'How to verify ISBN and calculate checksum digit in COBOL?
My problem is I get a different out put from what I am supposed to get: look very below for the output wanted. here is the output I get:
978-1734314502 (correct and valid)
978-1734314509 (incorrect, contains a non-digit)
978-1788399081 (correct and valid)
978-1788399083 (incorrect, contains a non-digit)
Here is what's the question is asking me to do:
do a modern Cobol program to perform ISBN validation of a series of 10-digit ISBNs stored in a user-inputted file.
Include three “subprograms” in the form of paragraphs:
2.1. readISBNnum - Prompts the user for the name of an ASCII file containing the list of ISBN numbers. Reads the values of the ISBN numbers and processes them. If the file does not exist, the program should produce an error message and re-prompt for the filename.
2.2. isValidate - Checks the validity of the ISBN, i.e. whether or not it contains
characters it shouldn’t. Responses should include an indication of whether a number contains erroneous characters.
2.3. checkSUM - Extracts the individual digits, and calculates the checksum digit.Produce an output for each ISBN number in the file, identifying whether it is valid or not
Here is what I have done so far:
IDENTIFICATION DIVISION.
PROGRAM-ID. testSubs.
ENVIRONMENT DIVISION.
CONFIGURATION SECTION.
REPOSITORY.
FUNCTION ALL INTRINSIC
FUNCTION validISBN13.
INPUT-OUTPUT SECTION.
FILE-CONTROL.
DATA DIVISION.
FILE SECTION.
WORKING-STORAGE SECTION.
01 IX PIC S9(4) COMP.
01 TEST-ISBNS.
02 FILLER PIC X(14) VALUE '978-1734314502'.
02 FILLER PIC X(14) VALUE '978-1734314509'.
02 FILLER PIC X(14) VALUE '978-1788399081'.
02 FILLER PIC X(14) VALUE '978-1788399083'.
01 TEST-ISBN REDEFINES TEST-ISBNS
OCCURS 4 TIMES
PIC X(14).
PROCEDURE DIVISION.
MAIN-PROCEDURE.
PERFORM
VARYING IX
FROM 1
BY 1
UNTIL IX > 4
DISPLAY TEST-ISBN (IX) ' ' WITH NO ADVANCING
END-DISPLAY
IF validISBN13(TEST-ISBN (IX)) = -1
DISPLAY '(incorrect, contains a non-digit)'
ELSE
DISPLAY '(correct and valid)'
END-IF
END-PERFORM.
GOBACK.
END PROGRAM testSubs.
IDENTIFICATION DIVISION.
FUNCTION-ID. validISBN13.
ENVIRONMENT DIVISION.
CONFIGURATION SECTION.
REPOSITORY.
FUNCTION ALL INTRINSIC.
INPUT-OUTPUT SECTION.
FILE-CONTROL.
DATA DIVISION.
FILE SECTION.
WORKING-STORAGE SECTION.
01 PASSED-SIZE PIC S9(6) COMP-5.
01 IX PIC S9(4) COMP.
01 WORK-FIELDS.
02 WF-DIGIT PIC X.
02 WF-COUNT PIC 9(2).
88 WEIGHT-1 VALUE 1, 3, 5, 7, 9, 11, 13.
88 WEIGHT-3 VALUE 2, 4, 6, 8, 10, 12.
02 WF-SUM PIC S9(8) COMP.
LINKAGE SECTION.
01 PASSED-ISBN PIC X ANY LENGTH.
01 RETURN-VALUE PIC S9.
PROCEDURE DIVISION USING PASSED-ISBN
RETURNING RETURN-VALUE.
CALL 'C$PARAMSIZE'
USING 1
GIVING PASSED-SIZE
END-CALL.
COMPUTE-CKDIGIT.
INITIALIZE WORK-FIELDS.
