Older blog entries for lmjohns3 (starting at number 4)

15 Oct 2002 (updated 15 Oct 2002 at 11:54 UTC) »

Last night I got the hacking urge after working a little on GStreamer. I knew I had to wake up early today to head to work—our carpool group has decided to try to beat rush hour so we have to leave at 7—but just two hours of hacking was not enough : I couldn’t get to sleep. I just added measures and beats and a clock to the playondemand filter, which means I can start writing the sequencer library on top of it now. Drumbox is starting to appear possible. Yay !

So, at any rate, I finally managed to get to sleep, but I had to promise myself that I would get up early and hack before going to work. Sick, you say ? No ! Demented ! The early morning programming helped fuel the need for a green tea at home, and then the usual morning coffee at work ... now I am pretty wired but must wait til this evening to start building the sequencer. Looks like those plans to go running are getting thwarted.

Code generation

Work is fine, I’m getting to the middle stages of writing a code generator for CORBA 3.0. It’s difficult at this point because there is a lot of obscure debugging to do, and Python is probably not the easiest language to debug (can anybody say “eval” ?).

I am also starting to work on a code generator for GStreamer plugins and applications. It is remarkably similar in concept to this CORBA generator task, but the GStreamer app is more fun (because it’s not work, of course). And many thanks to the libglade-2 and Gnome 2 Python bindings, application building and execution is as simple as writing a script and editing an XML file (using Glade for the wysiwyg warm fuzzies along the way). As long as things like low latency and small execution time aren’t high on the priority list.

Red Hat 8

I finally saw a Red Hat 8 desktop last night. It looks really good. Kind of remarkable how the Gnome 2 desktop (or at least the Red Hat 8 version) is kind of splitting the difference between MacOS and Windows. It’s also nice to see the usability of Linux reaching out a little bit more toward the average computer user (though I think it’ll be a while yet before it’s on point, if there is really a point to reach). Over the past few months I have truly started enjoying using Linux myself : the Gnome 2 apps have made huge strides in usability and functionality, the looks are getting better all the time, and the same old Linux power is still there (I am just starting to learn shell scripting, for example.). Now, though, I am longing for all my programs to come out in Gnome 2 debian packages : evolution, gnumeric, gnucash, galeon, the gimp, emacs (but only for the font antialiasing !).

Emacs is really useful

Update ! I just discovered the isearch-regexp function in emacs. C-M-s. Your life as a programmer will never be the same. Now that I’m on the topic, I think I will list some (default on debian) emacs keybindings that I find helpful. “Point” is the cursor, “mark” is set by pressing C-<space>.

  • M-/ — completes the text preceding point by looking for matching strings in all open buffers. Dealing with long function and variable names is really easy with this.
  • C-/ — undo the last command.
  • M-\ — delete all horizontal whitespace surrounding point.
  • M-x tags-search – look through all files in a source tree for a given function or variable name. This will prompt you for a tree to use if you are not already visiting a TAGS file. Also see the ctags(1) function.
  • C-x r o — open a rectangle of whitespace with corners at point and mark. Useful in combination with the other rectangle functions for mass function/variable name prefixing or deprefixing, LaTeX table manipulation, etc.
  • C-x r k — kill the rectangle with corners at point and mark.
  • C-x r t — fill each line in the rectangle with corners at point and mark. This prompts you for the text to fill in. Very useful for things like mass prefixing rows of text.
  • M-l, M-c, M-u — downcase, capitalize, and upcase the word following point (the end of a word depends on the major mode). I never thought I would use these functions until I learned the shortcut keys. Now I can’t live without them ; Notepad and Word are evil demons because they do other things with these keys.
  • M-q — fill the current paragraph, wrapping long lines at the boundary set by C-u <numbers> C-x f (set-fill-prefix). This is really useful with filladapt mode.
  • C-f (C-b), M-f (M-b), C-M-f (C-M-b) — move point one character, word, or sentence forward (or back).
  • C-t, M-t, C-M-t — transpose the characters, words, or sentences surrounding point.
  • C-d (<backspace>), M-d (M-<backspace>), C-M-d (C-M-<backspace>) — delete the character, word, or sentence after (or before) point.

Happy typing !

Work and scripting languages

Work is going well. I have finished a first pass at a Java code generator for our CORBA 3 implementation. It will probably take another week or so to create all the remaining templates, and then probably two to four weeks to iron out bugs.

I wrote the generator in Python (displaying that well known affinity for one's preferred scripting languge), mostly so I could use the supernifty print-using-values-from-a-hash operator. I know somewhere deep down that Perl is likely better suited to this task, but I really don't know Perl that well.

Development followed the classic Leif Python pattern :

  1. Write colossal single file with necessary classes and functions from a first glance at problem.
  2. Realize colossal single file is difficult to maintain and hard for others to read.
  3. Reanalyze structure of program, split colossal file into smaller files (usually one per class).
  4. Add functionality to smaller files until they are colossal.
  5. Go to step 2 for each new colossal file.

