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COBOL Tutorial

COBOL EXHIBIT Statement

Legacy
Obsolete

The EXHIBIT statement represents a legacy debugging mechanism in COBOL programming, historically employed for program tracing, variable display, and execution monitoring during the development and maintenance phases of COBOL applications. While this statement served important debugging purposes in earlier COBOL implementations, modern development environments have superseded its functionality with more sophisticated debugging tools, integrated development environments, and enhanced DISPLAY statement capabilities that provide superior program analysis and troubleshooting capabilities.

Historical EXHIBIT Statement Usage

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IDENTIFICATION DIVISION.
PROGRAM-ID. EXHIBIT-LEGACY-DEMONSTRATION.
 
DATA DIVISION.
WORKING-STORAGE SECTION.
01  LEGACY-DEBUGGING-VARIABLES.
    05  DEBUG-COUNTER           PIC 9(5) VALUE 0.
    05  PROCESSING-STATUS       PIC X(10) VALUE 'STARTING'.
    05  CURRENT-RECORD-ID       PIC 9(6) VALUE 0.
    05  CALCULATION-RESULT      PIC 9(7)V99 VALUE 0.
    05  ERROR-COUNT             PIC 9(3) VALUE 0.
    05  ITERATION-COUNT         PIC 9(4) VALUE 0.
 
01  BUSINESS-DATA-FIELDS.
    05  CUSTOMER-ID             PIC 9(8) VALUE 12345678.
    05  CUSTOMER-NAME           PIC X(30) VALUE 'JOHN DOE ENTERPRISES'.
    05  ACCOUNT-BALANCE         PIC 9(9)V99 VALUE 15000.75.
    05  TRANSACTION-AMOUNT      PIC 9(7)V99 VALUE 2500.00.
    05  TRANSACTION-TYPE        PIC X(10) VALUE 'CREDIT'.
    05  PROCESSING-DATE         PIC 9(8) VALUE 20240115.
 
01  CONTROL-FLOW-VARIABLES.
    05  LOOP-CONTROL            PIC 9(3) VALUE 1.
    05  CONDITION-FLAG          PIC X VALUE 'Y'.
        88  CONDITION-TRUE      VALUE 'Y'.
        88  CONDITION-FALSE     VALUE 'N'.
    05  BRANCH-INDICATOR        PIC X(5) VALUE 'MAIN'.
    05  SUBROUTINE-LEVEL        PIC 9(2) VALUE 0.
 
01  PERFORMANCE-METRICS.
    05  RECORDS-PROCESSED       PIC 9(7) VALUE 0.
    05  SUCCESSFUL-OPERATIONS   PIC 9(7) VALUE 0.
    05  FAILED-OPERATIONS       PIC 9(5) VALUE 0.
    05  EXECUTION-TIME          PIC 9(6) VALUE 0.
 
PROCEDURE DIVISION.
MAIN-PROCESSING.
    *> Legacy EXHIBIT usage for program entry tracing
    EXHIBIT 'PROGRAM START' PROCESSING-STATUS
    
    PERFORM INITIALIZE-PROCESSING
    PERFORM DEMONSTRATE-EXHIBIT-VARIATIONS
    PERFORM BUSINESS-LOGIC-WITH-EXHIBIT
    PERFORM CLEANUP-PROCESSING
    
    *> Legacy EXHIBIT usage for program exit tracing
    EXHIBIT 'PROGRAM END' PROCESSING-STATUS
    STOP RUN.
 
INITIALIZE-PROCESSING.
    MOVE 'INIT' TO PROCESSING-STATUS
    ADD 1 TO DEBUG-COUNTER
    
    *> Legacy EXHIBIT for initialization tracing
    EXHIBIT 'INITIALIZATION' DEBUG-COUNTER PROCESSING-STATUS
    
    MOVE 'READY' TO PROCESSING-STATUS
    DISPLAY 'Initialization completed'.
 
