Blog of Zane Ashby

Idel IRC Client

zane.a@demonastery.org (Zane Ashby) — Sun, 09 Jun 2013 19:35:00 +1200

I made an IRC client. In fact for the past few months I've been doing a lot of client-side work using AngularJS.

I can't possibly praise AngularJS enough; this HTML and JavaScript framework from Google has completely changed the way that I write for the web. It's great for developing rich, responsive interfaces, and has a fantastic community (#AngularJS on Freenode). Best of all, it's perfect for writing large testable and maintainable JavaScript apps.

As a daily user of IRC, I've built a ton of bots, and frequently bounce between clients (currently using hexchat through znc ). I don't have any spectacular needs in a client though, so I decided that this would be a cool opportunity to build my own using 100% client-side web technology.

Being evil with narrow-to-region-indirect

zane.a@demonastery.org (Zane Ashby) — Mon, 22 Apr 2013 16:55:00 +1200

Following up on my last post, here is how you can define a custom operator for evil-mode (which is where the true power of Vim comes into play).

It is trivially easy to set this up using evil-define-operator. Here is the code:

(evil-define-operator evil-narrow-indirect (beg end type)
  "Indirectly narrow the region from BEG to END."
  (interactive "<R>")
  (evil-normal-state)
  (narrow-to-region-indirect beg end))

Now all that is left is to bind it to a key! I'm using "m":

(define-key evil-normal-state-map "m" 'evil-narrow-indirect)
(define-key evil-visual-state-map "m" 'evil-narrow-indirect)

Eval all of this, and now we have everything in place to say "mit" or "mi}", etc.

Narrow-to-region-indirect for Emacs

zane.a@demonastery.org (Zane Ashby) — Fri, 19 Apr 2013 01:25:00 +1200

I'm once again an Emacs convert. I used Emacs a fair bit back in 2011 as my main editor (when vimpulse was a viable alternative to native Vim and I forced Emacs upon myself for as long as I could), I even wrote a few posts about extending it. But eventually I gave it up as it was starting to feel sluggish with everything I was throwing at it (looking back, it was more than likely just a bad minor-mode or two).

However in the time I've been away from Emacs I feel as though the eco-system has really modernized. We now have emacs-starter-kit and prelude to get you up and running quickly with sane defaults, we have package.el since Emacs 24, along with MELPA as a maintained repository of elisp packages, and even a set of decent color themes! And of course I can't leave out evil (the extensible vi layer) which I could not do without.

Litc, a Literate-style Program Compiler

zane.a@demonastery.org (Zane Ashby) — Fri, 01 Mar 2013 15:45:00 +1300

CoffeeScript v1.5.0 was released a few days ago. One of the new features touted in this release was the addition of "Literate CoffeeScript". This was an additional mode in the compiler that allows it to process files ending with .litcoffee that contain both Markdown and CoffeeScript together to form a literate program.

Literate programming, introduced by Donald Knuth, is a technique of writing programs in the natural order and style that you would use if you were to verbally describe the way a program works. Literate programming is designed to break the order of source code required by traditional compilers. It can be fun to build programs in this way by simply starting a document with a description and a list of headers for each feature.

I thought it was really cool to see this in CoffeeScript, but it made me wonder why exactly this needed to be a CoffeeScript extension and not another tool available for any language. So I wrote a small utility to do exactly that.

There are several utilities out there already for assisting with literate programming, however I have a crazy case of Not Invented Here so I decided it would be fun to write my own take on the idea.

Hello, Leap World!

zane.a@demonastery.org (Zane Ashby) — Wed, 23 Jan 2013 00:20:00 +1300

By now, most people that keep up to date with tech news will have heard about the small $70USD 3D motion sensing controller by Leap Motion (make sure to see the demo if you haven't already) that is claiming to open up some incredible possibilities for the future of computer input.

In a nutshell, the Leap is a device similar to Microsoft's Kinect; it uses a pair of infrared cameras and some clever math to build a point cloud and detect hands + fingers + tools inside of this point cloud and return information about these using a simple API. Though where the Leap really excels is in speed and accuracy. This thing is fast, in my brief test on an i7 CPU and USB3 connection I was seeing between 2-5ms of latency, which is perfect for an input device and quite a feat considering the accuracy, which is right down to the millimeter level.

WacomWebPlugin PKGBUILD

zane.a@demonastery.org (Zane Ashby) — Sun, 13 Jan 2013 19:10:00 +1300

After a short stint of hacking on WacomWebPlugin I've tagged the repository as v0.1 and released my first ever PKGBUILD for ArchLinux. If you have a Wacom device on Linux then go and try it out!

Since the last update:

Device id is no longer hardcoded.
The eraser device is now also used.
No more phantom presses since we use the proximity events to change the pen type.

All in all the plugin is feeling a lot more stable than before.

WacomWebPlugin Updated

zane.a@demonastery.org (Zane Ashby) — Tue, 08 Jan 2013 14:00:00 +1300

Nine months ago, I published WacomWebPlugin , a project aiming to implement the Wacom Tablet Plugin API on the Linux OS where the official browser plugin isn't available. The plugin allows websites to make use of tablet features such as pressure-sensitivity. The most well known user of this API is DeviantART's Muro web app.

My initial proof-of-concept was hacked together using the FireBreath framework, which makes it easy to implement cross-platform and cross-browser plugins. I was able to get enough of a plugin working to allow basic pressure-sensitive drawing on Muro. However, the code was crap and was full of repetition and global state. I published it nonetheless.

Over the last couple of days I've had some interest from a curious Githubber wanting to port his notetaking program (hoodle ) to the web, so I've decided to revive and rewrite the project. After updating my copy of FireBreath and being unable to compile the plugin without some modifications, I realised that I don't really need the large FireBreath dependency after all (the plugin will likely only ever target Linux).

HashTWM Updates

zane.a@demonastery.org (Zane Ashby) — Fri, 21 Dec 2012 16:30:00 +1300

For the first time in.. a while, I have had a sudden inclination to do some updates to HashTWM . So far I've mostly just done some cleanups and code style changes, but one major feature that I've just added is the ability to whitelist a few window classes and have HashTWM only tile those windows, as opposed to all (or blacklisting). I believe this was a feature suggested to me a while ago that I had misinterpreted (durr). Oh well it is finally done and is very useful :)

Just in time for the end of the world.

What's Next.

I have conceived many pet projects with the goal of replacing HashTWM in the long run, but I think that the best chance that HashTWM has is for me to port features from those prototypes back into the mainline.