I enjoy writing Python programs because I get the opportunity to see the structure of my program evolve. Thanks to Python's fascist indentation policies, I actually get to see the design of my programs in the way they code is laid out on my screen. I like that in a programming language. Also, did I mention that the print-using-values-from-a-hash operator is groovy ?

The other fantastic thing about scripting programs (in general) is their ability to adapt to changing external environments automatically thanks to functions like eval and doing things like executing code over elements of a list. So, for example, in this code generator, a general enough driver class in Python is able to dynamically read values in from code templates and adapt to those values accordingly. Change the template, change the resulting functionality. Want to generate a different output language or add new functionality to an existing output language ? Just write a new set of self-referential templates. No compilation needed.

GStreamer and drumbox

This weekend I spent quite a bit of time working on some things related to GStreamer. In particular, I got a new web site for drumbox whipped up, and I started moving code from the old drumbox libs into the playondemand filter. wingo suggested I look in to making a GInterface for a sequencer element, so I think I will take a look this week.

The app will still take a while to program, at least several months, but I am looking forward to it now. After reducing the scope of the drumbox interface itself, the project is looking much more feasible (and easier to debug).

Fonts and the Gnome 2 desktop

I finally figured out how to get the fonts I want (i.e. Verdana) using my Debian Gnome 2 desktop ! I had to add

dir "/var/lib/defoma/x-ttcidfont-conf.d/dirs/TrueType"
to my /etc/X11/XftConfig file. Things now are looking really good.
8 Sep 2002 (updated 19 Sep 2002 at 18:13 UTC) »

technical writing in Austria

I'm learning quickly here that my education as a Franklin Scholar helped give me one exceedingly valuable skill : technical writing. There are literally millions and millions of people in the world who :

  1. do not speak English as a native language, or perhaps are native English speakers but lack solid grammar skills,
  2. are working in technical disciplines, e.g. computer science or mechanical engineering, and
  3. have to write papers or documentation in English to publish their work.

Now most people, for the most part, do a really good job of communicating their ideas. However, they often need help with pesky prepositions, difficult sentence constructions, or common usage problems in their English writing. English is not an easy language to learn well ! In addition, the only editing help the people from the above lists have usually comes from one of two sources :

  1. colleagues who have concentrated in English studies and don't know much about the technical side of the papers they are proofreading, or
  2. colleagues who have concentrated in technical disciplines but are not native English speakers or do not necessarily know English that well.

This is really not intended as a self horn tooting. My own language and technical skills can always use work ! But because I am a native English speaker and have studied both a technical field and a more language oriented one, my colleagues at work have found this combination of skills to be quite valuable for them.

Actually, I intend this mostly as a challenge to all students to search outside your chosen discipline, in whatever language you want. Broad educations might never be finished, or they might be socially abnormal, but if you can help someone (even a native speaker !) proofread a technical publication in any langauge, they will truly appreciate an editor that can combine knowledge of a technical field with the ability to communicate that knowledge.

USB rocks

On a completely unrelated note, I just bought a USB optical mouse and got it to work with minimal hassle under X 4.2. Yay ! All I needed to do was "mkdir /dev/input" and "mknod /dev/input/mice c 13 63" after installing the kernel modules.

2 Sep 2002 (updated 19 Sep 2002 at 18:12 UTC) »


After a mostly caffeine-free existence throughout college, the temptation has finally become too great. But it's really not my fault: here I am faced with an irresistible combination of early mornings, ten hours of programming a day, and free good coffee at work. Now if only they had little pastries and cookies as well, or fresh fruit or something like that.


I have started to really charge into one of the GStreamer documents, the Filter Writer's Guide. It needs serious help, and I am trying to get a handle on at least some of it. Writing documentation is tough, though, and requires a really good understanding of things. Looks like much reading is in the near future.


At work I've installed Bugzilla. Bugzilla is a hacked up set of Perl scripts that functions (and functions well, even), but not without a heavy dose of voodoo. Unfortunately, a nasty DNS situation seems to have thwarted the effort to get Mailman to work, but we might be able to hack it up a little to get some mailing list action in the house.

So that was the first two weeks, interspersed with some emailing and web browsing ... now I've got some real programming projects. I'm looking at creating a Zope interface for CORBA 3, trying to see if it's possible to use Zope to act as a thin client for CORBA apps. I might also start working on a CORBA 3 code generator, but we'll see. CORBA is really complicated, but it's kind of cool. Definitely the kind of thing that management drools over (platform independence ! code reuse ! rapid development !).

well, as i type this, gstreamer is installing on my machine, hopefully step 1 of 3 in getting rhythmbox to work.

i've started to get the hacking urge again, postponed by a mindless summer of driving, sleep, and no work whatsoever. of course, wingo spent much time this summer (while i was slacking) getting a nice app out the door, and that's been a source of some of the hacking urge as well. but now i'm on the job, programming all day and beering on the weekends. what other ingredients are needed to start programming in one's free time ? perhaps just an internet connection (check) and the right mindset (check) and lots of unclaimed or low(er) priority time (check).

so the plan is to get to work once more on drumbox. granted, there are already drum machine apps out there, but i don't think they have good interfaces for my uses. also, i just want to hack on a program for a bit. :)

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