What are character sets in COBOL?

Character sets in COBOL define the collection of characters that can be used in text data, including alphabetic, numeric, special characters, and their ordering for sorting and comparison operations.

What is a collating sequence in COBOL?

A collating sequence in COBOL defines the order of characters for sorting and comparison operations, determining how characters are compared and ordered in text processing.

How do you define character sets in COBOL?

Character sets are defined using SPECIAL-NAMES paragraph, collating sequence definitions, and character set specifications that determine valid characters and their ordering.

What are the standard character sets in COBOL?

Standard character sets include EBCDIC (mainframe), ASCII (distributed systems), and various international character sets for different languages and regions.

How do character sets affect sorting in COBOL?

Character sets determine the collating sequence used for sorting operations, affecting the order in which characters and strings are arranged in sorted output.

How do you validate character set compliance in COBOL?

Character set compliance is validated using character validation routines, collating sequence checks, and character set verification procedures.

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COBOL Character Sets

Character sets in COBOL define the collection of characters that can be used in text data processing. They determine valid characters, their ordering for sorting operations, and the collating sequence used for comparisons and text processing throughout COBOL applications.

Understanding Character Sets

Character sets define the alphabet of characters available for text processing, including alphabetic characters, numeric digits, special symbols, and their ordering relationships. Proper character set definition ensures consistent text processing and sorting behavior.

Character Set Components

1. Alphabetic Characters

Alphabetic characters include letters of the alphabet, both uppercase and lowercase, used for text data representation.

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       WORKING-STORAGE SECTION.
       01 ALPHABETIC-CHARS.
           05 UPPERCASE-LETTERS PIC X(26) VALUE 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'.
           05 LOWERCASE-LETTERS PIC X(26) VALUE 'abcdefghijklmnopqrstuvwxyz'.
           05 MIXED-CASE-LETTERS PIC X(52) VALUE 
               'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz'.
       
       01 ALPHABETIC-VALIDATION.
           05 CHAR-TO-VALIDATE PIC X(1).
           05 IS-ALPHABETIC    PIC X(1).
               88 ALPHABETIC-VALID VALUE 'Y'.
               88 ALPHABETIC-INVALID VALUE 'N'.
       
       PROCEDURE DIVISION.
       VALIDATE-ALPHABETIC-CHAR.
           MOVE 'N' TO IS-ALPHABETIC
           PERFORM CHECK-UPPERCASE
           IF ALPHABETIC-INVALID
               PERFORM CHECK-LOWERCASE
           END-IF.
       
       CHECK-UPPERCASE.
           PERFORM VARYING INDEX FROM 1 BY 1
               UNTIL INDEX > 26
               IF UPPERCASE-LETTERS(INDEX:1) = CHAR-TO-VALIDATE
                   MOVE 'Y' TO IS-ALPHABETIC
                   EXIT PERFORM
               END-IF
           END-PERFORM.
       
       CHECK-LOWERCASE.
           PERFORM VARYING INDEX FROM 1 BY 1
               UNTIL INDEX > 26
               IF LOWERCASE-LETTERS(INDEX:1) = CHAR-TO-VALIDATE
                   MOVE 'Y' TO IS-ALPHABETIC
                   EXIT PERFORM
               END-IF
           END-PERFORM.

2. Numeric Characters

Numeric characters include digits 0-9 used for numeric data representation and calculations.

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       WORKING-STORAGE SECTION.
       01 NUMERIC-CHARS.
           05 DIGITS          PIC X(10) VALUE '0123456789'.
           05 HEX-DIGITS      PIC X(16) VALUE '0123456789ABCDEF'.
           05 BINARY-DIGITS   PIC X(2) VALUE '01'.
       
       01 NUMERIC-VALIDATION.
           05 CHAR-TO-CHECK   PIC X(1).
           05 IS-NUMERIC      PIC X(1).
               88 NUMERIC-VALID VALUE 'Y'.
               88 NUMERIC-INVALID VALUE 'N'.
       
