Filters to be used within the convert filter are base64-encode, base64-decode, quoted-printable-encode and quoted-printable-decode. Note: those are not in the string filter, as currently reported by the manual!Example usage is:<?php$h = fopen('gecodeerd.txt', 'r');stream_filter_append($h, 'convert.base64-decode');fpassthru($h);fclose($h);?>Or<?php$filter = 'convert.base64-decode';$file = 'coded.txt';$h = fopen('php://filter/read=' . $filter . '/resource=' . $file,'r'); fpassthru($h);fclose($h);?>