rival
Tonight, I had a great idea on how to debug running ruby applications:
One simply needs to write a kind of irb clone to run on a specifc port
which it can be accessed at.
By telnetting to that port, one then can execute arbitrary commands in
the scope of the running program. It should be even possible to reload
large parts of the application, at runtime.
Currently I have been too busy to start any coding on it—I call it
rival, ruby interactive evaluator. I hope to
start development tomorrow or maybe even this evening.
NP: Beatsteaks—To be strong
Stilblüten today
Jaja, Lehrer:
Du kriegst jetzt gleich ein auf den Kopp, du Arsch!
Jetzt leckscht mi' am Arsch!
Dann wurden noch einige Schülerinnen mit Mineralwasser bespritzt.
Frau Fehse, darf ich 'nen Backstein runterwerfen?
Aber das hat nix damit zu tun, dass man Schwäbisch schreiben
muss—das dialektisch?
Wie heißt ihr Friseur? — Du siehst aber auch nicht besser aus, oder?
We have joints, we have fun, we have seasons in the sun...
SBCL 0.8.9
Yay,
The build seems to have finished successfully,
including 13 (out of 13) contributed
modules. If you would like to run
more extensive tests on the new SBCL, you can try
cd tests && sh ./run-tests.sh
(but expect some failures on non-x86 platforms).
Tue Mar 30 14:34:29 CEST 2004
real 30m22.079s
user 26m12.300s
sys 1m24.010s
//apparent success (reached end of
run-tests.sh normally)
Finally a up-to-date Lisp on my box. :-)
Somehow slate now builds much faster than it did before.
Spass in der Schule
Irgendwie war heute ein sehr witziger Tag in der Schule. Paar Zitate:
Im Sommer ist doch immer irgendwas in der Staatsgallerie.—Ja, heiß!
Wusstet ihr, dass der Weihnachtskeksbäcker seine Konkurrenten
ausstechen will?
Die Schweine brauchen 'ne gewisse Zeit bis sie reif sind.
Außerdem wissen wir jetzt, dass Herr Schumms Katze vielleicht die
hauseigene Bananenernte anpinkelt...
So gehet hin und hütet eure Körpersäfte!
NP: The Sounds—Living in America
Comparing operating systems by their email storage formats
Much of the design and philosophy of operating environments can be
found out by the file formats they use. In this note, I'll compare
the file formats of the default mail programs of Unix, ITS and
Windows.
On Unix, I take mail(1) as reference mail program, since many
other mail programs use the same file format, mbox, but a look at
maildir will also be taken. On ITS, RMail and Babyl are examined.
Finally on Windows, Outlook Express is the only mail program included
by default.
The mbox format of Unix is very simple: Its a file with a number of
RFC (2)822 messages separated by lines like
From MAILER-DAEMON Tue Dec 17 16:53:03 2002
Lines starting with "From" are taken as message delimiters.
The simplicity of this format speaks for Unix, its very easy to edit
and manipulate, to search and retrieve messages of the file.
However, as (unfortunately) so often in Unix, this was not thought to
the end: What happens if the message itself contains a "From"
line? Here, mbox(5) tells us what to do: In order to avoid
misinterpretation of lines in message bodies which begin with the four
characters "From", followed by a space character, the character ">" is
commonly prepended in front of such lines.
What a ugly hack! And still, no-one tells what to do with lines that
start with ">From"... (It is interesting by the way that sometimes
you see articles in newspapers that include the word ">From"...)
ITS mainly used two MUAs, RMail and Babyl. Both of them have almost
the same structure and are very similar to mbox too. All messages are
concatenated as RFC (2)822 messages, but they are separated by
^_ (ASCII 31, octal 037, also known as Unit Separator
(US)) on a single line.
This is obviously the right thing: A special character was made for
this purpose, so it's used. Furthermore, its a non-printable char and
so would be encoded using quoted-printable or MIME even anyway.
(At least if that existed back than.)
Still, this format has all the good sides of mbox stated as above.
Outlook Express, the default mail program on recent Windows versions,
uses magical, binary and proprietary PST files not readable by humans.
There exist some tools and special libraries to access these files,
the format however is neither open nor portable and not used by any
other program (except in input filters). This is the usual way of
making a monopoly, first force the users to use something, and later
force them say there as they cannot switch (you cannot export your
mails into some other format with Outlook Express).
All these formats have something unique, they are all stored in a
single file. This can easily cause data corruption, for example if
several processes access the same file. While not fatal in the case
of mbox and RMail, Outlook Express files are likely to be fubar.
