parse_ini.php

<?php 
  const FILENAME = 'loadlog.ini';
  const FILEPATH = './' . FILENAME;

  $foo = $_POST['foo'];
  $bar = $_POST['bar'];

  $content = 'foo=' . $foo;
  $content .= '\n'; // \n are ascii code for breakline a.k.a enter
  $content .= 'bar=' . $bar;

  // write to file first if there's payload
  if ($foo || $bar) {
    file_put_contents(FILEPATH, $content);
  }

  // read file and parse it
  $parsed_file = parse_ini_file(FILEPATH);

  /**
   * it should be parsed to array
   * so you can access it like $parsed_file['foo']
   */
  print_r($parsed_file);