public static function getFilterURL($filename, $fromCharset, $toCharset = null)
    {
        if ( $toCharset === null ) {
            return sprintf('php://filter/convert.mbstring.encoding.%s/resource=%s', $fromCharset, $filename);
        } else {
            return sprintf('php://filter/convert.mbstring.encoding.%s:%s/resource=%s', $fromCharset, $toCharset, $filename);
        }
    }
public static function getFilterURL($filename, $fromCharset, $toCharset = null)
    {
        if ( $toCharset === null ) {
            return sprintf('php://filter/convert.mbstring.encoding.%s/resource=%s', $fromCharset, $filename);
        } else {
            return sprintf('php://filter/convert.mbstring.encoding.%s:%s/resource=%s', $fromCharset, $toCharset, $filename);
        }
    }
public static function getFilterURL ( $ filename , $ fromCharset , $ toCharset = null ) { if ( $ toCharset === null ) { return sprintf ( 'php://filter/convert.mbstring.encoding.%s/resource=%s' , $ fromCharset , $ filename ) ; } else { return sprintf ( 'php://filter/convert.mbstring.encoding.%s:%s/resource=%s' , $ fromCharset , $ toCharset , $ filename ) ; } }
Return filter URL
@param string $filename
@param string $fromCharset
@param string $toCharset
@return string
Return filter URL