#!/usr/bin/php
<?php

if (!isset($argv[1])) {
	echo "Argument missing\n";
	exit(2);
}

$arg = $argv[1];

if (!file_exists($arg) && !is_dir($arg)) die("File does not exist\n");

$d = filemtime($arg);

if ($d == 0) die("Unknown modification date\n");

rename($arg, date("Y-m-d", $d).'_'.$arg);