DEMONSTRATE-EXHIBIT-VARIATIONS.
    MOVE 'DEMO' TO PROCESSING-STATUS
    
    *> Basic EXHIBIT usage - displaying single variable
    EXHIBIT 'CUSTOMER-ID' CUSTOMER-ID
    
    *> EXHIBIT with multiple variables
    EXHIBIT 'CUSTOMER-DATA' CUSTOMER-ID CUSTOMER-NAME ACCOUNT-BALANCE
    
    *> EXHIBIT with literal and variables
    EXHIBIT 'TRANSACTION-INFO' TRANSACTION-TYPE TRANSACTION-AMOUNT
    
    *> EXHIBIT in conditional processing
    IF ACCOUNT-BALANCE > 10000
        EXHIBIT 'HIGH-BALANCE-CUSTOMER' CUSTOMER-ID ACCOUNT-BALANCE
    ELSE
        EXHIBIT 'STANDARD-CUSTOMER' CUSTOMER-ID ACCOUNT-BALANCE
    END-IF
    
    *> EXHIBIT in loop processing
    PERFORM VARYING LOOP-CONTROL FROM 1 BY 1 UNTIL LOOP-CONTROL > 5
        ADD 1 TO ITERATION-COUNT
        EXHIBIT 'LOOP-ITERATION' LOOP-CONTROL ITERATION-COUNT
    END-PERFORM.
 
BUSINESS-LOGIC-WITH-EXHIBIT.
    MOVE 'BUSINESS' TO PROCESSING-STATUS
    EXHIBIT 'BUSINESS-LOGIC-START' PROCESSING-STATUS
    
    PERFORM PROCESS-CUSTOMER-TRANSACTION
    PERFORM VALIDATE-BUSINESS-RULES
    PERFORM UPDATE-ACCOUNT-BALANCE
    
    MOVE 'COMPLETE' TO PROCESSING-STATUS
    EXHIBIT 'BUSINESS-LOGIC-END' PROCESSING-STATUS.
 
PROCESS-CUSTOMER-TRANSACTION.
    ADD 1 TO SUBROUTINE-LEVEL
    EXHIBIT 'SUBROUTINE-ENTRY' SUBROUTINE-LEVEL
    
    ADD 1 TO CURRENT-RECORD-ID
    EXHIBIT 'PROCESSING-RECORD' CURRENT-RECORD-ID
    
    EVALUATE TRANSACTION-TYPE
        WHEN 'CREDIT'
            EXHIBIT 'CREDIT-TRANSACTION' TRANSACTION-AMOUNT
            PERFORM PROCESS-CREDIT-TRANSACTION
        WHEN 'DEBIT'
            EXHIBIT 'DEBIT-TRANSACTION' TRANSACTION-AMOUNT
            PERFORM PROCESS-DEBIT-TRANSACTION
        WHEN OTHER
            EXHIBIT 'UNKNOWN-TRANSACTION' TRANSACTION-TYPE
            ADD 1 TO ERROR-COUNT
    END-EVALUATE
    
    SUBTRACT 1 FROM SUBROUTINE-LEVEL
    EXHIBIT 'SUBROUTINE-EXIT' SUBROUTINE-LEVEL.
 
PROCESS-CREDIT-TRANSACTION.
    EXHIBIT 'CREDIT-PROCESSING-START' ACCOUNT-BALANCE TRANSACTION-AMOUNT
    
    ADD TRANSACTION-AMOUNT TO ACCOUNT-BALANCE
    ADD 1 TO SUCCESSFUL-OPERATIONS
    
    EXHIBIT 'CREDIT-PROCESSING-END' ACCOUNT-BALANCE
    EXHIBIT 'CREDIT-SUCCESS' SUCCESSFUL-OPERATIONS.
 
