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Javier Jimenez
Javier Jimenez

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COBOL on Ubuntu: Installation, Setup, and First Steps

#cobol #ubuntu #beginners #tutorial

Prerequisites – Installing Homebrew and ASDF on Ubuntu

Documentation (Official?)

Popular Frameworks / Toolkits

(COBOL doesn’t use modern frameworks; these are the most common ones)

  1. GnuCOBOL (OpenCOBOL) — standard open-source compiler.
  2. TinyCOBOL — simple and educational.
  3. COBOL-IT — commercial, mainframe-compatible.

🛠️ Installation on Ubuntu 

sudo apt update sudo apt install open-cobol # or sudo apt install gnucobol
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🍺 Installation with Homebrew 

brew install gnu-cobol
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📦 Standard Package Manager

COBOL **does not have an official package manager* (it’s not a modular ecosystem like Node or PHP).*

🔧 Installation with ASDF

There is no official ASDF plugin for COBOL.

📝▶️ Create and Run a COBOL File

Important: In COBOL, the first 7 characters of each line must remain empty because they were originally reserved for sequence numbers used on punched cards. These numbers allowed cards to be physically reordered if shuffled. Even though they’re no longer needed today, this historical structure is preserved for compatibility, so these first eight characters are still treated as a special non-code area.
cobol.es – IBM – Cobol for Linux

Col: 1 2 3 4 5 6 7 8 | | | | | | | └──→ Code begins here | | └────→ Indicator (comments, continuation…) └──────────────→ Sequence area (1–6) 000100*······Sample program 000200 IDENTIFICATION DIVISION. 000300 PROGRAM-ID.··HELLOWORLD. 000400 ENVIRONMENT DIVISION. 000500 DATA DIVISION. 000600 WORKING-STORAGE SECTION. 000700 01·MESSAGE·PIC·X(20)·VALUE·"HELLO·WORLD". 000800 PROCEDURE DIVISION. 000900 DISPLAY·MESSAGE. 001000 STOP·RUN.
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Note: There is a “free format” mode >>SOURCE FORMAT FREE that supposedly allows skipping the blank spaces, but it didn’t work for me.

Create file: touch hello.cob

 *COBOL SAMPLE PROGRAM TO VERIFY COBOL INSTALLATION *IMPORTANT - Reminder: COBOL code must begin at COLUMN 8. *Use '*' in column 7 for comments. IDENTIFICATION DIVISION. PROGRAM-ID. HELLO. PROCEDURE DIVISION. DISPLAY "COBOL is installed and working!". STOP RUN.
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Same file in free format (no comments):

>>SOURCE FORMAT FREE IDENTIFICATION DIVISION. PROGRAM-ID. HELLO. PROCEDURE DIVISION. DISPLAY "Hello COBOL World". STOP RUN.
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Compile:

cobc -x hello.cob -o hello
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Run:

./hello
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🟦 Basic COBOL Example

What It Does:

  1. Reads a text file.
  2. The file contains two numbers per line (e.g., 5 7).
  3. Multiplies them.
  4. Prints to console: "the result is = X"

Input file (datos.txt)

Example content:

125 745 313 246787 140 4467
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Mini COBOL Program

Create file: multiplicar.cob

 *-------------------------------------------------------------* * PROGRAM TO READ TWO VALUES, MULTIPLY THEM, AND DISPLAY THEM * *-------------------------------------------------------------* IDENTIFICATION DIVISION. PROGRAM-ID. MULTIPLY. ENVIRONMENT DIVISION. INPUT-OUTPUT SECTION. FILE-CONTROL. SELECT FILEIN ASSIGN TO "datos.txt" ORGANIZATION IS LINE SEQUENTIAL. DATA DIVISION. FILE SECTION. FD FILEIN. 01 RECORD-LINE PIC X(50). WORKING-STORAGE SECTION. 01 NUM1 PIC 9(9). 01 NUM2 PIC 9(9). 01 RESULT PIC 9(18). 01 END-FILE PIC X VALUE "N". PROCEDURE DIVISION. MAIN-LOGIC. OPEN INPUT FILEIN PERFORM UNTIL END-FILE = "S" READ FILEIN AT END MOVE "S" TO END-FILE NOT AT END PERFORM PROCESS-LINE END-READ END-PERFORM CLOSE FILEIN STOP RUN. PROCESS-LINE. UNSTRING RECORD-LINE DELIMITED BY SPACE INTO NUM1 NUM2 COMPUTE RESULT = NUM1 * NUM2 DISPLAY "the result is = " RESULT.
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📝▶️ How to Compile and Run 

# Compile file: cobc -x multiplicar.cob -o multiplicar #Run compiled program ./multiplicar
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Expected output:

the result is = 35 the result is = 6 the result is = 40
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Top comments (1)

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oscarpincho profile image
Oscar Pincho •

me voy a robar esto 😼