Codes

COBOL

GnuCOBOL

Installation

Ubuntu

apt install gnucobol

Alma Linux

dnf install gnucobol

Arch Linux

pacman -S gnucobol

Examples

Fibonacci Numbers

      * Fibonacci Numbers 
       IDENTIFICATION DIVISION.
       FUNCTION-ID. FIBONACCI.
       DATA DIVISION.
       LOCAL-STORAGE SECTION.
       01 t1 PIC 99.
       01 t2 PIC 99.
       LINKAGE SECTION.
       01 n PIC 99.
       01 r PIC 9(8).
       PROCEDURE DIVISION USING n RETURNING r.
       IF n = 0 THEN
           COMPUTE r = 0
       ELSE IF n = 1 THEN
           COMPUTE r = 1
       ELSE
           COMPUTE t1 = n - 2
           COMPUTE t2 = n - 1
           COMPUTE r =
               FUNCTION FIBONACCI (t1) +
               FUNCTION FIBONACCI (t2)
       END-IF.
       EXIT FUNCTION.
       END FUNCTION FIBONACCI.

       IDENTIFICATION DIVISION.
       PROGRAM-ID. FIB.
       ENVIRONMENT DIVISION.
       CONFIGURATION SECTION.
       REPOSITORY.
           FUNCTION FIBONACCI.
       DATA DIVISION.
       WORKING-STORAGE SECTION.
       01 A PIC 99.
       PROCEDURE DIVISION.
       ACCEPT A FROM COMMAND-LINE
           DISPLAY FUNCTION FIBONACCI (A).
           STOP RUN.

      *> Example
      *>     compile:
      *>         cobc -x fib.cob
      *>     run:
      *>         ./fib 30