COBOL Tutorial

COBOL LC_COLLATE Environment Variable - Quick Reference

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Overview

The LC_COLLATE environment variable controls the collation sequence used for string comparison and sorting operations in COBOL applications. This is essential for internationalized applications that need to handle different languages and character sets properly.

Purpose and Usage

String collation - Defines character ordering for sorting
Internationalization - Supports multiple languages and locales
String comparison - Controls how strings are compared
Sorting operations - Affects SORT verb behavior
Locale-specific rules - Handles language-specific character ordering

Collation Concept

Standard ASCII: 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, Z

German Collation: A, Ä, B, C, D, E, F, G, H, I, J, K, L, M, N, O, Ö, P, Q, R, S, T, U, Ü, V, W, X, Y, Z

Swedish Collation: 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, Z, Å, Ä, Ö

Different locales have different rules for ordering characters, especially accented characters.

Syntax and Usage

LC_COLLATE is set as an environment variable and affects all string comparison and sorting operations in the COBOL program.

Environment Variable Syntax

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* Setting LC_COLLATE environment variable
* Unix/Linux shell
export LC_COLLATE=en_US.UTF-8
 
* Windows Command Prompt
set LC_COLLATE=en_US.UTF-8
 
* JCL for mainframe
//SETUP    EXEC PGM=IEFBR14
//SYSPRINT DD SYSOUT=*
//SYSIN    DD *
SET LC_COLLATE=en_US.UTF-8
/*
 
* Common locale values
LC_COLLATE=C              * Standard ASCII ordering
LC_COLLATE=POSIX          * POSIX standard ordering
LC_COLLATE=en_US.UTF-8    * US English with UTF-8
LC_COLLATE=de_DE.UTF-8    * German with UTF-8
LC_COLLATE=fr_FR.UTF-8    * French with UTF-8
LC_COLLATE=es_ES.UTF-8    * Spanish with UTF-8
LC_COLLATE=ja_JP.UTF-8    * Japanese with UTF-8

LC_COLLATE is set as an environment variable before running the COBOL program.

COBOL Program Example

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* COBOL program demonstrating LC_COLLATE effects
       IDENTIFICATION DIVISION.
       PROGRAM-ID. COLLATE-DEMO.
       
       ENVIRONMENT DIVISION.
       CONFIGURATION SECTION.
       
       DATA DIVISION.
       WORKING-STORAGE SECTION.
       01  STRING-ARRAY.
           05  STRING-ITEM OCCURS 5 TIMES PIC X(20).
       01  I              PIC 9(2).
       01  J              PIC 9(2).
       01  TEMP-STRING    PIC X(20).
       
       PROCEDURE DIVISION.
       MAIN-LOGIC.
           * Initialize array with mixed case and accented characters
           MOVE "Apple"     TO STRING-ITEM(1)
           MOVE "Äpfel"     TO STRING-ITEM(2)
           MOVE "Banana"    TO STRING-ITEM(3)
           MOVE "Cherry"    TO STRING-ITEM(4)
           MOVE "Zebra"     TO STRING-ITEM(5)
           
           * Sort the array using current collation rules
           PERFORM SORT-ARRAY
           
           * Display sorted results
           PERFORM VARYING I FROM 1 BY 1 UNTIL I > 5
               DISPLAY STRING-ITEM(I)
           END-PERFORM
           
           STOP RUN.
       
       SORT-ARRAY.
           * Simple bubble sort using current collation
           PERFORM VARYING I FROM 1 BY 1 UNTIL I > 4
               PERFORM VARYING J FROM 1 BY 1 UNTIL J > 5 - I
                   IF STRING-ITEM(J) > STRING-ITEM(J + 1)
                       MOVE STRING-ITEM(J) TO TEMP-STRING
                       MOVE STRING-ITEM(J + 1) TO STRING-ITEM(J)
                       MOVE TEMP-STRING TO STRING-ITEM(J + 1)
                   END-IF
               END-PERFORM
           END-PERFORM.

