BiggiWiki

This is a very specific charset converter, but you should be able to rewrite the code to fit your own needs. It's meant to convert an XML file from UTF-8 to ISO-8859-1, nothing else (well maybe the other way around too, I made support for that anyway).

NOTE: If you need anything else but XML, you need to change “Content-Type”. It should be very easy to automate, I was just too lazy (maybe you can use $_FILES['convertme']['type'] - Please send me the changes if you do fix it).
NOTE: In the uploaded file I also replace 'encoding=“UTF-8”' with 'encoding=“ISO-8859-1”' (or whatever charset they choose), so you probably need to comment that out.

<?php
// Which charsets do we support?
$charsets[] = "ISO-8859-1";
$charsets[] = "UTF-8";

if (!isset($_POST['charsetto'])) {
?>
        <html>
        <title>Charset converter</title>
        <body>
        <center><h3>Charset converter</h3></center>
        <form action="?" method="post" enctype="multipart/form-data">
        Convert charset from: <select name="charsetfrom">
<?php
        foreach (array_reverse($charsets) as $charset) {
                echo "<option value=\"".$charset."\">".$charset."</option>";
        }
?>
        </select><br>
        Convert charset to: <select name="charsetto">
<?php
        foreach ($charsets as $charset) {
                echo "<option value=\"".$charset."\">".$charset."</option>";
        }
?>
        </select><br>
        <input type="file" name="convertme" id="convertme"><br>
        <input type="submit" value="Convert">
        </form>
        </body>
        </html>
<?php
} else {
        $readcontent = file_get_contents($_FILES['convertme']['tmp_name']);
        $convertedcontent = iconv($_POST['charsetfrom'], $_POST['charsetto'], $readcontent);
// Replace encoding header
        $convertedcontent = str_replace("encoding=\"".$_POST['charsetfrom']."\"", "encoding=\"".$_POST['charsetto']."\"", $convertedcontent);

        header("Content-Description: File Transfer");
//      header("Content-Type: application/octet-stream");
        header("Content-Type: text/xml");
        header("Content-Disposition: attachment; filename=".basename($FILES['convertme']['name']));
        header("Content-Transfer-Encoding: binary");
        header("Expires: 0");
        header("Cache-Control: must-revalidate");
        header("Pragma: public");
        header("Content-Length: ".$FILES['convertme']['size']);
        ob_clean();
        flush();
        echo $convertedcontent;

}
?>