When debugging and optimizing programs, developers sometimes need to generate and investigate into the assembly generated by the compiler. Generating a mixed source and assembly list will help a lot for debugging and optimization. gcc can achieve this by working with the assembler. Generate assembly list mixed with the source code Just add these gcc…
The apache’s default “404 Error not found” page seems ugly. And may some hosting service put theire ads in it. We can add some entry in .htaccess to change the defualt 404 error page. This method can also be used for some other error codes. A list of the server returned codes can be found…
With a list of servers, it is common that one or more are down or crash. Lots cluster management tools can detect the aliveness of servers. However, it can be easily done with ping with a Bash script. I summarize the script that I used and share it here: check-alive-server.sh. Usage: usage: ./check-alive-server.sh file Each…
Shutting down servers is a common operations for managing a cluster. However, if this server is configured to a Xen Dom0 and has Xen VMs (DomUs), the VMs should be shutdown first to avoid data lost on these VMs. xm supports a -a option to shutdown all VMs: # xm shutdown -a Add the -w…
I frequently run some commands/scripts on a batch of servers whose IPs are already collected in a file. I usually use a simple loop and call the ssh to run these commands remotely and automatically. This operation, however, is common and can be abstracted into a separate script. Here is the script that I come…
With Emacs, I feel happy. I love the rich functions of Emacs, such as compiling, quickly jumping to the lines with compilation error and debugging with gdb, and more. I ever wrote small tips posts about Emacs before. But it is a good idea to put them together and keep adding new ones. Here comes…
QT and GTK applications use different settings for cursor styles. This makes the mouse cursor styles for QT applications in the GNOME / MATE desktop environment or GTK applications in the KDE desktop environment look different with other programs. In the post [[configuring-mouse-cursor-style-for-gtk-applications-in-kde-desktop]], we talked about how to configure the mouse cursor style for GTK…
`diff` and `patch` are tools to create patches and apply patches to source code, which is widely used in the open-source world, such as Linux kernel and application. patch: applying patches To apply a patch to a single file: $ patch < foo.patch If the foo.patch does not identify the file the patch should be...
XPS files is a format from MS on Windows. Evince can view some XPS files, but fails to view some. To view XPS files generated on Windows on a Linux system, we can use mupdf. It works very well. I like it much especially in the situation that Evince fails to open the XPS file….
An introduction to the general method of installing Domain-U on Xen is introduced here: Setting Up Stable Xen DomU with Fedora: Unmodified Fedora 12 on top of Xenified Fedora 12 Dom0 with Xen (this is a general introduction, some details are changed, such as ‘xl’ replacing ‘xm’, LVM backing the disk for higher performance. But…
Fedora Linux starts to use systemd to manage system service. The /etc/inittab is no longer used by systemd. The old method of editing /etc/inittab to change system runlevel does not work anymore. This post introduces a “manual” way to change the boot levels. For the general method, please check https://www.systutorials.com/change-systemd-boot-target-linux/. systemd uses ‘targets’ instead of…
I ever discussed Starting KDE from Command Line by startx for KDE and GNOME. Recently, I installed MATE desktop on Fedora 17 and am very happy with it—dear, Gnome 2 is back. However, I checked the /etc/X11/xinit/Xclients script which is called by ‘startx’ and it only includes ‘startkde’ and ‘gnome-session’ without support to MATE. But…
Copying some text to a new file is a common operation on Linux. I usually do this by opening the file with ‘vim’, pasting the text in ‘vim’, and then saving the file. I learned a more efficient and quicker way from my advisor during one discussion with him when I show him some results….
The new development of Xen and Linux kernel make it easy to install Xen on Fedora as the Domain-0 now. This post uses Fedora 17 as an example platform to introduce how to set up Domain-0 on Fedora Linux. Compared to our old method (https://www.systutorials.com/setting-up-stable-xen-dom0-with-fedora-xen-3-4-3-with-xenified-linux-kernel-2-6-32-13-in-fedora-12/) which requires manually compiled Xen and patched kernel, the current…
Linux booting is usually controlled by Grub or the new Grub2. Setting the default booting entry is a frequent operations. Here, we introduce how to set the default entry in Grub2 and Grub. Setting the default booting entry in grub2 Note1: With some version of grub2, the grub2-set-default method and the script below may not…
We may drop the file system caches on Linux to free up memory for applications. Kernels 2.6.16 and newer provide a mechanism via the /proc/ to make the kernel drop the page cache and/or inode and dentry caches on command. We can use this mechanism to free up the memory. However, this is a non-destructive…
This post introduces how to erase / blank / format a DVM+RW media on Linux in the command line. First, you need to find out the device of the DVD/CD+RW drive on your Linux box. For example, on my box with Linux 3.3.4 kernel, my DVD/CD+RW drive is /dev/sr0. You can also see what the…
MPlayer is a universal (nearly) movie/music player on Linux and many more systems. It’s also my favourite player and MPlayer plays movie or music files in any format that I drop to it. Now, let’s take a look at how to use MPlayer play DVD. MPlayer plays “DVD” in many formats: DVD disks, ISO files,…
This post compiles a list of tutorials on the Internet for Linux beginners. Linux beginners usually get headache from the “seemed” complexity of the Linux operation system. But once they get into the gate and get familiar with Linux, they will love it. UNIX Tutorial for Beginners “A beginners guide to the Unix and Linux…
Vim is my favourite text editor and I also prefer to use Vim to compose Email. I ever used Vim as Thunderbird’s External editor with the help of plugin. I started to use KMail as my email client on KDE and I find it is not hard to configure KMail to use Vim as email…