The comparison operations in this program will use the LC_COLLATE setting.

SORT Verb Usage

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* Using SORT with LC_COLLATE
       IDENTIFICATION DIVISION.
       PROGRAM-ID. SORT-COLLATE.
       
       ENVIRONMENT DIVISION.
       INPUT-OUTPUT SECTION.
       FILE-CONTROL.
           SELECT INPUT-FILE ASSIGN TO "INPUT.DAT"
                  ORGANIZATION IS LINE SEQUENTIAL.
           SELECT OUTPUT-FILE ASSIGN TO "OUTPUT.DAT"
                   ORGANIZATION IS LINE SEQUENTIAL.
           SELECT SORT-FILE ASSIGN TO "SORTWK".
       
       DATA DIVISION.
       FILE SECTION.
       FD  INPUT-FILE.
       01  INPUT-RECORD     PIC X(80).
       
       FD  OUTPUT-FILE.
       01  OUTPUT-RECORD    PIC X(80).
       
       SD  SORT-FILE.
       01  SORT-RECORD.
           05  SORT-KEY     PIC X(30).
           05  SORT-DATA    PIC X(50).
       
       PROCEDURE DIVISION.
       MAIN-LOGIC.
           * Sort using current LC_COLLATE setting
           SORT SORT-FILE
                ON ASCENDING KEY SORT-KEY
                INPUT PROCEDURE IS INPUT-PROC
                OUTPUT PROCEDURE IS OUTPUT-PROC
           
           STOP RUN.
       
       INPUT-PROC SECTION.
           OPEN INPUT INPUT-FILE
           READ INPUT-FILE
               AT END SET END-OF-INPUT TO TRUE
           END-READ
           
           PERFORM UNTIL END-OF-INPUT
               MOVE INPUT-RECORD TO SORT-RECORD
               RELEASE SORT-RECORD
               READ INPUT-FILE
                   AT END SET END-OF-INPUT TO TRUE
               END-READ
           END-PERFORM
           
           CLOSE INPUT-FILE.
       
       OUTPUT-PROC SECTION.
           OPEN OUTPUT OUTPUT-FILE
           RETURN SORT-FILE
               AT END SET END-OF-SORT TO TRUE
           END-RETURN
           
           PERFORM UNTIL END-OF-SORT
               MOVE SORT-RECORD TO OUTPUT-RECORD
               WRITE OUTPUT-RECORD
               RETURN SORT-FILE
                   AT END SET END-OF-SORT TO TRUE
               END-RETURN
           END-PERFORM
           
           CLOSE OUTPUT-FILE.

The SORT verb will use LC_COLLATE rules for determining sort order.

Common Use Cases

LC_COLLATE is essential in various scenarios where proper string ordering is critical for application functionality.

International Applications

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* Multi-language customer data processing
       IDENTIFICATION DIVISION.
       PROGRAM-ID. INT-CUSTOMER-SORT.
       
       DATA DIVISION.
       WORKING-STORAGE SECTION.
       01  CUSTOMER-RECORD.
           05  CUST-NAME    PIC X(50).
           05  CUST-COUNTRY PIC X(2).
           05  CUST-LANGUAGE PIC X(5).
       
       01  SORTED-CUSTOMERS.
           05  CUSTOMER OCCURS 1000 TIMES.
               10  SORT-NAME    PIC X(50).
               10  SORT-COUNTRY PIC X(2).
               10  SORT-LANG    PIC X(5).
       
       PROCEDURE DIVISION.
       MAIN-LOGIC.
           * Set appropriate collation based on primary language
           * This would be done via environment variable
           
           * Sort customers by name using locale-appropriate collation
           PERFORM SORT-CUSTOMERS-BY-NAME
           
           * Display sorted customer list
           PERFORM DISPLAY-CUSTOMERS
           
           STOP RUN.
       