The major features I will be wanting to add are:

A scripting language of some kind, at least as a way of enabling more powerful configuration. Leaning towards a Scheme (maybe Chicken).
More powerful keybindings (and even chaining) using a keyhook (from HackWM ).
Some kind of remote, for external displays/control. This should keep it nice and light while allowing you to see tags, and other useful info.

Hopefully as my Windows laptop gets more use in the coming months I will be able to contribute more time to HashTWM. Thanks to everyone that has been following the project and still has an interest :)

Happy Holidays!

"Monkey Patching" in Ruby

zane.a@demonastery.org (Zane Ashby) — Thu, 29 Nov 2012 18:00:00 +1300

I don't use a whole lot of Ruby in my day to day work, but it is a language that is very quickly growing on me for several reasons.

As I further integrate jekyll into my website pipeline, I'm finding more of a need to extend it with plugins, no surprises there. One particular plugin that I was previously using is jekyll-assets . I have since moved over to jekyll-asset-pipeline as it better serves my needs, but this article remains.

Jekyll-assets provides a sprockets based asset pipeline, closely mirroring the pipeline present in Rails. The asset pipeline allows me to quickly concatenate and process multiple JavaScript and CSS files into single output bundles; reducing the amount of requests made when loading a page, and thereby improving load time. I also use it to build CoffeeScript and SASS stylesheets.

What is Monkey Patching?

Monkey patching refers to the ability to modify existing code at runtime and outside of regular means (ie. editing the original source). This can be useful as a way to add often-needed functions to a basic type, and in the case of Ruby where everything is an object, this can even include adding methods to numbers themselves (which are of the FixNum class), for example:

A Jekyll hook for Gitolite

zane.a@demonastery.org (Zane Ashby) — Tue, 20 Nov 2012 21:39:00 +1300

I'm back again to share a quick hook for updating a jekyll based website or blog upon pushing to gitolite .

What is Jekyll?

jekyll is a small website/blog generator written in Ruby. It takes several templates, pages and posts, and combines them into a fully functional site ready to be served by any webserver.

I've used Jekyll to power this blog for a few months now as the ability for me to write posts in Markdown and keep them stored in git is highly valuable for me. Previously I have been building the site locally and pushing the generated content to my VPS, but this is suboptimal and causes massive changesets (as you can imagine). Time to move that processing to the server where it rightly belongs.

Live project documentation in Redmine

zane.a@demonastery.org (Zane Ashby) — Sun, 18 Nov 2012 13:27:00 +1300

Continuing this series of posts on Gitolite hooks, this time I will be adding live project documentation to Redmine, using Doxygen.

Background.

Documentation is often as important as code itself, especially when working in a team or introducing new programmers.

But keeping generated documentation up to date is a pain, and it really shouldn't be.

At CodeShack we use Redmine as our project/task tracker. From here our developers have access to relevant projects with the ability to directly view the repository for that project, so why not add a "Documentation Tab" too?

A SkypeKit transport for DCBot

zane.a@demonastery.org (Zane Ashby) — Mon, 29 Oct 2012 22:30:00 +1300

A couple of posts back I walked through putting together a (somewhat) decoupled bot system using ZeroMQ and a bunch of scripts in various languages.

The transports I supplied as part of the example were for IRC and a local console. At the time I had also written a very basic SkypeKit transport but had decided not to release it as I was unsure about the terms and conditions surrounding this type of use (it previously had banned "server-side" usage, and likely still does, however my interpretation of that is a little fuzzy). So while I'm still unsure about it I figure there's no harm in releasing it with a disclaimer that you use this at your own risk.

A Redmine hook for repo updates

zane.a@demonastery.org (Zane Ashby) — Sun, 28 Oct 2012 13:50:00 +1300

In my last post I showed how to build a simple hooking system for gitolite Now I just want to share a very small script used to update Redmine changesets when you push to a git repository.

Background.

Redmine has an excellent repository viewer built in. It is even capable of reading through commit messages and closing tickets based on the contents, a very useful feature that we are taking advantage of. Due to this, having a team member commit a bug fix can fire off an email to the person who originally created the bug ticket, or at least it should.

The problem.

By default Redmine only processes these repositories when you visit the repository tab in a project. This makes sense, how else is it supposed to know when you've actually updated the repository? The most common solution to the problem is to set up cron to run a task to tell Redmine to update all repositories. Excellent, we can use this in a hook and make it all on demand and avoid wasting precious cycles ;)

A hooking system for Gitolite

zane.a@demonastery.org (Zane Ashby) — Fri, 07 Sep 2012 23:42:00 +1200

gitolite is a wonderful tool that makes hosting git repositories pain-free. Gitolite also supports adding custom hooks but for whatever reason I found it a little hard to get my head around for what I wanted (a post-receive hook per repository).

For that reason I've written up a guide to setting up custom post-receive hooks for your repositories to automate various actions. Let's get started.

Building a decoupled IRC bot. Part Two: Functionality

zane.a@demonastery.org (Zane Ashby) — Sun, 05 Aug 2012 00:44:00 +1200

Welcome to part three of this series. In this post I'm going to show how easy it is to turn what is currently a completely useless bot into something genuinely useful to you and your team.

Why Use a Bot?

We interact with many systems every working day, and very often we are doing this as part of a larger team.

Bots in whatever shape or form allow us to coordinate, automate, and enrich communication amongst our team.

In this example we will build in the ability for our bot to notice a bug ID within a message and return some data about that bug.

Building a decoupled IRC bot. Part One: Transports

zane.a@demonastery.org (Zane Ashby) — Sun, 22 Jul 2012 00:20:00 +1200

Welcome to part two (well, "One" because we started at "Zero") of this series. One thing I realised after writing the first part is that I didn't really provide a definition of decoupling (which is kind of important).

What is Decoupling?

When referring to software, it is the process of removing coupling or dependencies between individual parts of a system. When decoupling is achieved correctly, the failure of one part of a system should not result in the other parts failing.

The bot that we are implementing is only loosely decoupled, in the sense that one part failing won't cause the bot to lose a connection (unless the transport is the part failing of course).

Building a decoupled IRC bot. Part Zero: Core

zane.a@demonastery.org (Zane Ashby) — Mon, 16 Jul 2012 08:30:00 +1200

In todays episode of demonastery.org I'm going to build yet another IRC bot!

For this series however I am going to focus on the idea of decoupling. That is to say, separating out the functionality of the bot from the transports by way of a message queue (in this case we will be using ZeroMQ). By the end of this three part series we will have a bot that is mostly decoupled, allowing functionality and transports to be added and removed on the fly. Each part of this bot can run on separate machines and will be written in different languages!

