Running Bash on Linux, macOS, WSL, and Git Bash

1. Choose a primary Bash lab

For a DevOps-focused Bash course, the clearest primary environment is a current Linux distribution with a recent Bash release. Ubuntu LTS or another mainstream Linux VM gives you a complete host environment while remaining easy to reset.

2. Detect Bash and its version

Do not build a script around a feature until you know which Bash version is guaranteed on the target systems.

command -v bash || {
  printf 'Bash is not available on PATH\n' >&2
  exit 1
}

bash --version | head -n 1
printf 'current BASH_VERSION=%s\n' "${BASH_VERSION-<not running bash>}"

# Major version, when currently running Bash
if [[ -n ${BASH_VERSINFO+x} ]]; then
  printf 'major=%s minor=%s patch=%s\n'     "${BASH_VERSINFO[0]}" "${BASH_VERSINFO[1]}" "${BASH_VERSINFO[2]}"
fi

Features such as associative arrays and mapfile require Bash rather than generic POSIX sh, and very old Bash releases may lack improvements you expect.

3. Bash is only one part of portability

Many shell scripts fail across platforms because of external utility differences, not because of Bash itself. GNU and BSD variants of common commands can have different options.

4. Bash choices on Windows

On Windows, two common options serve different goals:

# In any environment, collect facts before assuming behavior:
printf 'bash=%s\n' "$BASH_VERSION"
printf 'ostype=%s\n' "$OSTYPE"
uname -srm
command -v sed
command -v awk
command -v grep

# WSL commonly exposes WSL-specific markers:
if grep -qi microsoft /proc/version 2>/dev/null; then
  printf 'WSL-like Linux environment detected\n'
fi

5. Create a repeatable course workspace

Use a predictable directory tree so commands can be copied between lessons without depending on random working directories.

mkdir -p "$HOME/devops-academy/bash"/{bin,data,logs,tmp,tests}
cd "$HOME/devops-academy/bash"

printf '%s\n'   '# Bash Course Workspace'   ''   '- bin/: scripts'   '- data/: sample inputs'   '- logs/: generated logs'   '- tmp/: disposable lab state'   '- tests/: later automated tests'   > README.md

find . -maxdepth 1 -type d -print | sort
cat README.md

6. Build a tool preflight instead of failing mysteriously

Production scripts should detect critical dependencies early and emit actionable errors.

required=(bash grep sed awk find)
missing=()

for tool in "${required[@]}"; do
  command -v "$tool" >/dev/null 2>&1 || missing+=("$tool")
done

if ((${#missing[@]})); then
  printf 'Missing required tools: %s\n' "${missing[*]}" >&2
  exit 127
fi

printf 'Preflight passed\n'

You will learn arrays and robust error handling later. For now, focus on the principle: validate prerequisites explicitly.

7. Knowledge check

8. Summary

A dependable Bash environment is defined by more than the presence of a bash executable. Bash version, operating system, external utility variants, filesystem behavior, line endings, and available dependencies all affect automation. Establish your supported platform matrix and verify it explicitly.

9. Further reading

• GNU Bash Reference Manual — Bash Invocation and Shell Compatibility Mode.
• Microsoft WSL documentation — Linux distributions, filesystems, and interop behavior.
• Apple shell scripting documentation and macOS manual pages.
• Git for Windows documentation — Git Bash environment and bundled tools.
• POSIX utility specifications for portable external-command behavior.