🖮 CICS

CICS File Control

Intermediate 🕑 25 min read 👁 3 views

CICS File Control

CICS provides commands to access VSAM files in an online environment. File operations are handled through FCT (File Control Table) definitions.

File Control Commands

Command	Description
READ	Read a record
WRITE	Add new record
REWRITE	Update record
DELETE	Remove record
STARTBR	Start browse
READNEXT	Read next in browse
READPREV	Read previous in browse
ENDBR	End browse
RESETBR	Reposition browse

READ Options

INTO - Data area for record
RIDFLD - Record key field
KEYLENGTH - Key length
UPDATE - Lock for update
GTEQ/EQUAL - Match type

Common Response Codes

RESP	Meaning
NORMAL	Successful
NOTFND	Record not found
DUPREC	Duplicate record
NOSPACE	No space in file
NOTOPEN	File not open
INVREQ	Invalid request
LENGERR	Length error

Record Locking

UPDATE option locks record until:

REWRITE is issued
DELETE is issued
UNLOCK is issued
Task ends

Code Example

       WORKING-STORAGE SECTION.
       01 WS-EMP-KEY      PIC 9(6).
       01 WS-EMP-RECORD.
          05 WS-EMP-ID    PIC 9(6).
          05 WS-EMP-NAME  PIC X(30).
          05 WS-EMP-DEPT  PIC X(10).
          05 WS-SALARY    PIC 9(7)V99.
       01 WS-RESP         PIC S9(8) COMP.
       01 WS-RESP2        PIC S9(8) COMP.
       01 WS-LENGTH       PIC S9(4) COMP VALUE 53.

       PROCEDURE DIVISION.

      * READ RECORD
       READ-EMPLOYEE.
           MOVE "123456" TO WS-EMP-KEY.
           EXEC CICS READ
               FILE('EMPFILE')
               INTO(WS-EMP-RECORD)
               RIDFLD(WS-EMP-KEY)
               LENGTH(WS-LENGTH)
               RESP(WS-RESP)
               RESP2(WS-RESP2)
           END-EXEC.

           EVALUATE WS-RESP
               WHEN DFHRESP(NORMAL)
                   PERFORM DISPLAY-RECORD
               WHEN DFHRESP(NOTFND)
                   MOVE "RECORD NOT FOUND" TO WS-MESSAGE
               WHEN OTHER
                   PERFORM HANDLE-ERROR
           END-EVALUATE.

      * READ FOR UPDATE
       READ-FOR-UPDATE.
           EXEC CICS READ
               FILE('EMPFILE')
               INTO(WS-EMP-RECORD)
               RIDFLD(WS-EMP-KEY)
               LENGTH(WS-LENGTH)
               UPDATE
               RESP(WS-RESP)
           END-EXEC.

      * REWRITE RECORD
       UPDATE-EMPLOYEE.
           MOVE 80000.00 TO WS-SALARY.
           EXEC CICS REWRITE
               FILE('EMPFILE')
               FROM(WS-EMP-RECORD)
               LENGTH(WS-LENGTH)
               RESP(WS-RESP)
           END-EXEC.

      * WRITE NEW RECORD
       ADD-EMPLOYEE.
           MOVE "999999" TO WS-EMP-ID.
           MOVE "NEW EMPLOYEE" TO WS-EMP-NAME.
           EXEC CICS WRITE
               FILE('EMPFILE')
               FROM(WS-EMP-RECORD)
               RIDFLD(WS-EMP-KEY)
               LENGTH(WS-LENGTH)
               RESP(WS-RESP)
           END-EXEC.

      * DELETE RECORD
       DELETE-EMPLOYEE.
           EXEC CICS DELETE
               FILE('EMPFILE')
               RIDFLD(WS-EMP-KEY)
               RESP(WS-RESP)
           END-EXEC.

      * BROWSE RECORDS
       BROWSE-EMPLOYEES.
           MOVE "000000" TO WS-EMP-KEY.
           EXEC CICS STARTBR
               FILE('EMPFILE')
               RIDFLD(WS-EMP-KEY)
               GTEQ
               RESP(WS-RESP)
           END-EXEC.

           PERFORM UNTIL WS-RESP NOT = DFHRESP(NORMAL)
               EXEC CICS READNEXT
                   FILE('EMPFILE')
                   INTO(WS-EMP-RECORD)
                   RIDFLD(WS-EMP-KEY)
                   LENGTH(WS-LENGTH)
                   RESP(WS-RESP)
               END-EXEC
               IF WS-RESP = DFHRESP(NORMAL)
                   PERFORM DISPLAY-RECORD
               END-IF
           END-PERFORM.

           EXEC CICS ENDBR
               FILE('EMPFILE')
           END-EXEC.