>>SOURCE FORMAT IS FREE
*> cobol-read-sequential-file.cob — read a fixed-width customer file
*>          to end of file and print control totals
*> Dialect: GnuCOBOL 3.x, free format
*> Status : desk-checked against the GnuCOBOL 3.2 Programmer's Guide;
*>          NOT compiled (no cobc on the authoring machine)
*> Inputs : datasets/cobol-read-sequential-file.dat (LINE SEQUENTIAL,
*>          LF line endings, 60 bytes per record, 12 records)
*>          code/cobol-read-sequential-file.cpy (the record layout)
*> Outputs: one DISPLAY line per record plus four control-total lines
*> Build  : cobc -x -I code -o read-customers code/cobol-read-sequential-file.cob
*>          (run from the folder that holds code/ and datasets/)
*> Run    : ./read-customers   (Windows: read-customers.exe)
IDENTIFICATION DIVISION.
PROGRAM-ID. READ-CUSTOMERS.
ENVIRONMENT DIVISION.
INPUT-OUTPUT SECTION.
FILE-CONTROL.
    SELECT Customer-File
        ASSIGN TO "datasets/cobol-read-sequential-file.dat"
        ORGANIZATION IS LINE SEQUENTIAL
        FILE STATUS IS WS-File-Status.
DATA DIVISION.
FILE SECTION.
FD  Customer-File.
    COPY "cobol-read-sequential-file.cpy".
WORKING-STORAGE SECTION.
77 WS-File-Status       PIC XX.
01 WS-Flags.
   05 WS-EOF-Flag       PIC X VALUE "N".
      88 End-Of-File          VALUE "Y".
77 WS-Record-Count      PIC 9(5)     VALUE 0.
77 WS-Debit-Total       PIC 9(9)V99  VALUE 0.
77 WS-Credit-Total      PIC 9(9)V99  VALUE 0.
77 WS-Net               PIC S9(9)V99 VALUE 0.
77 WS-Show-Amount       PIC Z(6)9.99.
77 WS-Show-Total        PIC Z(8)9.99.
77 WS-Show-Net          PIC -(9)9.99.
77 WS-Show-Count        PIC ZZZZ9.
PROCEDURE DIVISION.
Main-Paragraph.
    OPEN INPUT Customer-File
    IF WS-File-Status NOT = "00"
       DISPLAY "Open failed, file status " WS-File-Status
       STOP RUN
    END-IF
*> Priming read, then loop while the last read succeeded.
    PERFORM Read-Next-Customer
    PERFORM UNTIL End-Of-File
       PERFORM Process-Customer
       PERFORM Read-Next-Customer
    END-PERFORM
    CLOSE Customer-File
    PERFORM Show-Totals
    STOP RUN.

Read-Next-Customer.
    READ Customer-File
       AT END
          SET End-Of-File TO TRUE
       NOT AT END
          ADD 1 TO WS-Record-Count
    END-READ
    IF WS-File-Status NOT = "00" AND WS-File-Status NOT = "10"
       DISPLAY "Read failed, file status " WS-File-Status
       STOP RUN
    END-IF.

Process-Customer.
    MOVE Cust-Balance TO WS-Show-Amount
    DISPLAY Cust-Id " " Cust-Name " " Cust-City " "
            WS-Show-Amount " " Cust-DC
    EVALUATE Cust-DC
       WHEN "D"
          ADD Cust-Balance TO WS-Debit-Total
       WHEN "C"
          ADD Cust-Balance TO WS-Credit-Total
       WHEN OTHER
          DISPLAY "Unexpected flag [" Cust-DC "] on " Cust-Id
    END-EVALUATE.

Show-Totals.
    MOVE WS-Record-Count TO WS-Show-Count
    DISPLAY "Records read : " WS-Show-Count
    MOVE WS-Debit-Total TO WS-Show-Total
    DISPLAY "Debit total  : " WS-Show-Total
    MOVE WS-Credit-Total TO WS-Show-Total
    DISPLAY "Credit total : " WS-Show-Total
    COMPUTE WS-Net = WS-Debit-Total - WS-Credit-Total
    MOVE WS-Net TO WS-Show-Net
    DISPLAY "Net owed     : " WS-Show-Net.