michelou / cobol-examples

Playing with COBOL on Windows

Playing with COBOL on Windows

This repository gathers COBOL code examples coming from various websites - mostly from the Mainframestechhelp website - or written by ourself. In particular it includes several build scripts (Bash scripts, batch files, Make scripts) for experimenting with the COBOL language on a Windows machine.

Ada, Akka, C++, Deno, Docker, Erlang, Flix, Golang, GraalVM, Haskell, Kafka, Kotlin, LLVM, Modula-2, Node.js, Rust, Scala 3, Spark, Spring, TruffleSqueak and WiX Toolset are other topics we are continuously monitoring.

Project dependencies

This project depends on the following external software for the Microsoft Windows platform:

• Git 2.45 (release notes)
• GnuCOBOL 3.2 (release notes, news file)
• MSYS2 2024 ³ (changelog)

Optionally one may also install the following software:

• ConEmu (release notes)
• Visual Studio Code 1.89 (release notes)

☛ Installation policy
When possible we install software from a Zip archive rather than via a Windows installer. In our case we defined C:\opt\ as the installation directory for optional software tools (in reference to the /opt/ directory on Unix).

For instance our development environment looks as follows (May 2024) ¹:

C:\opt\ConEmu\    ( 26 MB)
C:\opt\Git\       (367 MB)
C:\opt\GnuCOBOL\  (548 MB)
C:\opt\msys64\    (2.8 GB)
C:\opt\VSCode\    (341 MB)

🔎 Git for Windows provides a Bash emulation used to run git.exe from the command line (as well as over 250 Unix commands like awk, diff, file, grep, more, mv, rmdir, sed and wc).

Directory structure ▴

This project is organized as follows:

bin\
csis-examples\{README.md, MonthTable, etc.}
docs\
dovey-examples\{README.md, Colors, etc.}
examples\{README.md, helloworld, etc.}
harris-examples\{README.md, 100Doors, FizzBuzz, etc.}
moseley-examples\{README.md, Elapsed, etc.}
README.md
RESOURCES.md
setenv.bat

where

• directory bin\ provides several utility batch files
• directory csis-examples contains several COBOL examples from the University of Limerick.
• directory docs\ contains several COBOL related papers/articles (docs\README.md).
• directory examples\ contains COBOL examples grabbed from various websites (examples\README.md).
• directory harris-examples contains COBOL examples from Mike Harris GitHub repository.
• file README.md is the Markdown document for this page.
• file RESOURCES.md is the Markdown document presenting external resources.
• file setenv.bat is the batch command for setting up our environment.

We also define a virtual drive – e.g. drive T: – in our working environment in order to reduce/hide the real path of our project directory (see article "Windows command prompt limitation" from Microsoft Support).

🔎 We use the Windows external command subst to create virtual drives; for instance:

> subst T: %USERPROFILE%\workspace\dart-examples

In the next section we give a brief description of the batch files present in this project.

Batch/Bash commands

setenv.bat ²

We execute command setenv.bat once to setup our development environment; it makes external tools such as git.exe, make.exe and sh.exe directly available from the command prompt.

   > setenv
   Tool versions:
   cobc 3.3.0, make 4.4.1,
   git 2.45.0, diff 3.10, bash 5.2.26(1)-release
    
   > where git make sh
   C:\opt\Git\bin\git.exe
   C:\opt\Git\mingw64\bin\git.exe
   C:\opt\msys64\usr\bin\make.exe
   C:\opt\Git\bin\sh.exe
   C:\opt\Git\usr\bin\sh.exe
   

Command setenv help displays the help messsage :

> setenv help
Usage: setenv { <option> | <subcommand> }
 
  Options:
    -bash       start Git bash shell instead of Windows command prompt
    -debug      print commands executed by this script
    -verbose    print progress messages
 
  Subcommands:
    help        print this help message

Footnotes ▴

[1] Downloads ↩

In our case we downloaded the following installation files (see section 1):

ConEmuPack.230724.7z                (  5 MB)
gnucobol-3.2-aio-20240306-user.msi  ( 92 MB)
msys2-x86_64-20240113.exe           ( 83 MB)
PortableGit-2.45.0-64-bit.7z.exe    ( 41 MB)
VSCode-win32-x64-1.89.1.zip         (131 MB)

☛ GnuCOBOL distribution
We prefer the All-in-One distribution from SuperBOL over the GnuCOBOL distribution from Arnold Trembley.

[2] setenv.bat usage ↩

Batch file setenv.bat has specific environment variables set that enable us to use command-line developer tools more easily.

It is similar to the setup scripts described on the page "Visual Studio Developer Command Prompt and Developer PowerShell" of the Visual Studio online documentation.

For instance we can quickly check that the two scripts Launch-VsDevShell.ps1 and VsDevCmd.bat are indeed available in our Visual Studio 2019 installation :

> where /r "C:\Program Files (x86)\Microsoft Visual Studio" *vsdev*
C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\Common7\Tools\Launch-VsDevShell.ps1
C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\Common7\Tools\VsDevCmd.bat
C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\Common7\Tools\vsdevcmd\core\vsdevcmd_end.bat
C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\Common7\Tools\vsdevcmd\core\vsdevcmd_start.bat

Concretely, in our GitHub projects which depend on Visual Studio (e.g. michelou/cpp-examples), setenv.bat does invoke VsDevCmd.bat (resp. vcvarall.bat for older Visual Studio versions) to setup the Visual Studio tools on the command prompt.

[3] MSYS2 libraries ↩

Some COBOL examples depend on the gmp library – A free library for arbitrary precision arithmetic – which is part of our local MSYS2 installation.

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mics/May 2024 ▲