Bash

Bash is the shell that runs the internet’s infrastructure. Born in 1989 as a free replacement for the Bourne shell, it became the default on virtually every Linux distribution and macOS (until Catalina switched to ZSH). When someone says “write a shell script,” they almost always mean Bash. It’s the glue language of DevOps — the thing you reach for when you need to chain commands together, automate a deployment, parse some logs, or write a quick CI/CD pipeline step.

Bash scripting is deceptively simple on the surface but hides a minefield of gotchas underneath. Unquoted variables split on whitespace. [ ] and [[ ]] behave differently. Exit codes matter but are easy to ignore. Pipelines silently swallow errors unless you set pipefail. Despite all of this, Bash remains the most portable scripting option across Unix-like systems — if it has a terminal, it probably has Bash. For anything more complex than a few dozen lines, most teams reach for Python or Go, but for bootstrapping, glue scripts, and Dockerfiles, nothing beats the immediacy of a Bash one-liner.

Why it matters: Bash is everywhere. Every Dockerfile RUN command, every CI pipeline step, every cron job, and every quick automation hack runs through it. Fluency in Bash isn’t optional for anyone working in DevOps or infrastructure — it’s the common language of every Unix-like system you’ll ever touch.