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《计算机应用与软件》2018,(4)
网络打印机处于网络中的关键节点,是许多敏感信息的处理介质。由于厂商对打印机安全关注度不高、设备固件更新周期长、用户安全意识弱等因素,导致黑客对打印机攻击易于成功。研究网络打印机工作原理及PJL、Post Script、PCL等打印机语言特点,利用打印语言的安全缺陷设计针对网络打印机的脆弱性测试脚本,测试拒绝服务攻击、保护绕过和远程代码执行攻击,设计并实现网络打印机脆弱性分析系统。该系统可以利用测试脚本对目标网络打印机进行攻击进而测试目标的脆弱性。最后利用常见品牌的打印机做实验,验证了系统的有效性。 相似文献
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打印机是一种机电一体化的精密设备,结构一般都比较复杂,相对计算机的其他外部设备,故障率也比较高,但通常也比较容易处理,下面小编就喷墨打印机、针式打印机和激光打印机这三种类型,分别介绍一下常见故障和解决方法。 相似文献
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微型打印机由于性能稳定、价格便宜、体积小等特性,近年来在工业控制、医疗设备、仪器仪表、通讯等方面得到了广泛应用。但其通常都是采用查询方式打印。这实际上使CPU的有效工作时间与打印机的工作时间串行起来。这大大降低了CPU的利用率。若采用中断方式打印,可使CPU的有效工作时间与打印机的工作时间并行起来。CPU在启动打印中断服务程序后继续执行主程序,处理其它任务。这样不仅提高了CPU的利用率,而且还可以使CPU与多个外设并行工作。本文以《TW-41》型通讯系统为例,说明微型打印机中断方式打印的实现原理。在《TW-41… 相似文献
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本文给出了在C语言中控制DPK3600打印机的几种方法,对其它类型的打印机只要查看相应的使用手册并换以相应的控制码即可。 一、利用流概念控制打印机LPT1、LPT2 在C语言中,对外部设备的输入输出处理就是读写设备的过程。因此,使用打印机如同使用普通的磁盘文 相似文献
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菅高俊 《计算机与应用化学》1995,12(3):226-228
广泛流行的C语言具有很好的图形处理功能,也能很好地处理微机与打印机、绘图仪之间的通讯。本文用FORTRAN语言完成实验数据的处理,用C语言实现图形屏幕显示,打印机打印或绘图仪绘制。充分利用了各自语言的优势,具有一定的应用价值。 相似文献
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本文介绍了使用Windows图形设备接口打印机及打印机假说脱机API函数 配置打印机属性的一种方法。由于具有对设备透明的特点,该程序适用于各种打印机进行属性配置。 相似文献
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为解决VxWorks系统下尚无USB打印机驱动的问题,提出了一种基于VxWorks系统的USB打印机驱动软件的设计方法.详细描述了VxWorks系统的USB设备驱动模型、USB打印机驱动的工作原理、驱动软件的设计流程和具体实现.该方法中包括USB打印机驱动软件的主要设计思路和实现过程,实际应用表明该方法能够满足VxWorks系统下的USB打印需求. 相似文献
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阐述了linux下驱动程序的基本概念和中断处理方法,以uClinux下的异步串行口为例,详细分析了串行驱动的实现过程,该方法和思路为在嵌入式linux下访问其他串行通信外设提供了很好的借鉴。 相似文献
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Various mechanisms for hardening the Linux kernel (for example, enforcing system call policies, device driver failure recovery, protection against exploitation of bugs in code) are proposed in the literature. The main problem with these mechanisms is that, they require changes in the kernel code leading to the possibility of introducing new bugs and hence increasing the testing time. We propose a message filter model as an extension to object‐oriented wrappers for the Linux kernel, to dynamically provide various filtering capabilities to the kernel. This model works as a comprehensive framework for specifying system call policies, handling device driver faults, protecting the kernel against exploits of bugs in code etc, without modifying the existing kernel code. This considerably reduces the possibility of creating new bugs in the kernel code. We have integrated policies for system call interception and device driver failure handling, into the Linux kernel (2.6.9), using message filter model. Our experiments show that the overhead due to our filter objects is very low, making it a useful mechanism for providing filtering capabilities to the Linux kernel. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
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This paper describes the EUROShoeE (extended user-oriented shoe enterprise) Project which aims to aid the shoe industry to transform its goods from being mass produced to being mass customized. This paper focuses on the results obtained in the critical field of the flexible handling of limp, synthetic and natural materials. An innovative device that enables a multipoint grasp, firm hold, and gentle transfer of limp items is presented. The design process used fully implemented digital mock-ups and ran extended virtual trims to accomplish the analysis of the prospective fixtures dynamic behavior as a stand-alone device and as an integrated end-effector of a robotic system. The prototype of the robotic device was created, and performance tests were started. 相似文献
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嵌入式Linux的应用环境与台式机中的应用环境有很大的不同.这主要是由外设的多样性和对鲁棒性的需求不同造成的.从这些不同点出发,可以得出结论,在嵌入式Linux中,用户进程直接操作外设是更合理和简便的方式.而这种操作涉及到在用户进程中进行外设地址读写与中断处理.它们必须使用间接的和有技巧性的方法来实现.尤其是中断,要处理好响应时间与嵌套等问题. 相似文献
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It is more important to properly handle exceptions, than to prevent exceptions from occurring, because they arise from so many different causes. In embedded systems, a vast number of exceptions are caused by hardware devices. In such cases, numerous software components are involved in these hardware device-originated exceptions, ranging from the device itself to the device driver, the kernel, and applications. Therefore, it takes a lot of time to debug software that fails to handle exceptions. This paper proposes a lightweight device exception testing method, and a related automation tool, AMOS v3.0. The proposed method artificially triggers more realistic device exceptions in runtime, and monitors how software components handle exceptions in detail. AMOS v3.0 has been applied to the exception testing of car-infotainment systems in an automobile company. The results based on this industrial field study have revealed that 39.13% of the failures in exception handling were caused by applications, 36.23% of the failures were caused by device drivers, and 24.64% were derived from the kernel. We conclude that the proposed method is highly effective, in that it can allow developers to identify the root cause of failure for exception handling. 相似文献
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2008年,又一个新年开始,按照古语:一年之计在于春。芯片厂商以及主板厂商在相互拼杀了2007年之后,2008年又将迎来全新的挑战,而在能够决定全年成败的上半年时间里也就成了厂商相互争夺的焦点。2007年里我们看到了不少新技术的发展,同时也有很多里程碑式的事件发生,而在2008这个充满期待和创新的一年里,又有哪些主板新技术值得我们期待呢? 相似文献