- strtr: documentation ( source)
<?php
$nom = "Märie Du jean Grénaille";
$nom = strtr($nom,"ÁÀÂÄÃÅÇÉÈÊËÍÏÎÌÑÓÒÔÖÕÚÙÛÜÝáàâäãåçéèêëíìîïñóòôöõúùûüýÿ","AAAAAACEEEEEIIIINOOOOOUUUUYaaaaaaceeeeiiiinooooouuuuyy");
echo $nom;
$nomfilter = array(" ÁÀÂÄÃÅÇÉÈÊËÍÏÎÌÑÓÒÔÖÕÚÙÛÜÝáàâäãåçéèêëíìîïñóòôöõúùûüýÿ");
$nomremplacement = array("_AAAAAACEEEEEIIIINOOOOOUUUUYaaaaaaceeeeiiiinooooouuuuyy");
//$nom = str_replace($nomfilter, $nomremplacement, $nom);
//echo $nom;