       PROCEDURE DIVISION.
       VALIDATE-NUMERIC-CHAR.
           MOVE 'N' TO IS-NUMERIC
           PERFORM VARYING INDEX FROM 1 BY 1
               UNTIL INDEX > 10
               IF DIGITS(INDEX:1) = CHAR-TO-CHECK
                   MOVE 'Y' TO IS-NUMERIC
                   EXIT PERFORM
               END-IF
           END-PERFORM.

3. Special Characters

Special characters include punctuation marks, symbols, and control characters used for formatting and data representation.

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       WORKING-STORAGE SECTION.
       01 SPECIAL-CHARS.
           05 PUNCTUATION     PIC X(10) VALUE '.,;:!?-()'.
           05 SYMBOLS         PIC X(10) VALUE '@#$%&*+=/'.
           05 WHITESPACE      PIC X(3) VALUE ' '.
           05 CONTROL-CHARS   PIC X(5) VALUE X'000D0A09'.
       
       01 SPECIAL-VALIDATION.
           05 CHAR-TO-EXAMINE PIC X(1).
           05 IS-SPECIAL      PIC X(1).
               88 SPECIAL-VALID VALUE 'Y'.
               88 SPECIAL-INVALID VALUE 'N'.
       
       PROCEDURE DIVISION.
       VALIDATE-SPECIAL-CHAR.
           MOVE 'N' TO IS-SPECIAL
           PERFORM CHECK-PUNCTUATION
           IF SPECIAL-INVALID
               PERFORM CHECK-SYMBOLS
           END-IF
           IF SPECIAL-INVALID
               PERFORM CHECK-WHITESPACE
           END-IF.
       
       CHECK-PUNCTUATION.
           PERFORM VARYING INDEX FROM 1 BY 1
               UNTIL INDEX > 10
               IF PUNCTUATION(INDEX:1) = CHAR-TO-EXAMINE
                   MOVE 'Y' TO IS-SPECIAL
                   EXIT PERFORM
               END-IF
           END-PERFORM.

Collating Sequence Definition

1. Standard Collating Sequences

Define standard collating sequences for consistent character ordering and comparison operations.

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       ENVIRONMENT DIVISION.
       CONFIGURATION SECTION.
       SPECIAL-NAMES.
           COLLATING-SEQUENCE IS STANDARD-COLLATING
           ALPHABET STANDARD-COLLATING IS
               'A' THROUGH 'Z'
               'a' THROUGH 'z'
               '0' THROUGH '9'
               SPACE
               '.' ',' ';' ':' '!' '?' '-' '(' ')'.
       
       DATA DIVISION.
       WORKING-STORAGE SECTION.
       01 COLLATING-SEQUENCE-DATA.
           05 COLLATING-TABLE PIC X(100).
           05 COLLATING-INDEX PIC 9(3).
           05 COLLATING-ORDER PIC 9(3).
       
       PROCEDURE DIVISION.
       INITIALIZE-COLLATING-SEQUENCE.
           MOVE 'ABCDEFGHIJKLMNOPQRSTUVWXYZ' TO COLLATING-TABLE(1:26)
           MOVE 'abcdefghijklmnopqrstuvwxyz' TO COLLATING-TABLE(27:26)
           MOVE '0123456789' TO COLLATING-TABLE(53:10)
           MOVE ' .,;:!?-()' TO COLLATING-TABLE(63:10).

2. Custom Collating Sequences

Define custom collating sequences for specific business requirements and sorting needs.

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       ENVIRONMENT DIVISION.
       CONFIGURATION SECTION.
       SPECIAL-NAMES.
           COLLATING-SEQUENCE IS CUSTOM-COLLATING
           ALPHABET CUSTOM-COLLATING IS
               '0' THROUGH '9'
               'A' THROUGH 'Z'
               'a' THROUGH 'z'
               SPACE
               '-' '.' ',' '(' ')'.
       
