Pramendra Pandeya
COBOL/400
Cobol Coding Format
n Sequence
n Indicator
n Area / Margin A
n Area / Margin B
n Identification
The sequence field is used to assign sequence numbers to the coding lines. This field is optional. The first three positions represent page numbers and the next three positions are the line numbers. The indicator can contain asterisk, slash or hyphen. Area or margin A is from 8 – 11 positions. Area An entries can be continued into area B if required. Division name, section names, paragraph names should be coded in Area A. Area or margin B starts from position 12 – 72. The entries of a paragraph should be coded in Area B. The identification field is ignored by the compiler at the time of compilation.
Cobol Words & Data Names
n Reserved Word
n Valid Word
n Data Names
n Literals- boolean,numeric,non-numeric,Char String type.
n Figurative Constant
The cobol word must not exceed 30 characters. It cannot begin or end with a hyphen and cannot contain a blank or any special character except hyphen. A data name refers to the storage space in the memory where the actual value is stored. The data names are only one form of identifiers. A data name must be a user defined word and not a reserved word. Literal means a value which remains unchanged through out the execution of a program. A numeric literal is made of only digits. Nonnumeric literals is composed of characters which are enclosed within quotation marks. The figurative constants are special type of literals whose values may be frequently used by most programs. The figurative constants are zero, space, high-values, low-values, quotes and all literal. The value of the literals can be specified in hexadecimal.
Reserve Words
n Char String with predefined meaning in cobol
n 5 type of reserve words – keywords, optional words, Special Chars, Figurative Chars, Special registers
n Keywords- are reqd. within given clause, entry or statements
n Optional Words – No effect on execution of pgm like KEY IS
n Special Chars- +,/,-,* <,>,<>,>=,<=
n Figurative constants :- zero/zeros/zeroes
n Space/spaces, High-value/’s
n Low-Value/’s – for EBCDIC,ASCII Collating Sequence
n Quote/’s – Quotation mark char must be non-numeric
Sections & Paragraphs
n Identification Division –
- Paragraphs, Entries, Clause
n Environment Division
-Sections,paragraphs ,entries,clause,phrases
n Data Division
-Sections,Entries,Clause,Phrases
n Procedure .Division - sections, paragraph, sentences,Statements, Phrases
Entries- series of clauses ending with period. Identification ,,Environment,,Data Division.
Clauses- set of cobol chars string- Identification, Environement , Data Division
Sentences- series of one or more statments- Procedure Division.
Statements- valid cobol verbs & operand- Procedure Division.
Phrases- Clause,Statement subdivided into small units called pharases - Procedure Division
IDENTIFICATION DIVISION.
This is the first division of every cobol source program. Program-id is the only required paragraph and all other paragraphs are optional. The entry in the program-id paragraph contains the program name to be used to identify the program object. The program name can consist of 1 to 30 characters.
IDENTIFICATION DIVISION.
ID DIVISION.
PROGRAM-ID. entry
[AUTHOR. entry]
[INSTALLATION. entry]
[DATE-WRITTEN. entry]
[DATE-COMPILED. entry]
[SECUIRTY. entry]
ENVIRONMENT DIVISION
This division is the most machine dependent division. The computer and all peripheral devices required by the program are described. The configuration section contains the computer used for the purpose of compilation and execution of the program. The input output section contains the information regarding files to be used in the program.
ENVIRONMENT DIVISION
CONFIGURATION SECTION.
SOURCE-COMPUTER. source-computer.
OBJECT-COMPUTER. object-computer.
[SPECIAL NAMES. special-names.]
INPUT-OUTPUT SECTION.
FILE-CONTROL. file-control-entry.
[I-O-CONTROL. input-output-control-entry]
ACESS MODES :-
Access mode is a COBOL term that defines the manner in which data in a logical or physical file is to be processed. The three access modes are sequential, random, and dynamic.
Sequentxal-Access Mode: Allows reading and writing records of a file in a serial manner; the order of reference as implicitly determined by the position of a record in the file.
Random-Access Mode: Allows reading and writing records in a programmes specified manner; the control of successive references to the file is expressed by specifically defined keys supplied by the user.
Dynamic-Access Mode: Allows a specific input-output request to determine the access mode. Therefore, records may be processed sequentially and/or randomly.
ORGANIZATION
Data Organization is the permanent logical structure of the file. You tell the computer how to retrieve records from the file by specifying the access mode. In COBOL you can specify any of four types of data organization, and three access modes. In a COBOL program, data organization can be sequential, indexed, relative, or TRANSACTION.
DATA DIVISION
This division in COBOL program consists of every data item processed by the program is described. Unless a data item is described in the data division, it cannot be used in the procedure division. The sections in this division are file section, working-storage section, linkage section, report section, screen section. The working-storage section contains data items which are required as intermediate results. Each section of this division is optional if there is no data that may be described in a particular section. If sections are included must appear in the order.
DATA DIVISION
FILE SECTION.
file-section entries
WORKING-STORAGE SECTION.
working-storage entries
Level Structure
n Elementary Data Item
n Group Data Item
n Hierarchical structure
n Data Description Entry
¨ Level Number
¨ Data Item
¨ Picture Clause
¨ Data Type
¨ Size
¨ Value Clause
The data to be processed are internally stored in a specific area in the memory of a computer. The area corresponding to a particular data item is referenced by the data name used in the description of the said item. An elementary data item is one which the programmer would always like to refer to as a whole and not in parts. A group data item refers to the combination of a few elementary data items. The concept of level numbers is specified to describe the heirarchical structure. A data description entry describes a data item. It consists of a level number, data name or filler followed by a number of optional clauses terminated by a period. Except for the level number no other component can appear in area A.
PROCEDURE DIVISION.
n Structure
¨ Statement
¨ Sentence
¨ Paragraph
¨ Sections
Syntax Notation Sample
identifier-1
STATEMENT literal-1 item-2
TO identifier-m ROUNDED identifier-n
END-STATEMENT
ON SIZE ERROR imperative statement
Syntax Notation
n The Statement keyword must be specified
n The operand is required either identifier literal
n The operand item-1 is optional, if coded separate by comma.
n Each entry maybe assigned the keyword Rounded
n The ON keyword is optional for Size Error
n The End-Statement keyword may be coded to end the statement. It is not a required delimiter.
MOVE VERBS
It becomes necessary to move data from one place in the memory to another place. When the sending field is numeric and the receiving field is numeric or numeric edited the data movement is called numeric data transfer. When both the sending and receiving fields are alphabetic, alphanumeric or alphanumeric edited the data movement is called alphanumeric
n MOVE 15 TO A
n MOVE A TO B, C, D
n MOVE CORRESPONDING FILE-1 TO FILE-2
CORR
.
ARITHMATIC VERBS
n ADD
Add verb is used to find the sum of two or more number and to store the sum.
