The following code applies changes to some article.
<?php
$old_article = file_get_contents('./old_article.txt');
$diff = $_SERVER['patch']; /* Let's say that someone pasted a patch to html form */
$errors = '';
$new_article = xdiff_string_patch($old_article, $diff, XDIFF_PATCH_NORMAL, $errors);
if (is_string($new_article)) {
echo "New article:\n";
echo $new_article;
}
if (strlen($errors)) {
echo "Rejects: \n";
echo $errors;
}
?>