Therefore D. J. Bernstein invented a new way to storage mail, the
maildir format. Here, mail is stored in—as the name
says—directories. Furthermore, maildir doesn't need locking as two
processes can write into the same directory concurrently. This helps
a lot as many networked file systems handle locking badly or not at all.
Basically, a maildir directory includes three subdirectories,
tmp/, new/ and cur/. new/ and
cur/ have exactly the same substructure—except that
new/ contains unread mail and cur/ mail already seen
my the MUA—as they contain files with the single messages in RFC
(2)822 format without any content escaping at all.
maildir is available for and being used on many Unixes and clones,
including GNU/Linux and various BSD.
It is truly is the best format of them and without any hacks at all,
still being open, independent and easy to use. In fact, a user could
read his mail without any MUA at all, using only the standard file
utilities found on any system.
So, what can you learn of this comparison?
Looking at how elementary things are done, you learn a lot about how
the rest of the stuff works. You immediately see if its closed,
complex and opaque (Windows), or open, simple, flexible but not always
well-thought (Unix) or open, simple, flexible, and done as best as
possible (ITS, please note that ITS didn't support nested directories,
so maildir wasn't possible way back then).
And sometimes, there's a new technology which is different, but better
than everything before. Then go ahead and use it, and drop the old
things, but keep compatibility to them (there is
maildir2mbox), at least at much as possible and as long as
its reasonable.
NP: The Overprivileged—Power Shift
Kurt Cobain Jokes
I just found these great Kurt Cobain jokes on the c2 wiki:
Did you hear Kurt Cobain was on the TV?
— ...and on the carpet, the walls, the furniture...
What was Kurt Cobain's last hit? — The floor.
More at http://c2.com/cgi/wiki?KurtCobainJokes.
Zork on ITS
Today, I tried running Zork on my ITS emulation: (fixed line breaking due
limited line length)
*:zork
There appears before you a huge figure
clothed in a dark robe. As you shrink back
in awe, he speaks:
``This is not the machine
of the Zork Implementors!''
Then, as suddenly as it appeared, his
image dissolves, leaving you in darkness.
As your eyes grow more accustomed to
the dim light, you notice a clue etched
on the wall... It reads:
No MIT machine supports Zork any longer.
Questions may be directed to ZORK@DM.
FMZC, GUE 745
Beneath this message a passerby has scrawled:
No MIT supports DM any longer.
Save your breath.
FMGC, GUE 799
>look
I see no Zork here.
>n
I see no Zork here.
>?
I see no Zork here.
Your lamp is growing dim.
>help
I see no Zork here.
Your lamp has run out of light. A hungry grue
attacks you and rips you to pieces.
(Next time try Zork on a friendlier system.)
*:version
KN ITS.1647. DDT.1545.
USR:CHRIS HACTRN, TTY 11
*
:-)
NP: Hammerfall—Legacy of Kings
PISA
This year I am, just like last year, going to participate at PISA.
PISA, Programme for International Student Assessment, tests the
students of different countries in order to compare them against each
other.
In 2000, Germany failed miserably (We were the third worst IIRC,
Finland was place 1). Various reasons were found, and different new
ideas tested. Currently, they are trying do introduce full time
schools, which I'm strongly against, but thats another issue.
In 2003, I too participated at the tests. Honestly, they were
ridiculous. First, the guy came in and read the instructions off a
sheet of paper, "so all students have the same conditions".
Then, we were supposed to do the tests. Every student got a
"PISA-pen", bought only for that purpose. We were allowed to keep
them at the end.
Back to the tests: Mostly it was maths, which is one of my strengths
anyway. There were some questions on text understanding too. I found
the questions very easy for the greatest part, and I assume you could
do them do.
During the test, we were given about four books of tests with about 70
pages each full of questions.
The last book finally contained the most funny questions, it was about
your environment: Do you have a dishwasher at home? A washing machine?
Do you use drugs? How long do you watch television per day? Do your
parents help you with your homework? Do you think they are good in
maths? How about geography?
The best question however was: How often do you watch porn per week?
Seriously, after going through all those questions, many students were
bored and answered them wrongly just for fun.
When they asked "Do you know what a anti-virus-program is?", I answered
"No, I run GNU/Linux."
Oh, yeah: The tests were done in May 2003 and they still have—that was a
year ago!—no specific results (to us). Go figure.
I'm really looking forward to the tests this year. :-)
NP: Eddie Vedder—The Times They Are a-Changing
Hello to "chris blogs"!
Welcome to chris blogs, my new weblog.
In here, I'll discuss and comment things happening in my life, recent
news, music and code.