PROCESS-DEBIT-TRANSACTION.
    EXHIBIT 'DEBIT-PROCESSING-START' ACCOUNT-BALANCE TRANSACTION-AMOUNT
    
    IF ACCOUNT-BALANCE >= TRANSACTION-AMOUNT
        SUBTRACT TRANSACTION-AMOUNT FROM ACCOUNT-BALANCE
        ADD 1 TO SUCCESSFUL-OPERATIONS
        EXHIBIT 'DEBIT-SUCCESS' ACCOUNT-BALANCE SUCCESSFUL-OPERATIONS
    ELSE
        ADD 1 TO FAILED-OPERATIONS
        EXHIBIT 'INSUFFICIENT-FUNDS' ACCOUNT-BALANCE TRANSACTION-AMOUNT
        EXHIBIT 'DEBIT-FAILURE' FAILED-OPERATIONS
    END-IF.
 
VALIDATE-BUSINESS-RULES.
    EXHIBIT 'VALIDATION-START' CUSTOMER-ID ACCOUNT-BALANCE
    
    *> Validate customer ID format
    IF CUSTOMER-ID < 10000000 OR CUSTOMER-ID > 99999999
        ADD 1 TO ERROR-COUNT
        EXHIBIT 'INVALID-CUSTOMER-ID' CUSTOMER-ID ERROR-COUNT
    END-IF
    
    *> Validate account balance limits
    IF ACCOUNT-BALANCE < 0
        ADD 1 TO ERROR-COUNT
        EXHIBIT 'NEGATIVE-BALANCE' ACCOUNT-BALANCE ERROR-COUNT
    END-IF
    
    IF ACCOUNT-BALANCE > 1000000
        EXHIBIT 'HIGH-BALANCE-ALERT' CUSTOMER-ID ACCOUNT-BALANCE
    END-IF
    
    EXHIBIT 'VALIDATION-END' ERROR-COUNT.
 
UPDATE-ACCOUNT-BALANCE.
    EXHIBIT 'UPDATE-START' CUSTOMER-ID ACCOUNT-BALANCE
    
    *> Simulate database update
    ADD 1 TO RECORDS-PROCESSED
    EXHIBIT 'RECORD-UPDATE' RECORDS-PROCESSED
    
    *> Calculate new balance for audit
    COMPUTE CALCULATION-RESULT = ACCOUNT-BALANCE * 1.001
    EXHIBIT 'BALANCE-CALCULATION' CALCULATION-RESULT
    
    EXHIBIT 'UPDATE-COMPLETE' CUSTOMER-ID ACCOUNT-BALANCE.
 
CLEANUP-PROCESSING.
    MOVE 'CLEANUP' TO PROCESSING-STATUS
    EXHIBIT 'CLEANUP-START' PROCESSING-STATUS
    
    *> Display final statistics using EXHIBIT
    EXHIBIT 'FINAL-STATISTICS' RECORDS-PROCESSED SUCCESSFUL-OPERATIONS
    EXHIBIT 'ERROR-STATISTICS' FAILED-OPERATIONS ERROR-COUNT
    EXHIBIT 'PROCESSING-COMPLETE' DEBUG-COUNTER
    
    MOVE 'FINISHED' TO PROCESSING-STATUS
    EXHIBIT 'CLEANUP-END' PROCESSING-STATUS.

Modern Alternatives to EXHIBIT

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IDENTIFICATION DIVISION.
PROGRAM-ID. MODERN-DEBUGGING-ALTERNATIVES.
 
DATA DIVISION.
WORKING-STORAGE SECTION.
01  MODERN-DEBUG-SYSTEM.
    05  DEBUG-ENABLED           PIC X VALUE 'Y'.
        88  DEBUG-ON            VALUE 'Y'.
        88  DEBUG-OFF           VALUE 'N'.
    05  DEBUG-LEVEL             PIC 9 VALUE 1.
        88  DEBUG-BASIC         VALUE 1.
        88  DEBUG-DETAILED      VALUE 2.
        88  DEBUG-VERBOSE       VALUE 3.
    05  DEBUG-TIMESTAMP         PIC X(14).
    05  DEBUG-SEQUENCE          PIC 9(6) VALUE 0.
    05  DEBUG-MODULE            PIC X(20).
    05  DEBUG-MESSAGE           PIC X(100).
 
