Method tell

/**
 * Returns the current position of the file read/write pointer.
 *
 * @return  mixed
 *
 * @since   1.7.0
 */
public function tell()
{
    if (!$this->fh) {
        $this->setError(Text::_('JLIB_FILESYSTEM_ERROR_STREAMS_FILE_NOT_OPEN'));
        return false;
    }
    // Capture PHP errors
    $php_errormsg = '';
    $track_errors = ini_get('track_errors');
    ini_set('track_errors', true);
    switch ($this->processingmethod) {
        case 'gz':
            $res = gztell($this->fh);
            break;
        case 'bz':
        case 'f':
        default:
            $res = ftell($this->fh);
            break;
    }
    // May return 0 so check if it's really false
    if ($res === false) {
        $this->setError($php_errormsg);
    }
    // Restore error tracking to what it was before
    ini_set('track_errors', $track_errors);
    // Return the result
    return $res;
}