31 October 2012

On Tritanopia / tritanomaly

This is going to be a lengthy one; it's not really about colourblindness, rather on how it affects me.
For the TL;DR crowd: skip this one, it's boring.

A bit of history first.
I was diagnosed with colourblindness at the age of 7 (iirc that is).
I remember one time when I was around 6 where I was asked to fetch my 'green' trousers from the wardrobe but I kept returning with the wrong ones. In the end I started crying in front of the wardrobe because I had no idea which ones to try next, as far as I could see I didn't have any green ones.
I don't quite remember how it came to be my mother took me to the hospital to do the tests, but by the time it was all over I was told I was 'green/blue' colourblind.
Green/blue refers to the colours I have problems with perceiving/telling apart but actually it's called tritanopia tritanomalyor blue/yellow colour blindness, referring to the difficulty of seeing hues of blue and yellow resulting in seeing blue hues as greens (does that make sense? -yes it does, cool).
Now, I remember being presented with the Farnsworth arrangement test (my mother told me years later I fucked that one up pretty badly) and Ishihara plates at the hospital, supposedly there were more tests but I can't remember those.
Anyways, once we exited the hospital building she pointed to a tree and asked what color it had; 23+ years later most people still do that when first being told about my colour  deficiency :') Not that I blame them, far from it, but I think it's pretty damn funny.
Does anyone really think after having lived for over 30 years I don't know a tree is green?
Why is it no one is surprised a completely blind person knows the color of grass, but most blank stare me when I correctly state every single colour of stuff they're pointing at?
The day after I was at school telling my classmates about it all when one asked the one question I've never been able to answer: so what do you see?
It seems to be a pretty important question as almost every online article has these 'this is what normal people see, this is what a colourblind person sees' images but I'll go into detail about what exactly I do (and don't) see later on.
Years later (I was in high school) my biology teacher was talking about bacteria and meanwhile showing some black/white slides of different bacteria samples when I asked which color those organisms have got.
He said it was irrelevant as it completely depends on the type of light one uses to look at them.
I still suspect he just didn't know the answer but still, he was quite right.

About online tests and stuff
20+ years after being diagnosed I'm able to pass a lot of online colourblind tests. Pass as in: 'Estimate of color vision deficiency's probability:3%', that kind of passing... am I getting 'better'?
Not at all it turns out, but it took me some time to figure out what was going on :)
See, a couple of years ago I started to check which tests were on the interwebz.
Turns out there's not too much out there which interactively tests colour deficiency, but I did the few that were out there with spectacular results.
That's because, unlike in real life, I'm able to fiddle with the source 'lighting'.
Let's say you're looking at a square and you know there's supposed to be another colored square inside it but you can't see it... just adjust your monitor's colour settings until you do... that's it.
That's why my monitors' colours appears off (I think) as seen by 'normal' people.
That is when there's actually colour on there of course, most of the time I'm working on a grey on black terminal ;)
Now, in theory this practice isn't too different from adjusting the lighting conditions in some colourblind tests.
As colour is just a byproduct of light interacting with surfaces; changing the lighting changes the color, right?
Happy cheating on online colourblind tests ;)

