public function input($filename, $input)
    {
        if (substr($filename, strlen($this->_settings['ext']) * -1) !== $this->_settings['ext']) {
            return $input;
        }

        $tmpFile = tempnam(TMP, 'TYPESCRIPT');
        $cmd = $this->_settings['typescript'] . " " . escapeshellarg($filename) . " --out " . $tmpFile;
        $this->_runCmd($cmd, null);
        $output = file_get_contents($tmpFile);
        unlink($tmpFile);
        return $output;
    }