template.sh

#!/usr/bin/env bash
#: Your comments here.
set -o errexit
set -o nounset
set -o pipefail
work_dir=$(dirname "$(readlink --canonicalize-existing "${0}" 2> /dev/null)")
readonly conf_file="${work_dir}/script.conf"
readonly error_reading_conf_file=80
readonly error_parsing_options=81
readonly script_name="${0##*/}"
a_option_flag=0
abc_option_flag=0
flag_option_flag=0
trap clean_up ERR EXIT SIGINT SIGTERM
usage() {
    cat <<USAGE_TEXT
Usage: ${script_name} [-h | --help] [-a <ARG>] [--abc <ARG>] [-f | --flag]
DESCRIPTION
    Your description here.
OPTIONS:
-h, --help
        Print this help and exit.
-f, --flag
        Description for flag option.
-a
        Description for the -a option.
--abc
        Description for the --abc option.
USAGE_TEXT
}
clean_up() {
    trap - ERR EXIT SIGINT SIGTERM
    # Remove temporary files/directories, log files or rollback changes.
}
die() {
    local -r msg="${1}"
    local -r code="${2:-90}"
    echo "${msg}" >&2
    exit "${code}"
}
if [[ ! -f "${conf_file}" ]]; then
    die "error reading configuration file: ${conf_file}" "${error_reading_conf_file}"
fi
# shellcheck source=script.conf
. "${conf_file}"
parse_user_options() {
    local -r args=("${@}")
    local opts
# The following code works perfectly for 
    opts=$(getopt --options a:,f,h --long abc:,help,flag -- "${args[@]}" 2> /dev/null) || {
        usage
        die "error: parsing options" "${error_parsing_options}"
    }
eval set -- "${opts}"
while true; do
    case "${1}" in
--abc)
            abc_option_flag=1
            readonly abc_arg="${2}"
            shift
            shift
            ;;
-a)
            a_option_flag=1
            readonly a_arg="${2}"
            shift
            shift
            ;;
--help|-h)
            usage
exit 0
            shift
            ;;
--flag|-f)
            flag_option_flag=1
shift
            ;;
--)
            shift
            break
            ;;
        *)
            break
            ;;
    esac
    done
}
parse_user_options "${@}"
if ((flag_option_flag)); then
    echo "flag option set"
fi
if ((abc_option_flag)); then            # Check if the flag options are set or ON:
    # Logic for when --abc is set.
    # "${abc_arg}" should also be set.
    echo "Using --abc option -> arg: [${abc_arg}]"
fi
if ((a_option_flag)); then
    # Logic for when -a is set.
    # "${a_arg}" should also be set.
    echo "Using -a option -> arg: [${a_arg}]"
fi
exit 0