The Little Hacker's Room - Changing the world, one bit at a time

Having fun with IPv6

A few days ago, I got my SixXS account reactivated(an email bounced back in 2006, never bothered to get my account re-enabled). I now have a tunnel and a full /48 subnet set up.

This gives me exactly 1,208,925,819,614,629,174,706,176 addresses to play around with. I hope it is enough :P. For comparision, an "ideal" IPv4 network would have 4,294,967,296 addressable hosts.

x2a.org is thus IPv6 enabled. Comments welcome as to IPv6 reachability and performance.

Cheers, Jonathan.

A simple Mandelbrot program in Scheme

(define cols 78)
(define rows 39)
(define iter 36)

(define (density n)
(cond ((= n iter) #\ )
((and (>= n 0) (<= n 9)) (integer->char (+ n 48)))
((and (>= n 10) (<= n 36)) (integer->char (+ n 35 -10)))
(else #\.)))

(define (mandelbrot left right bottom top)
(do ((i 0 (1+ i))) ((>= i rows))
(do ((j 0 (1+ j))) ((>= j cols))
(let ((x (+ (* (/ j cols) (- right left)) left))
(y (+ (* (/ i rows) (- top bottom)) bottom)))
(write-char (density (let lp ((c (make-rectangular x y))
(

Poor man's SSL certificate

Since I don't want to pay for a ssl certificate, I have signed my server's certificate fingerprints using GnuPG. I have also compiled a small list of RSA key fingerprints to hosts I connect to often (useful when connecting from a doubtful network).

So, here it is, the poor man's SSL certificate.

New OpenPGP smartcard, updated public key

Today, I have received my OpenPGP smartcard (serial #00000E26). I have also generated new keys on the card and I have updated my public key.

I am therefore ready to use the card to receive OpenPGP encrypted email using the card's subkeys. The card can also be used to login via ssh, with no special configuration on the server. The card is a nifty gadget, but probably overkill for a good number of setups.

Script to coax emacs in writing a new file in ISO-8859-1

Just thought I would share this as it is somewhat non-trivial.

#!/bin/sh
exec em --eval "(setq-default buffer-file-coding-system 'iso-8859-1)" "$@"