Core_Upload::format_name

protected function format_name()
{
    if ($this->filename)
    {
        $this->file['name'] = $this->filename;
    }
    else if ($this->config['rename'])
    {
        // 重命名文件
        $ext = File::ext_by_mime($this->file['type']);      // 获取文件后缀
        $this->file['name'] = Text::random() . $ext;
    }
    else
    {
        // 对文件名做特殊字符过滤处理
        $this->clean_filename();

        if ($this->config['remove_spaces'])
        {
            $this->file['name'] = preg_replace('#\s+#', '_', $this->file['name']);
        }
    }

    return $this;
}