#!/usr/bin/env sh

[ "$#" -lt 1 ] && { echo "No arguments provided" >&2 ; exit 1; }
[ "$#" -gt 1 ] && { echo "Too many arguments provided" >&2 ; exit 2; }

# shellcheck disable=SC1090
{ [ -f "$1" ] && . "$1"; } || { echo "$1 does not exist" >&2 ; exit 3; }