Progress0 of 0 lessons

CICS FETCH CHILD - Fetch Child Process

CICS FETCH CHILD fetches a specific child process, enabling child process management and output processing in CICS environments. It provides efficient child process fetching capabilities for CICS applications.

What is CICS FETCH CHILD?

CICS FETCH CHILD fetches a specific child process, enabling child process management and output processing. It provides efficient child process fetching capabilities, allowing applications to fetch a specific child process.

Command Syntax

cobol
1
2
3
4
5
EXEC CICS FETCH CHILD
    CHILD(child-id)
    [RESP(response-code)]
    [RESP2(response-code-2)]
END-EXEC.

Parameters Explained

CHILD Parameter

Specifies the child process to fetch:

  • Must be a valid child process ID
  • Identifies specific child
  • Required for all FETCH CHILD operations
  • Must be active child process

RESP Parameters

Response codes returned by the command:

  • RESP: Primary response code
  • RESP2: Secondary response code
  • Always check these codes for command success
  • Handle command failures appropriately

Child Process Types

1. Basic Child Processes

  • Basic child processes: Basic child processes
  • Mapped child processes: Mapped child processes
  • Unmapped child processes: Unmapped child processes
  • Custom child processes: Custom child processes

2. Advanced Child Processes

  • Advanced child processes: Advanced child processes
  • Secure child processes: Secure child processes
  • Encrypted child processes: Encrypted child processes
  • Compressed child processes: Compressed child processes

3. Specialized Child Processes

  • Specialized child processes: Specialized child processes
  • High-performance child processes: High-performance child processes
  • Low-latency child processes: Low-latency child processes
  • High-throughput child processes: High-throughput child processes

Implementation Example

cobol
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
WORKING-STORAGE SECTION.
01 WS-RESPONSE            PIC S9(8) COMP.
01 WS-RESPONSE2           PIC S9(8) COMP.
01 WS-CHILD-ID            PIC X(8) VALUE 'CHILD001'.
 
PROCEDURE DIVISION.
    * Fetch specific child process
    EXEC CICS FETCH CHILD
        CHILD(WS-CHILD-ID)
        RESP(WS-RESPONSE)
        RESP2(WS-RESPONSE2)
    END-EXEC.
    
    IF WS-RESPONSE NOT EQUAL DFHRESP(NORMAL)
        EXEC CICS WRITE OPERATOR
            TEXT('FETCH CHILD command failed')
        END-EXEC
        EXEC CICS RETURN END-EXEC
    END-IF.
    
    * Child process fetched successfully
    * Continue processing

Child Process Processing

1. Child Process Preparation

Child process preparation includes:

  • Child process validation
  • Child process formatting
  • Child process encoding
  • Child process processing

2. Child Process Transmission

Child process transmission includes:

  • Child process routing
  • Child process delivery
  • Transmission confirmation
  • Error handling

3. Output Management

Output management includes:

  • Process management
  • Output formatting
  • User experience
  • Performance optimization

Common Response Codes

Success Response Codes

  • NORMAL (0): Child process fetched successfully
  • FETCH (4): Child process fetched

Error Response Codes

  • INVREQ (16): Invalid request
  • NOTFND (20): Child process not found
  • LENGERR (22): Length error
  • FETCH (24): Fetch error

Best Practices

1. Child Process Preparation

  • Prepare child process appropriately
  • Validate child process content
  • Handle different child process types
  • Ensure child process integrity

2. Error Handling

  • Check all response codes
  • Handle fetch failures
  • Implement retry logic
  • Log error conditions

3. Performance Optimization

  • Minimize child process fetching
  • Use efficient child process formats
  • Optimize process updates
  • Manage process resources

Explain It Like I'm 5 Years Old

Imagine you're looking for a specific toy:

When you want to find a specific toy, you look around your room and pick up the exact toy that you're looking for. You know exactly which toy you want, and you won't be happy until you find that specific toy.

CICS FETCH CHILD is like looking for a specific toy. The computer program looks around and picks up the exact child process that it's looking for. It knows exactly which child process it wants, and it won't be happy until it finds that specific child process.

Just like you look for a specific toy to play with, the computer program looks for a specific child process to work with!

Exercises

Exercise 1: Child Process Fetching

Write a CICS FETCH CHILD command to fetch a specific child process.

cobol
1
2
3
4
5
EXEC CICS FETCH CHILD
    CHILD(WS-CHILD-ID)
    RESP(WS-RESPONSE)
    RESP2(WS-RESPONSE2)
END-EXEC.

Exercise 2: Child Process Processing

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

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

Quiz

Question 1

What is the primary purpose of CICS FETCH CHILD?

Answer: B) To fetch a specific child process

Question 2

Which parameter specifies the child process to fetch?

Answer: A) CHILD

Related Concepts

CICS Child Process Processing

Child process processing and output in CICS

CICS Process Management

Process management and user interaction in CICS

CICS Output Processing

Output processing and child process display in CICS