       WORKING-STORAGE SECTION.
       01 CUSTOM-COLLATING-DATA.
           05 CUSTOM-TABLE    PIC X(100).
           05 CUSTOM-ORDER    PIC 9(3).
           05 CUSTOM-POSITION PIC 9(3).
       
       PROCEDURE DIVISION.
       INITIALIZE-CUSTOM-COLLATING.
           MOVE '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ' TO CUSTOM-TABLE(1:36)
           MOVE 'abcdefghijklmnopqrstuvwxyz' TO CUSTOM-TABLE(37:26)
           MOVE ' -.,()' TO CUSTOM-TABLE(63:6).
       
       FIND-COLLATING-POSITION.
           MOVE 0 TO CUSTOM-POSITION
           PERFORM VARYING CUSTOM-INDEX FROM 1 BY 1
               UNTIL CUSTOM-INDEX > 100
               IF CUSTOM-TABLE(CUSTOM-INDEX:1) = SEARCH-CHAR
                   MOVE CUSTOM-INDEX TO CUSTOM-POSITION
                   EXIT PERFORM
               END-IF
           END-PERFORM.

Character Set Validation

1. Complete Character Set Validation

Validate text data against complete character set definitions to ensure data integrity.

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       WORKING-STORAGE SECTION.
       01 COMPLETE-CHARSET.
           05 VALID-CHARS     PIC X(100) VALUE 
               'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789 .,;:!?-()'.
           05 CHARSET-LENGTH  PIC 9(3) VALUE 100.
       
       01 VALIDATION-RESULTS.
           05 VALIDATION-STATUS PIC X(1).
               88 VALIDATION-PASSED VALUE 'P'.
               88 VALIDATION-FAILED VALUE 'F'.
           05 INVALID-COUNT   PIC 9(3) VALUE 0.
           05 MAX-INVALID     PIC 9(3) VALUE 10.
       
       PROCEDURE DIVISION.
       VALIDATE-COMPLETE-CHARSET.
           MOVE 'P' TO VALIDATION-STATUS
           MOVE 0 TO INVALID-COUNT
           
           PERFORM VARYING CHAR-INDEX FROM 1 BY 1
               UNTIL CHAR-INDEX > INPUT-LENGTH
               PERFORM VALIDATE-SINGLE-CHAR
           END-PERFORM
           
           IF INVALID-COUNT > MAX-INVALID
               MOVE 'F' TO VALIDATION-STATUS
           END-IF.
       
       VALIDATE-SINGLE-CHAR.
           MOVE INPUT-TEXT(CHAR-INDEX:1) TO CURRENT-CHAR
           MOVE 'N' TO CHAR-VALID-FLAG
           
           PERFORM VARYING VALID-INDEX FROM 1 BY 1
               UNTIL VALID-INDEX > CHARSET-LENGTH
               IF VALID-CHARS(VALID-INDEX:1) = CURRENT-CHAR
                   MOVE 'Y' TO CHAR-VALID-FLAG
                   EXIT PERFORM
               END-IF
           END-PERFORM
           
           IF CHAR-VALID-FLAG = 'N'
               ADD 1 TO INVALID-COUNT
           END-IF.

2. Character Set Conversion

Convert between different character sets for system interoperability and data exchange.

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       WORKING-STORAGE SECTION.
       01 CHARSET-CONVERSION.
           05 SOURCE-CHARSET   PIC X(20).
           05 TARGET-CHARSET   PIC X(20).
           05 CONVERSION-TABLE PIC X(256).
           05 CONVERSION-STATUS PIC X(1).
               88 CONVERSION-SUCCESS VALUE 'S'.
               88 CONVERSION-FAILED VALUE 'F'.
       
       01 CONVERSION-DATA.
           05 INPUT-TEXT       PIC X(100).
           05 OUTPUT-TEXT      PIC X(100).
           05 TEXT-LENGTH      PIC 9(3).
       
