#!/bin/sh

source .env

while IFS= read -r line; do
    key=${line%=*}
    if [ -n "$key" ]; then
        if [ ${key:0:1} != "#" ]; then
            val=$(eval echo \$$key)
            if [ -z "$val" ]; then
                echo $key
            fi
        fi
    fi
done < .env.sample