PHP mappath(...)

<?phpfunction resolverelatives($arr) {  $new = array();  foreach ($arr as $path) {    if ($path === '.') continue;    if ($path === '..' and count($new)) {array_pop($new); continue;}    $new[] = $path;  }  return $new;}function mappath($from, $to, $sep = DIRECTORY_SEPARATOR) {  $arrfrom = explode($sep, $from);  $arrto = explode($sep, $to);  if (!strlen($arrto[0]) and strlen($arrfrom[0])) return $to;  elseif (strlen($arrto[0]) and !strlen($arrfrom[0])) {    user_error(__FUNCTION__.' Can\'t map path from absolute to relative path.');    return false;  }  while (count($arrfrom) and count($arrto) and $arrfrom[0] === $arrto[0]) {array_shift($arrfrom); array_shift($arrto);}  $uplen = count($arrfrom)-1;  $newpath = array();  for ($i = 0; $i < $uplen; $i++) $newpath[] = '..';  foreach ($arrto as $aaaah) $newpath[] = $aaaah;  return implode($sep, $newpath);}echo '<img src="'.mappath($_SERVER['PHP_SELF'], '/images/test.jpg').'" />';?>