       SORT-CUSTOMERS-BY-NAME.
           * Sort using current LC_COLLATE setting
           * This ensures proper ordering for the target locale
           PERFORM VARYING I FROM 1 BY 1 UNTIL I > CUSTOMER-COUNT
               * Sort logic using current collation rules
               * Names will be ordered according to locale rules
           END-PERFORM.

Customer names are sorted according to locale-specific collation rules.

Report Generation

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* Generating reports with proper collation
       IDENTIFICATION DIVISION.
       PROGRAM-ID. COLLATED-REPORT.
       
       DATA DIVISION.
       WORKING-STORAGE SECTION.
       01  REPORT-HEADER.
           05  HEADER-TITLE    PIC X(60) VALUE "Customer Report".
           05  HEADER-DATE     PIC X(10).
       
       01  CUSTOMER-LINE.
           05  CUST-NUM       PIC 9(6).
           05  FILLER         PIC X(2) VALUE SPACES.
           05  CUST-NAME      PIC X(30).
           05  FILLER         PIC X(2) VALUE SPACES.
           05  CUST-BALANCE   PIC 9(8)V99.
       
       PROCEDURE DIVISION.
       MAIN-LOGIC.
           * LC_COLLATE affects how customer names are sorted
           * and displayed in the report
           
           PERFORM GENERATE-REPORT
           STOP RUN.
       
       GENERATE-REPORT.
           * Sort customer data using current collation
           PERFORM SORT-CUSTOMER-DATA
           
           * Generate report with properly sorted names
           PERFORM WRITE-REPORT-HEADER
           PERFORM WRITE-CUSTOMER-LINES
           
           * Names will appear in locale-appropriate order
           * e.g., German names: Müller, Möller, Möller, Müller
           *      French names: André, Bernard, Céline, Denis

Reports display data in locale-appropriate collation order.

Data Validation

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* Validating data using collation-aware comparisons
       IDENTIFICATION DIVISION.
       PROGRAM-ID. COLLATE-VALIDATION.
       
       DATA DIVISION.
       WORKING-STORAGE SECTION.
       01  VALIDATION-RECORD.
           05  FIELD-NAME    PIC X(30).
           05  FIELD-VALUE   PIC X(50).
       
       01  VALIDATION-RULES.
           05  RULE OCCURS 10 TIMES.
               10  RULE-FIELD    PIC X(30).
               10  RULE-MIN      PIC X(50).
               10  RULE-MAX      PIC X(50).
       
       PROCEDURE DIVISION.
       MAIN-LOGIC.
           * Validate data using current collation rules
           PERFORM VALIDATE-RECORD
           STOP RUN.
       
       VALIDATE-RECORD.
                       * Check if field value is within range using collation
            IF FIELD-VALUE >= RULE-MIN(1) AND
               FIELD-VALUE <= RULE-MAX(1)
                DISPLAY "Field " FIELD-NAME " is valid"
            ELSE
                DISPLAY "Field " FIELD-NAME " is out of range"
            END-IF
            
            * Collation affects how the comparison is performed
            * e.g., "ä" might be considered between "a" and "b"
            * depending on the locale setting.

Data validation uses collation-aware string comparisons.

Best Practices and Tips

Following these best practices ensures effective use of LC_COLLATE in COBOL applications.

LC_COLLATE Best Practices

Set appropriate locale - Choose locale that matches your data
Use UTF-8 encoding - Ensure proper character set support
Test with real data - Verify collation behavior with actual data
Document locale requirements - Specify required LC_COLLATE settings
Consider performance - Complex collation rules may impact performance
Handle mixed locales - Plan for applications with multiple languages

Common Locale Settings

Locale	Description	Use Case
C	Standard ASCII ordering	Simple English applications
en_US.UTF-8	US English with UTF-8	US-based applications
de_DE.UTF-8	German with UTF-8	German applications
fr_FR.UTF-8	French with UTF-8	French applications
es_ES.UTF-8	Spanish with UTF-8	Spanish applications
ja_JP.UTF-8	Japanese with UTF-8	Japanese applications

