xml.php

<?php

function ec_dreammail_escape_xml($string) {
  return htmlentities($string, ENT_QUOTES, 'UTF-8');
}

/**
 * Returns FALSE if there are unsafe characters.
 */
function ec_dreammail_sanitize_xml($string) {
  $length = strlen($string);
  for ($i = 0; $i < $length; $i++) {
    $current = ord($string[$i]);
    if (!(($current == 0x9) || ($current == 0xA) || ($current == 0xD) || 
        (($current >= 0x20) && ($current <= 0xD7FF)) || 
        (($current >= 0xE000) && ($current <= 0xFFFD)) || 
        (($current >= 0x10000) && ($current <= 0x10FFFF)))) {
      return FALSE;
    }
  }
  return TRUE;
}