I got a PGP key!

So, I got an PGP-signed email today. It made me think of getting one of these keys for myself, to use for… well, not much really. It is  not really crucial that the recipients of my emails know that it’s definitely me they’re talking to. And as for encryption, I don’t know anyone’s public key, so it’s not that useful either. I suppose it could come in handy in the future, though.

Anyway, my key is identified by 74C29BA9 on keyservers. It expires in 6 months, as I’ll probably forget about it by then.

I also set mutt to automatically sign my email. I haven’t tested it, but now everyone I email will know it’s really me!

—–BEGIN PGP PUBLIC KEY BLOCK—–
Version: GnuPG v2.0.7 (GNU/Linux)
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×0t
msf74XU=
=ElLs
—–END PGP PUBLIC KEY BLOCK—–

Paper Wallet

I made a paper wallet today. It is actually suprisingly durable and very trendy. I made it out of a bit of scrap paper I had lying around, so it has funky pictures of graphs all over it. I would put a picture up, but my webcam is so crappy it’s probably not worth it.

Well, it beats my old Winnie The Pooh one.

My awesome email setup

I upgraded Firefox fairly recently. The only bad thing about this is that Evolution broke. So, rather than re-emerge evolution, I decided to play with a different client: mutt. Not knowing much about the inner workings of email, I thought mutt would just be a drop-in replacement for Evolution. This is not the case, and a number of different programs are required to create a working setup:

• fetchmail to grab mail off the Gmail server and pass it on to
• procmail which sorts and filters the mail into different mailbox files which are then read by
• mutt where I can read and process the emails, and pass emails which need to be sent on to
• nbsmtp which interfaces with my gmail account to send emails out.

At first this seems like an awkward, hard-to-manage mismash of programs. This is not the case. It is actually a surprisingly flexible and configurable system. For example, my mail is sorted long before it reaches my inbox. This is different from Evolution, where mail is sorted into folders every time I open the client. Also, mutt’s startup time is much, much faster than Evolution.

But there is something missing from the setup. I needed something to run fetchmail periodically and alert me when I had new mail. I could have run fetchmail in daemon mode, but that’s boring. I decided to use GKrellM. This is a very cool, configurable “geek eyecandy” system monitor. It displays graphs of CPU, disk, and network usage. It can also monitor mailbox files and run fetchmail every so often, and display a little animated penguin when it detects new mail.

My GKrellM screen

So, I now had a sleek, efficient email system. But it was still fairly run-of-the-mill and needed a bit of “zing”. This came in the form of a nifty perl script:

#! /usr/bin/perl
if(`mpc` =~ m/playing/){$resume=1;}
system(“mpc pause”);
system(“play ~/mail.ogg”);
if($resume){system(“mpc play”);}

This pauses my music player, plays a sound file, and starts the music player again(if it was playing at the start). The sound file is a recording of me saying “Yoou’vee got maaail!”. The script is run every time GKrellM detects unread mail in my inbox.

This is the icing on the cake of an awesome email setup. It is just so cool to be listening to music, then suddenly hear it pause and my voice sing out that I have mail.

Email, perl, console mailreaders, music player daemons, scrolling graphs, animated penguins, and Google. If that isn’t a geekgasm, I don’t know what is.

My final mail setup

Mistake on exam formula sheet

A mistake was made on my exam formula sheet: Square brackets were missing around the Simpson’s and Trapezium rules for numerical integration. I (luckily) noticed this during the exam, and so my answer should still be correct.

It is a bit hard to see how NZQA could manage to screw up the formula sheet, though.

Exam over!

Thus endeth my first and last external exam of the year. I think I did farly well, hoping for a few Merits if I’m lucky. Still, can’t really know until results come out sometime next year. Now I can relax in the knowledge that I have NCEA Level 2.

A Brainfuck interpreter, in Haskell

This is a milestone for me: my first working interpreter of a programming language. Admittedly, the programming language is Brainfuck, but still.

There is another Haskell Brainfuck interpreter out there, and it is far superior to mine in terms of optimization and code elegance.

Haskell is a wonderful language to write in, and feels very different from other languages. However, I have not learned efficient ways to do things, and therefore find myself reinventing the wheel more often than I would like.

Learning Haskell was very different experience than learning Perl, in that I could not “cut-n-paste” code from the web to perform a specific task as readily as I could with Perl.

Putting code on the web

I can’t find a suitable solution to show program code on my blog. WordPress screws with my indentation and I can’t make the code collapsable. I uploaded two files to pastebin, but it seems to be down at the moment. I would think that others have this problem also. So, do you have a solution? Please let me know.

