Any Questions!

Agenda

• Fun with Functions

– how to get the system date

• Condition Names

• INDARA and SI

• Iteration

• Logical Files

• Positioning the file pointer

IBM LibraryCOBOL

reference linksIBM Boulder, Colorado library

 

http://publib.boulder.ibm.com/infocenter/iseries/v5r4/index.jsp

 

COBOL Programmers Manual

 

http://publib.boulder.ibm.com/iseries/v5r2/ic2924/books/c0925393.pdf

 

 

Fun with Functions

Refer to COBOL Intrinsic functions handout

Move FUNCTION CURRENT DATE (1:8) to …

Condition Names

• Used with Code Fields– Eg. ARE-THERE-MORE-RECORDS– Eg. FINAL-GRADE– Eg. Indicators

Condition Names

01 ARE-THERE-MORE-RECORDS PIC X(3) VALUE ‘YES’.88 THERE-ARE-MORE-RECORDS VALUE ‘YES’.88 END-OF-FILE VALUE ‘NO’.

IF THERE-ARE-MORE-RECORDSREAD EMPLOYEE-FILE.

IF END-OF-FILEPERFORM TERMINATION-RTN.

Set Verb

• Used to initialize fields to a Condition-Name.

01 ARE-THERE-MORE-RECORDS PIC X(3).

88 THERE-ARE-MORE-RECORDS VALUE ‘YES’.

88 END-OF-FILE VALUE ‘NO’.

SET END-OF-FILE TO TRUE.

Conditions Cont’d

01 WORK-DAYS PIC X(3).88 MONDAY VALUE ‘MON’.88 TUESDAY VALUE ‘TUE’.88 WEDNESDAY VALUE ‘WED’.88 THURSDAY VALUE ‘THU’88 FRIDAY VALUE ‘FRI’.

SET MONDAY TO TRUE.IF FRIDAY

DISPLAY ‘GO HOME EARLY’.

Conditions Cont’d

01 FALL-MONTHS PIC X(3).88 SEPTEMBER VALUE ‘SEP’.88 OCTOBER VALUE ‘OCT’.88 NOVEMBER VALUE ‘NOV’.88 DECEMBER VALUE ‘DEC’.

IF OCTOBERDISPLAY ‘HAPPY HALLOWEEN!!’

SET DECEMBER TO TRUE.

INDARA and SI

The relation ship between the externally declared (DDS) interactive screen file

and the COBOL internally declared indicator usage area

As externally defined and created in DDS

0000.30 A DSPSIZ(24 80 *DS3)

0000.40 A INDARA In file area (GLOBAL)

0000.50 A CA03(03 'Function Key 03 =

0000.60 A CA12(12 'Function Key 12 =

0000.70 A R SCREEN1

0000.80 A 1 9'ENTER' in RECORD area (LOCAL)

0000.90 A 1 26'PAYROLL DEPARTMENT'

0001.00 A 1 59'C1401.1'

0001.10 A 3 2'Type choice, press Enter.'

0001.20 A 5 4'Employee number . .'

0001.30 A EEMPNO 5D 0I 5 24ALIAS(SCR1_EMPLOYEE_NUMBER)

0001.40 A 99 ERRMSG('Employee number not

0001.50 A Re-enter valid number.' 99

0001.60 A 23 2'F3=Exit'

SI special indicators - send to the screen for screen behavior / actionControl-area - keyed response received form the “screen”

0018.00 FILE-CONTROL.

0019.00 SELECT DISPLAY-FILE

0020.00 ASSIGN TO WORKSTATION-HM100DSP-SI

0021.00 ORGANIZATION IS TRANSACTION

0022.00 CONTROL-AREA IS WS-CONTROL.

0030.00 DATA DIVISION.

0032.00 FILE SECTION.

0033.00

0034.00 *File Definition for a Program Described File

0036.00 FD DISPLAY-FILE.

0038.00 01 DISPLAY-RECORD.

0039.00 COPY DD-ALL-FORMATS OF HM100DSP.

0045.00

0046.00 WORKING-STORAGE SECTION.

indicatorsRESPONSE and RESULTING

0078.00 01 WS-CONTROL.

0079.00 05 WS-FUNCTION-KEY PIC X(2).

0080.00 88 WS-FUNCTION-KEY-03 VALUE '03'.

0083.00 88 NO-FUNCTION-KEY-WAS-PRESSED VALUE '00'.

0084.00 05 WS-DEVICE-NAME PIC X(10).

0085.00 05 WS-RECORD-FORMAT PIC X(10).

0087.00 01 WS-INDICATOR-LIST.

0088.00 05 IN99 INDICATOR 99 PIC 1 VALUE B'0'.

0089.00 88 INCORRECT-ACTION-CODE VALUE B'1'.

0090.00 88 CORRECT-ACTION-CODE VALUE B'0'.

0091.00 05 IN98 INDICATOR 98 PIC 1 VALUE B'0'.

0092.00 88 INVALID-HORSE VALUE B'1'.

0093.00 88 VALID-HORSE VALUE B'0'.

0094.00 05 IN97 INDICATOR 97 PIC 1 VALUE B'0'.

0095.00 88 REPORT-PRINTED VALUE B'1'.

0096.00 88 REPORT-NOT-PRINTED VALUE B'0'.

