Mikrotik RouterOS time interval parser

RouterOSparseInterval.php

<?php
function RouterOSparseInterval($in) {
  $pattern = "/(\d+)([wdhms])/";

  $multipliers = array(
    "w" => 604800,
    "d" => 86400,
    "h" => 3600,
    "m" => 60,
    "s" => 1
  );
  
  preg_match_all($pattern, $in, $matches, PREG_SET_ORDER);

  $total = 0;
  foreach($matches as $m) {
    $total = $total + $m[1] * $multipliers[$m[2]];
  }
  
  if(count($matches) == 0) {
    $total = -1;
  }
  return($total);
}