01  LOGGING-SYSTEM.
    05  LOG-FILE-NAME           PIC X(30) VALUE 'DEBUG.LOG'.
    05  LOG-RECORD              PIC X(200).
    05  LOG-COUNTER             PIC 9(7) VALUE 0.
    05  LOG-LEVEL               PIC X(8).
        88  LOG-INFO            VALUE 'INFO'.
        88  LOG-WARNING         VALUE 'WARNING'.
        88  LOG-ERROR           VALUE 'ERROR'.
        88  LOG-DEBUG           VALUE 'DEBUG'.
 
01  BUSINESS-VARIABLES.
    05  CUSTOMER-ID             PIC 9(8) VALUE 12345678.
    05  CUSTOMER-NAME           PIC X(30) VALUE 'MODERN CUSTOMER'.
    05  ACCOUNT-BALANCE         PIC 9(9)V99 VALUE 25000.50.
    05  TRANSACTION-AMOUNT      PIC 9(7)V99 VALUE 1500.00.
 
PROCEDURE DIVISION.
MAIN-PROCESSING.
    PERFORM INITIALIZE-DEBUG-SYSTEM
    PERFORM DEMONSTRATE-DISPLAY-ALTERNATIVES
    PERFORM DEMONSTRATE-CONDITIONAL-DEBUGGING
    PERFORM DEMONSTRATE-STRUCTURED-LOGGING
    PERFORM DEMONSTRATE-PERFORMANCE-MONITORING
    STOP RUN.
 
INITIALIZE-DEBUG-SYSTEM.
    MOVE FUNCTION CURRENT-DATE TO DEBUG-TIMESTAMP
    MOVE 'MAIN' TO DEBUG-MODULE
    
    IF DEBUG-ON
        PERFORM LOG-DEBUG-MESSAGE
    END-IF.
 
DEMONSTRATE-DISPLAY-ALTERNATIVES.
    MOVE 'DISPLAY-DEMO' TO DEBUG-MODULE
    
    *> Modern alternative to EXHIBIT - Enhanced DISPLAY
    DISPLAY 'Customer Processing Started'
    DISPLAY 'Customer ID: ' CUSTOMER-ID
    DISPLAY 'Customer Name: ' CUSTOMER-NAME
    DISPLAY 'Account Balance: ' ACCOUNT-BALANCE
    
    *> Formatted display with labels
    DISPLAY 'Transaction Details:'
    DISPLAY '  Amount: $' TRANSACTION-AMOUNT
    DISPLAY '  Balance: $' ACCOUNT-BALANCE
    
    *> Conditional display based on debug level
    IF DEBUG-DETAILED
        DISPLAY 'Debug Level: Detailed'
        DISPLAY 'Timestamp: ' DEBUG-TIMESTAMP
        DISPLAY 'Module: ' DEBUG-MODULE
    END-IF
    
    *> Multi-line formatted display
    DISPLAY 'Customer Summary:'
    DISPLAY '=================='
    DISPLAY 'ID: ' CUSTOMER-ID ' Name: ' CUSTOMER-NAME
    DISPLAY 'Balance: $' ACCOUNT-BALANCE
    DISPLAY '=================='.
 
