Bash Scripting — Menu-Driven Scripts

Welcome to Chapter 28 — Menu-Driven Scripts 🎛️

Command-line tools don’t have to be boring walls of text. A well-crafted menu turns a pile of scripts into a polished, user-friendly toolkit that anyone on your team can operate — no documentation required.

In this chapter you’ll learn how to build interactive, menu-driven Bash scripts from the ground up.

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What You’ll Learn

Lesson	Topic	Link
01	Full CLI Menu with case	Full CLI Menu
02	Sub-Menus	Sub-Menus
03	Dynamic Menus from Arrays	Dynamic Menus
04	Color and ANSI Codes	ANSI Colors
05	Exit and Quit Handling	Exit & Quit
06	Practice Exercises	Exercises

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Why Menu-Driven Scripts?

Think about the last time you handed a Bash script to a colleague. Did they know which arguments to pass? Probably not. Menus solve that:

• Discoverability — users see every option at a glance.
• Safety — invalid choices are caught before damage is done.
• Professionalism — a clean menu feels like a real application.

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Quick Preview

Here’s a taste of what you’ll be building by the end of this chapter:

#!/usr/bin/env bash
set -euo pipefail

PS3="Choose an option: "
options=("Show Disk Usage" "Show Memory" "Quit")

select opt in "${options[@]}"; do
    case "$opt" in
        "Show Disk Usage") df -h ;;
        "Show Memory")     free -m ;;
        "Quit")            echo "Bye!"; break ;;
        *)                 echo "Invalid option $REPLY" ;;
    esac
done

By Lesson 06, you’ll add colors, sub-menus, dynamic options, and graceful exit handling on top of this foundation.

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Prerequisites

Before starting this chapter, make sure you’re comfortable with:

• Functions — we’ll use them heavily for sub-menus.
• case statements — the backbone of menu dispatch.
• Loops — while and select loops drive the menu cycle.
• read — capturing user input.

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Conventions Used

Convention	Meaning
$	Regular user prompt
#	Root prompt (use with caution)
→	Expected output
💡	Helpful tip
⚠️	Watch out — common mistake

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Ready? Let’s start with Lesson 01 — Full CLI Menu with case. 🚀