JDobbelstein.dev()

A custom Vimsh

2011-01-10T01:04:00+01:00

Your browser does not support the video element.

The previous video demonstrates a simple hack using a custom version of the vim plugin vimsh. The new features are: An option g:vimsh_filetype to customize the syntax coloration in the prompt buffer; Another option g:vimsh_split_method to control where the prompt pops. Cf. the vim functions :below and :above. Improve g:vimsh_sh_arg parsing using... Read A custom Vimsh

Debugging GObjects in Glib

2010-10-01T00:58:00+02:00

can't read SVG ? go www.getfirefox.com

I'm working (since too long) on a Haskell binding to the XFCE library "xfconf" because, you know, in order to improve one programming skills, one should write code. Anyway, after harassing the Haskell mailing-lists with my newbie questions, I got a not-so-bad working binding to xfconf.

… memory leaks apart.

It took me a lots of efforts to finally solve this memory issue, mainly because I'm a bad programmer who don't know a damn about software runtime and also because I don't know what tools to use with Haskell.

I. The situation I.a. Why do I care about memory leaks ? Because I am poor. Poor people tend to have old computers. Old computers tend to have a small amount of RAM. And, sadly, recent GNU/linux distributions tend to be really bloated. Practical advantages of hunting memory leak are 1) you get to know more stuff about software debugging 2) you... Read Debugging GObjects in Glib

Unicode in Python and i18n in Fedora

2010-08-10T13:45:00+02:00

When I was playing with the ports4dotclear system (see the previous post about it), I had to fix a number of Unicode handling errors in both Python and Perl. For those of you who do not know what is Unicode, it's the technology which allows me to write this kind of stuff: «æ€¶ŧ←»® or «你好世界».

I was forced to use Unicode because, well, XML-RPC communications are in XML and thus require the content to be encoded in UTF-8 (a Unicode encoding/decoding charset).

All this mess leads me to this conclusion : Unicode sucks in Python 2.x ! (and Fedora i18n has still some strange artifacts)

I. Python There is a well known unicode bug in Python 2.x. It's really a shame it didn't got fix earlier, although I may have read the new python 3k fixed it. Anyway, this bug pops when you play with POSIX pipes and wide characters. It's very annoying because you don't understand why a simple shell redirection (on stdout) should change the python... Read Unicode in Python and i18n in Fedora

A port system for DotClear

2010-07-26T18:36:00+02:00

can't read SVG ? go www.getfirefox.com

(SVG source)

For the ones who favor their command line interface over graphical terminals, here comes a bundle of Makefiles and scripts to easily publish new entries on a DotClear2 blog with XML-RPC enabled.

It is loosely based on *BSD ports and the idea behind static blog generators like jekyll, which in fact I've never used so the comparison might be more about what I think they are and what I'd like to use. Nevertheless, the few features I have aimed for are:

automation, otherwise I would not waste whole days on the command line
integration with VIM, the text editor
pure text files, a very simple and universal way to store data. Moreover ones can manage the whole damned thing with Git.
extensible, as in the Unix philosophy where you combine a myriad of small programs to achieve your task

The project is available on GitHub.

I. Quick demo Computer science is all about speeding things up. This system doesn't escape the rule. Using it for posting a new entry on a DotClear2 blog is as quick as typing: bash:Goldberg $ make new Enter directory name: foobar New directory created: [999_foobar] bash:Goldberg $ cd 999_foobar bash:Goldberg/999_foobar $ make edit... Read A port system for DotClear

First attempt with SVG

2010-07-16T19:35:00+02:00

can't read SVG ? go www.getfirefox.com

(SVG source)

SVG diagrams are scalable. They should be a perfect fit for this elastic CSS theme. Let's try.

can't read SVG ? go www.getfirefox.com (SVG source) The diagram on the right shows how you can use SVG to display clean and elegant diagrams. This one was created with Inkscape. On Opera™ and Mozilla™ browsers, the schema is displayed with a transparent background. Unfortunately, webkit-based software still... Read First attempt with SVG