Lambda concealing in Vim

zane.a@demonastery.org (Zane Ashby) — Fri, 13 Jul 2012 13:30:00 +1200

One of the features I miss the most from Emacs when using Vim is the ability to mask certain strings as other strings (eg. Unicode symbols). The most often used case for this is when dealing with Greek characters (such as lambda), or when writing Tex.

Luckily, a guy named Vince Negri wrote a patch for Vim to provide a "Conceal" functionality. Most of the examples I've found for using this functionality deal with either Tex, or only with certain languages. It turns out it's pretty easy to force it for all file types though, simply place this at the end of your .vimrc:

au VimEnter * syntax keyword Statement lambda conceal cchar=λ
au VimEnter * hi! link Conceal Statement
au VimEnter * set conceallevel=2

And enjoy your beautiful new λ's :)

The Perfect Android Emulator

zane.a@demonastery.org (Zane Ashby) — Thu, 08 Mar 2012 00:00:00 +1300

I've recently been getting further into Android development and as most people that have touched the official SDK know, the Android emulator is giant pain in the ass to work with. The reason it is slow is a combination of factors (ARM - x86 conversion, slow screen updates), but fortunately thanks to the Androidx86 project you don't have to live with it any more.

The Androidx86 project aims to port AOSP to the x86 architecture and supply drivers for common devices; it does this well and is getting better with every release. I'm going to show you how to set up the perfect Android VM for development (this assumes you have the rest of the SDK working fine, including access to adb from the command-line).

LogPixels DPI hack

zane.a@demonastery.org (Zane Ashby) — Wed, 04 Jan 2012 00:00:00 +1300

Here's a handy tip for those netbook users out there in dire need of more screen estate. You can force a DPI value of lower than 96 by using the Windows registry. To do so open regedit, navigate to HKEY_CURRENT_CONFIG/Software/Fonts/LogPixels and change the decimal value from 96 to something lower such as 80. Then log out and back in and you will see the changes. I'm using a value of 80 on my netbook and it is about the most that I will drop it while still keeping things (half) readable. You will notice that it really hinders the readability of fonts as well as having some strange bitmap scaling artifacts, but if you're like me and can adjust to it then the extra screen space gained is well worth it :)

You can view a side by side comparison of the my desktop with LogPixels at 80 and at 96 by viewing this imgur album.

Docstrings in my Chicken?

zane.a@demonastery.org (Zane Ashby) — Sun, 13 Nov 2011 00:00:00 +1300

Here's a little bit of amateur code to enable the use of docstrings in Chicken Scheme. I haven't written any Scheme in a few months and don't have any formal training in the ninja art of explicit renaming macros so I'd appreciate any feedback from Scheme veterans:

;;; Docstrings for Chicken!

;; The hash-table that will contain the procedures and their associated
;; documentation strings as well as their code for later use.
(define *documentation-hash-table* (make-hash-table))

;; Documented define er-macro
(define-syntax (define* form r c)
  (let* ((args-form (second form))     ; (proc args)
         (proc-name (first args-form)) ;  proc
         (doc (third form))            ; "The docstring"
         (body (drop form 3)))         ; (everything else)
    (hash-table-set! *documentation-hash-table* proc-name (list doc body)) ; insert the doc and code body
    `(,(r 'define) ,args-form ,@body))) ; Define the procedure as normal

;; Example of a documented procedure, will print a nice-ish list of documented procedures
(define* (print-docs)
  "Print a list of documented procedures"
  (hash-table-walk *documentation-hash-table*
    (lambda (key val)
      (printf "~a => ~a~n  ~a~n~n" key (first val) (second val)))))

Another example of why Scheme is such a fun language to work with :)

Twitter's Bootstrap

zane.a@demonastery.org (Zane Ashby) — Fri, 04 Nov 2011 00:00:00 +1300

To me, one of the most annoying parts of prototyping a new web application is getting a presentable look and feel up quickly. When I'm prototyping stuff I love to have a good looking interface from the start, even if that interface will be changed before going live.

Recently, Twitter released a wonderful CSS/JS framework named Bootstrap for this exact purpose. As stated it is a toolkit "[...] designed to kickstart development of webapps and sites.". It combines an aesthetically pleasing base styling (based somewhat off of Twitter itself) of HTML elements with an easy to use CSS grid, great browser compatibility, and various optional Javascript modules to extend functionality of things such as Drop-down menus and modal dialogs.

Das Keyboard Ultimate

zane.a@demonastery.org (Zane Ashby) — Wed, 12 Oct 2011 00:00:00 +1300

I took the plunge recently and bought my first mechanical keyboard, the Das Keyboard Ultimate. It was very hard to find someone that would ship one to NZ, but eventually I found AusPCMarket that ships the Das as well as several other "clicky keyboards". The Das is known for being a bit pricey.. the Ultimate set me back $230NZD (incl shipping and GST) at the current exchange rate and was delivered in just over a week. If you need to justify the price by thinking of it as an investment, then do :)

Tiny Memcached Wrapper

zane.a@demonastery.org (Zane Ashby) — Fri, 12 Aug 2011 00:00:00 +1200

No posts in a while huh! Been pretty busy and haven't thought of much to blog about lately. But I've been playing with Memcache and wanted to share a tiny class I made to add easy caching to my PHP projects. This PHP class just provides a nice simple interface to use by extending the Memcached class:

<?php
// Call the class whatever you want
class MyCache extends \Memcached {
    function cache($key, $time, $func) {
        if (($val = $this->get($key)) === false) {
            $val = $func();
            $this->set($key, $val, strtotime($time) - time());
        }
        return $val;
    }
}

Emacs Tip: Vimpulse

zane.a@demonastery.org (Zane Ashby) — Thu, 07 Jul 2011 00:00:00 +1200

One thing I love about Emacs is that it is so extensible. I was an avid Vim user for a long time and it took me several tries to switch to Emacs, but I will never look back. With the Vimpulse addon to the built-in viper-mode, Emacs becomes a powerful Vim impersonator, capable of being extended with Emacs-Lisp.

A lot of my time is spent doing web development, and so strong HTML editing ability is essential in any editor I use. Vim has this amazing concept of text objects which allows you to be very efficient when transforming text; one of the most useful when doing web development is therefore the XML/HTML tag text object. I would use this all the time by invoking cit to change text between a pair of tags. To demonstrate, here's a piece of text you might have sitting in a file:

<title>Hello |World</title>

Now with the cursor somewhere in between the tags (visualized above by the pipe, '|') we can go into command mode and type cit and the above will be replaced with:

<title>|</title>

Ready to be edited!

Well sadly, Vimpulse doesn't have this feature by default, probably one of the very few parts of Vim that it doesn't emulate in fact! (NB. Evil contains emulation for this already) But not to worry, we can just add it in! This is Emacs after all.

