By: ab

January 9, 2015 11:36 am

3,969 views

LJDT: DOSBox and Game Emulation for Fun

The majority of this series has been very practical, because most of the time I am a dreadful bore and focus on things that are very practical. Want to predictably modify a config file on ten thousand boxes without leaving your computer or manually wasting weeks of your life? Done. Want to read multi-GB files […]

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By: ab

October 30, 2013 10:09 am

5,252 views

LJDT: KVM, Snapshots, and Disk Resizing

Have you ever wanted to resize a disk in a VM and wondered how insanely painful that would be? After all, from the old days of platter-based spinning drives in computers (sorry to those of you still living in those days), before SANs with resizable LUNs, file-backed VMs, and other marvels of recent times, disks […]

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By: ab

August 7, 2013 2:53 pm

4,617 views

LJDT: LDAP Data and Schema Comparisons

Have you ever wanted to compare data between eDirectory trees, or schema between servers, or objects between entirely different directories (OpenLDAP and eDirectory, for example)? It should be possible, of course, as both systems are accessible via LDAP. Still, how does one go about doing this kind of comparison? Well, because you are running on […]

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By: ab

July 18, 2013 11:26 am

16,901 views

LJDT: Reliable Service / Connection Tests; netcat, not ping, is the correct tool

Me: "I cannot get to your site." Helpdesk: "Hmm, let me check. I can ping it, so it must be okay." Me: "No, pinging has nothing to do with access to the site." Helpdesk: "No, you're crazy, I can ping it so it's your problem. Goodbye." If […]

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By: ab

January 7, 2010 3:04 pm

1,725 views

Virtualization: What is required for life, the universe, and everything?

Lately, for a spare project, I have been tinkering with a technology known as OpenVZ. It is (based on my limited understanding) a container-style virtualization technology. A bit of the background is available at various places (http://en.wikipedia.org/wiki/OpenVZ) online (http://wiki.openvz.org/) found via Google, but in a nutshell it is OS virtualization which […]

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By: ab

November 12, 2009 4:10 pm

5,660 views

ECMAScript/JavaScript Development Without a Web Browser

Have you ever been coding Java and suddenly wanted to do something using loosely-typed variables or worked out an issue with a little less Java-ness? Have you ever wanted to take advantage of the familiarity people have with some languages (ECMAScript/JavaScript) while still using something that is not a web browser as an environment? Have […]

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By: ab

October 8, 2009 4:27 pm

3,917 views

LJDT: The 'watch' command

Do you ever find yourself running a command, pressing the up-arrow, then [Enter], then the up-arrow, then [Enter], then the up-arrow.... this is a great exercise that will get your fingers used to typing random odd key sequences without your eyes paying attention, but otherwise it's a complete waste of time. A command I have […]

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By: ab

September 28, 2009 4:13 pm

4,583 views

LJDT: Base64 Encoding

So going back to the bit about encoding and enciphering consider an early use of encoded data, the ROT-13 encoding. This was done back long before computers came into being, unsurprisingly, for political purposes to hide data from untrusted parties while transferring it between two other trusted parties. The name comes from the word Rotation […]

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By: ab

September 8, 2009 1:54 pm

3,609 views

LJDT: Workspaces

For a while now I have taken for granted the marvelous functionality commonly referred-to as "workspaces" in the X window system. Anybody using a graphical interface with X already probably has this functionality present by default and in many distributions the feature of multiple workspaces is even enabled by default The idea behind this […]

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By: ab

August 21, 2009 2:20 pm

2,645 views

LJDT: Installed RPM Size

Sometimes I find myself wondering how big an installed RPM's files really are. Use a simple script to do all of the calculating of file sizes, plus see how to recreate the RPM from the system where the package is installed in the latest addition to Linux Just Does That. So first a refresher on […]

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