DEMONSTRATE-CONDITIONAL-DEBUGGING.
    MOVE 'CONDITIONAL-DEBUG' TO DEBUG-MODULE
    
    *> Debug information only when enabled
    IF DEBUG-ON
        ADD 1 TO DEBUG-SEQUENCE
        DISPLAY 'Debug [' DEBUG-SEQUENCE '] Entering conditional logic'
        
        IF ACCOUNT-BALANCE > 20000
            DISPLAY 'Debug [' DEBUG-SEQUENCE '] High balance customer'
            DISPLAY 'Debug [' DEBUG-SEQUENCE '] Balance: ' ACCOUNT-BALANCE
        END-IF
        
        DISPLAY 'Debug [' DEBUG-SEQUENCE '] Exiting conditional logic'
    END-IF
    
    *> Verbose debugging with detailed information
    IF DEBUG-VERBOSE
        DISPLAY 'Verbose Debug Information:'
        DISPLAY 'Module: ' DEBUG-MODULE
        DISPLAY 'Timestamp: ' DEBUG-TIMESTAMP
        DISPLAY 'All Variables:'
        DISPLAY '  CUSTOMER-ID: ' CUSTOMER-ID
        DISPLAY '  CUSTOMER-NAME: ' CUSTOMER-NAME
        DISPLAY '  ACCOUNT-BALANCE: ' ACCOUNT-BALANCE
        DISPLAY '  TRANSACTION-AMOUNT: ' TRANSACTION-AMOUNT
    END-IF.
 
DEMONSTRATE-STRUCTURED-LOGGING.
    MOVE 'STRUCTURED-LOG' TO DEBUG-MODULE
    
    *> Structured logging with levels
    SET LOG-INFO TO TRUE
    MOVE 'Processing customer transaction' TO DEBUG-MESSAGE
    PERFORM WRITE-LOG-ENTRY
    
    SET LOG-DEBUG TO TRUE
    STRING 'Customer ID: ' DELIMITED BY SIZE
           CUSTOMER-ID DELIMITED BY SIZE
           ' Balance: ' DELIMITED BY SIZE
           ACCOUNT-BALANCE DELIMITED BY SIZE
           INTO DEBUG-MESSAGE
    END-STRING
    PERFORM WRITE-LOG-ENTRY
    
    *> Error logging simulation
    IF ACCOUNT-BALANCE < TRANSACTION-AMOUNT
        SET LOG-ERROR TO TRUE
        STRING 'Insufficient funds - Balance: ' DELIMITED BY SIZE
               ACCOUNT-BALANCE DELIMITED BY SIZE
               ' Required: ' DELIMITED BY SIZE
               TRANSACTION-AMOUNT DELIMITED BY SIZE
               INTO DEBUG-MESSAGE
        END-STRING
        PERFORM WRITE-LOG-ENTRY
    END-IF.
 
WRITE-LOG-ENTRY.
    ADD 1 TO LOG-COUNTER
    MOVE FUNCTION CURRENT-DATE TO DEBUG-TIMESTAMP
    
    STRING DEBUG-TIMESTAMP DELIMITED BY SIZE
           ' [' DELIMITED BY SIZE
           LOG-LEVEL DELIMITED BY SPACE
           '] ' DELIMITED BY SIZE
           DEBUG-MODULE DELIMITED BY SPACE
           ': ' DELIMITED BY SIZE
           DEBUG-MESSAGE DELIMITED BY SIZE
           INTO LOG-RECORD
    END-STRING
    
    *> Write to log file (simulated with DISPLAY)
    DISPLAY LOG-RECORD
    
    *> In real implementation, write to actual log file
    *> WRITE LOG-FILE-RECORD FROM LOG-RECORD.
 
DEMONSTRATE-PERFORMANCE-MONITORING.
    MOVE 'PERFORMANCE' TO DEBUG-MODULE
    
    *> Performance monitoring with timing
    DISPLAY 'Performance Monitoring Started'
    DISPLAY 'Records Processed: ' LOG-COUNTER
    DISPLAY 'Debug Messages: ' DEBUG-SEQUENCE
    
    *> Memory usage simulation
    DISPLAY 'Memory Usage Simulation:'
    DISPLAY 'Variables allocated: 15'
    DISPLAY 'Working storage used: 2KB'
    
    *> Execution path tracing
    DISPLAY 'Execution Path:'
    DISPLAY '1. Initialize Debug System'
    DISPLAY '2. Display Alternatives'
    DISPLAY '3. Conditional Debugging'
    DISPLAY '4. Structured Logging'
    DISPLAY '5. Performance Monitoring'
    
    DISPLAY 'Performance Monitoring Completed'.
 