ADD A TO B
ADD A B C TO D
ADD 15 A TO B
ADD A, B GIVING C
ADD A, B GIVING C, D, E
n SUBTRACT
This verb is used to subtract one, or the sum of two or more numbers from one or more numbers and to store the result.
SUBTRACT A FROM B
SUBTRACT A B FROM C
SUBTRACT A B FROM C GIVING D
SUBTRACT 15 FROM A B
SUBTRACT A B FROM 60 GIVING C
n MULTIPLY
This statement causes one or more multiplicants to be multiplied by a multiplier and to store the products
MULTIPLY A BY B
MULTIPLY A BY B GIVING C
MULTIPLY A BY B C D
MULTIPLY A BY B C GIVING D E
MULTIPLY TAX BY .06 GIVING TOTAL-TAX
n DIVIDE
The purpose of this verb is to divide one number by another and to store the result.
DIVIDE 5 INTO B
DIVIDE 5 INTO B GIVING C
DIVIDE 3 INTO A GIVING C D
DIVIDE 2 INTO B C GIVING D E
DIVIDE A BY 3 GIVING C
DIVIDE A INTO B GIVING C REMAINDER D
n COMPUTE
This verb is so powerful that all computations performed by the other four verbs can also be done by using only the Compute verb.
¨ ARITHMETIC EXPRESSION MAY CONSIST OF LITERALS
¨ PARENTHESES TO SPECIFY THE ORDER
¨ ARITHMETIC EXPRESSION PRECEEDED BY + OR –
COMPUTE identfier-1 = arithmetic-expression
n CORRESPONDING OPTION
The corresponding option can be used with add and subtract verbs. The rules to be following during corresponding option are the id1 and id2 must refer to group items. The identifiers must not be data items with level numbers 66, 77, 88. The data items in id1, id2 can take part only when they have the same data name and same qualifiers. Only numeric data items are considered for addition and subtraction. Filler data items are ignored.
When ever an arithmetic operation is executed, if the number of places in the fractional part of the result happens to be greater than the number of places provided for the fractional part in the receiving field, truncation will occur. However if rounded option is specified, 1 is added to the last digit whenever the most significant digit being thrown out is greater than or equal to 5. The rounded option cannot be specified for the identifier that receives the remainder in the divide operation.
The on size error enables the programmer to take measures in case a size-error condition arises.
¨ ADD id1 TO id2
¨ SUBTRACT id1 FROM id2
n ROUNED OPTION
n ON SIZE ERROR
n NOT ON SIZE ERROR
Data Division Clauses
The display usage is most common form of internal data. Each character of the data is represented in one byte. If no usage is specified it will be taken display as default.
When the usage is specified as binary the numeric data item must be an integer with no assumed decimal point. The data item should not contain any character other than 9 or S.
In case of COMP-1 , it will be represented in one word in the float point form. The number is actually represented in hexadecimal. The picture clause cannot be specified for COMP-1 data items.
The usage of COMP-2 is the same as that of COMP-1 except that the data is represented internally in two words. The advantage is that it increases the precision of the most significant digit.
In packed-decimal form of internal representation the numeric data is represented in the decimal form, but one digit takes half a byte.
n USAGE
¨ DISPLAY
¨ BINARY
¨ COMP-1
¨ COMP-2
¨ PACKED-DECIMAL
Conditions
The relational condition indicates a comparison between two operands. The sign condition determines whether or not the algebraic value of an operand is positive, negative or zero. The value of zero is not considered as positive for an arithmetic expression. The class condition is very useful for the validation of the input data. It determines whether or not the value of an operand is numeric, alphabetic, alphabetic-upper, alphabetic-lower. A condition name is an entity which itself is a condition and as such can have either a true or false value. However condition name cannot be defined independently, and must be associated to a data name called the conditional variable. A condition name entry specifies either a single value or a set of value or a range of variables. Any of the simple conditions can be preceded by the logical operator NOT. It reverses the value of the condition . Two simple conditions can be joined by the logical operators AND, OR.
n Relational Condition
n Sign Condition
n Class Condition
n Condition-name Condition
n Negated Simple Condition
n Compound Condition
During execution if the condition is found to be true, the statements represented by statement-1 are executed. On the other hand if the condition is found to be false, the statement-2 are executed. Normally an if statement should be terminated by period. We may encounter a situation where no action needs to be specified if the condition is true, but some actions are necessary if the condition is false. In that case the continue phrase can be specified for the true condition and code the actions required for the false condition.
IF Loop
IF condition THEN
statement-1
ELSE
statement-2
END-IF
n CONTINUE
It will continue to execute the nexr statements after END-IF.
n Nested IF
PERFORM
The perform statement is used to execute a group of consecutive statements written elsewhere in the program. During execution when a perform statement is encountered, a temporary departure from the normal sequential execution takes place and the statements contained in the specified paragraph are executed. Upon completion of the execution of the statements in the paragraph the control implicitly returns to the next statement following the perform statement. In case of simple perform the paragraph or range of paragraph gets executed only once whereas in case of times option the execution is repeated for the specified number of times. In case of until option it is expected that the condition should be false in the beginning and as a result of the repeated execution the condition would become true at some stage. However the perform statement may not be terminated as soon as the condition becomes true. The range must be completely executed before the termination.
n Perform paragraph-1
n Perform paragraph-1 THRU paragraph-n
n Perform paragraph-1 integer/identifier TIMES
n Perform paragraph-1 UNTIL condition
n Perform paragraph-1 VARYING identifier-1
FROM identifier-2 BY identifier-3 UNTIL condition
In case of test before the condition is tested at the beginning of each repeated execution of the specified perform. On the other hand if, test after is specified, the condition is tested at the end of the each repeated execution of perform. Thus if the condition is true at the very beginning, the statements or paragraph is not executed at all when test before is specified and it is executed once when test after is specified.
n Inline Perform
n PERFORM
statement1
statement2 ……
END-PERFORM
n PERFORM WITH TEST BEFORE UNTIL condition
statement1 ….
END-PERFORM
n PERFORM WITH TEST AFTER UNTIL condition
statement1 ….
END-PERFORM
EVALUATE
EVALUATE month
WHEN 4 OR 6 OR 9 OR 11
MOVE 30 TO days
WHEN 2
MOVE 28 TO days
WHEN OTHER
MOVE 31 TO days
END-EVALUATE
INITIALIZE
The purpose of this verb is to initialize identifier-1 which can be either a group item or an elementary item. When identifier-1 specifies a group item, only those items that belong to the category denoted by the replacing phrase will be initialized by the value denoted by id-2. The initialization process is equivalent to the execution of a sequence of implicit move statement where the sending field is id-2 and the receiving field is the elementary items of identifier-1. It also provides the ability to set selected groups or elementary data items to predetermined values (zero or spaces).
