Zend\Diactoros\Stream::tell PHP Method

    public function tell()
    {
        if (!$this->resource) {
            throw new RuntimeException('No resource available; cannot tell position');
        }
        $result = ftell($this->resource);
        if (!is_int($result)) {
            throw new RuntimeException('Error occurred during tell operation');
        }
        return $result;
    }