Executing a Simple COBOL Program Using WSL and Shell Scripting

Introduction

COBOL (Common Business-Oriented Language) is a programming language that has been widely used in business, finance, and administrative systems for decades. With the advent of Windows Subsystem for Linux (WSL), developers can now run Linux distributions directly on Windows, making it easier to work with languages like COBOL. In this article, we will walk through the steps to execute a simple COBOL program using WSL, including how to handle common issues related to file formats when using Windows text editors.

Prerequisites

Before we begin, ensure you have the following:

1. Windows 10 or later with WSL enabled.

2. GnuCOBOL installed in your WSL environment.

3. A basic understanding of COBOL programming.

Step 1: Install WSL and GnuCOBOL

1. Enable WSL: Open PowerShell as an administrator and run:

    wsl --install
   

   This command installs the default Linux distribution (usually Ubuntu).

2. Open WSL: After installation, open your WSL terminal (search for "Ubuntu" in the Start menu).

3. Install GnuCOBOL: In the WSL terminal, run the following commands to update the package list and install GnuCOBOL:

    sudo apt update
    sudo apt install gnucobol
   

Step 2: Create a Simple COBOL Program

1. Open a Text Editor: You can use a text editor like nano or vim in WSL. For example, to create a file named hello.cbl, run:

    nano hello.cbl
   

2. Write the COBOL Code: Enter the following simple COBOL program:

    IDENTIFICATION DIVISION.
    PROGRAM-ID. HELLO.
    PROCEDURE DIVISION.
        DISPLAY "Hello, World from COBOL!".
        STOP RUN.
   

3. Save and Exit: In nano, press CTRL + O to save, then Enter, and CTRL + X to exit.

Step 3: Create a Shell Script to Compile and Run the Program

1. Create a Shell Script: Create a new shell script named run_cobol.sh:

    nano run_cobol.sh
   

2. Add the Following Code:

    #!/bin/bash
   
    # Compile the COBOL program
    cobc -x -o hello hello.cbl
   
    # Check if compilation succeeded
    if [ $? -eq 0 ]; then
        echo "Compilation successful. Running program..."
        ./hello
    else
        echo "Compilation failed."
    fi
   

3. Save and Exit: Save and exit the script as you did before.

Step 4: Make the Shell Script Executable

Run the following command to make your script executable:

chmod +x run_cobol.sh

Step 5: Handling Windows Notepad File Issues

If you created or edited your COBOL program or shell script using Windows Notepad, you might encounter issues when running the script in WSL. This is due to Windows-style line endings (CRLF) that are not compatible with Unix/Linux systems.

Converting Line Endings

1. Install dos2unix: If you haven't already, install dos2unix to convert line endings:

    sudo apt install dos2unix
   

2. Convert the Script: Convert your shell script to Unix format:

    dos2unix run_cobol.sh
   

Step 6: Run the Shell Script

Now you can run your shell script to compile and execute your COBOL program:

./run_cobol.sh

If everything is set up correctly, you should see the output:

Compilation successful. Running program...
Hello, World from COBOL!

Conclusion

In this article, we demonstrated how to execute a simple COBOL program using WSL and shell scripting. We also addressed common issues related to file formats when using Windows text editors. By following these steps, you can easily develop and run COBOL programs in a Linux environment on your Windows machine.