Org-mode Conky Colorizer

zane.a@demonastery.org (Zane Ashby) — Sun, 05 Jun 2011 00:00:00 +1200

Just whipped up a little script to colorize my org-mode todo lists for display via Conky. It's bound to be of use to someone so I thought I'd better share :)

Here's a screenshot of it in action, sitting in the corner of my desktop.

Adding FreeType to our Demo

zane.a@demonastery.org (Zane Ashby) — Sun, 05 Jun 2011 00:00:00 +1200

Continuing on from my Chicken Scheme, and OpenGL tutorial, I'm going to show you how to extend it to render pretty FreeType text using the FTGL library. Follow the code below for details as always; it's really easy! :)

Users of ArchLinux can get FTGL with a simple sudo pacman -S ftgl. Debian should be something like sudo apt-get install libftgl-dev.

Alright lets start by loading up the code from last time ...

Org-agenda-sms.el

zane.a@demonastery.org (Zane Ashby) — Thu, 12 May 2011 00:00:00 +1200

So my warmup for today was to rewrite my old org-mode agenda notification code to use Emacs lisp instead of Python. The aim of this code is to check your org-mode agenda for any headings with DEADLINEs and create a vcalendar for each, and then send them to your phone via Clickatell.

More Practical Chicken

zane.a@demonastery.org (Zane Ashby) — Thu, 12 May 2011 00:00:00 +1200

As I love sharing code on my blog, and I love Chicken Scheme, I'm going to share a couple of handy and practical features that I've made use of recently.

Anyone that has used C++ for longer than a few minutes has probably noticed that literal constants (*numbers and such*) often have a suffix attached to them. The most common place that you'll see this is when writing floating-point decimals, ie. 1.0f.

They might seem a little pointless at first, but they have their uses; I swear that I once read of a way to add your own types into the language too.

But anyway, I searched for a way to do this in Chicken too, and it turns out it's really easy (of course!). Chicken provides a function called set-parameterized-read-syntax! that can emulate this functionality quite nicely.

Here's a real world case that I used recently, I wanted to be able to convert from inches into pixels, based on a known DPI (in this case 180). The code to set this up looks like this:

FileTools C++ Class

zane.a@demonastery.org (Zane Ashby) — Sun, 08 May 2011 00:00:00 +1200

Here is the source for the FileTools C++ Class promised a few posts back, which uses inotify to monitor files for changes.

Again we start off with the class header:

CodeTools C++ Class

zane.a@demonastery.org (Zane Ashby) — Sat, 07 May 2011 00:00:00 +1200

As promised a couple of posts back, I will present a C++ class to compile some arbitrary code using GCC and load it into memory.

The code is pretty simple, we start off with the class header:

// CodeTools.hpp

#include <stdio.h>
#include <stdlib.h>
#include <dlfcn.h>

typedef class CodeTools {
public:
    static bool compileString(char*, bool (*callback)(void*));
    static bool compileFile(char*, bool (*callback)(void*));

private:
} *pCodeTools;

Fun with Renoise and Fluxus

zane.a@demonastery.org (Zane Ashby) — Mon, 02 May 2011 00:00:00 +1200

Amidst my experimentations with livecoding I decided to purchase the amazing Renoise Tracker (and overall DAW) while it is on special (30% discount!). My intentions are to play around with Renoise to make music (online and off), and using the built in OSC and JACK support, coordinate the music using Fluxus, and of course be able to respond to it. I am also toying with the idea of using an Arduino or two as input devices. Fun stuff I reckon :P

For anyone wondering how to make Fluxus respond to the Renoise audio, it is simple using JACK:

; If I remember correctly you may need to connect the Renoise
; output to the Fluxus input using something like qjackctl first

(start-audio "renoise:output_01_left" 1024 44100) ; This will tell Fluxus to listen to the left channel..
(gain 1)

; .. and later in your render loop, using the "gh" function you can react to the sound
(every-frame
  (begin
    (scale (vmul (vector (gh 1) (gh 2) (gh 3)) 0.1))
    (draw-torus)))

Pretty neat. Using OSC it is also really simple to control Renoise. First you will want to enable the OSC server in the Renoise preferences, and then you can use the following:

(osc-destination "osc.udp://localhost:8000") ; With the port you specify in the preferences
(osc-send "/renoise/song/bpm" "i" (list 120)) ; Set the BPM to 120
(osc-send "/renoise/transport/start" "" (list)) ; Start playback
(osc-send "/renoise/transport/stop" "" (list)) ; Stop playback

Next up is to get Fluxus working nicely with Emacs.. and I promise some more updates will come shortly (including the code I've promised) :)

C++ Eval? Hell yes.

zane.a@demonastery.org (Zane Ashby) — Sat, 16 Apr 2011 00:00:00 +1200

Recently I've been getting back into live coding, and as part of that I have been experimenting with a simple livecoding framework in C++.

One of my experiments involves using C++ as a scripting language, by compiling code on the fly (using g++, but any compiler should work) into a shared object, and then dlopen-ing the resultant file and hooking up the necessary functions.

By doing this I can have full access to the engine/framework and speed is never a concern. It also means I can modify it later to load any arbitrary shared object (ie. generated via C or any other language, perhaps Chicken?).

The workflow I desired to achieve was to have an OpenGL context open, blank at first. From there I could open the editor of my choice, hack on some high level C++/OpenGL, and when I saved the file, the engine would recompile the file and load it, causing its rendering function to be overridden with the new one.

I'm happy to say I've achieved what I was after!

Change GTK display on the fly

zane.a@demonastery.org (Zane Ashby) — Sat, 09 Apr 2011 00:00:00 +1200

While working on my netbook away from my desktop machine, I pondered how I could view my email clients display (claws-mail, a GTK app), without having to resort to something such as VNC.

I know this can be done using utilities such as xmove, which essentially act as a proxy X server that can detach a client from one display and move it to another. But this requires you to start xmove before the application, and to tell the application to launch with its display on xmove.

Nah. We need something cooler than this.

After using some Google fu it became apparent that the GTK library has a function named gtk_window_set_screen which is demonstrated in the gtk-demo application that comes with the GTK sources. This function allows the application to switch X11 display on the fly.. provided the application has a way to do so (which barely any do, apart from the GIMP, because most don't need to).

So I decided to look into ways of doing code injection in Linux, as a way of being able to call that function inside our target application. Turns out this is easy as pie using GDB.

