I’m probably missing something here but I’m trying to save environment variables with newlines into a .env file. Ideally I want to do this with all available env variables (output of env).

Take this variable:

export MY_VAR="Line 1
Line 2
Line 3"

How do I save this in a .env file that would look like:
variables.env

MY_VAR=Line 1nLine2nLine3

And how can I do this with all available env variables, like from env? I tried this:

while IFS= read -r -d '' line; do
    line=$(echo -n "$line" | sed '$!s/$/\n/' | tr -d 'n')
    echo "$line" >> variables.env
done < <(env -0)