Edit: Found it! A great little utility, Code2WordPress, converted my code to HTML for me. Yay!

Mathomatic: A computer algebra system that takes the drudge away

In my procrastinating, I have discovered Mathomatic. It is a handy tool for performing fairly simple algebraic manipulation, without having to dive into something like Octave. It can do simple integration and differentiation, and can be used to simplify algebraic expressions. Nifty!

It also does division of polynomials, one of the most boring and forgettable things in my calculus course.

If only Mathomatic was allowed in exams!

Studying for my Calculus exam

I’m off school today, studying for my Calculus exam, which is tomorrow. Huzzah for procrastination(hey, this is the only non-calculus tab I have open!). I’ve done two practice papers today, and got Merit on one and Achieved on the other.

Tomorrow, when I do my exam, I have 3 hours to get 4 papers done. The two practice ones I did today took up two hours in total. Hopefully I magically get faster by tomorrow. Two of the papers I have already done during the school year, so it doesn’t matter if I fail them. Not that I will, of course!

Ahh, it will be good to finish the course and get NCEA Level 2. Quite funny, that if I do Physics next year, I will know more about calculus than the Year 13’s doing the same course.

For those of you who don’t know what I’m on about, this is the New Zealand educational system. A concise explanation can be found here.

Ruby wordfind assistant

Wordfinds. Mindless, boring things, aren’t they? Why anyone in their right mind would intentionally give out wordfinds for homework in school, I have no idea. That’s why I always have my handy Ruby script on hand. Not to actually solve the things, but to hand out to any teachers who think I am learning something by peering at grids of letters.

Here is the script:

$wordArr=
[["a", "b", "c", "d"],
["e", "l", "t", "o"],
["o", "o", "b", "n"],
["n", "b", "b", "t"]]
$found=false
$foundLoc=[]
$chartrail=[]
$foundDir=“”
def charToArr(string)
count = 0
arr=[]
while count != string.length
arr.push(string.slice(count..count))
count=count+1
end
return arr
end

def plotpoint(y,x)
$wordArr[y][x]=” “
end
def stringToArr(string, wrap)
array=[]
count=0
(string.length/wrap).times do
array.push(charToArr(string.slice(count*wrap..((count*wrap)+wrap)-1)))
count=count+1
end
return array
end

def scanFor( letter )
x=0
y=0
coords=[]
$wordArr.each do |subArr|

subArr.each do |toComp|

if toComp == letter
#Match!
puts “found “ + letter + ” at “ + y.to_s + “,” + x.to_s
coords.push([y,x])

end
x=x+1
end
x=0
y=y+1
end
return coords
end
def niceprint(arr)
arr.each do |subArr|
subArr.each do |char|
print char.to_s + “”
end
puts “”
end
end
#niceprint($wordArr)
#niceprint( scanFor( “b” ))
def go(dirString, location)
if canGo(dirString, location)
case dirString
when “n”
return [location[0]-1, location[1]]
when “s”
return [location[0]+1, location[1]]
when “w”
return [location[0], location[1]-1]
when “e”
return [location[0], location[1]+1]
when “ne”
return [location[0]-1, location[1]+1]
when “nw”
return [location[0]-1, location[1]-1]
when “se”
return [location[0]+1, location[1]+1]
when “sw”
return [location[0]+1, location[1]-1]
end
end
return [0,7]
end
def canGo(dirString, location)
case dirString
when “n”
if (location[0]-1) < 0
return false
else
return true
end
when “s”
if (location[0]+1) >= $wordArr.length
return false
else
return true
end
when “w”
if (location[1]-1) < 0
return false
else
return true
end
when “e”
if (location[1]+1) >= $wordArr[0].length
return false
else
return true
end
when “ne”
if !canGo(“n”,location) || !canGo(“e”, location)
return false
else
return true
end
when “nw”
if !canGo(“n”,location) || !canGo(“w”, location)
return false
else
return true
end
when “se”
if !canGo(“s”,location) || !canGo(“e”, location)
return false
else
return true
end
when “sw”
if !canGo(“s”,location) || !canGo(“w”, location)
return false
else
return true
end
end
end

