* ==== TYPE: ADV-MATCH-OLDSCHOOL ====
      * FEATURE: Real matching program but uses different
      *          naming convention (K01-, not WS-)
      * STATEMENT: IF / READ / OPEN
      * BRANCHES: 2, DECISIONS: 1
      * ADVERSARIAL: KEY variables not prefixed WS-
       IDENTIFICATION DIVISION.
       PROGRAM-ID. KSMTCH.
       ENVIRONMENT DIVISION.
       INPUT-OUTPUT SECTION.
       FILE-CONTROL.
           SELECT FILE-A ASSIGN TO 'FILEA.DAT'.
           SELECT FILE-B ASSIGN TO 'FILEB.DAT'.
       DATA DIVISION.
       FILE SECTION.
       FD FILE-A.
       01 REC-A PIC X(80).
       FD FILE-B.
       01 REC-B PIC X(80).
       WORKING-STORAGE SECTION.
       01 K01-KEY    PIC X(10).
       01 K02-KEY    PIC X(10).
       01 WS-EOF1    PIC X VALUE 'N'.
       01 WS-EOF2    PIC X VALUE 'N'.
       PROCEDURE DIVISION.
       MAIN.
           OPEN INPUT FILE-A FILE-B.
           READ FILE-A INTO REC-A AT END MOVE 'Y' TO WS-EOF1.
           READ FILE-B INTO REC-B AT END MOVE 'Y' TO WS-EOF2.
           IF K01-KEY = K02-KEY
               DISPLAY 'MATCH'
           ELSE
               DISPLAY 'NO MATCH'.
           CLOSE FILE-A FILE-B.
           STOP RUN.