INITIALIZE identifier-1
ALPHABETIC
REPLACING ALPHANUMERIC DATA BY id-2
NUMERIC
LIKE
n Allows to copy a data items characteristics
01 WS-CUST-NO LIKE CUSTNO
01 A.
05 B PIC S999V9999.
05 C LIKE B.
05 A PIC XX
05 B LIKE A (+3)
ARRAY & TABLE Handling
Table is a group of data consisting of similar items. COBOL/400 compiler allows tables to be defined from one to seven dimensions. To define a one dimensional table define a group item which has a elementary item with one occurs clause. Each element of the elementary item can be accessed by subscripting the elementary item. The integer in occurs clause must be a positive integer. The occurs clause cannot be specified for an item whose level number is 01, 66, 77, 88. When a data item is described with the occurs clause, the data name as well as any of its subordinate items cannot be referred without a subscript. Redefines clause cannot appear in the same data description entry which contain an occurs clause.
n One Dimensional Array or Table
01 TAX-TABLE.
02 TAX-RATE PIC 99 OCCURS 5 TIMES.
n Two Dimensional Array or Table
01 SALES-TABLE.
02 BRANCH OCCURS 12 TIMES.
03 MONTH-SALES PIC 9(6)V99 OCCURS 30 TIMES.
n Three Dimensional Array or Table.
01 SALES-TABLE.
02 BRANCH OCCURS 12 TIMES.
03 MONTH-SALES OCCURS 30 TIMES.
04 SALES-MAN PIC 9(5)V99 OCCURS 5 TIMES.
ArrayTable Handling – Perform
This form of perform is used when a nested repetition of the range is required while varying more than one identifier. This helps us to add or read data into a multidimensional table.
PERFORM para-1 THRU para-2
VARYING identifier-1 FROM identifier-2
BY identifier-3 UNTIL condition-1
AFTER identifier-4 FROM identifier-5
BY identifier-6 UNTIL condition-2
AFTER ….
Sequential Files – Select
The file-control paragraph names each file and identifies the file through these entries in Environment division of input-output section. This entry specifies the names of the file and assigns the peripheral device which hold that file. The file names that appear in the select clauses must be unique and all these files must be described in Data Division. The word Optional may be used only for input files. When the object program is executed, the optional files need not be present on every occasion. If the keyword Optional is omitted then the file must be present during execution of the program, if the file is not found an execution error will occur.
n DISK, DATABASE, PRINTER, FORMATFILE
SELECT [OPTIONAL] file-name
ASSIGN TO literal-1
[ORGANIZATION IS SEQUENTIAL]
[ACCESS MODE IS SEQUENTIAL]
[FILE STATUS IS dataname-1 dataname-3]
File Status
This clause must be specified in the File-control paragraph. The value is moved into the data name every time an input output statement is executed. The data name should be defined in the Data Division as a two character alphanumeric field.
n Monitors the processing of each I/O request
n Value is moved into data name by OS
n Can monitor errors and exceptional conditions
n Dataname-1 must be defined in Data Division
n Dataname-5 - Extended file status
¨ For non transaction files must be a 6 byte group item
¨ For transaction file must be 4 alphanumeric item
Cobol Program – Example
IDENTIFICATION DIVISION.
PROGRAM –ID. FIRST1.
ENVIRONMENT DIVISION.
CONFIGURATION SECTION.
SOURCE-COMPUTER. AS-400.
OBJECT-COMPUTER. AS-400.
INPUT-OUTPUT SECTION.
FILE-CONTROL.
SELECT INPUT-FILE ASSIGN TO DATABASE-FILE1
FILE STATUS IS IN-STATUS.
DATA DIVISION.
FILE SECTION.
FD INPUT-FILE LABEL RECORDS STANDARD.
01 INPUT-RECORD……..
WORKING-STORAGE SECTION.
• IN-STATUS PIC XX.
88 FILE-OK VALUE “OO”.
Select – Transaction File
When the organization is transaction and access is sequential. When the program issues a write the screen is displayed on the workstation and when read statement is encountered in the program the system sends the values entered by the user on the workstation.
n WORKSTATION
SELECT file-name ASSIGN TO literal-1
[ORGANIZATION IS TRANSACTION]
[ACCESS MODE IS SEQUENTIAL]
[FILE STATUS IS dataname-1 dataname-3]
[CONTROL-AREA IS dataname-4]
The function-key identifies which function key the operator pressed to terminate the transaction. The device name is stored in workstation-id. The data record format referenced by the last I/O statement is stored in the format name.
Assign
n DISK
¨ Program Described data
n DATABASE
¨ Externally Described Data
n PRINTER
¨ Program Described Printer File
n FORMATFILE
¨ Externally Described Printer File
n WORKSTATION
¨ Display Files
¨ Subfiles
FILENAME : 1 – 10 character name
ATTRIBUTE : SI
Control-Area – 1
n Device dependent and system dependent information
n Control I/O operations for Transaction Files
n Can be 2, 12 or 22 characters
SELECT SCREEN-F ASSIGN TO WORKSTATION-DSFP01
ORGANIZATION IS TRANSACTION
FILE STATUS IS FILE-STAT
CONTROL-AREA IS TRANS-CTL-AREA.
FD SCREEN-F LABEL RECORDS OMITTED.
01 SCREEN-REC ……
Control-Area - 2
WORKING-STORAGE SECTION.
01 FILE-STAT PIC XX.
01 TRANS-CTL-AREA.
02 FUNCTION-KEY PIC XX.
88 ENTER-KEY-PRESSED VALUE “00”.
88 FUNCTION3-PRESSED VALUE “03”.
02 WORKSTATION-ID PIC X(10).
02 FORMAT-NAME PIC X(10).
Boolean Data Item
n Primary use is for indicators for WORKSTATION and FORMAT file
n PICTURE IS 1
n USAGE IS DISPLAY
n INDICATOR clause associates an indicator defined in DDS with a Boolean data item
n Can have value of: B”0”, B”1”, B’0’, B’1’ or ZERO
Boolean Data Item – Example
• ONE PIC 1 VALUE B”1”.
77 IN41 PIC 1 INDIC 41.
88 CUSTOMER-VALID VALUE ZERO.
88 CUSTOMER-INVALID VALUE B”1”.
01 IN12 PIC 1 INDIC 12.
88 ITEM-OK VALUE B”0”.
88 ITEM-ERROR VALUE B”1”.
01 IN16 PIC 1 VALUE ZERO.
MOVE B”1” TO IN41.
Copy Statement – Format 1
Compilation of the source program containing COPY statements is logically equivalent to processing all COPY statements before processing the resulting source program. The effect of processing a COPY statement is that the library text associated with text-name is copied into the source program, logically replacing the entire COPY statement, beginning with the word COPY and ending with the period, inclusive. When the REPLACING phrase is not specified, the library text is copied unchanged. If text-name is not qualified, QLBLSRC is assumed as the file name.
If the file name is not qualified by a library name, it is assumed to reside i A COPY statement may appear in the source program anywhere a character string or a separator may appear; however, a COPY statement must not be specified within a COPY statement. The resulting copied text must not contain a COPY statement n a library in the library list.
