How do you use CICS REWRITE?

Use CICS REWRITE with RESP parameters to check response codes and handle any errors appropriately.

What are the different types of rewrites?

Rewrite types include basic rewrites (standard, mapped, unmapped, custom), advanced rewrites (advanced, secure, encrypted, compressed), and specialized rewrites (specialized, high-performance, low-latency, high-throughput).

When should you use CICS REWRITE?

Use CICS REWRITE when building applications that need rewrite management capabilities, when implementing rewrite processing, when managing rewrites, when building rewrite systems, or when implementing rewrite functionality.

CICS REWRITE - Rewrite

CICS REWRITE provides rewrite management capabilities, enabling rewrite processing and output processing in CICS environments. It provides efficient rewrite capabilities for CICS applications.

What is CICS REWRITE?

CICS REWRITE provides rewrite management capabilities, enabling rewrite processing and output processing. It provides efficient rewrite capabilities, allowing applications to manage rewrite operations.

Command Syntax

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EXEC CICS REWRITE
    [RESP(response-code)]
    [RESP2(response-code-2)]
END-EXEC.

Parameters Explained

RESP Parameters

Response codes returned by the command:

RESP: Primary response code - indicates the success or failure of the rewrite operation
RESP2: Secondary response code - provides additional error information when RESP indicates failure
Always check these codes for command success before proceeding with data processing
Handle command failures appropriately to prevent application errors

Rewrite Types

1. Basic Rewrites

Basic rewrites: Standard rewrite operations that handle simple rewriting without special formatting
Mapped rewrites: Rewrite operations that use predefined field mappings to structure rewrite data
Unmapped rewrites: Raw rewrite operations that handle unstructured rewriting without predefined field mappings
Custom rewrites: Specialized rewrite operations designed for specific application requirements

2. Advanced Rewrites

Advanced rewrites: Complex rewrite operations that handle sophisticated rewriting processing and validation
Secure rewrites: Rewrite operations that include encryption and security features for sensitive rewriting
Encrypted rewrites: Rewrite operations that automatically encrypt rewrite data
Compressed rewrites: Rewrite operations that handle compressed rewriting streams and automatically compress rewrite data

3. Specialized Rewrites

Specialized rewrites: Rewrite operations tailored for specific protocols or communication methods
High-performance rewrites: Optimized rewrite operations designed for maximum throughput and efficiency
Low-latency rewrites: Rewrite operations optimized for minimal delay and real-time processing requirements
High-throughput rewrites: Rewrite operations designed to handle large volumes of rewriting efficiently

Implementation Example

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WORKING-STORAGE SECTION.
01 WS-RESPONSE            PIC S9(8) COMP.
01 WS-RESPONSE2           PIC S9(8) COMP.
 
PROCEDURE DIVISION.
    * Rewrite operation
    EXEC CICS REWRITE
        RESP(WS-RESPONSE)
        RESP2(WS-RESPONSE2)
    END-EXEC.
    
    IF WS-RESPONSE NOT EQUAL DFHRESP(NORMAL)
        EXEC CICS WRITE OPERATOR
            TEXT('REWRITE command failed')
        END-EXEC
        EXEC CICS RETURN END-EXEC
    END-IF.
    
    * Rewrite operation completed successfully
    * Continue processing

Rewrite Processing

1. Rewrite Preparation

Rewrite preparation includes:

Rewrite validation - ensuring the rewrite operation is properly configured and authorized
Rewrite formatting - preparing data structures and buffers for rewrite data
Rewrite encoding - setting up proper character encoding and data transformation
Rewrite processing - initializing the rewrite operation and preparing for rewriting

2. Rewrite Transmission

Rewrite transmission includes:

Rewrite routing - directing rewrite data to the appropriate processing location
Rewrite delivery - ensuring rewrite data reaches the correct destination within the application
Transmission confirmation - verifying that rewrite was completed successfully
Error handling - managing transmission failures and implementing retry mechanisms

3. Output Management

Output management includes:

User management - handling user sessions and maintaining connection state
Output formatting - structuring rewrite data for presentation or further processing
User experience - ensuring smooth data flow and responsive application behavior
Performance optimization - maximizing rewrite efficiency and minimizing resource usage

Common Response Codes

Success Response Codes

NORMAL (0): Rewrite operation completed successfully - rewriting was completed without errors
REWRITE (4): Rewrite operation completed - operation completed with rewrite-specific status

Error Response Codes

INVREQ (16): Invalid request - the rewrite operation parameters are incorrect or unauthorized
NOTFND (20): Resource not found - the specified rewrite resource does not exist
LENGERR (22): Length error - the rewrite data length exceeds expected limits
REWRITE (24): Rewrite error - a rewrite-specific error occurred during the operation

Best Practices

1. Rewrite Preparation

Prepare rewrite appropriately - ensure all necessary resources and configurations are in place
Validate rewrite content - verify that rewrite data meets expected format and quality standards
Handle different rewrite types - implement flexible processing to accommodate various rewriting formats
Ensure rewrite integrity - maintain data consistency and prevent corruption during rewriting

2. Error Handling

Check all response codes - always examine both RESP and RESP2 for complete error information
Handle rewrite failures - implement appropriate recovery mechanisms for failed rewrite operations
Implement retry logic - provide automatic retry capabilities for transient failures
Log error conditions - maintain detailed logs for troubleshooting and monitoring purposes

3. Performance Optimization

Minimize rewrite operations - reduce unnecessary rewrite calls to improve overall performance
Use efficient rewrite formats - choose appropriate data formats to minimize processing overhead
Optimize user updates - streamline user interface updates to reduce response time
Manage user resources - efficiently allocate and manage system resources for rewrite operations

Explain It Like I'm 5 Years Old

Imagine you're erasing and writing again:

When you want to erase and write again, you take an eraser and erase what you wrote, then you write something new. If you erase and write again, you have something new. If you don't erase and write again, you have the same thing.

CICS REWRITE is like erasing and writing again. The computer program takes an eraser and erases what it wrote, then it writes something new. If it erases and writes again, it has something new. If it doesn't erase and write again, it has the same thing.

Just like you erase and write again, the computer program erases and writes again!

Exercises

Exercise 1: Rewrite Operation

Write a CICS REWRITE command to perform a rewrite operation.

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EXEC CICS REWRITE
    RESP(WS-RESPONSE)
    RESP2(WS-RESPONSE2)
END-EXEC.

Exercise 2: Rewrite Processing

How would you implement comprehensive rewrite processing that handles different rewrite types and requirements?

Answer: Identify different rewrite types and appropriate handling, implement rewrite validation and encoding, handle different rewrite types and capabilities, implement proper error handling for rewrite failures, optimize rewrite operations for performance, and maintain rewrite integrity throughout the process.

Quiz

Question 1

What is the primary purpose of CICS REWRITE?

A) To format rewritesB) To provide rewrite management capabilitiesC) To validate rewritesD) To edit rewrites

Answer: B) To provide rewrite management capabilities

Question 2

Which parameter specifies the response code?

A) RESPB) RESPONSEC) CODED) REWRITE

Answer: A) RESP

CICS REWRITE - Rewrite

What is CICS REWRITE?

Command Syntax

Parameters Explained

RESP Parameters

Rewrite Types

1. Basic Rewrites

2. Advanced Rewrites

3. Specialized Rewrites

Implementation Example

Rewrite Processing

1. Rewrite Preparation

2. Rewrite Transmission

3. Output Management

Common Response Codes

Success Response Codes

Error Response Codes

Best Practices

1. Rewrite Preparation

2. Error Handling

3. Performance Optimization

Explain It Like I'm 5 Years Old

Exercises

Exercise 1: Rewrite Operation

Exercise 2: Rewrite Processing

Quiz

Question 1

Question 2

Related Concepts

CICS Rewrite Processing

CICS User Management

CICS Output Processing

Related Pages