cobol/log.cbl

       IDENTIFICATION DIVISION.
       PROGRAM-ID. LOG-TRANSACTION.

       ENVIRONMENT DIVISION.
       INPUT-OUTPUT SECTION.
       FILE-CONTROL.
           SELECT LOG-FILE ASSIGN TO "data/transactions.log"
               ORGANIZATION IS LINE SEQUENTIAL.

       DATA DIVISION.
       FILE SECTION.
       FD LOG-FILE.
       01 LOG-RECORD         PIC X(256).

       WORKING-STORAGE SECTION.
       01 WS-TIMESTAMP        PIC X(20).
       01 WS-DETAILS          PIC X(200).

       LINKAGE SECTION.
       01 LS-DETAILS          PIC X(200).

       PROCEDURE DIVISION USING LS-DETAILS.
       MAIN-LOGIC.
           MOVE FUNCTION CURRENT-DATE TO WS-TIMESTAMP
           MOVE LS-DETAILS TO WS-DETAILS

           OPEN EXTEND LOG-FILE
           STRING WS-TIMESTAMP DELIMITED BY SIZE
                  ": " DELIMITED BY SIZE
                  WS-DETAILS DELIMITED BY SIZE
                  INTO LOG-RECORD
           WRITE LOG-RECORD
           CLOSE LOG-FILE
           GOBACK.