COPY -text-name
|--OF------library-name --file-name--|
|-----REPLACING---identifier-1--------BY----identifier-2--|
n Places prewritten text
n Standardize file, record descriptions, procedures
n Nested copy not allowed
n Filename is not qualified, checks the library list
n SUPPRESS in copy statement is not printed on source
Copy Statement – Example
FD EMPLOYEE-FILE
LABEL RECORD STANDARD.
01 EMPLOYEE-REC.
COPY EMPREC OF WIPROLIB-MEMBER
REPLACING ENAME BY EMP-NAME.
02 EMP-NO PIC S9(8).
02 EMP-NAME PIC X(25).
02 ADDRESS PIC X(30).
02 CITY PIC X(20).
Copy Statement – Format – 1
The Format 2 COPY statement (DD, DDR, DDS, or DDSR option) can be used to create COBOL Data Division statements to describe the records in file that exists on the system. The Format 2 COPY statement can be used only in the Data Division, and it is the user's responsibility to precede the statement with a group level item that has a level-number less than 05. It must be used under the FD entry for each file with EXTERNALLY-DESCRIBED-KEY specified. The record formats are level checked when file is opened.
n DD-format-name
n DD-ALL-FORMAT
n DDR-format-name
n DDR-ALL-FORMAT
n DDS-format-name
n DDS-ALL-FORMAT
n DDSR-format-name
n DDSR-ALL-FORMAT
n -I, -O, -I-O
n -INIDCATOR, -INDICATORS -INDIC
Copy Statement – Format-2-DDS
The DDS option copies in the internal DDS format field names. The DD option is used to reference alias (alternate) names. The specification of an alias name in DDS allows a data name of up to 30 characters to be included in the COBOL program. When the DD option is used, any alias names present replace the corresponding DDS field names. All underscores in the alias names are translated into hyphens before any replacing occurs.
n Text and key field definitions included in compilation
n File and library defaults same as Format 1 copy
n Default is I-O
n DDS option copies the DDS format field names
n DD option references alias names
¨ Allows Data name of 30 characters
¨ Any alias name replaces field names
¨ Underscores translated into hyphen
Copy Statement – Format - 3
The DDR option does everything that the DD option does. It also replaces the invalid COBOL characters @, #, $, and _ in a field name (or alias
name, if applicable) with the corresponding valid COBOL characters A, N, D, and -. As well, it removes underscores from the end of a field name.
The DDSR option does everything that the DDS option does. It also copies the internal DDS format field names, replacing the invalid COBOL characters @, #, $, and _ with the valid COBOL characters A, N, D, and - accordingly. This option also removes any underscores from the ends of the field names.
n DDR option does everything the DD option does
n DDSR option does everything the DDS option does
n Both DDR and DDSR options
¨ Invalid COBOL characters are replaced
¨ Removes underscores from end of the field names
¨ Reduces need for replacing option
Example
FLD_A FLD-A
NUMBER#1 NUMBERN1
CITY@7 CITYA7
TOTAL$ TOTALD
Format Level Structure
n Table of comments generated at the beginning of each format
¨ Indicates format, file, library used
n Comments showing how the key fields are defined
¨ Name, Retrieval, Type
n If redefinition is required to allow for the generation of multiple formats, a group level name is generated
¨ 05 file-name-RECORD PIC X(size of largest record).
n For each format a group level name is assigned
¨ I-O format. 05 format-name.
¨ OUTPUT. 05 format-name-O.
¨ INPUT. 05 format-name-I.
INSPECT
The INSPECT statement specifies that characters of a data item are to be counted (tallied) or replaced.
. It will count the occurrence of x specific character (alphabetic, numeric, or special character) in a data item.
. It will fill all or portions of a data item with spaces or zeros.
. It will translate characters from one collating sequence to another.
INSPECT Statement Exxmples
The following examples illustrates some uses of the INSPECT statement. In all instances, the programmer has initialized the COUNTR field to zero before the INSPECT statement is executed.
INSPECT ID-1 REPLACING CHARACTERS BY ZERO.
INSPECT ID-1 TALLYING COUNTR FOR CHARACTERS REPLACING CHARACTERS BY SPACES. INSPECT ID-1 REPLACING CHARACTXRS BY ZEROS BEFORE INITIAL QUOTE.
INSPECT ID-1 TALLYING COUNTR FOR CHARACTERS AFTER INITIAL "S" REPLACING ALL "A" BY "O".
INSPECT ID-1 TALLYING COUNTR FOR LEADING "0" REPLACING FIRST "A" BY "2" AFTER INITIAL "C".
INSPECT ID-1 CONVERTING "ABCD" TO "XYZX" AFTER QUOTE BEFORE "#".
STRING
.
The STRING statement strings together the partial or complete contents of two or more data items or literals into one single data item. One STRING statement can be written instead of a series of MOVE statements.
UNSTRING
The STRING statement strings together the partial or complete contents of two or more data items or literrals into one single data item. One STRING statement can be written instead of a series of MOVE statements.
Indicator & Data Field Structure
n If indicator exist in the format
06 format-name-(I or O)-indic.
07 INXX PIC 1 INDIC XX. ( XX is the indicator name.)
n Data field structures
06 Field-name PIC …….
n If external name in the DDS is a COBOL reserved word, suffix-DDS
¨ STATUS becomes STATUS-DDS in data division.
Example:
05 SAMPLE-I.
07 SAMPLE-I-INDIC.
08 IN01 PIC 1 INDIC 01.
08 IN04 PIC 1 INDIC 04.
07 FLD1 PIC …
07 FLD2 PIC …
Copy and File Name
n No implied connection between external filename in the ASSIGN clause and file named in the Format 2 copy
FILE-CONTROL
SELECT FILEA ASSIGN TO DATABASE-filename
…….
FILE SECTION.
FD FILEA ….
01 FILEA-REC.
COPY DDS-FORMAT1 OF filename
Working-Storage Section.
The system creates a separate memory location for the above three examples. In the first case the system copies the indicators and the field name whose usage is for input only. In the second format it copies the field names whose usage is for output only. In third case when I or O is not specified then by default it is considered as I-O. This is generally used for physical or logical files.
WORKING-STORAGE SECTION.
01 DISPLAYIN.
COPY DDS-DSPREC-I OF DSPFL
05 DSPREC-I.
06 DSPREC-I-INDIC.
07 IN03 PIC 1 INDIC 03.
06 EMPNO PIC X(5).
01 DISPLAYOUT.
COPY DDS-DSPREC-O OF DSPFL.
01 DETAILREC.
COPY DDS-ORDDTL OF CUSPF
Open – Sequential File
The processing of a file begins with the execution of an OPEN statement. When a file is opened in the input mode, it becomes an input file. The file must be an existing file unless the OPTIONAL phrase in the select clause is used. The reads can be read sequentially. When a file is to be created for the first time (program described file) it must be opened in the output mode and subsequently records can be placed by the write statement. The extend mode is useful when an existing file should be appended with new records at the end. When a file is opened in I-O mode, records can be read with the read statement and can be written on the file through Rewrite statement.