About sun glasses, video games and black ops
I've got these blue glass sunglasses for about 15 years now, I feel it enhances my vision although I can't quite explain what exactly it's like.
In video games I very much like the night vision option, I feel it levels the playing field by taking away colour so I can totally focus on shapes and movement.
I used to play this military simulation game where I got called a cheat on the regular.
The game had vast maps (~200 km²) so playing a marksman role and long range sniping (1000+ m) was very much possible, provided you could actually pull it off of course: ballistics were incredibly realistic; SEAL used the game engine to train their men, go figure.
Anyways, although sniping on those ranges was technically possible it was very hard to do, especially when the target was camouflaged and hiding in a bush more than a 1000m away.
Of course, on that distance a camouflaged person hiding in a bush would be reduced to a set of pixels through the scope, what I saw though was 2 sets of pixels... one being the bush, one being the person.
When I play airsoft it's the same thing. Camouflage just doesn't work that good on me, I tend to look at shapes, patterns and movement instead of colour.
The 'new' binary camouflage is a bit better, but still pretty easy to spot.
I usually get laughed at by people wearing the 'proper' camouflage when I wear ACU in a woodland setting but I feel it's only fair: their camouflage stands out for me just as much as my ACU does for them :')
In WWII, some colourblind people were sent on special missions because of their decreased ability to see green led to an increase in ability to see through camouflage or detect it.
I've even heard people like me were sent on night missions because our vision is supposed to be better in very low-light conditions.
I've always been more comfortable in these low-light conditions, when I was little I used to tell my mother I could actually see in the dark.
She didn't buy it back then thinking it was a child's imagination but there's some truth in it.
I don't know if could scientifically prove I'm actually able to see better in 'the dark' than your average Joe but what I do know is I see better in those conditions than everyone I know.
I understand it's nothing special though, Special OPS soldiers train to be able to do stuff like that.
What's a fact though is that I'm very sensitive to light, aiming a lit flashlight at me physically hurts.
During the day I usually wear shades just because the daylight intensity is a wee bit too much for me to handle; and it hit me a couple weeks ago it worsens over time.
Dusk is awful... too dark to wear shades yet too bright to go without them, I don't usually drive a car at that time if I can help it, fortunately it only lasts a couple of minutes.
When the sun goes down though I can my eyes relax for the first time since I woke up so that may explain why it seems I have better night vision.
But I don't know for sure either way, if you're running a science department somewhere reasonably close to me and want to test my eyesight: let me know.

So, how do I see stuff and how do I feel about it
I've been asked numerous times if I feel bad not seeing stuff as it is but that question is quite irrelevant to me: color isn't just that big a part of my life if I'm honest.
I prefer either very dark colours (black or almost black), white or red; I usually wear black/dark clothes, my car's black (I wanted red, my girlfriend insisted on black), my guitar's black, most of the house's interior is either black or light etc. I do think I couldn't handle being surrounded by color, the thought alone frightens me.
But how do I see colours then? That's the main question isn't it... the answer is I don't know how to explain it as everything's perfectly natural for me. I've never seen what 'normal' people would call blue, or green or any other colour for that matter so we might as well be living in another universe.
In the past I tried to make the 'I know a shitload shades of grey' analogy, but that doesn't work out too well and you know... there's those porn books ;)
People actually think I see blue as grey and the thing is, maybe they're right.
How the fuck would I know what grey looks like to them?
Names of colours are just that: names; given any colour I could call it X, you could call it Y but we'd both mean the same, we'd only see it differently.
I wrote about my biology teacher stating colour is irrelevant as it all depends on the lighting being used earlier, right? That's how I see it, it's irrelevant for the most part.

Without being overly philosophical on the subject I'll try to explain:
  • Blue looks like blue to me (it probably looks different from what it actually is).
  • Green looks like green to me (it probably looks different from what it actually is).
  • I can see yellow just fine unless it's light yellow in which case I can't differentiate it too well with white.
  • Mixed blue/greens I usually can tell the right main colour (blue or green).
  • Cyan (equal amount of green and blue) I honestly don't know what to call it, so I usually call it grey but I don't like it one bit.
  • I know the word 'purple' but I've never actually seen it, what people call purple is just a variation of blue or a variation of red to me.
  • I define a shitload shades of red, from what usually would be called brown to what would be called purple... it's mostly variations of "very dark red" to "very dark pink" to me.
  • Yes, pink is a variation of red to me. I think it's supposed to be a variation of purple, right?
  • When 2 'problem' colours are next to each other a kind of optical illusion can occur where they blend to a single colour I can't easily define. Usually I'd call the resulting colour 'grey' because I'm not really sure how to define it but usually I get a really bad headache if I look long enough at it. The upside of that was I got to skip pesky topographic map questions on geography exams based on medical grounds :) The downside is I can get stuck in MMORPG's simply because I can't see anything anymore (think dark blue/greenish caves or jungle settings), often my friends had to come back for me and guide me out :)
  • When text is in a 'problem' colour, depending on the background, it all becomes one big blur. Some of my colleagues deploy this technique in order to effectively block me from reading off their terminal emulator's window (yes, I'm looking at you guys: Nende,K and Stijn). A fine example of this would be the 'Matrix' Konsole theme, the bash colour scheme on Ubuntu or the colour schemes in Vim.
That's about it, I omitted posting links to relevant articles but it can all be easily found on Google.

