matched occurrence of Pseudo-Text-1, Identifier-1, Literal-1 and Word-1 in the library text is replaced by the corresponding Pseudo-Text-2, Identifier-2, Literal-2 or Word-2 in the REPLACING phrase.

Pseudo-Text is any COBOL text encloded in double equal signs (e.g. ==ADD 1==).

It allows us to replace a series of words or characters as opposed to an individual identifier, literal or word.

620

How the REPLACING worksHow the REPLACING works

The REPLACING phrase tries to match text-words in the library text with text-words before the BY in the REPLACING phase.If a match is achived then as text is copied from the library it is replaced by the matching REPLACING phrase text.

For purposes of matching, each occurrence of aseparator commasemicolonspace

in pseudo-text-1 or in the library text is considered to be a single space.

Each sequence of one or more space separators is considered to be a single space.

Comment lines in either the library or REPLACING phrase text are treated as a single space.

621

Text-WordsText-Words

The matching procedure in the REPLACING phrase operates on text-words.

A text word is ; A literal including opening and closing quotes A seperator other than;

A SpaceA Pseudo-Text delimiterA Comma

Opening and closing parentheses Any other sequence of contiguous characters, bounded by separators.

622

Text-Word ExamplesText-Word Examples

MOVE1 Text Word

MOVE Total TO Print-Total4 Text Words - MOVE Total TO Print-Total

MOVE Total TO Print-Total.5 Text Words - MOVE Total TO Print-Total .

PIC S9(4)V9(6)9 Text words - PIC S9 ( 4 ) V9 ( 6 )

“PIC S9(4)V9(6)”1 Text word - “PIC S9(4)V9(6)”

623

IDENTIFICATION DIVISION. PROGRAM-ID. COPYEG1. AUTHOR. Michael Coughlan. ENVIRONMENT DIVISION. FILE-CONTROL. SELECT StudentFile ASSIGN TO "STUDENTS.DAT" ORGANIZATION IS LINE SEQUENTIAL. DATA DIVISION. FILE SECTION. FD StudentFile. COPY COPYFILE1. PROCEDURE DIVISION. BeginProg. OPEN INPUT StudentFile READ StudentFile AT END SET EndOfSF TO TRUE END-READ PERFORM UNTIL EndOfSF DISPLAY StudentNumber SPACE StudentName SPACE CourseCode SPACE FeesOwed SPACE AmountPaid READ StudentFile AT END SET EndOfSF TO TRUE END-READ END-PERFORM STOP RUN.

IDENTIFICATION DIVISION. PROGRAM-ID. COPYEG1. AUTHOR. Michael Coughlan. ENVIRONMENT DIVISION. FILE-CONTROL. SELECT StudentFile ASSIGN TO "STUDENTS.DAT" ORGANIZATION IS LINE SEQUENTIAL. DATA DIVISION. FILE SECTION. FD StudentFile. COPY COPYFILE1. PROCEDURE DIVISION. BeginProg. OPEN INPUT StudentFile READ StudentFile AT END SET EndOfSF TO TRUE END-READ PERFORM UNTIL EndOfSF DISPLAY StudentNumber SPACE StudentName SPACE CourseCode SPACE FeesOwed SPACE AmountPaid READ StudentFile AT END SET EndOfSF TO TRUE END-READ END-PERFORM STOP RUN.

01 StudentRec. 88 EndOfSF VALUE HIGH-VALUES. 02 StudentNumber PIC 9(7). 02 StudentName PIC X(60). 02 CourseCode PIC X(4). 02 FeesOwed PIC 9(4).

02 AmountPaid PIC 9(4)V99.

01 StudentRec. 88 EndOfSF VALUE HIGH-VALUES. 02 StudentNumber PIC 9(7). 02 StudentName PIC X(60). 02 CourseCode PIC X(4). 02 FeesOwed PIC 9(4).

02 AmountPaid PIC 9(4)V99.

COPY Example 1COPY Example 1

624


02 StudName PIC X(20) OCCURS XYZ TIMES02 StudName PIC X(20) OCCURS XYZ TIMES. 02 StudName PIC X(20) OCCURS XYZ TIMES02 StudName PIC X(20) OCCURS XYZ TIMES.