OPEN INPUT file-name1, [file-name2]
OUTPUT
EXTEND
I-O
Open Output
n DISK, DATABASE
n Physical File is cleared when opened for OUTPUT
¨ Contains no records
n Logical File opened for OUTPUT treated as EXTEND
¨ No records are deleted
Open - Transaction File
OPEN I-O file-name
Close
CLOSE file-name-1 [WITH LOCK]
[, file-name-2 [WITH LOCK]] ……
n SEQUENTIAL files
n TRANSACTION files
Write – Sequential File
The execution of the WRITE statement, the record is released from the record area and is written into the file. Once the record is written it is no longer available in the record area. The first WRITE statement, writes the first record and the subsequent Write writes the record sequentially.
WRITE record-name [FROM identifier-1]
BEFORE ADVANCING id-2 LINES
AFTER literal
[AT END-OF-PAGE imperative statement-1]
[NOT AT END-OF-PAGE imperative statement-2]
END-WRITE
Write – Transactional File
WRITE record-name [FROM identifier-1]
FORMAT [IS] identifier-2
INDICATOR IS identifier-3
INDICATOR ARE
INDIC
END-WRITE
Read – Sequential File
This verb makes the next logical record available from an input file. The read record is placed in the record area described in the File Section of the Data Division. The next time the READ is encountered the record is placed in the same record area as that of first record. When there are no more records in the file the At End clause will be executed. The INTO option may be used to read a record into record area for the file and then get it moved to the area indicated by identifier-1. The Read with Into option is a combination of READ followed by MOVE.
READ file-name [NEXT RECORD]
[ INTO identifier-1] [WITH NO LOCK]
[FORMAT IS identifier-3 / literal-1]
[AT END imperative statement-1]
[NOT AT END imperative statement-2]
END-READ
Read – No Lock
This verb makes the next logical record available from an input file. The read record is placed in the record area described in the File Section of the Data Division. The next time the READ is encountered the record is placed in the same record area as that of first record. When there are no more records in the file the At End clause will be executed. The INTO option may be used to read a record into record area for the file and then get it moved to the area indicated by identifier-1. The Read with Into option is a combination of READ followed by MOVE.
n Can be used when the file is opened for update (I-O)
n Increases performance
n Releases a record locked by previous read
n Error message if file not opened for I-O
n If not specified, the record is locked if the file is opened for I-O
Read – Format
n Name of the record format for this I-O
n If an identifier is specified it must be a character of 10 and should be defined in one of the following :
¨ Working-storage section
¨ Linkage section
¨ Record description entry
n If a literal is specified must be 10 characters or less
n Value of blanks is treated as though no format is specified
Read – Transaction
READ file-name [RECORD] [INTO identifier-1]
[FORMAT [IS] identifier-2]
INDICATOR IS identifier-3
INDICATOR ARE
INDIC
AT END imperative-statement-1
NOT AT END imperative-statement-2
END-READ
Select - Indexed File - along with Organization.
In indexed sequential files the records are stored in the key sequence order. Thus we can access the desired record. An indexed file can be accessed either sequentially or randomly. While creating an indexed file the records are written sequentially and in the ascending order of the key. When the indexed file is accessed randomly, the sequence in which the records are accessed is controlled by the programmer by specifying the value of a data item called record key. The organization clause specifies that the file is an indexed file.
n DISK, DATABASE
SELECT file-name
ASSIGN TO literal-1
[ORGANIZATION IS INDEXED]
[ACCESS MODE IS SEQUENTIAL / RANDOM / DYNAMIC ]
RECORD KEY IS EXTERNALLY-DESCRIBED-KEY
[WITH DUPLICATES]
[FILE STATUS IS dataname-1 dataname-3]
Database Vs Disk
The RECORD KEY clause specifies the record key data item on the basis of which the file is sequenced. The data item in record key clause may be numeric or alphanumeric. If two or more records has the same record key that the duplicate phrase has to be specified.
n Database provides the following additional functions
ENVIRONMENT DIVISION
¨ SELECT clause may specify EXTERNALLY-DESCRIBED-KEY and DUPLICATES
¨ RECORD KEY data item may be numeric
PROCEDURE DIVISION
¨ FORMAT phrase for I/O statements
¨ DB-FORMAT-NAME
¨ FIRST, LAST, or PRIOR of SEQUENTIAL retrieval
¨ EXTERNALLY-DESCRIBED-KEY with START
Database Vs Disk -1
The RECORD KEY clause specifies the record key data item on the basis of which the file is sequenced. The data item in record key clause may be numeric or alphanumeric. If two or more records has the same record key that the duplicate phrase has to be specified. The program must agree with the database file, regarding whether or not duplicates are allowed for the file. When the program OPENs the file, a file status of 95 will be returned if the file and the program does not agree. Processing may continue but the results may be unpredictable.
n Database provides the following additional functions
ENVIRONMENT DIVISION
¨ SELECT clause may specify EXTERNALLY-DESCRIBED-KEY and DUPLICATES
¨ RECORD KEY data item may be numeric
Database Vs Disk -2
The DB-FORMAT-NAME is a cobol reserve word and is a special register of 10 characters in length. It contains the name of the record format read or written by the last successful I/O operation for a DATABASE, FORMATFILE or WORKSTATION file. The EXTERNALLY-DESCRIBED-KEY is also a reserved word and must be used in the assign clause if it is DATABASE. The keys determined by the records formats are copied by the required Format 2 copy statement under the FD for the file. The copied formats will be level checked when the file is opened.
PROCEDURE DIVISION entries – example.
¨ FORMAT phrase for I/O statements
¨ DB-FORMAT-NAME
¨ FIRST, LAST, or PRIOR of SEQUENTIAL retrieval
¨ EXTERNALLY-DESCRIBED-KEY with START
EXTERNALLY-DESCRIBED-KEY
The EXTERNALLLY-DESCRIBED-KEY may be specified for any indexed file. It must be specified for indexed file with multiple key fields that are not adjacent or not in sequence by high to low order key fields from left to right in the record. It must be specified for multiple format indexed files if the key fields are not in the same position in all record formats. In the above example the last must use since the key field are not properly ordered
n KEY of the file is customerno / invoiceno and the record layout is :
COBOL Program – Indexed
FILE-CONTROL.
SELECT MASTFILE ASSIGN TO DATABASE-MASTFILE
ORGANIZATION IS INDEXED
ACCESS IS DYNAMIC
RECORD KEY IS MAST-KEY WITH DUPLICATES
FILE STATUS IS MAST-STATUS.
DATA DIVISION.
FILE SECTION.
FD MASTFILE LABEL RECORDS STANDARD.
01 MAST-RECORD
02 MAST-KEY ……..
. . .
WORKING-STORAGE SECTION.
• MAST-STATUS PIC XX.
