Method seek

/**
 * Seek the file
 *
 * Note: the return value is different to that of fseek
 *
 * @param   integer  $offset  Offset to use when seeking.
 * @param   integer  $whence  Seek mode to use.
 *
 * @return  boolean  True on success, false on failure
 *
 * @link    https://www.php.net/manual/en/function.fseek.php
 * @since   1.7.0
 */
public function seek($offset, $whence = SEEK_SET)
{
    if (!$this->fh) {
        $this->setError(Text::_('JLIB_FILESYSTEM_ERROR_STREAMS_FILE_NOT_OPEN'));
        return false;
    }
    $retval = false;
    // Capture PHP errors
    $php_errormsg = '';
    $track_errors = ini_get('track_errors');
    ini_set('track_errors', true);
    switch ($this->processingmethod) {
        case 'gz':
            $res = gzseek($this->fh, $offset, $whence);
            break;
        case 'bz':
        case 'f':
        default:
            $res = fseek($this->fh, $offset, $whence);
            break;
    }
    // Seek, interestingly, returns 0 on success or -1 on failure.
    if ($res == -1) {
        $this->setError($php_errormsg);
    } else {
        $retval = true;
    }
    // Restore error tracking to what it was before
    ini_set('track_errors', $track_errors);
    // Return the result
    return $retval;
}