Shell 腳本如何輸出幫助信息？

作者展示了一個技巧，將幫助信息寫在 Bash 腳本腳本的頭部，然后只要執行"腳本名 + help"，就能輸出這段幫助信息
https://samizdat.dev/help-message-for-shell-scripts/

#!/bin/bash
###
### my-script — does one thing well
###
### Usage:
###   my-script <input> <output>
###
### Options:
###   <input>   Input file to read.
###   <output>  Output file to write. Use '-' for stdout.
###   -h        Show this message.

help() {
	awk -F'### ' '/^###/ { print $2 }' "$0"
}

if [[ $# == 0 ]] || [[ "$1" == "-h" ]]; then
	help
	exit 1
fi


echo Hello World