Select – Relative File-Display File
A relative file is organized in such a way that each record is identified by a relative record number. The relative record number specifies the position of the record from the beginning of the file. A relative file can be accessed sequentially or randomly. When the file is accessed sequentially, the records are accessed in the increasing order of the relative record number. When the file is accessed randomly the programmer must specify the relative record number. The record is directly accessed regardless of the previous access of any other record in the file. Access mode dynamic means the file is accessed sequentially or randomly. If access mode is not specified default of sequential is assumed. The relative key identifies the data item that contains the relative record number of I/O requests for the file. The dataname-4 cannot be a part of the record in the relative file. For sequential access this phrase is required only if the START verb will be used for the file. This key is must for random or dynamic access. The dataname-4 must be an unsigned integer data item.
n DISK, DATABASE
SELECT file-name ASSIGN TO literal-1
ORGANIZATION IS RELATIVE
[ACCESS MODE IS SEQUENTIAL / RANDOM / DYNAMIC ]
RELATIVE KEY IS dataname-4
[FILE STATUS IS dataname-1 dataname-3]
COBOL Program – Relative
FILE-CONTROL.
SELECT RELFILE ASSIGN TO DATABASE-RELFILE
ORGANIZATION IS RELATIVE
ACCESS IS SEQUENTIAL
RELATIVE KEY IS RECNO
FILE STATUS IS REL-STATUS.
DATA DIVISION.
FILE SECTION.
FD RELFILE LABEL RECORDS STANDARD.
01 REL-RECORD
. . .
. . .
WORKING-STORAGE SECTION.
REL-STATUS PIC XX.
77 REC-NO PIC 9(5) VALUE ZERO.
Open – Index, Relative File
The relative file is cleared, and initialized to deleted records.
OPEN INPUT file-name1, [file-name2]
OUTPUT
I-O
Read – Sequential with Dynamic Access
READ file-name NEXT [RECORD]
FIRST
PRIOR LAST
[INTO identifier-1] [WITH LOCK]
[FORMAT [IS] identifier-2]
AT END imperative-statement-1
NOT AT END imperative-statement-2
END-READ
Read – Random Retrieval
READ file-name [RECORD]
[INTO identifier-1] [WITH LOCK]
[FORMAT [IS] identifier-2]
INVALID KEY imperative-statement-1
NOT INVALID KEY imperative-statement-2
END-READ
Read – Example
Logicial File ORDERS
If SEQUENTIAL access
READ ORDERS
READ ORDERS FORMAT IS “MASTER”
READ ORDERS FORMAT IS “DETAILS”
If RANDOM access : RECORD KEY ______
READ ORDERS
READ ORDERS FORMAT IS “MASTER”
READ ORDERS FORMAT IS “DETAILS”
Write – Indexed, Relative
At the time of execution of the WRITE statement, the file must be open either in OUTPUT or I-O mode
WRITE record name
[FROM identifier-1]
[FORMAT [IS] identifier-2]
INVALID KEY imperative-statement-1
NOT INVALID KEY imperative-statement-2
END-WRITE
Rewrite :
The statement is used to update an existing record by the contents of the record specified in the record name. The file must be opened in I-O mode. The FROM phrase indicates the record area from which data is replaced. The last I/O statement for the file must have been a successfully processed READ statement without the lock phrase. The format phrase is required for files with more than one format. The invalid key is required only for indexed files. For sequential access, the last I/O for this file must have been a successful read statement.
REWRITE recordname
[FROM identifier-1]
[FORMAT [IS] identifier-2]
INVALID KEY imperative-statement-1
NOT INVALID KEY imperative-statement-2
END-REWRITE
Delete
This statement deletes the data contained in the specified record of the file. The file must be opened in I-O. The last input / output statement must have been a successfully processed READ statement without the no lock phrase. It logically removes a record from the indexed or relative file. The record in no longer accessible. In case of indexed file the key is removed from the index, the record cannot be read and the space is not reusable. In case of relative file the record cannot be read, the space can be reused by a WRITE to the relative record of the deleted record.
DELETE file-name RECORD
[FORMAT [IS] identifier-2]
INVALID KEY imperative-statement-1
NOT INVALID KEY imperative-statement-2
END-DELETE
Start
This statement is used to position within an indexed or relative file for subsequent sequential retrieval. The file must be opened in the input or I-O mode and the access must be sequential or dynamic. The data name in the key phrase must be the record key. If the key phrase is omitted, the relational operator equal to with data name equal to that of the record key is assumed. The invalid key condition arises if the condition specified by the key phrase cannot be met.
START file-name
KEY IS EQUAL TO =
GREATER THAN >
NOT LESS THAN NOT <
GREATER THAN OR EQUAL TO >=
[FORMAT [IS] identifier-2]
INVALID KEY imperative-statement-1
NOT INVALID KEY imperative-statement-2
END-START
Set Condition name
01 EOF-MASTER PIC X VALUE “N”.
88 EOF-YES VALUE “Y”.
88 EOF-NO VALUE “N”.
01 EMP-CHECK PIC X VALUE “N”.
88 FOUND VALUE “Y”.
88 NOT-FOUND VALUE “N”.
READ MASTER AT END SET EOF-MASTER TO TRUE
READ EMF-FILE INVALID KEY MOVE “N” TO EMP-CHECK
NOT INVALID KEY MOVE “Y” TO EMP-CHECK
END-READ.
Declaratives Section –Error Handling
This provides a method of running procedures that are run apart from the main flow of the program as a debugging aid. It must be at the beginning of the procedure division. If the declaratives are specified the entire procedure division must be divided into section. Declarative sections are preceded by the keyword DECLARATIVES and followed by keywords END DECLARATIVES. Each of the section should starts with a USE sentence which defines the condition that execute the following procedural paragraphs. These procedural paragraphs specify the action to be taken. After the procedure is executed, control is returned to the routine that activated it. Exception and Error have the same meaning and can be used interchangeably.
n Debugging Aid
DECLARATIVES
USE AFTER STANDARD {EXCEPTION/ERROR }
PROCEDURE ON filename1, filename2 ..
INPUT
OUTPUT
EXTEND
I-O
END-DECLARATIVES
Declaratives Section – Example 1
01 END-INPUT PIC X VALUE SPACE.
88 END-OF-INPUT VALUE “E”.
01 ERROR-FLAG PIC X VALUE SPACE.
88 ERROR-TRUE VALUE “1”.
01 ERROR-DATA.
05 FILLER PIC X(21) VALUE “STATEMENT FAILING IS”.
05 OP-NAME PIC X(9).
05 FILLER PIC X(16) VALUE “FILE STATUS IS”
05 STATUS-VALUE PIC XX.
01 INPUT-MSG.
05 FILLER PIC X(30) VALUE “ERROR ON INPUT FILE”.
01 I0-MSG.
05 FILLER PIC X(30) VALUE “ERROR ON MASTER FILE”.
01 OUTPUT-MSG.
05 FILLER PIC X(30) VALUE “ERROR ON OUTPUT FILE”.
Declaratives Section – Example 2
PROCEDURE DIVISION.