       PROCEDURE DIVISION.
       CONVERT-CHARSET.
           PERFORM INITIALIZE-CONVERSION-TABLE
           PERFORM CONVERT-TEXT
           PERFORM VALIDATE-CONVERSION.
       
       INITIALIZE-CONVERSION-TABLE.
           IF SOURCE-CHARSET = 'EBCDIC' AND TARGET-CHARSET = 'ASCII'
               PERFORM INITIALIZE-EBCDIC-TO-ASCII-TABLE
           ELSE
               IF SOURCE-CHARSET = 'ASCII' AND TARGET-CHARSET = 'EBCDIC'
                   PERFORM INITIALIZE-ASCII-TO-EBCDIC-TABLE
               ELSE
                   MOVE 'F' TO CONVERSION-STATUS
               END-IF
           END-IF.
       
       CONVERT-TEXT.
           PERFORM VARYING CONV-INDEX FROM 1 BY 1
               UNTIL CONV-INDEX > TEXT-LENGTH
               PERFORM CONVERT-SINGLE-CHAR
           END-PERFORM.
       
       CONVERT-SINGLE-CHAR.
           MOVE INPUT-TEXT(CONV-INDEX:1) TO SOURCE-CHAR
           PERFORM FIND-TARGET-CHAR
           MOVE TARGET-CHAR TO OUTPUT-TEXT(CONV-INDEX:1).

International Character Sets

1. Multi-Language Support

Implement character sets for multiple languages and international text processing requirements.

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       WORKING-STORAGE SECTION.
       01 INTERNATIONAL-CHARSETS.
           05 ENGLISH-CHARSET  PIC X(100) VALUE 
               'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789 .,;:!?-()'.
           05 SPANISH-CHARSET  PIC X(120) VALUE 
               'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789 .,;:!?-()ñÑáéíóúü'.
           05 FRENCH-CHARSET   PIC X(120) VALUE 
               'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789 .,;:!?-()àâäçéèêëïîôùûü'.
           05 GERMAN-CHARSET   PIC X(120) VALUE 
               'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789 .,;:!?-()äöüß'.
       
       01 LANGUAGE-SELECTION.
           05 CURRENT-LANGUAGE PIC X(2).
               88 ENGLISH VALUE 'EN'.
               88 SPANISH VALUE 'ES'.
               88 FRENCH VALUE 'FR'.
               88 GERMAN VALUE 'DE'.
       
       PROCEDURE DIVISION.
       SELECT-LANGUAGE-CHARSET.
           EVALUATE CURRENT-LANGUAGE
               WHEN 'EN'
                   MOVE ENGLISH-CHARSET TO ACTIVE-CHARSET
               WHEN 'ES'
                   MOVE SPANISH-CHARSET TO ACTIVE-CHARSET
               WHEN 'FR'
                   MOVE FRENCH-CHARSET TO ACTIVE-CHARSET
               WHEN 'DE'
                   MOVE GERMAN-CHARSET TO ACTIVE-CHARSET
               WHEN OTHER
                   MOVE ENGLISH-CHARSET TO ACTIVE-CHARSET
           END-EVALUATE.

Best Practices for Character Sets

Consistency: Use consistent character sets throughout the application
Documentation: Document character set requirements and assumptions
Validation: Validate data against defined character sets
Conversion: Implement proper character set conversion routines
Testing: Test with various character sets and languages
Standards: Follow industry standards for character set definitions

COBOL Character Sets

Understanding Character Sets

Character Set Components

1. Alphabetic Characters

2. Numeric Characters

3. Special Characters

Collating Sequence Definition

1. Standard Collating Sequences

2. Custom Collating Sequences

Character Set Validation

1. Complete Character Set Validation

2. Character Set Conversion

International Character Sets

1. Multi-Language Support

Best Practices for Character Sets

Character Encoding

Collating Sequence

String Processing

Data Validation

Text Processing

Internationalization