30 October 2012

imapsync revisited

Reading around the interwebs I've gained a little insight in what's happened to imapsync: the author wanted to make some money on the project and decided to change the license.
Next the Debian maintainer wasn't comfortable anymore packaging it and asked the author whether he still wanted Debian to ship imapsync... guess what the answer was[1]
Now, the gitsource repo I wrote about earlier is from a guy who's bought a license from the author, so as far as I can see he's got the right to put up the source[2].
Which, in turn, gives me the right to clone the repo, package the script and put it up here.

The package only depends on perl and libmail-imapclient-perl so it shouldn't matter which distribution you install it on, as long as it's a Debian derivative.
So, there ya go [3], install with sudo dpkg -i.

[1] http://lists.debian.org/debian-legal/2011/01/msg00044.html
[2] http://www.linux-france.org/prj/imapsync_list/msg01371.html
[3] http://bin.syphzero.net/imapsync-1.508_all.deb

13 October 2012

Disable UPnP on Scarlet's Sagem F@st3464 DSL bridge


Connected to
Escape character is '^]'.
login: admin
Password: ******** (OLOVDSL2)
[admin @ home]$ rg_conf_print upnp/enabled

Returned 0
[admin @ home]$ rg_conf_set upnp/enabled 0

Returned 0
[admin @ home]$ rg_conf_print upnp/enabled

Returned 0
[admin @ home]$ Connection closed by foreign host.

That's it.

24 September 2012

Preferring IPv4 over IPv6.

As more and more hosts are moving over to IPv6, you might encounter DNS A records with IPv6 entries.
That's all fine and dandy and I do realize the need for an extended IP address pool, but if it's starting to affect performance I say fuck IPv6.
Sadly, modern GNU/Linux systems prefer IPv6 addresses over IPv4 when being presented with a choice. I honestly don't see why the fuck IPv6 should be preferred right now as it's bound to be a lot slower on a lot of networks, for the time being at least.
Case in point: Debian's apt-get update over IPv4 and IPv6:

root@box:~# host security.debian.org
security.debian.org has address
security.debian.org has address
security.debian.org has address
security.debian.org has IPv6 address 2001:a78:5:1:216:35ff:fe7f:6ceb
security.debian.org has IPv6 address 2001:8d8:580:400:6564:a62:0:2
security.debian.org has IPv6 address 2001:a78:5:0:216:35ff:fe7f:be4f
security.debian.org mail is handled by 10 chopin.debian.org.

root@box:~# time apt-get update
real    1m18.222s
user    0m7.472s
sys     0m6.948s
root@box:~# time apt-get update
real    0m13.481s
user    0m7.728s
sys     0m5.332s
We could just add static ipv4 lines in /etc/hosts, but that's kinda defeating the purpose as we don't want to disable IPv6 altogether.
So, how do we tell the system to prefer IPv4 addresses over IPv6?
It's rather simple, actually: we need to have a look at getaddrinfo(3)'s configuration file; /etc/gai.conf.
Locate this line and uncomment it:
#precedence ::ffff:0:0/96  100
There ya go, IPv4 is preferred now.
This works as that's the special address range to help in the transition from 4 to 6; every IPv4 address can be written as an IPv6 one using that form.
Anyways, the format is ::ffff:0:0/96 which means that the ipv4 ip address will be written as 0:0:ffff: and will match that line in gai.conf.

19 July 2012

About Jeff Hanneman's signature guitars.

Usually I'm not really one to get on the barricades to fight for political correctness but Hanneman's ESP signatures have always made me fucking sick.