Performance Considerations

Simple collation - C locale is fastest for basic operations
Complex rules - Asian languages may have slower collation
Memory usage - Collation tables require additional memory
Sorting performance - Large datasets may be affected by collation complexity
Caching - Some systems cache collation tables for performance
Testing - Always test performance with actual data volumes

When to Use Different LC_COLLATE Settings

Use Case	Recommended Setting	Reasoning
Simple English data	C or en_US.UTF-8	Fast, standard ordering
International data	Appropriate locale	Proper character ordering
Legacy systems	C	Compatibility with existing data
Multi-language apps	Primary language locale	Best user experience
Performance critical	C	Fastest collation

LC_COLLATE Quick Reference

Operation	Effect	Example
String comparison	Uses locale collation rules	IF A > B (uses LC_COLLATE)
SORT verb	Sorts using collation sequence	SORT FILE ON ASCENDING KEY
INSPECT	Character classification	INSPECT STRING TALLYING
String functions	Case conversion rules	FUNCTION UPPER-CASE
Data validation	Range checking	IF VALUE >= MIN AND <= MAX

Test Your Knowledge

1. What is the primary purpose of the LC_COLLATE environment variable in COBOL?

To control file I/O operations
To define the collation sequence for sorting and comparing strings
To set numeric formatting rules
To control date and time formatting

2. Which of the following operations is most affected by LC_COLLATE?

Arithmetic operations
String comparison and sorting operations
File operations
Date calculations

3. What happens if LC_COLLATE is not set in a COBOL program?

The program will terminate with an error
The system will use the default collation sequence
All string operations will fail
The program will use ASCII ordering only

4. Which locale setting would be appropriate for sorting German text?

LC_COLLATE=C
LC_COLLATE=de_DE.UTF-8
LC_COLLATE=en_US
LC_COLLATE=POSIX

5. How does LC_COLLATE affect the SORT verb in COBOL?

It has no effect on SORT operations
It determines the collation sequence used for sorting
It only affects SORT operations on numeric fields
It controls the sort algorithm used

COBOL Tutorial

COBOL LC_COLLATE Environment Variable - Quick Reference

Overview

Purpose and Usage

Collation Concept

Syntax and Usage

Environment Variable Syntax

COBOL Program Example

SORT Verb Usage

Common Use Cases

International Applications

Report Generation

Data Validation

Best Practices and Tips

LC_COLLATE Best Practices

Common Locale Settings

Performance Considerations

When to Use Different LC_COLLATE Settings

LC_COLLATE Quick Reference

Test Your Knowledge

Frequently Asked Questions

Related Concepts

LC_CTYPE Environment Variable

LC_MESSAGES Environment Variable

String Operations

SORT Verb

Data Validation

Related Pages

COBOL Tutorial

COBOL LC_COLLATE Environment Variable - Quick Reference

Overview

Purpose and Usage

Collation Concept

Syntax and Usage

Environment Variable Syntax

COBOL Program Example

SORT Verb Usage

Common Use Cases

International Applications

Report Generation

Data Validation

Best Practices and Tips

LC_COLLATE Best Practices

Common Locale Settings

Performance Considerations

When to Use Different LC_COLLATE Settings

LC_COLLATE Quick Reference

Test Your Knowledge

Frequently Asked Questions

What is the difference between LC_COLLATE and other LC_* environment variables?

How do you set LC_COLLATE in a COBOL program?

What are the common LC_COLLATE values and their meanings?

How does LC_COLLATE affect performance in COBOL applications?

What should you consider when choosing an LC_COLLATE setting for a COBOL application?

Related Concepts

LC_CTYPE Environment Variable

LC_MESSAGES Environment Variable

String Operations

SORT Verb

Data Validation

Related Pages