>>SOURCE FORMAT IS FREE
*> gnucobol-std-dialects-ibm.cob - one program, compiled once per dialect,
*>   that prints how big four COMP items are, how DISPLAY shows them, and
*>   what an ADD that outgrows its PICTURE leaves behind
*> Dialect: GnuCOBOL 3.x, free format; meant to be compiled three ways:
*>          cobc -x gnucobol-std-dialects-ibm.cob
*>          cobc -x -std=ibm gnucobol-std-dialects-ibm.cob
*>          cobc -x -std=ibm -fbinary-truncate gnucobol-std-dialects-ibm.cob
*> Status : desk-checked against the GnuCOBOL 3.2 source and test suite;
*>          NOT compiled (no cobc on the authoring machine)
*> Inputs : none
*> Outputs: six lines on standard output
*> Run    : ./gnucobol-std-dialects-ibm
*>          (Windows: gnucobol-std-dialects-ibm.exe)

IDENTIFICATION DIVISION.
PROGRAM-ID. DIALECT-PROBE.

DATA DIVISION.
WORKING-STORAGE SECTION.
*> Four binary items. USAGE COMP is USAGE BINARY in GnuCOBOL; how many
*> bytes each one gets is the binary-size setting of the dialect.
01 WS-Tiny     PIC 9(2)  COMP VALUE 12.
01 WS-Count    PIC 9(4)  COMP VALUE 5000.
01 WS-Delta    PIC S9(4) COMP VALUE -12.
01 WS-Total    PIC 9(5)  COMP VALUE 12345.
*> A plain DISPLAY item to print the byte counts in.
01 WS-Bytes    PIC 9(2).

PROCEDURE DIVISION.
MAIN-PARA.
    *> FUNCTION LENGTH of a non-national item is its size in bytes.
    MOVE FUNCTION LENGTH(WS-Tiny) TO WS-Bytes
    DISPLAY "WS-TINY   PIC 9(2)  COMP  BYTES " WS-Bytes
            "  SHOWS " WS-Tiny
    MOVE FUNCTION LENGTH(WS-Count) TO WS-Bytes
    DISPLAY "WS-COUNT  PIC 9(4)  COMP  BYTES " WS-Bytes
            "  SHOWS " WS-Count
    MOVE FUNCTION LENGTH(WS-Delta) TO WS-Bytes
    DISPLAY "WS-DELTA  PIC S9(4) COMP  BYTES " WS-Bytes
            "  SHOWS " WS-Delta
    MOVE FUNCTION LENGTH(WS-Total) TO WS-Bytes
    DISPLAY "WS-TOTAL  PIC 9(5)  COMP  BYTES " WS-Bytes
            "  SHOWS " WS-Total

    *> 5000 + 7000 = 12000: five digits in a four-digit PICTURE.
    *> No ON SIZE ERROR, so binary-truncate decides what is stored.
    ADD 7000 TO WS-Count
    DISPLAY "ADD 7000 TO WS-COUNT            SHOWS " WS-Count

    EVALUATE WS-Count
        WHEN 12000
            DISPLAY "WS-COUNT IS 12000"
        WHEN 2000
            DISPLAY "WS-COUNT IS 2000"
        WHEN OTHER
            DISPLAY "WS-COUNT IS SOMETHING ELSE"
    END-EVALUATE

    GOBACK.