Archive for the ‘Backend’ Category

File Under: Backend

Learn Enough Unix for Your Resume

On the resume that convinced Wired to hire me, I said that I knew enough about Unix that it didn’t scare me anymore. This wasn’t exactly true. Unix was still a chilling concept for me when I arrived at the San Francisco office armed with a copy of Unix for Dummies. The managing editor steered me to my desk and instead of the Macintosh I was hoping for, there sat a purple SGI machine.

I realized then that I needed to learn a lot about Unix fast. Initially I tried using SGI’s graphical user interface, which mimicked the Macintosh desktop fairly well, but soon realized that it was just too damn slow. So I stole some better Unix books from the engineering staff and found a nice Unix expert to help me. Soon I was cp-ing, mv-ing, and chmod-ing like lightning. Unix still gives me the occasional nightmare, but basically I love it. It’s fast, it makes sense (most of the time), and anyone can figure it out with a little work. Plus, it looks great on a résumé. If you can convince a prospective employer that you have a working knowledge of Unix, you’re one step ahead of everyone else who is too scared even to try figuring it out.

I’ve put together a very basic explanation of Unix to get you started. But first, a warning. Unix is very powerful. The wrong collection of keystrokes can blow away files that you’ll probably never be able to recover, so practice on sample files before you move on to anything important.

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File Under: Backend, Security

Set Up a Linux Firewall on Your Network

Go outside and pop the hood of your car. You should see a thick metal barrier at the back of the engine compartment. This is called the firewall. To see how it works, poke a small hole in the fuel line so that a tiny amount of gasoline starts dripping on the engine block. Now close the hood, start the car, and head out on the highway (Some of you may choose to save life and limb (and time!) by merely visualizing this exercise).

If you have positioned the puncture correctly, within a few minutes the escaped gasoline should ignite and cause a small engine fire. At this point you may see smoke emerge from the engine compartment. Continue driving. You should be able to proceed a considerable distance before the heat becomes uncomfortable and toxic fumes and flames start to enter the passenger compartment.

The reason you can drive so far with a flaming engine is because the firewall is a highly effective barrier between the engine compartment and the passenger compartment. If your car had no firewall, the engine fire would have already melted the dashboard electronics and plastic, destroyed the upholstery, and toasted you to a crisp.

Now. Pull over and very carefully extinguish the fire.

A similar principle can be applied to networked computers. Picture your machine as the cozy, tricked-out interior of your automobile, and the outside world as the dirty but powerful engine that makes it go. It won’t do to have the vulnerable components of your network exposed to the engine’s maliciously raging heat — it’s best to install a firewall.

Let us abandon our weakening metaphor here before it carries us into a ping-pong tournament without a paddle. A firewall, in the networking sense, is a machine that straddles the interface between a private network and the Internet at large, and follows predetermined rules for allowing certain traffic to pass, while blocking traffic that’s unwanted.

So, how to get yourself one of those disaster-averting firewalls? You can start by reading on.

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File Under: Backend, Programming, Software

CVS for Beginners


OK. You and ten of your closest pals have decided to work on the greatest-ever web page/Perl script/whatever. You all want to work on the same file from the same location at the same time. Then when you’re good and ready, you’ll roll out releases of the code.

Does it sound like a logistical impossibility? Well it’s not if you have the right tool — a source control system.

A good source control system is the secret behind any successful web development project. If you look at any large-scale software development project, you’ll see a source control system at work.

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File Under: Backend

Set Up Dynamic DNS

Now that everybody* has a home broadband connection, the need for IP addresses is a growing concern. With the rollout of IPv6 still pending, IP addresses are a limited resource. ISPs are understandably reluctant to hand a static IP address to every US$50/month subscriber. Some ISPs do, and some allow you to pay extra for one. For the most part, though, they’re a bit of a pain to get.

* not everybody

This is not a problem for the majority of home broadband users. Their needs — efficient web browsing, quick downloading of large files, “always-on” service, productive hours spent on WoW or AIM — are met admirably by the service provided. Giving them a static IP address, if they even noticed, would just result in increased security headaches as their insecure Windows machines suddenly had fixed addresses, making them easier to break into.

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File Under: Backend

Set Up a Home Server

Setting up a home server running an open-source operating system is a popular and useful activity. Useful in what ways, you may ask. You could use it to run a website (I use a home server to power my world travel website, luxagraf.net), collect and send e-mail messages, store your OpenID credentials or serve your music around the home.

As you can guess, we have a great many tutorials on Webmonkey for getting the most out of that machine in your closet. But here are some guidelines for the hardware side of it.

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