Mimicking Threading in PHP

zane.a@demonastery.org (Zane Ashby) — Sun, 03 Apr 2011 00:00:00 +1300

People often criticize PHP for not having the ability to use threading), which is a fair point and quite often a drawback. Here I am presenting a method for mimicking threads through forking) of the PHP interpreter. This may not work as well on a Windows system since AFAIK forks are more expensive there than on unix (*I would love to be proven wrong however!*). You will also need to make sure that you have the extension=sockets.so somewhere in your php.ini.

The code is very simple and short, it works using socket IPC and PHP serialization:

Chicken Scheme, and OpenGL

zane.a@demonastery.org (Zane Ashby) — Sat, 02 Apr 2011 00:00:00 +1300

Today I'm posting an example of how you can quickly get started with OpenGL using Chicken Scheme.

I am posting the code in full, but I have commented it pretty well and so everything should be quite simple to understand.

Unless you take out the texture rendering, you will probably want to get SOIL for your distribution (Archers can get it with sudo pacman -S soil).

Acer Aspire ONE D255E

zane.a@demonastery.org (Zane Ashby) — Sun, 27 Mar 2011 00:00:00 +1300

A week ago I went searching for a small netbook. My requirements were pretty simple; it needed to be cheap, and be able to dual boot Linux and Windows 7. Because I'm in New Zealand, the first place I checked out was Dick Smith Electronics, which currently had a great special running on the Acer Aspire ONE D255E (**$399 NZD**, roughly $300 USD). Now the specs listed on the site were actually false, but the actual specs of the laptop are higher.

The machine uses the Intel Atom N455 processor, which is a dual core CPU running at 1.66GHz. It has 1GB of DDR3 memory, a 250GB Hard Drive (non-SSD of course), 10.1" LED LCD at 1024x600 (which is tiny, but well suited to a window manager such as ratpoison. The VGA port also handles my 1920x1080 display with no trouble), and comes with Windows 7 Starter edition. These specs seem reasonable to me, and I'm used to getting the most out of my hardware. For interest sake, the machine also has a built-in webcam, 2-in-1 card reader, 802 11b/g/n Wifi (Atheros), a Synaptics touchpad that has basic multi-touch support, and a 3-cell Li-ion battery that gives roughly 4 hours of battery life (can also upgrade to a 6-cell). This particular machine has no bluetooth, although it seems to be an optional extra (along with internal 3G), and of course no optical drive.

The first thing I did when I unboxed this machine (after installing the battery) was format the hard drive (*Windows 7 starter is plenty capable, but it's not for me*). After getting a hold of an external optical drive I proceeded to install Windows 7 Ultimate on it, giving Win7 about 60GB of space, using a single partition only (there's a trick to getting rid of the System Reserved partition, but it's a pretty simple one). Once installed, I booted the machine up, and surprise surprise, there's pretty much nil driver support for this thing using the built-in Win7 drivers. Even VGA was limited to 800x600. Luckily I have an extra machine on standby that I was able to use to download some drivers. Unfortunately this system is new enough that the drivers are only just hitting the net, and I wasn't able to find the correct ones on the Acer site itself (If you want the names and download locations, ask in the comments). But after spending a couple of hours finding the correct ones, it was up and running smoothly.

A Newbie Guide to Call/cc

zane.a@demonastery.org (Zane Ashby) — Mon, 14 Mar 2011 00:00:00 +1300

I haven't had much to write about in the last couple of weeks, but I've really wanted to do a small piece on the magic of call-with-current-continuation in Scheme, aka. call/cc.

For some reason I had a difficult time wrapping my head around this little statement, even though it isn't terribly complicated at all (from an end coder perspective that is; I don't want to imagine the headaches it causes for the compiler hackers ;)). For all intents and purposes, you can think of call/cc as a glorified return or a smart goto statement (and that is how it will sound when I try to explain it).

But first of all, what is this continuation thing?

You can think of a continuation as an object that represents the position of execution in a running program. If we call a continuation object as though it were a function, we will jump to that position in the program, and continue the flow from there.

A Scheme Infix Transformer

zane.a@demonastery.org (Zane Ashby) — Tue, 08 Mar 2011 00:00:00 +1300

As promised in the last post, I am going to share an infix function, that takes a list that looks like (1 + (2 * 3)) and turns it into (+ 1 (* 2 3)) (Prefix).

Creating this function was a perfect place to start playing with Unit Testing as well. Something that I have not used much of until now.

Unit testing is really useful in this situation. We can write a tiny test that checks if our infix/lr (lr because it parses left to right, not that it matters) function gives the appropriate result. That test will look like this:

; Load the lightweight unit testing unit
(use srfi-78)

; And write the test
(check (infix/lr '(1 + (2 * 3) + 4)) ; Check that this
       =>                            ; matches
       '(+ (+ 1 (* 2 3)) 4))         ; this

An Intro to Scheme Macros

zane.a@demonastery.org (Zane Ashby) — Mon, 07 Mar 2011 00:00:00 +1300

In this post I want to go a little deeper into the macro system of Scheme (particularly Chicken), and share a couple of macros I've created.

First of all, macros are what make Scheme and Lisp so exciting. Macros offer the ability to evaluate code at compile time, and modify the structure of a program before it even runs. You can think of it as a really really powerful #define, but where #define lets you modify text, a Lisp macro lets you modify the code structure itself.

There are a couple of different kinds of macro available in Scheme, and as I'm somewhat of a young schemer I'm not completely sure which are available across all implementations and which are only available in Chicken. But I will assume that the macros here can be ported with relative ease.

The first kind, looks a lot like a regular ol' function. It is even called like a function, only when this macro is read it leaves behind whatever it returns. Here's an annotated example:

; Here we are going to create a new macro called "return-me"
; that will simply return in a list whatever is passed to it
(define-syntax return-me
  (syntax-rules () ; Any symbols placed in this list will be ignored
    [(return-me body ...) ; This is what the arguments should look like
     (list body ...)])) ; And this is how they should be transformed

; Example
(return-me "Hello" "World") => ("Hello" "World")

A Brief Foray into Haskell

zane.a@demonastery.org (Zane Ashby) — Sun, 06 Mar 2011 00:00:00 +1300

I've tried to learn Haskell in the past and found it completely horrible to look at. That was, until I got around to learning Scheme and decided to look deeper into it.

A couple of nights ago a friend showed me a small piece of Haskell code which reads a series of lines formatted like this:

a 1
b 2
c 3

And sums up the second column. The code looks like this:

foldl1 (+) (map (\c -> read (c !! 1)) (map words (lines "a 1\nb 2\nc 3")))

At first glance, I was at a total loss as to what was going on. So I fumbled around in ghci for a while figuring out what each part was doing.