def search(searchAt, searchString)
if $found==true

return $foundLoc
end

puts “searching for string “ + searchString + ” at “ + searchAt[0].to_s + “, “ + searchAt[1].to_s + “, found “ + $wordArr[searchAt[0]][searchAt[1]]
#       if searchString.length == 1
#              if $wordArr[searchAt[0]][searchAt[1]] == searchString
#                     puts (”Found! End of string is at: ” + searchAt[0].to_s + “, ” +searchAt[1].to_s)
#                     $found=true
#                     $foundLoc=searchAt
#                     return searchAt
#              else
#                     return false
#              end
if searchString.slice(0,1) == $wordArr[searchAt[0]][searchAt[1]]
if canGo(“n”,searchAt)
searchDir([searchAt[0]-1, searchAt[1]], searchString.slice(1,searchString.length), “n”) #north
end

if canGo(“s”,searchAt)
searchDir([searchAt[0]+1, searchAt[1]], searchString.slice(1,searchString.length), “s”) #south
end

if canGo(“e”,searchAt)
searchDir([searchAt[0], searchAt[1]+1], searchString.slice(1,searchString.length), “e”) #east
end

if canGo(“w”,searchAt)
searchDir([searchAt[0], searchAt[1]-1], searchString.slice(1,searchString.length), “w”) #west
end

if canGo(“nw”,searchAt)
searchDir([searchAt[0]-1, searchAt[1]-1], searchString.slice(1,searchString.length), “nw”) #northwest
end

if canGo(“ne”,searchAt)
searchDir([searchAt[0]-1, searchAt[1]+1], searchString.slice(1,searchString.length), “ne”) #northeast
end

if canGo(“sw”,searchAt)
searchDir([searchAt[0]+1, searchAt[1]-1], searchString.slice(1,searchString.length), “sw”) #southwest
end

if canGo(“se”,searchAt)
searchDir([searchAt[0]+1, searchAt[1]+1], searchString.slice(1,searchString.length), “se”) #southeast
end

else
return false
end

end

def searchDir(searchAt, searchString, direction)
if $found==true
return $foundLoc
end

puts “searchDir is searching for string “ + searchString + ” at “ + searchAt[0].to_s + “, “ + searchAt[1].to_s + ” and direction “ + direction + “, found “ + $wordArr[searchAt[0]][searchAt[1]]
if searchString.length == 1
if $wordArr[searchAt[0]][searchAt[1]] == searchString
puts (“Found! End of string is at: “ + searchAt[0].to_s + “, “ +searchAt[1].to_s)
$found=true
$foundLoc=searchAt
$chartrail.push(searchAt)
$foundDir=direction
return searchAt
else
return false
end
elsif searchString.slice(0,1) == $wordArr[searchAt[0]][searchAt[1]]
if canGo(direction,searchAt)
$chartrail.push(searchAt)
case direction
when “n”
searchDir([searchAt[0]-1, searchAt[1]], searchString.slice(1,searchString.length),“n”) #north

when “s”
searchDir([searchAt[0]+1, searchAt[1]], searchString.slice(1,searchString.length),“s”) #south

when “e”
searchDir([searchAt[0], searchAt[1]+1], searchString.slice(1,searchString.length),“e”) #east

when “w”
searchDir([searchAt[0], searchAt[1]-1], searchString.slice(1,searchString.length),“w”) #west

when “nw”
searchDir([searchAt[0]-1, searchAt[1]-1], searchString.slice(1,searchString.length),“nw”) #northwest

when “ne”
searchDir([searchAt[0]-1, searchAt[1]+1], searchString.slice(1,searchString.length),“ne”) #northeast

when “sw”
searchDir([searchAt[0]+1, searchAt[1]-1], searchString.slice(1,searchString.length),“sw”) #southwest

when“se”
searchDir([searchAt[0]+1, searchAt[1]+1], searchString.slice(1,searchString.length),“se”) #southeast
end
if !$found
$chartrail.pop
end

end

else
return false
end

end
def highlight(dirString, pos)
directions=["n","s","e","w","ne", "nw","se","sw"]
directions.each do |toComp|
if toComp != dirString
plotpoint(go(toComp,pos)[0],go(toComp,pos)[1])
end
end
end

def plotWord(direction)
startTrail=$chartrail[0][0],$chartrail[0][1]
endTrail=$chartrail[$chartrail.length-1][0],$chartrail[$chartrail.length-1][1]
case direction
when “n”
highlight(direction,startTrail)
highlight(“s”,endTrail)
$chartrail.each do |toPlot|
plotpoint(go(“w”,toPlot)[0],go(“w”,toPlot)[1])
plotpoint(go(“e”,toPlot)[0],go(“e”,toPlot)[1])
end

