Writing a kernel module for FreeBSD

FreeBSD 7.0 has already been released. If you are a real hacker, the best way to jump in and learn it is hacking together an introductory kernel module. In this article I'll implement a very basic module that prints a message when it is loaded, and another when it is unloaded. I'll also cover the mechanics of compiling our module using standard tools and rebuilding the stock FreeBSD kernel. Let's do it!

Create a simple application with Hecl

These days, almost everyone has a cell phone; cell phones keep getting faster, smarter, and more capable, yet relatively few applications exist for them. The Hecl programming language makes it easy to script applications for your cell phone—with just a few lines of code, you can create applications that you can carry with you, everywhere.

Easy cell phone applications with Hecl

UPS (Uninterruptible Power Supply) installation and configuration

An inexpensive way to prevent unscheduled downtime or data loss due to power problems is with a UPS or Uninterruptible Power Supply. However, a UPS by itself is not enough for proper operation. Hardware, software, and configuration together make up a UPS system that will recover from unexpected power loss or power fluctuations that can damage systems and peripherals.


Beginners guide to database administration tools

Welcome to an introduction for the beginner to the basic manipulation of the MySQL database with free software. The purpose of this article is to show how universally straightforward it is to get started with installing and applying a high-grade enterprise ready database like MySQL, and to learn how to manipulate it via numerous free software approaches.

Virtualization in OpenSolaris

Recently there’s been a lot of news about OpenSolaris, more specifically in reference to the great progress made by virtualization technologies in it. In this article, I will exam some of these technologies, and compare them with the state of the art on other platforms.


OpenSolaris’ Zones is a mechanism that provides isolated environments with a subset of the host operating system’s privileges, allowing applications to run within the zone without any modifications (Xen is also capable of this). This makes zones useful for server consolidation, load balancing and much more.

How to get the best out of the history command in GNU/Linux

Anybody who has used the command line extensively to navigate, understand and configure GNU/Linux will know that in the course of a few months’ work it is possible to build up an extensive history of used commands. This necessitates some pro-active management to get the best out of it. Here are some tips to make the most of the history command.

How to back up your Master Boot Record (MBR): fail to prepare or prepare to fail

Backup, like security, is a well-worn mantra in the world of GNU/Linux—and even the most battle-hardened, street-wise user has, for whatever reason, thought about regular backups after disaster has already struck. It is an all too familiar story. System Administrators, by the very nature of their work, will have that imperative carved on their headstones. For them it will be a way of life. Desktop users, being responsible only for themselves, can afford to be a little more louche about such things. If it all goes a bit “arms in the air” there is no one to reproach them but themselves.

SPIP: Content management for publishers and writers

Content Management System (CMS) software comes nowadays in all shapes and colours, so you can afford to be picky and choose the one that fits your needs. And if you happen to be a writer or an editor of an online magazine, SPIP might be what you are looking for. While SPIP is not as well-known as, say, Joomla, it has a huge following in France, its country of origin. Unlike other CMS applications which cater for a broad user base that needs to manage “content”, SPIP is designed for a more specific audience and purpose.

The "alias" command

You almost certainly have speed dial set up on your home, office and mobile phone. It saves time, ensures against a failing memory and allows you to work smarter.

Devotees of the command line don’t have to be left out in the cold. One of the crown jewels of GNU/Linux is that every user, be he ne’er so base, has at his or her fingertips the kind of power of which even Caligula could not dream. Alright, I’m exaggerating—a little.

How to find .debs (even if you think they don't exist)

One of the biggest strengths of Debian (and derivatives like Ubuntu) is support for the .deb package. After all, it provides a one-click method of easily installing programs. Best of all, these programs are automatically updated via the official Debian repositories. Unfortunately, the official repositories aren’t always the best. Some programs aren’t always up to date (the latest version of Thunderbird is 2.0. However, the latest version in the repositories is 1.5).

Cleaning your OS in Kubuntu and GNOME

So, you’ve now taken the successful plunge and finally let the Microsoft nightmares fade into expensive and unpleasant memories.

You have your brand new, full-featured, Mandriva, Debian, or Kubuntu, free OS running your browser, email, and office, routines through a lovely KDE, or GNOME, desktop that’s simplicity itself to operate.

Next, you work out how to get all your free software repositories enabled and the true “Wow!” experience suddenly begins to hit you right between the eyeballs.

SSH beyond the command line

If you’re an experienced administrator, you’ve probably used SSH to remotely access a troublesome box or your personal computer. For those who don’t know: SSH it’s a great way to fiddle with a computer from miles away as if you were sitting at its keyboard, but it’s also just about the simplest and most secure way to configure your computer to let you access its files from anywhere. You can use SSH on nearly every operating system to transfer files to and from your computer over the internet or a LAN.

Is SSH for more than commands?

Zenoss: a great system monitoring program which tries to do everything right

I was happily hanging out in the sysadmin room of a major ISP around here in Western Australia (no, I wasn't meant to be there, if you really want to know!). Steve, the senior sysadmin in charge of the place, showed me a computer screen (running Vista, but I won’t comment on that) and said "Oh yeah, I'm sure you know about this...". "Yeah, I know Google maps" I answered. He looked at me embarrassed. "Err... actually, we use Zenoss server monitoring here... look close. That's our VPN!" It was a map of their server in Australia.


Subscribe to RSS - Hacking