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CICS WRITE JOURNALNUM - Journal Number Writing

CICS WRITE JOURNALNUM writes data to a journal with a specific number. It enables programs to write to journals, manage journal operations, and handle journal number writing in CICS applications.

What is CICS WRITE JOURNALNUM?

CICS WRITE JOURNALNUM is a command that allows programs to write data to a journal with a specific number. It provides journal writing capabilities, data storage, and journal management for CICS applications.

Command Syntax

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EXEC CICS WRITE JOURNALNUM
    JOURNALNUM(journal-number)
    FROM(data-area)
    LENGTH(data-length)
    [RESP(response-code)]
END-EXEC

Parameters

Required Parameters

  • JOURNALNUM(journal-number) - Number of the journal to write to
  • FROM(data-area) - Data area containing the data to write
  • LENGTH(data-length) - Length of the data to write

Optional Parameters

  • RESP(response-code) - Response code variable

Programming Examples

Basic Journal Writing

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WORKING-STORAGE SECTION.
01  JOURNAL-NUMBER      PIC S9(8) COMP VALUE 1.
01  JOURNAL-DATA          PIC X(100) VALUE 'This is journal data'.
01  JOURNAL-LENGTH        PIC S9(8) COMP VALUE 100.
01  RESPONSE-CODE        PIC S9(8) COMP.
 
PROCEDURE DIVISION.
    DISPLAY 'Writing to journal number: ' JOURNAL-NUMBER
    
    *> Write data to the journal
    EXEC CICS WRITE JOURNALNUM
        JOURNALNUM(JOURNAL-NUMBER)
        FROM(JOURNAL-DATA)
        LENGTH(JOURNAL-LENGTH)
        RESP(RESPONSE-CODE)
    END-EXEC.
    
    IF RESPONSE-CODE = DFHRESP(NORMAL)
        DISPLAY 'Journal written successfully'
        DISPLAY 'Data written: ' JOURNAL-DATA(1:JOURNAL-LENGTH)
    ELSE
        DISPLAY 'Error writing to journal: ' RESPONSE-CODE
    END-IF.

Error Handling

Common Response Codes

  • DFHRESP(NORMAL) - Journal written successfully
  • DFHRESP(INVREQ) - Invalid request or parameter
  • DFHRESP(LENGERR) - Data area length error
  • DFHRESP(NOTAUTH) - Not authorized to write to journal

Performance Considerations

Efficiency

  • • Lightweight Operation - WRITE JOURNALNUM is a lightweight command with minimal performance impact
  • • Data Area Size - Use appropriate data area size to avoid truncation
  • • Storage Impact - Consider the impact of large data writes on journal storage

Best Practices

  • • Error Handling - Always check the response code for error handling
  • • Journal Numbering - Use meaningful journal numbers for easier management
  • • Coordination - Coordinate journal writing with journal waiting

Explain It Like I'm 5 Years Old

Think of CICS WRITE JOURNALNUM like writing in a numbered notebook:

  • • Numbered Notebook: "You have notebook number 5" - Journal number
  • • Write Message: "You write a message in notebook 5" - Write data
  • • Message Length: "You count how many words you wrote" - Data length
  • • Save Message: "You save the message in notebook 5" - Journal written

Exercises

Exercise 1: Basic Journal Writing

Create a program that writes data to a journal number and then reads it back.

Exercise 2: Dynamic Data Writing

Write a program that writes different types of data to journals.

Exercise 3: Error Handling

Implement error handling for the WRITE JOURNALNUM command.

Related Concepts

Journal Management

Managing journals in CICS

WAIT JOURNALNUM

Waiting for journals

Task Coordination

Coordinating tasks

Data Writing

Writing data to journals

Error Handling

Handling journal errors