Hi,

> +    # process -y / -n arg.
> +    export AUTO_YN=${1:1:1}
> +    if [ -z $AUTO_YN ]; then
> +        export AUTO_YN=""
> +    fi

Why "export" ? Now all the child processes get it, making their environment
different from before.  This makes parse_args have system-wide side effects.

If we wanted to export it, we could do it explicitly after parse_args has
been called.