Templete for a new bash script

script.sh

#!/usr/bin/env bash

: Setup environment
set -o errexit
set -o nounset
set -o pipefail
if [[ "${TRACE-0}" == "1" ]]; then
    set -o xtrace
fi

filename=$(basename "$0")
cd "$(dirname "$0")"

: Load .env file if exists
if [ -f .env ]; then
    export "$(grep -v '^#' .env | xargs)"
fi

# Functions
print_error() {
    echo "${1}" >&2
}

print() {
    echo "${1}"
}

check_requirements() {
    requirements=("test" "which")

    for requirement in "${requirements[@]}"; do
        if ! command -v "${requirement}" &>/dev/null; then
            print_error "Can not find ${requirement}. Please be sure ${requirement} is installed."
            exit
        fi
    done
}

# $1 = question
# $2 = yes condition
promt_user() {
    read -r -p "${1} " yn
    case $yn in
    [Yy]*)
        "${@:2}"
        return
        ;;
    [Nn]*)
        return
        ;;
    *) print_error "Please answer yes or no." ;;
    esac
}

: Help
if [[ "${1-}" =~ ^-*h(elp)?$ ]]; then
    print "\
############################################################    
Usage: ./${filename} [arg1] [arg2]
############################################################
This bash script is for ...
############################################################
"
    exit
fi

: Main method
main() {
    check_requirements
    promt_user "Do you want to do this?" echo "yes I do"

}

main "$@"