PHP Page compare

gistfile1.txt

#!/usr/bin/php
<?php

# Define variables
$page_cache = 'page.cache';
$page_to_check = 'https://www.nvidia.co.uk/geforce/buy/';

# Check if argument is passed in
if (isset($argv[1])) {
  $page_cache_override = true;
} else {
  $page_cache_override = false;
}

# Cache page is argument is passed in
function cache_page($overwrite_cache, $page_to_check, $page_cache) {
  if ($overwrite_cache) {
    $homepage = file_get_contents($page_to_check);
    file_put_contents($page_cache, $homepage);
    echo "Cached page new page contents\n";
  }
}

function check_page($page_to_check, $page_cache) {
  # Get page and cache contents and load into variable
  $homepage = file_get_contents($page_to_check);
  $page_cache = file_get_contents($page_cache);

  echo md5($homepage) . "\n";
  echo md5($page_cache) . "\n";

  if ($homepage == $page_cache) {
    echo "Cached page is the same\n";
  } else {
    echo "Cached page differs\n";
    file_put_contents('current_page', $homepage);
    file_put_contents('current_cache', $page_cache);
  }
}

cache_page($page_cache_override, $page_to_check, $page_cache);
check_page($page_to_check, $page_cache);
?>