Filtering Wordpress Categories Using an Undocumented Hook

In this article, we will briefly cover Wordpress hooks and use an undocumented one in order to manipulate category listings. After some further digging, while it is not listed on the Wordpress filter list, it appears that this “undocumented hook” is mentioned on the get_terms() function reference. So, we’ll call this a somewhat undocumented hook. Anybody who knows me knows that I love Wordpress, if perhaps not more than any man should love a collection of code. I...

Creating a Basic Template System in PHP

After implmenting this template system in your webistes, you will achieve the following benefits If you have a lot of pages that use the same design. If you want to make a layout change in the header, menu, footer or right section then you don't have to update numerous files. You will have to edit a single php file You will have less vertical scrolling when typing PHP code as the whole section will be replaced by a single line of php (i.e we will use php include function to include...

Multiply in Excel

Multiplication is essential in Excel. Luckily it is extremely easy. To multiply numbers or cells in Excel, we must use a basic formula. All Formula’s in Excel begin with “=” Multiplication is essential in Excel.  Luckily it is extremely easy. To multiply numbers or cells in Excel, we must use a basic formula.  All Formula’s in Excel begin with “=” The asterisk “*” is used as the multiplication symbol between cells. In...

Some Linux admin commands everyone must know

I assume you know how to login and logout from Linux system and one Linux system is available in your network. Since this tutorial is based on admin commands, you should have access to the system with root privilege. For connecting to Linux you need any Telnet/SSH client like PuTTY. If you don’t have one yet, download PuTTY from the following site. http://www.chiark.greenend.org.uk/~sgtatham/putty/download.html OK, open your client, give host name/IP address and press Open button....

Create a KVM-based virtual server in 3 steps

The Linux Kernel-based Virtual Machine (KVM) is free, open source virtualization software for Linux based on the Intel VT-X and AMD-V hardware virtualization extensions and a modified version of QEMU (work is underway to get the required changes upstream). KVM—in the form of kvm.ko, a loadable kernel module that provides the core virtualization infrastructure and processor-specific modules kvm-intel.ko...

Creating Quality Document Scans

While we can all dream about the world of paper being replaced with computers and electronic documents, we all know that is still only a dream.  In the course of doing my graduate studies, I have often needed to make copies of articles and books reserved in the library.  I've grown accustom to scanning these documents and archiving them with the rest of my course work, and in the process I've learned to make high quality scans, suitable for printing if necessary, and still a ...

API overview

At a high level, the libvirt API can be divided into five API sections: the hypervisor connection API, the domain API, the network API, the storage volume API, and finally the storage pool API. All libvirt communication occurs after a connection is created for a given hypervisor (for example, as shown with the open call in Listing 6). The connection provides a path for all other APIs to work through. In the C API, this...

Libvirt and Python

The previous example illustrated the control of domains using the command-line utility virsh. Let's now look an example of domain control using Python. Python was the libvirt-supported scripting language and provides a clean, object-oriented interface to the libvirt API. In this example, I explore some of the same operations that I demonstrated with the virsh utility (list, suspend, resume, and so on). The...

Libvirt and the virtualization shell

Now that I've covered some of the architecture of libvirt, let's look at some examples of the use of the libvirt virtualization API. I start by using an application called virsh (virtualization shell), which is built on top of libvirt. This shell permits use of much of the libvirt functionality but in an interactive (shell-based) fashion. In this section, I demonstrate some of the aspects of VM manipulation...

Means of control

With libvirt, you have two distinct means of control. The first is demonstrated in Figure 1, where the management application and domains exist on the same node. In this case, the management application works through libvirt to control the local domains. The other means of control exist when the management application and the domains are on separate nodes. In this case, remote communication is ...