<?php

$code = file_get_contents("source.txt");

$code = str_replace("<", "&lt;", $code);
$code = str_replace(">", "&gt;", $code);

echo "<pre>" . $code . "</pre>";

/*
* Outputs:
* <?php
   $ip = $_SERVER['REMOTE_ADDR'];
   $date = date("F j, Y");
   $time = date("g:i a");
   $file = fopen('ip_logg.txt', 'a', 1);
   $text="IP: {$ip} - Dato: {$date} - Tid: {$time}\n";
   fwrite($file, $text);
   fclose($file);
   echo "<center><b>Din IP adresse er logget<br>{$ip}</b></center>";
?>

*/