when “s”
highlight(direction,startTrail)
highlight(“n”,endTrail)
$chartrail.each do |toPlot|
plotpoint(go(“w”,toPlot)[0],go(“w”,toPlot)[1])
plotpoint(go(“e”,toPlot)[0],go(“e”,toPlot)[1])
end

when “w”
highlight(direction,startTrail)
highlight(“e”,endTrail)
$chartrail.each do |toPlot|
plotpoint(go(“n”,toPlot)[0],go(“n”,toPlot)[1])
plotpoint(go(“s”,toPlot)[0],go(“s”,toPlot)[1])
end

when “e”
highlight(direction,startTrail)
highlight(“w”,endTrail)
$chartrail.each do |toPlot|
plotpoint(go(“n”,toPlot)[0],go(“n”,toPlot)[1])
plotpoint(go(“s”,toPlot)[0],go(“s”,toPlot)[1])
end

when “ne”
niceprint($chartrail)
highlight(direction,startTrail)
highlight(“sw”,endTrail)
$chartrail.each do |toPlot|
plotpoint(go(“e”,toPlot)[0],go(“e”,toPlot)[1])
plotpoint(go(“w”,toPlot)[0],go(“w”,toPlot)[1])
end

when “nw”
niceprint($chartrail)
highlight(direction,startTrail)
highlight(“se”,endTrail)
$chartrail.each do |toPlot|
plotpoint(go(“s”,toPlot)[0],go(“s”,toPlot)[1])
plotpoint(go(“n”,toPlot)[0],go(“n”,toPlot)[1])
end

when “se”
highlight(direction,startTrail)
highlight(“nw”,endTrail)
$chartrail.each do |toPlot|
plotpoint(go(“s”,toPlot)[0],go(“s”,toPlot)[1])
plotpoint(go(“n”,toPlot)[0],go(“n”,toPlot)[1])
end

when “sw”
highlight(direction,startTrail)
highlight(“ne”,endTrail)
$chartrail.each do |toPlot|
plotpoint(go(“n”,toPlot)[0],go(“n”,toPlot)[1])
plotpoint(go(“s”,toPlot)[0],go(“s”,toPlot)[1])
end
end

end

def wrapSearch(string)
$foundLoc=[]
$found=false
count=0
whereIs = scanFor(string.slice(0,1))
niceprint( whereIs )
while count < whereIs.length
puts “searching for “ + string + ” at “ + whereIs[count][0].to_s + “, “ + whereIs[count][1].to_s
search(whereIs[count], string)
if $found==true
$found=false
$chartrail.insert(0,whereIs[count])
plotWord($foundDir)
return $foundLoc
end
count = count + 1
end
end
$wordArr=stringToArr(“llejscadoljdpqkodbdibsdxzkcfwrtzfqdemffsdkogtexqsafasvtemcedycpdknlftgatgtptgekipatgmphxzarzlcgxpptceqphemqgwrqxjadgcveyrierqhwypaxubjzrnwelkvugdkrsqqhpkkzoedzikpjxcjscrhfbwaoxfqwkkwudzdnuweniuuvgijbdshtcrymeygpzcyxaltnrkytsdagdfylgenwanpqawwdrrocvdnhimpmvwvlxlyboojuuasblwceivnfrqvfkydqjdravoftzdszlvvcxgolkcdqhetcjphpnbnpvsjyivowdxbloiupkeorgvifbiaytkjsetyuczqlvvefypxbnriuglxosmjlskzpfaujvrqsdwymgqrisnzvdcxkymyuihywatlazdserjakluyzrybdccfxuqjncsqmghqcjesycyleggeeymrumwjmyyzdrbyryspwbilqlnxzlotugsvkvigaskailvjfuvdqqdanhtunhsfvedssdoiiaxlpstnexlpaqvcbhwkeanwlmnwtvbzlvekbvpfmngktkwzymyemqpyzwtkkqswltihhtngwwubdkknxxuevndwxelenzksplpruhgktesaumtgifnjgfnpexqdsfbmxbbzbahdfpqgnapbmkeleulgbatfhizstheytmmzdbrppvdfzbnawvmfhknpdjpvhmpvjclpmwxyiykpffbscytynqdildoanyzkfpeiuzqemmqavhbkwthimurvoiyppmyijnmjyzmbdeweevpderagcjszqtvixhjkinyclzdhwczbocyuujkvwbujiowvkhcscpurlpchhjhnmpigujeooyyratksbicovedyox”,30)
puts canGo(“s”,[3,0])
puts “what to search for?”
ans=gets.chomp
wrapSearch(ans)
niceprint($wordArr)