PERFORM
VARYING IX
FROM 1
BY 1
UNTIL IX GREATER THAN PASSED-SIZE
MOVE PASSED-ISBN (IX:1) TO WF-DIGIT
IF WF-DIGIT IS NUMERIC
ADD 1 TO WF-COUNT
IF WEIGHT-1
ADD NUMVAL(WF-DIGIT) TO WF-SUM
ELSE
COMPUTE WF-SUM = WF-SUM +
(NUMVAL(WF-DIGIT) * 3)
END-COMPUTE
END-IF
END-IF
END-PERFORM.
IF MOD(WF-SUM, 10) = 0
MOVE +0 TO RETURN-VALUE
ELSE
MOVE -1 TO RETURN-VALUE
END-IF.
GOBACK.
===================================================================================
IDENTIFICATION DIVISION.
PROGRAM-ID. sedol.
ENVIRONMENT DIVISION.
INPUT-OUTPUT SECTION.
FILE-CONTROL.
SELECT sedol-file ASSIGN "sedol.txt"
ORGANIZATION LINE SEQUENTIAL
FILE STATUS sedol-file-status.
DATA DIVISION.
FILE SECTION.
FD sedol-file.
01 sedol PIC X(6).
WORKING-STORAGE SECTION.
01 sedol-file-status PIC XX.
88 sedol-file-ok VALUE "00".
01 digit-num PIC 9 COMP.
01 digit-weights-area VALUE "1317391".
03 digit-weights PIC 9 OCCURS 7 TIMES.
01 weighted-sum-parts-area.
03 weighted-sum-parts PIC 9(3) COMP OCCURS 6 TIMES.
01 weighted-sum PIC 9(3) COMP.
01 check-digit PIC 9.
PROCEDURE DIVISION.
OPEN INPUT sedol-file
PERFORM UNTIL NOT sedol-file-ok
READ sedol-file
AT END
EXIT PERFORM
END-READ
MOVE FUNCTION UPPER-CASE(sedol) TO sedol
PERFORM VARYING digit-num FROM 1 BY 1 UNTIL digit-num > 6
EVALUATE TRUE
WHEN sedol (digit-num:1) IS ALPHABETIC-UPPER
IF sedol (digit-num:1) = "A" OR "E" OR "I" OR "O" OR "U"
DISPLAY "Invalid SEDOL: " sedol
EXIT PERFORM CYCLE
END-IF
COMPUTE weighted-sum-parts (digit-num) =
(FUNCTION ORD(sedol (digit-num:1)) - FUNCTION ORD("A")
+ 10) * digit-weights (digit-num)
WHEN sedol (digit-num:1) IS NUMERIC
MULTIPLY FUNCTION NUMVAL(sedol (digit-num:1))
BY digit-weights (digit-num)
GIVING weighted-sum-parts (digit-num)
WHEN OTHER
DISPLAY "Invalid SEDOL: " sedol
EXIT PERFORM CYCLE
END-EVALUATE
END-PERFORM
INITIALIZE weighted-sum
PERFORM VARYING digit-num FROM 1 BY 1 UNTIL digit-num > 6
ADD weighted-sum-parts (digit-num) TO weighted-sum
END-PERFORM
COMPUTE check-digit =
FUNCTION MOD(10 - FUNCTION MOD(weighted-sum, 10), 10)
DISPLAY sedol check-digit
END-PERFORM
CLOSE sedol-file
.
END PROGRAM sedol.
However, I should get the output to look like this:
1856266532 correct and valid
0864500572 correct and valid with leading zero
0201314525 correct and valid with leading zero
159486781X correct and valid with trailing uppercase X
159486781x correct and valid with trailing lowercase X
0743287290 correct and valid with leading and training zero
081185213X correct and valid with leading zero, trailing X
1B56266532 incorrect, contains a non-digit
159486781Z incorrect, contains a non-digit/X in check digit
1856266537 correct, but not valid (invalid check digit)
Sources
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Source: Stack Overflow
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