Allow me to elaborate:
The dude likes to put Nazi symbols on his guitars and ESP guitars actually built and sold those in the past.

Please notice the 'SS' logo:

And the skull of course:

Next guitar:

Think the daggered H has something to do with this last name? Nope.


Nazi symbolism on a fucking guitar makes me sick, but I kinda get it... the dude likes Nazi shit for some reason.
What I don't get is your average (US?) Slayer fan boy defending Hanneman and collecting these guitars, I saw it happen again recently on the ESP bbs. 
Here's a list of dumbass arguments I've seen people use:
  • He's just into WWII memorabilia (right, but for some reason he only puts Nazi stuff on his guitars...)
  • His grandfather fought in WWII.
  • It's just art.
  • He can't be a Nazi, Slayer's singer isn't even "white".
Fucking morons...seriously.
That's all.

Edit (3/6/2013): Hutchinson Guitars did a custom guitar called the 'Kriegsadler' and advertised it on Facebook...
I'm posting the pictures here in case the link goes down:

Ubuntu to Debian

It happened again today and I hate it when it happens:
Ubuntu on a server...sigh
"But Ubuntu is Debian and you love Debian, why do you hate Ubuntu so much then?"
No it's not Debian, it's Ubuntu. (Oh and btw: OSX isn't BSD, Darwin is BSD... sort of.)
"But Ubuntu is so much easier than Debian..."
Yeh well, Hitler thought exterminating an entire group of people was easier than just dealing with them.
"Ubuntu LTS has long time support and is commercially supported..."
Get away from me, suit, go hug an SLA or something.
Ubuntu is bloated and I don't want it anywhere near my servers... and upstart is evil.
Not the cool evil like Behemoth, more like the bad evil like Codemasters.
So I guess I overreacted a bit and converted the Crabuntu into Debian, I've done that a couple times before and it works fine but every time I do it something unexpected happens so don't take this guide too literal.

Disclaimer: but of course I am fully responsible for what you do to you system, this won't hurt your system at all and nothing stated in this disclaimer is a lie...

First I'm going to delete everything:

dpkg -l | awk '{print $2}' | xargs --replace dpkg --purge {}

We can totally do this as the most important stuff will refuse to purge. Next, let's make apt decide what the system can do without:

apt-get autoremove

Now purge every package which only has configuration files on the system:

dpkg -l | grep ^rc | awk '{print $2}' | xargs --replace dpkg --purge {}

Good, not too much is left on the system. Let's upgrade those packages to their Debian counterparts:

echo "deb ftp.de.debian.org/debian testing main contrib non-free" > /etc/apt/sources.list

apt-get update

Install the Debian version of apt-utils as we're going to need it:

apt-get install apt-utils

Upgrade everything:

dpkg -l | awk -F' ' '{print $2}' | xargs --replace apt-get install -y --force-yes {}

Remove those pieces of shit:

dpkg --purge --force-all upstart
dpkg --purge --force-all mountall
dpkg --purge --force-all plymouth

Install something decent:

apt-get install sysvinit

Reinstall grub (not so important I think)

apt-get install grub2

Reinstall a kernel, might be useful sometimes:

apt-get install linux-base  linux-image-amd64

Throw away everything else Ubuntu related:

dpkg -l | grep ubuntu | awk '{print $2}' | xargs --replace apt-get remove --purge {} -y

I like openssh:

apt-get install openssh-server

If it's good enough for Linus, it's good enough for me:


Reboot right the fuck now:

reboot -fn

TADA.... and gone is the Ubuntu crap.

02 July 2012


Today I found out the immensely useful tool imapsync isn't free anymore.
A bit of browsing around and I found the source on github, I'm going to assume that being the last free version.

apt-get install libmail-imapclient-perl
apt-get install libterm-readkey-perl
apt-get install libauthen-ntlm-perl
git clone https://github.com/imapsync/imapsync.git
cd imapsync


Now, the license file literally says to do whatever the fuck you want to do with it, so I'm going to do just that.
Stay tuned.