Bash script template, including functions, etc.

bash_template.sh

#!/bin/env bash
set -euo pipefail

EXIT_SUCCESS=0
EXIT_FAILURE=1

## insert functions here...

print_help() {
    echo "Commands:"
    echo "      ./bash_template.sh arg1"
    echo "      ./bash_template.sh help"
}

main() {
    case "${1}" in
        "help")
            print_help
            exit ${EXIT_SUCCESS};;
        "none")
            echo "No argument given!"
            print_help
            exit ${EXIT_FAILURE};;
        "*")
            echo "Invalid argument!"
            print_help
            exit ${EXIT_FAILURE};;
}

main ${1-none}