Quake 2 Hacking

zane.a@demonastery.org (Zane Ashby) — Sun, 20 Feb 2011 00:00:00 +1300

Quake 2 (aka id Tech 2) is a great game and engine to hack. The source is pretty well laid out and the code is small enough that it doesn't take forever to become familiar with it. It also has a great entity system that makes it a really suitable for prototyping.

I spent the last couple of nights stripping as much of the game code as I could out, right down to the essentials, and then stripping the game data down to the bare minimum as well. I built a plain cube map with a single info_null entity, that gets loaded on startup, acting as a gateway map. The info_null entity contains a "model" key, which loads an arbitrary md2 from disk (in this case, some couch model I found online).

Next I set about embedding Chicken Scheme into the game code as an interpreter, and a few thousand segfaults later, it works! I have output redirection and an "eval" command for the console, allowing you to type some code and get a response.

I also started on a high level API for controlling in game objects that I will just implement as I go, that looks a little like this:

(q2:fire-blaster (q2:get-player-by-name "Player"))

So for just a couple hours of work I have a decent engine and scripting language that can be built up in whatever direction I decide to go with it :D

Sawfish Theme, GperfectionHash

zane.a@demonastery.org (Zane Ashby) — Thu, 17 Feb 2011 00:00:00 +1300

Just a simple modern SawfishWM theme I made, modified from gperfection.

There is a dark version (named perfection-hash), and a light version (named gperfection-hash-light), to suit dark and light GTK themes (not included).

Font in title is "Helvetica Neue Bold 7".

To download, head over to http://hashbox.deviantart.com/art/Gperfection-Hash-for-Sawfish-197710239.

To install, unzip inside ~/.sawfish/themes/ and select gperfection-hash(light) in Sawfish configuration.

Have fun!

Chicken Scheme, and FFI

zane.a@demonastery.org (Zane Ashby) — Mon, 31 Jan 2011 00:00:00 +1300

As a follow up on yesterdays post I'm going to show how easy it is to integrate some third party functionality in to a web application to provide "automatic tagging" using libots.

To do this, we're going to use the Chicken FFI. Now this example is really so short that there's no point in splitting it into multiple blocks, so here we go:

;; FFI example
(import foreign)

; Add the libots header
(foreign-declare "#include <libots-1/ots/libots.h>")

; Declare the function we're going to use
(define ots-text-topics
  (foreign-lambda c-string "ots_text_topics" c-string c-string int))

; And here's another useful one
(define ots-summarize
  (foreign-lambda* c-string* ((c-string str) (int percent))
                   "OtsArticle* article = ots_new_article();
                    ots_load_xml_dictionary(article, \"en\");
                    ots_parse_stream(str, strlen(str), article);
                    ots_grade_doc(article);
                    ots_highlight_doc(article, percent);
                    size_t outlen = 0;
                    char *text = ots_get_doc_text(article, &outlen);
                    ots_free_article(article);
                    C_return(text);"))

And now to use it (the automatic tagging part):

;; OTS tagging
(let* ((num-tags 3)
       (body "This is the post you want to tag")
       (tags (ots-text-topics body "en" num-tags)))
  (display (string-append "The tags found are: " tags)))

Now all that's left is to compile it:

csc code.scm `pkg-config --cflags --libs glib-2.0 libots-1 libxml-2.0`

That's really all there is to it!

Chicken Scheme, and Web RAD

zane.a@demonastery.org (Zane Ashby) — Sun, 30 Jan 2011 00:00:00 +1300

Recently I've taken more of a liking to Chicken Scheme, and started trying to use it for more of my day to day development. Recently I wrote a port (PongClock ) of a JS + HTML5 Pong Clock into Chicken Scheme using the OpenGL + GLUT libraries. I couldn't believe how smoothly it went, since it was a line by line port, the only thing I needed to write myself were the graphics drawing routines, easy enough since we're only dealing with white rectangles after all, but now it functions as a cross platform screensaver (verified on Linux, OSX, and XP!).

But the area I spend most of my time in is web development, so I was pleased to find the Awful framework for Chicken. Despite the name it is anything but. A simple usage example looks like this:

;; Hello World!
(use awful)

(define-page "/"
  (lambda ()
    "Hello, World!"))

Yes, it really is that easy. Of course you'll most likely want to define your own template, and that is really easy to do too, my templates look something like this:

BLACK - Blog Engine

zane.a@demonastery.org (Zane Ashby) — Thu, 30 Dec 2010 00:00:00 +1300

As part of the migration of my blog to the Linode, I've cleaned up and restructured the code that powers this blog somewhat and made it available at BLACK for others to use. Right now it is there more as a reason for me to keep improving it than anything else, since it needs some work.. but hopefully it will become useful enough for someone else to use it in the future.

The "engine" revolves around the single function "post". An example of its usage is below:

<?php black\post($query, function ($post, $issingle) { ?>
  <a href="/<?= $post['id'] ?>/"><?= $post['title'] ?></a>
  <br />
  Posted on <?= date('l, F jS Y', $post['timestamp']) ?>
  <br />
  Tags for this post are <?= $post['tags'] ?>
  <br />
  Aaaannnd the post itself:
  <br />
  <?= $post['body'] ?>
  <br />
  <?php if ($issingle): ?>
     Viewing by post id, so insert Disqus commenting stuff here perhaps?
  <?php endif ?>
<?php }) ?>

Added into an existing website template, the provided function will be called for each post you have, printing them all out to the page.

New Server

zane.a@demonastery.org (Zane Ashby) — Mon, 27 Dec 2010 00:00:00 +1300

My blog has been migrated successfully to my Linode, which meant moving from one httpd (Apache) to another (Nginx), transferring MySQL data, and rewriting the rewrites ;)

So far so good. I wasn't expecting it to go smoothly at all. In celebration I've gone through my old posts and deleted or edited stuff that wasn't really relevant or interesting. So hopefully the average post quality has increased a bit :)

Cheers for now! And a belated Merry Christmas and Happy New Year to everyone!

My Linode Experience

zane.a@demonastery.org (Zane Ashby) — Sun, 05 Dec 2010 00:00:00 +1300

As mentioned in a previous post, I have been using a Linode for the past few months and I just want to say that the experience I've had has been perfect. I purchased a Linode 512 and I'm using it to host a few small websites on a pretty generic Nginx + PHP5.3 FastCGI stack, along with MySQL and Exim (as a send only MTA), and the whole setup sits comfortably in 50mb of memory and seems to perform well too (time will tell, I haven't done any benchmarks). No special configuration has been needed other than setting up a basic directory layout for my BDSM project, which takes care of pushing my websites from my development box.