•

Program check and response logic

0216.00 EVALUATE TRUE screen variable

0217.00 WHEN SCR1-ACTION-CODE OF PROMPT-I = 'P'

0218.00 PERFORM 210-print-rtn

0224.00 WHEN OTHER

0225.00 SET INCORRECT-ACTION-CODE TO TRUE

0227.00 END-EVALUATE.

0249.01

0249.02 if not ws-function-key-03

0249.03 move save-action to scr1-action-code of prompt-o

0249.04 move save-horse to scr1-horse-code of prompt-o

0249.05 * Write the prompt screen to the screen

0249.06 WRITE DISPLAY-RECORD

0249.07 FORMAT IS 'PROMPT '

0249.08 INDICATORS ARE WS-INDICATOR-LIST

0249.09 end-write

0249.11 * Wait for input

0249.12 READ DISPLAY FILE RECORD

Option Indicators and Conditions

01 WS-indicators. 05 IN90 INDICATOR 90 PIC 1.

88 display-message value B’1’.88 dont-display-message value B’0’.

Set display-message to true.Set dont-display-message to true.If display-messageIf don’t-display-messageIf not display-message

Response Indicators and Conditions

01 WS-Control.05 ws-function-key pic x(2).

88 F3 value ’03’88 F12 value ’12’.88 Enter value ’00’

05 ws-device-name pic x(10).05 ws-record-format pic x(10).

If F3If not F3

Iteration

Looping

BASIC Perform Statement

PERFORM (paragraph-name)

Basic PERFORM

READ Emp-File

PERFORM DSP-Rtn

STOP RUN

DSP-RTN

move emp-in to emp-out.

write dsp-record

format is ‘SCREEN’.

read dsp-file record.

PERFORM Until

PERFORM paragraph-name

UNTIL Condition

PERFORM Until

ConditionMet?

Execute Program

Statements

NO

YES

PERFORM Until

READ Emp-File

AT END Move ‘YES’ TO EOF.

PERFORM Dsp-Rtn UNTIL EOF = ‘Y’

STOP RUN

DSP-RTN

move emp-in to emp-out.

write dsp-record

format is ‘SCREEN’.

read dsp-file RECORD.

read emp-file

at end

move ‘YES’ to EOF.

PERFORM X Times

PERFORM (paragraph-name) THROUGH/THRU (paragraph-name)

(integer/variable) TIMES

PERFORM X Times

Number ofTimes Met?

Execute Program

Statements

NO

YES

PERFORM X Times

READ Emp-File

AT END Move ‘YES’ TO EOF.

PERFORM Dsp-Rtn

5 TIMES

STOP RUN

DSP-RTN

move emp-in to emp-out.

write dsp-record

format is ‘SCREEN’.

read dsp-file record.

PERFORM With Test After

PERFORM (paragraph-name) THROUGH/THRU (paragraph-name)

WITH TEST AFTER

UNTIL Condition

PERFORM With Test After

Condition Met?

Execute Program

Statements

NO

YES

PERFORM With Test After

READ Emp-File

AT END Move ‘YES’ TO EOF.

PERFORM Dsp-Rtn

WITH TEST AFTER

UNTIL EOF = ‘Y’

STOP RUN

DSP-RTN

move emp-in to emp-out.

write dsp-record

format is ‘SCREEN’.

read dsp-file record.

read emp-file

AT END

MOVE ‘YES’ TO EOF.

PERFORMs within PERFORMs

READ Emp-File

AT END Move ‘YES’ TO EOF.

PERFORM DSP-Rtn UNTIL 5 TIMES

STOP RUN

DSP-RTN

MOVE EMP-IN TO EMP-OUT.

PERFORM Write-Rtn

Iteration Statement to Use?

• Perform Until– Tests for the condition first– Statements are executed only if the condition is

true

• Perform With Test After– tests for the condition last– Statements are always executed at least once

Iteration Statement to Use?

• Perform X Times– Use this when you know the number of times

the paragraph(s) are to be executed.

Sorting Data

Using Access Paths

Physical Files vs Logical Files

EMPLOYEEPF *FILE

EMPLOYEE *FILE

Physical Files or Logical Files?

Externally Described Files

• Select Statement when physical/logical file has a key.

SELECT Cobol-file-name

ASSIGN TO database-actual-file-name

[ORGANIZATION IS INDEXED]

[ACCESS MODE IS SEQUENTIAL]

RECORD KEY is data-element.

(data-element could be EXTERNaLLY-DESCRIBED-KEY)

Externally Described Files

• Copying the record layout.

FD Cobol-file-name.01 Cobol-Record-Name.COPY DD-actualrecordname OF actualfilename.

(DD can be replaced by DDS if you require the 10 char field names instead of the aliases)

Handy Physical File Commands

DSPPFM – Display Physical File Member

Displays the contents of a Physical File in arrival sequence.

DSPFD – Display File Description

Information about the file – eg access path.

DSPFFD – Display File Field Description

Displays the fields in the file.

Positioning the File Pointer

Start Verb

Start Verb

Used only with Sequentially defined files.

Initialize the record key

START file-nameKey ConditionINVALID KEY

Perform Invalid-LogicNOT INVALID KEY

Perform valid-logicEND-START.