Previous Topic Next topic Print topic


AT END/INVALID KEY

Test the END-OF-FILE or AT END condition for files accessed sequentially, and test the INVALID KEY condition for files accessed randomly.
Restriction: This topic applies only when the AppMaster Builder AddPack has been installed, and applies only to Windows platforms.

Syntax: for Format 1

conditionalverb [AT] END ON filename
    statementblock

Syntax: for Format 2

conditionalverb INVALID [KEY] ON filename
    statementblock

Syntax Rules:

  1. S-COBOL defines 05 filename--END PIC X and 05 filename--INV PIC X as flags for the AT END and INVALID KEY conditions for each file.
  2. END ON filename and INVALID ON filename are 88-level file status condition names that S-COBOL provides with the AT END and INVALID KEY flags. You can use these as a condition in any conditional statement.
  3. Flag are set when the file is accessed by a READ, WRITE, etc., statement and before the AT END ON/INVALID KEY ON condition is valid.

Example:

PARA   MAIN-LOGIC
            OPEN INPUT MASTER-FILE
            REPEAT
                READ MASTER-FILE INTO MASTER-REC
                ... INVALID KEY
                    MASTER-REC = HIGH-VALUES
                ELSE-IF MASTER-TYPE = 'A'
                    PERFORM PROCESS-TYPE-A
                ELSE-IF MASTER-TYPE = 'C'
                    PERFORM PROCESS-TYPE-C
                ELSE
                    PERFORM PROCESS-OTHER-TYPES
            UNTIL INVALID KEY ON MASTER-FILE
            CLOSE MASTER-FILE
        STOP RUN
Previous Topic Next topic Print topic