LOG-DEBUG-MESSAGE.
    ADD 1 TO DEBUG-SEQUENCE
    MOVE FUNCTION CURRENT-DATE TO DEBUG-TIMESTAMP
    
    STRING '[' DELIMITED BY SIZE
           DEBUG-SEQUENCE DELIMITED BY SIZE
           '] ' DELIMITED BY SIZE
           DEBUG-TIMESTAMP DELIMITED BY SIZE
           ' ' DELIMITED BY SIZE
           DEBUG-MODULE DELIMITED BY SIZE
           ': Debug system initialized'
           INTO DEBUG-MESSAGE
    END-STRING
    
    DISPLAY DEBUG-MESSAGE.

Migration from EXHIBIT to Modern Debugging

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IDENTIFICATION DIVISION.
PROGRAM-ID. EXHIBIT-MIGRATION-GUIDE.
 
DATA DIVISION.
WORKING-STORAGE SECTION.
01  MIGRATION-EXAMPLES.
    05  SAMPLE-VARIABLE         PIC 9(5) VALUE 12345.
    05  SAMPLE-TEXT             PIC X(20) VALUE 'SAMPLE DATA'.
    05  SAMPLE-AMOUNT           PIC 9(7)V99 VALUE 1000.50.
 
PROCEDURE DIVISION.
MAIN-PROCESSING.
    PERFORM SHOW-MIGRATION-EXAMPLES
    STOP RUN.
 
SHOW-MIGRATION-EXAMPLES.
    DISPLAY 'EXHIBIT to Modern Debugging Migration Examples:'
    DISPLAY '=============================================='
    
    *> OLD WAY: EXHIBIT statement
    *> EXHIBIT 'VARIABLE-VALUE' SAMPLE-VARIABLE
    
    *> NEW WAY: Enhanced DISPLAY with formatting
    DISPLAY 'VARIABLE-VALUE: ' SAMPLE-VARIABLE
    
    *> OLD WAY: EXHIBIT with multiple variables
    *> EXHIBIT 'MULTIPLE-VALUES' SAMPLE-VARIABLE SAMPLE-TEXT SAMPLE-AMOUNT
    
    *> NEW WAY: Structured display with clear formatting
    DISPLAY 'MULTIPLE-VALUES:'
    DISPLAY '  Variable: ' SAMPLE-VARIABLE
    DISPLAY '  Text: ' SAMPLE-TEXT
    DISPLAY '  Amount: ' SAMPLE-AMOUNT
    
    *> NEW WAY: Conditional debugging
    IF SAMPLE-VARIABLE > 10000
        DISPLAY 'DEBUG: High value detected - ' SAMPLE-VARIABLE
    END-IF
    
    *> NEW WAY: Structured logging approach
    DISPLAY 'LOG: Processing sample data'
    DISPLAY 'LOG: Variable=' SAMPLE-VARIABLE 
            ' Text=' SAMPLE-TEXT 
            ' Amount=' SAMPLE-AMOUNT
    
    DISPLAY 'Migration examples completed'.

Best Practices and FAQ

Migration Strategies
  • • Replace EXHIBIT with DISPLAY statements
  • • Implement conditional debugging flags
  • • Use structured logging approaches
  • • Leverage modern IDE debugging tools
  • • Create comprehensive error handling
Modern Debugging Tools
  • • Integrated debuggers in IDEs
  • • Breakpoint and step debugging
  • • Variable watch windows
  • • Call stack analysis
  • • Performance profiling tools