I would highly recommended Linode to anyone looking for a VPS, the support is amazingly quick, and the uptime is great; and if you use my referral link to sign up I can get some extra credits, so that would of course be much appreciated :)

HashTWM Musings

zane.a@demonastery.org (Zane Ashby) — Sun, 07 Nov 2010 00:00:00 +1300

I know there has been a lot of requests for features to be implemented or fixed in HashTWM. But the reality is, I'm barely using Windows anymore and so I don't have an urgent need for HashTWM.

Despite all the progress around other tiling window managers for Windows I still believe there is room for improvement though, so I am putting some effort into getting a rewrite off the ground. My idea is to get a solid foundation built up that (if anything) through the power of open source, someone will be able to take and hopefully build their dream TWM out of.

Sawfish and Emacs/org-mode

zane.a@demonastery.org (Zane Ashby) — Wed, 27 Oct 2010 00:00:00 +1300

Hi there, Today I'm going to write a small example on connecting the Sawfish window manager to the Emacs text editor.

Why might you want to do this? Well mostly I just wanted to further my usage of Emacs, and thought the idea of being able to clock in and out of tasks in org-mode whenever I change workspace or window would be pretty cool. Of course both Sawfish and Emacs make extensive use of the Lisp programming language) so it is a natural fit :)

To start off, you'll want to be using the Sawfish window manager, and you'll want to have emacs.jl somewhere in your lisp path. From there you can put something like the following in your ~/.sawfish/rc:

;; Require emacs.jl for emacs functions
(require 'emacs)

;; Define a hook to be run on workspace change, utilizes the emacs-eval function defined in emacs.jl
(define (my-enter-workspace-hook)
  (emacs-eval (format nil "(org-clock-in-on-workspace-change %S)" (nth current-workspace workspace-names))))

;; Add our hook!
(add-hook 'enter-workspace-hook my-enter-workspace-hook)

You will need to reload Sawfish for these changes to take effect (or you can eval them from Emacs).

Scheme-to-PHP

zane.a@demonastery.org (Zane Ashby) — Tue, 28 Sep 2010 00:00:00 +1300

I'm writing this post to inform of my latest GitHub repo, Scheme-to-PHP, which contains the beginnings of a very very naive Scheme to PHP5 translator. It will do so by implementing r4rs (or maybe r5rs) forms and macros in Scheme, that return the equivalent strings of PHP code, hopefully forming a working PHP script. There will be a way of calling native PHP functions and classes, and Scheme functions such as map will be mapped (no pun intended) to the equivalent PHP function (eg. array_map).

This is being written using Chicken Scheme, which I'm currently spending most of my time hacking about with and is totally awesome :)

XMMSinatra

zane.a@demonastery.org (Zane Ashby) — Fri, 10 Sep 2010 00:00:00 +1200

Last night I released the first version of XMMSinatra, a tiny and minimal XMMS2 web client written in Sinatra (Ruby). You can find the code and a screenshot at the Github repository.

Hackfest Weekend

zane.a@demonastery.org (Zane Ashby) — Wed, 01 Sep 2010 00:00:00 +1200

Back from a really fun hacking weekend in Wellington, where I met some new people (and fellow hackers) and got to work on a project integrating TBB further into the HipHop-PHP compiler (and exposing it to PHP), which can be found at Github. We made some pretty good progress and came up with a few pretty graphs.

As mentioned in the last post, I have decided to purchase a Linode VPS for a couple of months to try it out, and so far I am super impressed with the overall service. I will be using it mainly as a LNMP (Linux, Nginx, MySQL, PHP) host and so far it is doing the job well. I will also be spending the coming months looking further into RoR, Perl, a couple of NoSQL servers (CouchDB, Redis), and maybe a message passing framework or two. This will also give me a chance to play around with some monitoring systems, and some deployment systems, such as Capistrano.

As a side-note, anyone have any ideas of what to do with a bunch of Clickatell SMS credits? I have an account with plenty of credits but it's sitting pretty stagnant at the moment.

Also really looking forward to visiting Christchurch in the coming weeks. Haven't been there in forever.

ProtoIRC

zane.a@demonastery.org (Zane Ashby) — Fri, 09 Jul 2010 00:00:00 +1200

So I made a tiny and very hackable IRC bot/client base in PHP for rapid prototyping. Of course I threw it on GitHub. It makes heavy use of PHP >= 5.3 closure support as well as regular expressions for defining just about everything. Basic knowledge of the IRC protocol is recommended. You can find more information in the README file in the previous link.

Here is an example of what a minimal bot looks like:

<?php
require('protoirc.php');

$irc = new ProtoIRC('nick@hostname:6667', function ($irc) {
        // This code will run on connect
        $irc->send('JOIN #channel');
});

$irc->in('/^:(.*)!~.* PRIVMSG (.*) :!echo (.*)/', function ($irc, $nick, $channel, $args) {
        // Arguments are self documenting
        $irc->send($channel, "Echoing '{$args}' for you {$nick}", 'green');
});

// Also available is the ability to catch stdin, irc in, and irc out. Set up timers, and call functions asynchronously (fork/join).

$irc->go();

HashTWM Patch

zane.a@demonastery.org (Zane Ashby) — Wed, 23 Jun 2010 00:00:00 +1200

This morning I woke up to find a patch waiting for me on GitHub that extends HashTWM's primitive tag support with what appears to be a more full featured, dwm-like tag support. Thanks to http://github.com/gtellalov for this patch :)

This is the beauty of open source :D

LibOrgParser Update

zane.a@demonastery.org (Zane Ashby) — Thu, 03 Jun 2010 00:00:00 +1200

Today I brought my LibOrgParser repository up to date with my local copy, for the first time in a while since I've been rather slack with my local repository.. but hopefully I got everything. The new version brings reading and writing functionality, as well as a new API, and the OrgQL utility, which lets you run simple SQL like queries on an org-mode file, thanks to the SQLite library. Queries that look like this,

SELECT ALL FROM /home/zanea/todo.org WHERE heading CONTAINS todo

Oh and I found this image I made a while ago, kinda neat I think :)

Add OrgQL to that, and that's pretty much my todo list flow :)

Edit: Oh and while we're at it, here's a one liner bash function for opening links in a file:

function nav() { grep -ohE "[[:alpha:]]*://[[:alnum:][:punct:]]*" $@ | while read; do xdg-open "$REPLY"; done; }

# use like this
nav todo.org someotherfile.txt

Misc Win32 Utilities

zane.a@demonastery.org (Zane Ashby) — Tue, 01 Jun 2010 00:00:00 +1200

Just created a new git repository on GitHub for my Miscellaneous Win32 utilities. Right now it just has my ExplorerGestures code, but I will be adding some more utilities as I find them on my hard drive.

