In this lesson, you will learn how to build context-aware help menus that adapt based on the state of your script, ensuring users always receive relevant guidance.
Beyond Static Documentation
While static documentation (like a standard man page) is helpful, a Dynamic Help System modifies its output based on what the user is currently doing or what errors they have triggered. Imagine a script that manages a backup rotation system: instead of dumping a 50-line instruction block, the help menu detects if a directory is missing and highlights the specific command needed to initialize that path.
The Logic of Context
To build this, you need a function that evaluates the "state" of the environment before displaying output. By using the case statement, you can inject conditional blocks into your help message.
show_help() {
local context=$1
echo "--- Tool Helper ---"
case $context in
"missing_config")
echo "Tip: It looks like you're missing a config file."
echo "Run 'mytool --init' to create one."
;;
"permission_denied")
echo "Tip: You lack permissions for this directory."
echo "Try running with 'sudo' or check your UID."
;;
*)
echo "General Usage: mytool [command] [options]"
;;
esac
}
# Implementation inside your main loop
if [[ ! -f "config.json" ]]; then
show_help "missing_config"
exit 1
fi
Why This Matters
By integrating this with Interactive Prompt UI Design, you turn a cold, error-prone script into a guided tool. When a user runs a command with incorrect arguments, instead of a generic "Invalid syntax" message, the dynamic system detects the specific point of failure and provides a relevant solution. This reduces user frustration and prevents them from having to switch windows to consult external manuals.
When writing complex scripts, consider what the user needs to see at the moment they reach an error, rather than just dumping everything they could see.
Key Takeaway: A dynamic help system improves usability by surfacing context-sensitive guidance only when the user is most likely to need it.