- var_dump: documentation ( source)
- html_entity_decode: documentation ( source)
- preg_replace: documentation ( source)
- setlocale: documentation ( source)
<?php
setlocale(LC_ALL, 'en_US.UTF-8');
$str = "u\u0308 a\u0302 a\u0308 o\u0300";
$str = preg_replace('/\\\\u([0-9a-f]+)/i', '&#x$1;', $str);
$str = html_entity_decode($str, ENT_QUOTES, 'UTF-8');
var_dump( iconv("UTF-8", "ISO-8859-1//TRANSLIT", $str) );