The Linux kernel has a generic driver for a graphic framebuffer named vesafb on intel boxes. It provides a nice large console for most of modern displays. Setting VESA modes for Linux kernel with 32-bit and 16-bit boot protocol are different. We introduce both methods here. Linux kernel with 32-bit boot protocol For machine with
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Tag: C
Creating a Child Process using posix_spawn in C in Linux
Posted onThe posix_spawn() and posix_spawnp() functions create a new child process from the specified process image constructed from a regular executable file. It can be used to replace the relative complex “fork-exec-wait” methods with fork() and exec(). However, compared to fork() and exec(), posix_spawn() is less introduced if you search on the Web. The posix_spawn() manual
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How to Create Fedora 20 Domain-U on Fedora 20 Domain-0
Posted onIn this post, creating a file-backed virtual block device (VBD) and installing Fedora 20 in the Xen DomU via internet will be introduced. This domain is created on a Fedora 20 Dom0 as introduced in https://www.systutorials.com/installing-xen-on-fedora-20-as-domain-0/. For better performance, you may consider using LVM backed VM. Create file-backed VBD The actual space of VBD will
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How to Catch the Signal Sent by Kill in C on Linux
Posted onPrograms may want to catch the kill signals sent by the kill command in C programs on Linux so that it can gracefully shutdown itself before it is killed. For example, I have a daemon progd running, and it may be killed by pkill progd. The progd may want to save some in-memory state to
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Making Emacs Start Up Faster
Posted onI use Emacs in terminals and start/close Emacs frequently as needed like in a file checking-editing-closing loop. However, Emacs seems take some time to start up especially some heavy modes are used. How to make Emacs start up faster? (If you just want the solution/script first, find the command in the summary section.) My solution
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How to Set Up A Gitolite Git Server – A Ten-Minute Tutorial
Posted onI ever introduced seting up git server using SSH or gitosis. However, gitolite is the way to go for managing git servers if you want an lightweight authentication layer. gitolite provides many very usefull features which can control each user’s right on each branch. I set up one gitolite git server and am very happy
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RAII-like Error Handling and Resource Management in C
Posted onError handling and resource management are pervasive in programs. RAII originated in C++ is great. With RAII, it is much easier to write easy-to-read code that allocats/deallocats resources in the constructor/destructors. By representing a resource with a local object, we are sure that local object’s destructor will release the resource and will not forget to
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Statically Linking C and C++ Programs on Linux with gcc
Posted onBefore statically linking you C and C++ programs, you should be aware of the drawbacks of the static linking especially with glibc. There are some good discussions already: with glibc you’re linking static programs which are not really static and some others here and here. That said, you can choose to statically link C and
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Linux UDP Programming Tutorial
Posted onUDP has its advantages over TCP, such as being relatively lightweight and receiving one packet per read call (recvmsg), although the programmers need to handle related issues, such as packet lost and out-of-order packets delivery. This post gives information and references on how to write UDP programs in a C/Linux environment. What is UDP Check
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How to Measure Time Accurately in Programs
Posted onIt is quite common to measure the time in programs using APIs like clock() and gettimeofday(). We may also want to measure the time “accurately” for certain purposes, such as measuring a small piece of code’s execution time for performance analysis, or measuring the time in time-sensitive game software. It is hard to measure the
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How to Copy Output of Commands in a Linux Terminal to X Selection or Clipboard
Posted onxclip is a tool to copy the copy the output of commands from a command line in a terminal to X selection or clipboard. It connects the command line interface and the X selections (clipboard) and is a very useful tool. For example, processing some text in vim in a terminal and then copying it
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Auto Keyboard Pressing Using xvkbd in Linux
Posted onAutomatic keyboard pressers are useful tools. However, it seems that there is no simple and easy to use automatic keyboard presser for Linux if you search for “automatic keyboard presser linux”. After some digging, I find using the xvkbd with some options is a good method for automatic keyboard pressing though it is not designed
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How to install no-ip client on Linux
Posted onnoip2 is a dynamic update client for No-IP to keep your current IP address synchronized with your No-IP domain, no matter whether the IP is dynamically requested via DHCP or static assigned. Furthermore, with the domain name, we can host site using a “static” domain whose CNAME points to the No-IP domain. noip2 is a
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ASCII Table and ASCII Code
Posted onThis post gives the ASCII table and ASCII code with ASCII control characters and ASCII printable characters and a tool to convert ASCII codes to ASCII characters. Introduction to ASCII table and ASCII code ASCII stands for American Standard Code for Information Interchange. An ASCII code is the numerical representation of a character since computers
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C++ Reference and Styles
Posted onC++ References Reference of the C++ Language Library, with detailed descriptions of its elements and examples on how to use its functions: http://www.cplusplus.com/reference/ C++ reference: http://www.cppreference.com/w/ C++ Styles I compile a list of C++ styles on the Internet. http://geosoft.no/development/cppstyle.html http://google-styleguide.googlecode.com/svn/trunk/cppguide.xml http://www.mactech.com/articles/develop/issue_02/C%2B%2B_Style_Guide_v007.html http://www.cs.uga.edu/~dkl/1302/Fall99/style.html
How to Print Notes on a PDF File with Acrobat, Adobe Reader and Foxit Reader
Posted onPrint PDF with notes is not that straightforward, especially when you want specific styles of the printed notes/comments. In this post, we introduce how to print notes on a PDF file with Acrobat, Adobe Reader and Foxit Reader. Acrobat The detailed method is posted on Adobe’s blog: Printing Sticky Notes on a PDF. Excerpt of
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Set Up SSH Server on Windows XP
Posted onIt is useful sometimes to set up a sshd server on a Windows. One example is using remote forwards tunnel to pass through the firewall. My platform is Windows XP SP3. The sshd server is sshwindows. It can be dowloaded from here: http://sshwindows.sourceforge.net/ . The version I use here is 3.8p1-1 20040709. It is really
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Java与C++在语言方面上的不同
Posted on1，Java抛弃了头文件、预处理机制、goto语句和多维数组。 2，Java不支持指针。 3，Java抛弃了联合体和结构体。 4，Java不支持独立函数。所有函数必须在类中声明。 5，Java不支持多重继承，可以使用接口模拟多重继承。 6，Java不支持运算符重载。 7，Java中布尔型不再用整数来代替。 8，Java中主函数必须有一个字符串类型的参数。 Java抛弃的C++中的这些机制和结构多数都是“危险”的，减少了语言的复杂性，增强了安全性，虽然在一定程度上减少了其灵活性。
Floating Point in Bash Shell
Posted onIntegers are natively supported in Bash shell. However, what if we use floating point in Bash shell? The short and direct answer is using ‘bc‘ command – “An arbitrary precision calculator language.” Just run bc and enter some floating point calculation expression, such as “1.2+8.2”, bc will give the result. In a script, we certainly
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Hashing Library for C
Posted onI try to find some Hashing libraries for C and find several good ones. The hsearch function in the GNU C library. There are other methods to organize information which later should be searched. The costs of insert, delete and search differ. One possible implementation is using hashing tables. The following functions are declared in
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