Copyfile2.cbl

01 NameTable2.01 NameTable2.COPY "CopyFile2.CBL" REPLACING XYZ BY COPY "CopyFile2.CBL" REPLACING XYZ BY 120120..

01 NameTable2. 02 StudName PIC X(20) OCCURS 120 TIMES.

625


02 CustOrder PIC 9(R).02 CustOrder PIC 9(R). 02 CustOrder PIC 9(R).02 CustOrder PIC 9(R).

Copyfile3.cbl

01 CopyData. 01 CopyData. COPY Copyfile3 REPLACING ==COPY Copyfile3 REPLACING ==RR== BY ==== BY ==44==.==.

01 CopyData. 02 CustOrder PIC 9(4).

626


02 CustOrder2 PIC 9(6)V99.02 CustOrder2 PIC 9(6)V99. 02 CustOrder2 PIC 9(6)V99.02 CustOrder2 PIC 9(6)V99.

Copyfile4.cbl

01 CopyData. 01 CopyData. COPY CopyFile4 REPLACING ==COPY CopyFile4 REPLACING ==V99V99== BY ====. == BY ====.

01 CopyData. 02 CustOrder2 PIC 9(6).

627


02 CustKey PIC X(3) VALUE "KEY".02 CustKey PIC X(3) VALUE "KEY".02 CustKey PIC X(3) VALUE "KEY".02 CustKey PIC X(3) VALUE "KEY".

Copyfile5.cbl

01 CopyData. 01 CopyData. COPY CopyFile5 REPLACING COPY CopyFile5 REPLACING "KEY""KEY" BY BY "ABC""ABC"..

01 CopyData. 02 CustKey PIC X(3) VALUE "ABC".

628



Copyfile5.cbl

01 CopyData. 01 CopyData. COPY CopyFile5 REPLACING COPY CopyFile5 REPLACING "CustKey""CustKey" BY BY "Cust""Cust"..

01 CopyData. 02 CustKey PIC X(3) VALUE "KEY". No Replacement

629



Copyfile5.cbl

01 CopyData. 01 CopyData. COPY CopyFile5 REPLACING COPY CopyFile5 REPLACING "KEY""KEY" BY == BY =="ABC"."ABC". 02 CustNum PIC 9(8)02 CustNum PIC 9(8)==. ==.

01 CopyData. 02 CustKey PIC X(3) VALUE "ABC". 02 CustNum PIC 9(8).

630



Copyfile5.cbl

* the ( is a textword replaced by @* the ( is a textword replaced by @

COPY copyfile5 REPLACING COPY copyfile5 REPLACING (( BY BY @@..

* the 3 between ( and ) is a textword replaced by the textword "three"* the 3 between ( and ) is a textword replaced by the textword "three"

COPY copyfile5 REPLACING COPY copyfile5 REPLACING 33 BY BY threethree..

* the ) is a textword replaced by &* the ) is a textword replaced by &

COPY copyfile5 REPLACING COPY copyfile5 REPLACING )) BY BY &&..

02 CustKey PIC X@3) VALUE "KEY".02 CustKey PIC X(three) VALUE "KEY".02 CustKey PIC X(3& VALUE "KEY".

631



Copyfile5.cbl

* the X before (3) is a textword replaced by pseudotext "Replace the X"* the X before (3) is a textword replaced by pseudotext "Replace the X"

COPY copyfile5 REPLACING COPY copyfile5 REPLACING XX BY == BY ==Replace the XReplace the X==.==.

* the pseudotext X(3) is replaced by X(19)* the pseudotext X(3) is replaced by X(19)

COPY copyfile5 REPLACING ==COPY copyfile5 REPLACING ==X(3)X(3)== == BY == BY ==X(19)X(19)==.==.

* the series of textwords X ( 3 ) is replaced by the series X ( 19 ) * the series of textwords X ( 3 ) is replaced by the series X ( 19 )

COPY copyfile5 REPLACING COPY copyfile5 REPLACING X(3)X(3) BY BY X(19)X(19)..

02 CustKey PIC Replace the X(3) VALUE KEY".02 CustKey PIC X(19) VALUE "KEY".02 CustKey PIC X(19) VALUE "KEY".

632



Copyfile5.cbl

* the textword PIC is replaced by the pseudotext Pic is Replaced* the textword PIC is replaced by the pseudotext Pic is Replaced

COPY copyfile5 REPLACING COPY copyfile5 REPLACING PICPIC BY == BY ==Pic is ReplacedPic is Replaced==.==.

* The P in PIC is not a textword by itself and so is not replaced* The P in PIC is not a textword by itself and so is not replaced

COPY copyfile5 REPLACING COPY copyfile5 REPLACING PP BY BY == ==But P in PIC not replacedBut P in PIC not replaced==.==.

02 CustKey Pic is Replaced X(3) VALUE "KEY". 02 CustKey PIC X(3) VALUE "KEY". No Replacement

DebugDebugging ging

PROCO PROCO MenusMenus


F10=directory


F10=directory



F10=user-menu



F10=user-menu









F10=DeleteWord





F10=DeleteWord















ALT key

CTRL key

ALT key

CTRL key

PROCO PROCO MenusMenus

Animate-MenuF1F1=help F2 F2=view F3F3=align F4F4=exchange F5F5=where F6 F6=look-up

F9/F10F9/F10=word-</> EscEscape AAnimate SStep WWch GGo ZZoom nx-IIf PPrfm RRst BBrk E Env QQury FFind L Locate TTxt

DDo

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