Managing mails the Unix way

2010-05-10T15:14:00+02:00

I am quite allergic to modern email programs such as Microsoft Outlook, KMail, Evolution or Thunderbird. After digging the web for a mail program that "sucks less", I've adopted mutt. In the same time, I've learned a lot of (not so useful) stuff about the email flow from servers to servers to servers to my brave old Unix mailbox. I am now using a split set of software to manage my emails. This could be confusing at first sight, but eventually I get the so-called do-one-thing-but-do-it-right quality of Unix systems. To summarize it, my messages go through the following path:

                         .--.               
                     _ -(    )- _           
                .--,(            ),--.      
            _.-(                       )-._ 
           (           INTERNET            )
            '-._(                     )_.-' 
                 '__,(            ),__'     
                      - ._(__)_. -          
                ^                      |
                |                      |
                |                      v
           .---------.           .-----------.
encryption | stunnel |           |  getmail  | deliver
           '---------'           '-----------'
                ^                      |
                |                      |
                |                      v
           .---------.           .----------.
      send | postfix |           | procmail |  filter
           '---------'           '----------'
                ^                      |
                |                      |
                |                      v
            .------.              .---------.
read/write  | mutt |<============>| dovecot |  store
            '------'              '---------'

Getmail, procmail, dovecot, mutt, postfix and stunnel. That's 6 programs to do what your Microsoft Outlook or Thunderbird do. But I can assure you that the former 6 programs offer a better experience compared to the latter ones.

I. Some vocabulary Before going further, let's redefine here some acronyms commonly used to talk about email systems. The list is based on the mail concept overview from the mutt wiki. MRA: Mail Retrieval Agent, the program fetching mails from the internet (such as fetchmail or getmail) MDA: Mail Delivery Agent, the program actually... Read Managing mails the Unix way

A new version for the "Deep Blue" DotClear theme

2010-05-02T23:40:00+02:00

After three whole nights and more than 30 cups of tea, my blog is using a new version of my "deep blue" theme. Key new features are:

Elastic CSS, this implies no more bitmap pictures :(
Refactoring of DotClear2 template to shift the center of the page to the left. This leaves a small opening for a side image on the right. This is a new proof that my poor CSS skills cannot overcome the xHTML tags and document structure of the original DotClear2 pages.
After many thoughts on the right CSS layout, I choose to use a CSS width based on em. Layouts based on page percent width are very tricky when it comes to displaying lines of code because text lines could be wrapped. CSS em attribute should garantee a similar appearance among screens and, let's dream, browsers. New pages width should be almost/at least 80 characters long. This might keep a text layout constant, even if you are zooming in/out, even if you are using different font sizes. Too wide or too big screens will be under-used. I don't care, use the space left to play with tiling window managers. Too small screens will have to go full screen and zoom out. Anyway if you cannot read 80 characters-long-line text, you should use another graphical terminal. (note: in fact, and perhaps due to limitation on the fonts, the length of text lines will never be constant. I've just tried to assure a minimal quality. See the next section for a concrete example)
Experimenting the CSS3 property rgba(r,g,b,alpha) to add some eye candy.
Experimenting another CSS3 property with the background-size declaration to scale the background image to full page height. Strangely browsers like Opera zoom both text and images, this can lead to unesthetic result.

Fixed line length is a myth The following paragraphs contain a dummy lorem ipsum text for reference and two 80 characters long strings. If you zoom or play with your font family/size you will see that this CSS with cste em block width is far from perfect. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Sed accumsan sollicitudin... Read A new version for the "Deep Blue" DotClear theme

Why Debian Lenny ?

2010-04-26T20:38:00+02:00

Because it is stable ! It means less trouble between packages and less time spent hunting incompatibilities between libraries. Here comes yet another example of dependency hell in the world of F/OSS where our two main protagonists will be libxml2 and PHP 5.x.

Recently I come across a little bug when I was playing with my LAMP server (actually it's more a LLPP system for I prefer Lighttpd and PostgreSQL). It appears PHP 5.2.x and libxml>2.7 do not play well together when parsing HTML/URI encoded messages (where characters as '<' or '>' are replaced by < or >). If you try to use a $xml_parser = new... Read Why Debian Lenny ?