DECLARATIVES.
INPUT-ERROR SECTION.
USE AFTER STANDARD ERROR PROCEDURE ON INPUT
INPUT-ERROR-PARA.
DISPLAY INPUT-MSG.
MOVE INPUT-STATUS TO STATUS-VALUE.
DISPLAY ERROR-DATA.
SET ERROR-TRUE TO TRUE.
I-O-ERROR SECTION.
USE AFTER STANDARD ERROR PROCEDURE ON I-O.
I-O-ERROR-PARA.
DISPLAY IO-MSG.
OUTPUT-ERROR SECTION.
USE AFTER STANDARD ERROR PROCEDURE ON OUTPUT.
OUTPUT-ERROR-PARA.
DISPLAY OUTPUT-MSG.
END DECLARATIVES.
MAIN-PROCESSING SECTION.
Inter Program Communication
The inter program communication facility provides the capability of transfer of control from one program to another and the capability of accessing same data items by two or more programs. The calling program contains the CALL statement and the called program is the sub program. The using phrase makes the referenced data items in the calling program available to the called subprogram. These referenced data items must be defined in the Linkage Section. The number of operands in each using phrase must be identical. The on exception handles exceptions that result from program existence, authority and storage.
Cancel
The memory space occupied by the program is released to the operating system after its cancellation. The next time the referenced subprogram is called, it will be in its initial state, rather than “last used state”. A program that has been called but has not yet executed its EXIT PROGRAM statement cannot be cancelled. If the cancel statement specifies a program that has not yet been called or that has already been cancelled, no action takes place for that program.
COPY - Database File
COPY - Transaction File 1/2
COPY - Transaction File 2/2
Call - Example
RUN UNIT
A run time is a set of one or more object programs which functions as a unit during program execution. One member of this set must be a main program which is not called by any program in the run unit.
Program Termination
Termination | Main Program | Sub Program |
EXIT PROGRAM | Nonoperational | Return to calling program |
STOP RUN | Return to calling program | Return directly to the program that called the main program |
GOBACK | Return to calling program | Return to calling program |
Subfile
Select – Transaction File
The access mode for workstation file which has subfile keywords specified must be dynamic and relative key clause. IF the access mode is sequential then relative key clause must not be coded.
SELECT DISPLAY-FILE ASSIGN TO WORKSTATION-DSP01
ORGANIZATION IS TRANSACTION
ACCESS IS DYNAMIC
RELATIVE KEY IS REC-NUM
FILE STATUS IS DSP-STAT
CONTROL-AREA IS DSP-AREA.
Write – Transaction (Subfile)
This statement is used to write a subfile record. The relative record number is specified by the relative key field.
WRITE SUBFILE record-name [FROM identifier-1]
FORMAT [IS] identifier-2
[{INDICATOR / INDIC} {IS/ARE} identifier-3]
[INVALID KEY imperative-statement-1]
[NOT INVALID KEY imperative-statement-2]
[END-WRITE]
Subfile Inquiry Tasks
n Load Subfile
¨ Write subfile records
n Display subfile
¨ Write subfile control record
n Processing
¨ Read subfile control record
Subfile Phrase I/O
n If SUBFILE phrase is specified
¨ Indicates that all formats referred to by the statement are subfile records (i.e. data records)
n If SUBFILE phrase is not specified
¨ Indicates that none of the formats referred to by the statement are subfile records
n Not verified at compile time.
n If specified incorrectly, file status value will be 92
SFLPAG = SFLSIZ
n Useful when
¨ Total number of subfile records to be displayed will fit on one page or
¨ Number of records to be placed in the subfile is unknown and could be large
n Program writes one page of subfile records at a time
n Subfile will not be extended
n No automatic support for ROLLUP ROLLDOWN keys
SFLPAG Not = SFLSIZ
n Program writes one page of subfile records at a time
n Subfile will be extended
n ROLLUP and SFLRCDNBR keywords required
n Automatic support for ROLLUP ROLLDOWN keys
Update Using Subfile
n Program loads the subfile
n Program displays the subfile
n User modifies the displayed records
n Program reads the subfile and updates the file
Read – Transaction File Subfile – NEXT MODIFIED
This statement is used only to read a format that is a subfile record. The next modified reads the next changed record in the subfile and the AT END phrase is used only with Next Modified.
READ SUBFILE file-name [NEXT MODIFIED RECORD]
[INTO identifier-1] [FORMAT IS identifier-3 / literal-1]
[{INDICATORS/INDIC} {IS/ARE} identifier-4]
[ INVALID KEY imperative statement-1]
[NOT INVALID KEY imperative statement-2]
[AT END imperative statement-3]
[NOT AT END imperative-statement-4]
END-READ
REWRITE – Transaction File Subfile
The relative key field determines which record is updated.
REWRITE SUBFILE record-name
[FROM identifier-1]
[FORMAT IS identifier-3 / literal-1]
[{INDICATORS/INDIC} {IS/ARE} identifier-4]
[ INVALID KEY imperative statement-1]
[NOT INVALID KEY imperative statement-2]
END-REWRITE
To Access Records - Subfile
The relative key field determines which record is updated.
n WRITE SUBFILE
n READ SUBFILE
n READ SUBFILE NEXT MODIFIED
n REWRITE SUBFILE
Random Read of Subfile - Example
The relative key field determines which record is read.
MOVE 5 TO REC-NO.
READ SUBFILE DISPLAY-FILE
INTO DSP-SUBF-INPUT-REC
FORMAT IS “ORDERL”
INVALID KEY SET NO-SF-REC TO TRUE
END-READ.
Sequential Retrieval of Subfile - Example
DATA DIVISION.
• EOF-FLAG PIC 1 VALUE ZERO.
88 NO-RECORDS VALUE B”1”.
88 MORE-RECORDS VALUE B”0”.
• REC-NUM PIC 999 VALUE ZERO.
PROCEDURE DIVISION.
PERFORM PARA10 UNTIL NO-RECORDS.
PARA10.
ADD 1 TO REC-NUM.
READ SUBFILE DISPLAY-FILE RECORD
INTO DSP-SUBF-INPUT-REC FORMAT IS “ORDERL”
INVALID KEY SET NO-RECORDS TO TRUE
NOT INVALID KEY SET MORE-RECORD TO TRUE
END-READ.
IF MORE-RECORDS
***PROCESS SUBFILE
Next Modified - Example 1
The first read statement read the data from the display screen into the subfile. The second read retrieves the first changed record in the subfile. The subsequent reads retrieve the next changed records. The relative key field is updated automatically.
READ SUBFILE DISPLAY-FILE RECORD
INTO DSP-CTL-INPUT-REC
FORMAT IS “CONTROLREC”
END-READ.
READ SUBFILE DISPLAY-FILE
NEXT MODIFIED RECORD
INTO DSP-SUBFL-INPUT-REC
FORMAT IS “ORDERL”
AT END SET NO-RECORDS TO TRUE
END-READ.
