Laravel env() Helper Without Framework

helpers.php

<?php
/**
 * Gets the value of an environment variable. Supports boolean, empty and null.
 *
 * @param  string  $key
 * @param  mixed   $default
 * @return mixed
 */
function env($key, $default = null)
{
    $value = getenv($key);

    if ($value === false) {
        return value($default);
    }

    switch (strtolower($value)) {
        case 'true':
        case '(true)':
            return true;
        case 'false':
        case '(false)':
            return false;
        case 'empty':
        case '(empty)':
            return '';
        case 'null':
        case '(null)':
            return;
    }
    
    if (starts_with($value, '"') && ends_with($value, '"')) {
        return substr($value, 1, -1);
    }

    return $value;
}

/**
 * Determine if a given string starts with a given substring.
 *
 * @param  string  $haystack
 * @param  string|array  $needles
 * @return bool
 */
function starts_with($haystack, $needles)
{
    foreach ((array) $needles as $needle)
    {
        if ($needle != '' && strpos($haystack, $needle) === 0) return true;
    }

    return false;
}

/**
 * Determine if a given string ends with a given substring.
 *
 * @param  string  $haystack
 * @param  string|array  $needles
 * @return bool
 */
function ends_with($haystack, $needles)
{
    foreach ((array) $needles as $needle)
    {
        if ((string) $needle === substr($haystack, -strlen($needle))) return true;
    }
    
    return false;
}