XML-RPC on DotClear

2010-01-15T23:52:00+01:00

XML-RPC is a protocol to remotely control a web application. Here is a short demo of XML-RPC to create, view and edit entry on the DotClear2 blog platform from the command line, using a tiny python script.

Your browser does not support either the video element or embedded OGG theora video. What can we do with dotclear.py ? Create post entry. List previous ones. Modify them ... or delete them. Locally, on your computer, using your favorite browser/text editor to preview/edit the blog entry. But why ??? Because I got bored and... Read XML-RPC on DotClear

Fedora RPM hacking

2010-01-14T03:57:00+01:00

Fedora is a distribution supported by Red Hat® which aims to be user-friendly. Unfortunately if you like to hack your software or to use exotic programs, you'll have to go through the RPM pipeline to nicely integrate your binaries with the rest of your system.

Here is an example on how to modify DVTM source code. We get the RPM source package, patch the code and regenerate a binary RPM the fedora-way.

Setting up development environment First, you have to create a directory rpmbuild where you will work. Simply install the rpmdevtools RPM and use : su -c 'yum install yum-utils rpmdevtools' rpmdev-setuptree Getting the source We will use yum, the fedora package manager, to download the source, extract them, and install the require build &... Read Fedora RPM hacking

Sondage dcWave

2009-12-20T02:51:00+01:00

Petit test pour tester l'usage de cette chose hautement inutile.

Bon alors la question est simple : j'ai un p'tit plug-in sous la main qui permet d'inclure plus ou moins sans soucis des Google Waves sous DotClear. Je cherche un logo pour le plug-in (et un occasion de poster sur DotClear / créer une Wave). Petit rappel, les logos de Wave et DotClear sont les suivants : Les propositions sont les suivantes :... Read Sondage dcWave

The headless case

2009-12-19T20:38:00+01:00

Imagine an old headless computer box and an `aptitude safe-upgrade` which failed. No keyboard nor screen connected to the box. No graphic card inside. The nightmare has begun... ... fortunately, Slitaz was here to help !

I came across a small annoying problem when upgrading my Debian headless 'server' one time : dpkg failed to remount read-write enabled my /boot partition or it was out of space and consequently the update of grub/initramfs did not work, letting my old server unable to reboot by itself. (yes I know, I could have confgured /etc/apt/apt.conf to work... Read The headless case

Wave plugin 0.2

2009-12-18T01:01:00+01:00

The GoogleWave plug-in for DotClear 2.x is updated with improvements and bugfixes.

Wave plugin 0.1

2009-12-15T01:59:00+01:00

Dotclear is great. Dotclear is simple (until you try to read and understand the code). Dotclear is W3C compliant. But ... there is not yet a plug-in to easily include a Google® Wave. ... so let's try to add a wave smoothly.

Edit: move from googleWave 0.1 to dcWave 0.2.0. Old div.waves on this pages do not work any more with my new javascript wrapper. To get the latest news, please go on the next entry No worries, I've looked everywhere on the web to find some clues on how to do it. The first version of the Dotclear plug-in gives the following result : Wave v0.1... Read Wave plugin 0.1

December desktop

2009-12-08T23:58:00+01:00

A small entry to test multimedia content.

Winter is coming ! /DS... Read December desktop

Welcome to Dotclear!

2009-12-08T22:26:00+01:00

So, following advice from here I've installed dotclear2 on my beloved private server. To get start with the software, let's test the entry system with this brief text describing how I configured my Debian with php5 and PostgreSQL.

Updating the Debian server aptitude update && aptitude safe-upgrade ... plus some configuration checks, including php5-gd, php5-pgsql, etc. Configuring Apache2 Simply by adding the configuration file cat /etc/apache2/conf.d/dotclear2.conf: Alias /dotclear2 /srv/dotclear2 php_admin_flag safe_mode off php_admin_flag... Read Welcome to Dotclear!