How to change variables in the .env file dynamically in Laravel?

Question

I want to create a Laravel web app that allows an admin user to change some variables(such as database credentials) in the .env file using the web backend system. But how do

Answer 1

Update Erick's answer with consideration of $old values covering sting, bool and null values.

public static function changeEnvironmentVariable($key,$value)
{
    $path = base_path('.env');

    if(is_bool(env($key)))
    {
        $old = env($key)? 'true' : 'false';
    }
    elseif(env($key)===null){
        $old = 'null';
    }
    else{
        $old = env($key);
    }

    if (file_exists($path)) {
        file_put_contents($path, str_replace(
            "$key=".$old, "$key=".$value, file_get_contents($path)
        ));
    }
}