Course · Ledger Systems

Teach COBOL.

Sixty-five years old and still moving most of the world's money. COBOL is not a relic — it is a bookkeeping instrument written as a language. Seven lessons, each with a working program and a drill you can run tonight.

Lesson 01

The shape of a program

COBOL is written in four divisions, always in the same order. The order is the discipline: who wrote it, what machine it runs on, what data exists, and only then what happens.

What to hold onto

  • IDENTIFICATION DIVISION names the program.
  • ENVIRONMENT DIVISION binds the program to files and hardware.
  • DATA DIVISION declares every field before a single instruction runs.
  • PROCEDURE DIVISION is the only place logic lives.
  • Free-format source (COBOL 2002 and later) removes the old column 7-72 rules, but many shops still keep them.

Source

       IDENTIFICATION DIVISION.
       PROGRAM-ID. HELLO-LEDGER.

       ENVIRONMENT DIVISION.

       DATA DIVISION.
       WORKING-STORAGE SECTION.
       01  WS-GREETING   PIC X(30) VALUE "LEDGER OPEN.".

       PROCEDURE DIVISION.
       MAIN-PARA.
           DISPLAY WS-GREETING
           STOP RUN.

Drill

Rewrite the program so it displays two lines: the greeting and today's literal date. Keep the division order intact.