Edit: Added some more utilities. Probably still more to come..

PrepFS

zane.a@demonastery.org (Zane Ashby) — Mon, 31 May 2010 00:00:00 +1200

Been a while since I posted anything here, and it's always good to have some fresh content, so I thought I'd post my latest creation PrepFS (Pre-process FS), a small utility FUSE filesystem, that enables preprocessing of files.

My main motivation behind creating this, is enabling modified .Xdefaults dependent on running window manager, or machine it is being viewed from. An Example of usage would be something like this:

~/.xinitrc

wm=`echo -e "openbox\nxmonad" | dmenu`
prepfs ~/.dotfiles/prepfs -b ~/.dotfiles/real -pp "gpp -D$wm -x \"%s\""
exec $wm

~/.dotfiles/real/.Xdefaults

#ifdef openbox
    blah*blah: blah
#else
    this*stuff: here
#endif

Then make sure ~/.Xdefaults is symlinked to ~/.dotfiles/prepfs/.Xdefaults

More information (including source) can be found here http://bbs.archlinux.org/viewtopic.php?pid=576680

MPD Class for PHP

zane.a@demonastery.org (Zane Ashby) — Mon, 31 May 2010 00:00:00 +1200

I've just been going through a couple of folders and I found a very basic PHP class I wrote to control the Music Player Daemon. Assuming the text protocol hasn't changed much it should still work fine :)

<?php
/*
 * Base MPDControl Class
 * Provide functions for connecting and retrieving raw data from MPD
 */
class MPDControl {
    var $hostname, $port, $timeout, $socket, $errno, $errstr;
    function MPDControl($hostname = 'localhost', $port = '6600', $timeout = 3) {
        $this->hostname = $hostname;
        $this->port = $port;
        $this->timeout = $timeout;
    }

    function connect() {
        $this->socket = @fsockopen($this->hostname, $this->port, $this->errno, $this->errstr, $this->timeout);
        if (!$this->socket) {
            return false;
        } else {
            $this->getData();
            return true;
        }
    }

    function disconnect() {
        $this->sendRaw('close');
        fclose($this->socket);
    }

    function getData() {
        $lines = Array();
        $line = '';
        while ((substr($line, 0, 2) != 'OK') && (substr($line, 0, 3) != 'ACK')) {
            $line = fgets($this->socket, 256);
            $lines[] = $line;
        }
        unset($lines[count($lines)-1]);
        return $lines;
    }

    function sendRaw($string) {
        fwrite($this->socket, $string."\n");
    }
}

ExplorerGestures

zane.a@demonastery.org (Zane Ashby) — Sat, 03 Oct 2009 00:00:00 +1300

So it's 2:56 in the AM and I've just hacked up a little app to enable moving up a directory in Windows Explorer by using the Thunar middle click + drag up gesture. You can find it at Win32-Hacks .

Enjoy.

Edit: This morning I've extended it to have left and right gestures to go backward and forward respectively just like Thunar and Nautilus. Down is used for exit rather than refresh as Windows seems to take care of this.

Automatic agenda notification

zane.a@demonastery.org (Zane Ashby) — Sat, 02 May 2009 00:00:00 +1200

This article will show you how to utilize Emacs org-mode, python, a Nokia mobile (others may work too), and an SMS gateway like Clickatell, in order to receive a daily agenda that fits nicely into the phones calendar by using the vCalendar format. Yes that's a fairly specialized combination, but hopefully will be useful to someone. I'm sure it's possible to do the same using bluetooth instead of and SMS gateway, and I may update this to reflect that at some stage..

I can haz assembly!

zane.a@demonastery.org (Zane Ashby) — Mon, 20 Apr 2009 00:00:00 +1200

Simple CPUID, I also experimented with a version using an extra buffer variable and printf. It may not be much to others but I'm learning!

; CPUID

section .data
    buffer:         db  "CPU Vendor ID: XXXXXXXXXXXX", 10, 0
    bufferlen:      equ     $ - buffer

section .text
    global _start

_start:
    mov     eax, 0          ; "Get maximum supported standard level and vendor ID string"
    CPUID               ; Call CPUID
    mov     [buffer+15], ebx        ; Move 4 bytes from ebx to buffer+15
    mov     [buffer+19], edx        ; Move 4 bytes from edx to buffer+19
    mov     [buffer+23], ecx        ; Move 4 bytes from ecx to buffer+23

    mov     eax, 4          ; write syscall
    mov     ebx, 1          ; stdout
    mov     ecx, buffer             ; buffer
    mov     edx, bufferlen      ; size of buffer
    int     80h                 ; call kernel

_exit:
    mov     eax, 1          ; exit syscall
    mov     ebx, 0          ; Return 0
    int     80h                 ; call kernel

A simple wallpaper wrapper

zane.a@demonastery.org (Zane Ashby) — Fri, 13 Mar 2009 00:00:00 +1300

Edit as necessary, requires hsetroot, mplayer, and a working xvidix on your graphics card (for video).

#!/bin/sh
# Set Wallpaper

# If $1 is not empty
if [ -n "$1" ] ; then
    case "$1" in
      last)
        # Grab last set wallpaper from file and store in $WALL
        WALL=`cat ~/desktop/lastwall`
        ;;
      *)
        # Set $WALL from command line and write to file for future use
        WALL=$1
        echo $1 > ~/desktop/lastwall
        ;;
    esac

    case "$WALL" in
        *.jpg|*.jpeg|*.png|*.gif|*.bmp)
            # $WALL is an image file, so use hsetroot to set it as the background
            echo Setting with hsetroot...
            hsetroot -full "$WALL"
            ;;
        *)
            # $WALL is likely not an image, so attempt to play with mplayer
            echo Setting with mplayer...
            # Blank out background first
            hsetroot -solid "#000000"
            # "Play" background using colorkey
            sudo mplayer -fs -vo xvidix -rootwin -colorkey 000000 -quiet "$WALL" &
            ;;
    esac

    # Return good
    exit 0
else
    echo Please specify an image or a video file to set, or use "last"

    # Return bad
    exit 1
fi

To use, run setwallpaper.sh /path/to/image/or/video/file or setwallpaper.sh last

Change fonts dynamically

zane.a@demonastery.org (Zane Ashby) — Wed, 18 Feb 2009 00:00:00 +1300

After some Q and A on the ArchLinux forums, I am left with this in my .zshrc, the ability to change fonts on the fly:

vim_font() {
    echo -e '\e]710;xft:Terminus:style=Regular\007'
    vim $*
    echo -e '\e]710;xft:lime:style=Regular\007'
}
alias vim='vim_font'