Next Modified - Example 2
The records that are changed by the user have the “MODFLG” is turned on by “MDT” returned from the display or a WRITE or REWRITE of a subfile record with SFLNXTCHG activated.
PERFORM PARA-LOOP UNTIL NO-RECORDS.
PARA-LOOP.
READ SUBFILE DISPLAY-FILE
NEXT MODIFIED RECORD
INTO DSP-SUBFL-INPUT-REC
FORMAT IS “ORDERL”
AT END SET NO-RECORDS TO TRUE
END-READ.
IF MORE-RECORDS
***PROCESS THE RECORD RETRIEVED**********
SFLNXTCHG
n If a subfile record is written (WRITE or REWRITE) with SFLNXTCHG active :
¨ The MODFLG for that record is turned on
¨ The record will be retrieved from the subfile by a READ SUBFILE NEXT MODIFIED after the next read of the display, even if the user did not modify any field in that record on the display
n READ SUBFILE NEXT MODIFIED retrieves records in the subfile with the MODFLG on.
n MODFLG is set off when the changed record is retrieved
SFLCLR
n All records are cleared from the file, but the file still exists
n There are no active records in the subfile
n Use WRITE SUBFILE to add records to the subfile
SFLINZ
n All records in the subfile are initialized
¨ Numeric fields - zeros
¨ Character fields - blanks
¨ DFT value for input fields only
n All records in the subfile are considered active
¨ To modify these records, you must READ, REWRITE
n If the subfile is displayed without editing, the fields will contain their initial values
n Input capable fields are underlined on the display
SFLINZ with SFLRNA
n All records in the subfile are initialized
n All records in the subfile are considered inactive
¨ To add records, you must WRITE SUBFILE
n The records cannot be read unless written to
n The display is the same as with SFLINZ without SFLRNA
Indicators Example 1/2
01 SCREEN-IN.
COPY DDS-FORMAT1-I OF DSPFILE.
05 FORMAT1-I.
06 FORMAT1-I-INDIC.
07 IN91 PIC 1 INDIC 91.
06 PORNBR PIC S9(6).
01 SCREEN-OUT.
COPY DDS-FORMAT1-O OF DSPFILE.
05 FORMAT1-O.
06 FORMAT1-O-INDIC.
07 IN11 PIC 1 INDIC 11.
07 IN12 PIC 1 INDIC 12.
06 PORNBR PIC S9(6).
01 WORK-INDICATORS.
05 IN11 PIC 1.
05 IN12 PIC 1.
05 IN91 PIC 1.
Indicators Example 2/2
……….
……….
READ DISPLAY-FILE INTO SCREEN-IN
FORMAT IS “FORMAT1”.
MOVE CORRESPONDING FORMAT1-I-INDIC TO WORK-INDICATORS.
…………………
………………
MOVE CORRESPONDING WORK-INDICATORS.
TO FORMAT1-O-INDIC
WRITE DISPLAY-REC FROM SCREEN-OUT
FORMAT IS “FORMAT”.
Indicators Example
The contents of IND-IN / IND-out are copied from/to the beginning of the record, on a byte by byte basis(group move). The indicator numbers are ignored.
01 IND-IN.
COPY DDS-FORMAT1-I-INDIC OF DSPFILE.
05 FORMAT1-I.
06 FORMAT1-I-INDIC.
07 IN91 PIC 1 INDIC 91.
01 IND-OUT.
COPY DDS-FORMAT1-O-INDIC OF DSPFILE.
05 FORMAT1-O.
06 FORMAT1-O-INDIC.
07 IN11 PIC 1 INDIC 11.
07 IN12 PIC 1 INDIC 12.
06 PORNBR PIC S9(6).
READ DISPLAY-FILE INTO SCREEN-IN
FORMAT IS “FORMAT1” INDICATORS ARE IND-IN.
WRITE DISPLAY-REC FROM SCREEN-OUT
FORMAT IS “FORMAT” INDICAOTRS ARE IND-OUT.
Local Data Area
n 1024 bytes of character data
n Automatically created by the system for each job
n Pass information between programs in a job
n Initialized to blanks
n One per job
n SBMJOB takes a copy
n Defined in the SPEC IAL-NAMES paragraph
n Access with ACCEPT and DISPLAY statements
Special-Names
Accept transfers data to the identifier from the LDA and Display transfer’s data into the LDA.
ENVIRONMENT DIVISION.
CONFIGURATION SECTION.
SPECIAL-NAMES.
LOCAL-DATA IS LDA..
ACCEPT identifier-1 FROM mnemonic-name.
DISPLAY identifier-1 UPON mnemonic-name.
LDA Example -1
CONFIGURATION SECTION.
SPECIAL-NAMES.
LOCAL-DATA IS LOCAL-DATA-AREA.
. . .
01 LDA-FIELDS.
02 NO-REC PIC S9(3) VALUE ZERO.
02 TOT-ORD PIC S9(5)V99 VALUE ZERO.
02 FILLER PIC X(1014).
. . .
DISPLAY LDA-FIELDS UPON LOCAL-DATA-AREA.
LDA Example -2
CONFIGURATION SECTION.
SPECIAL-NAMES.
LOCAL-DATA IS LDA.
. . .
01 LOCAL-FIELDS.
02 NUM-REC PIC S9(3).
02 TOT-ORDER PIC S9(5)V99.
02 FILLER PIC X(1014).
. . .
ACCEPT LOCAL-FIELDS FROM LDA.
Externally Described Printer File
n Less Coding - Describe once
n Less Maintenance - Change one place
n Improved Documentation - Standardize names
n Better Performance - Less system overhead
Write - Format File
WRITE record-name [FROM identifier-1]
FORMAT [IS] identifier-2
[{INDICATOR / INDIC} {IS/ARE} identifier-3]
[AT END-OF-PAGE imperative-statement-1]
[NOT AT END-OF-PAGE imperative-statement-2]
[END-WRITE]
Printer File Example ½
ENVIRONMENT DIVISION.
INPUT-OUTPUT SECTION.
FILE CONTROL.
SELECT PRINT-FILE
ASSIGN TO FORMATFILE-PRTF01.
DATA DIVISION.
FD PRINT-FILE LABEL RECORD IS STANDARD.
01 PRINT-REC PIC X(132).
Printer File Example 2/2
WORKING-STORAGE SECTION.
01 HEADING-REC.
COPY DDS-HEADING OF PRTF01.
01 DETAIL-REC.
COPY DDS-DETAIL OF PRTF01.
PROCEDURE DIVISION.
PARA01.
OPEN OUTPUT PRINT-FILE.
PRINT-HEADING
WRITE PRINT-REC FROM HEADING
FORMAT IS “HEADING” .
PRINT-DETAIL.
WRITE PRINT-REC FROM DETAIL-REC
FORMAT IS “DETAIL”
AT END-OF-PAGE PERFROM PRINT-HEADING.
***********************************************************************
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