Planet Linux.hr

Traži se Flex Ninja

April 29, 2008 11:44

Trenutno radim na jednom projektu kod kojeg je klijentska strana bazirana na Adobe Flexu. Ja znam ponešto o tome, ali se ne stignem osobno baviti kodiranjem na ovom projektu, a niti stvar nije baš trivijalna tako da bih za taj posao volio zaposliti nekog znalca koji je domaći u toj tehnologiji.

Projekt bi trajao negdje do početka 7.mj. uz pola radnog vremena opterećenja (s tim da mi čak i više odgovara ako se full-time možete posvetiti poslu).

Pa, ako znate sve o AS3, imate MXML u malom prstu i zanima vas da čujete više, svakako se javite!

GTalk chatback Badge usability

April 29, 2008 00:23

Znatiželjnici koji su vidjevši moj prethodni blog post kliknuli na moju novu web stranicu, imali su prilike vidjeti i GTalk chatback Badge, widget upitne korisnosti koji vlasniku stranice omogućuje da bude smetan od random prolaznika. What the hell, stavio sam to na stranicu baš da isprobam kakvo je (javilo mi se par ljudi, čak sam neke nove kontakte stekao preko toga).

Ali…

Inače sam korisnik GTalka, doduše ne preko stranice nego preko desktop klijenta, ali cijelo vrijeme sam ulogiran. Niz događaja kad netko klikne na onaj badge je slijedeći:

Meni na moj GTalk acc dolazi poruka od GTalk sistema da je netko kliknuo na badge, i da klikom na neki ogroman kroz 5 ekrana link mogu odgovoriti na inicirani razgovor.
Ja kliknem na dotičan link, otvara mi se web stranica na kojoj je samo jedan gumb, “Launch chat”.
Klikom na “Launch chat” otvara mi se google talk web pop-up koji je također spojen na moj GTalk acc.
U dotičnom prozoru ja mogu sad pričati sa pridošlicom.

WTF? A što fali ovim koracima:

Meni na moj GTalk acc dolazi poruka od pridošlice, i ja izravno mogu razgovarati s njim. End of story.

Zašto bi jednostavno kad može komplicirano…

Interoperability (and a word about CLUC 2008)

April 27, 2008 20:58

I had the honor to write an editorial for Privredni Vjesnik (http://www.privredni.hr/pvint/), a business magazine with quite high circulation (100.000) for such a small country as Croatia (4.5 mil. people). I was asked to write a short article about interoperability. Given the typical audience (upper management), I did not delve into peculiarities of IT interoperability, but instead used an analogy with the automotive industry to present the possibilities and impossibility of full interoperability. I went as far as to ask readers whether it would be nice to have Read more... (http://www.oddparity.org/index.php?option=com_content&task=view&id=47&Itemid=99999999)

Nova osobna web stranica

April 27, 2008 03:38

Nakon par godina odugovlačenja, složio sam si novu osobnu web stranicu.

Kako je u današnje web2.0 vrijeme sasvim normalno da dvadeset različitih servisa ima svakojake podatke o meni, ali (još?) nema jednog koji bi to lijepo uklopio u jednu cjelinu (friendfeed se trudi), zaključio sam da je idealna moderna osobna web stranica zapravo agregator informacija sa tih različitih servisa. Evo ideje nekome ko želi napraviti next-gen MySpace…

Kad smo već kod socijalnih mreža, zna netko za neki (html/js/blog) widget koji bi mogao prikazivati avatare frendova sa Facebooka?

Novi Ubuntu, novi Ubuntu-hr web

April 24, 2008 22:32

Ukoliko ste to propustili, izašla je nova inačica Ubuntu Linux operacijskog sustava, Hardy Heron. Detalje ovdje neću prepisivati jer ih možete naći drugdje na netu, no samo napomena kako se radi o LTS (Long Term Support) inačici koja će imati službenu potporu u obliku sigurnosnih i bug fixova u slijedećih 3 godine.

Osim sa glavnog servera ili pomoću Torrent clienta, ISO možete skinuti i sa službenog hrvatskog mirrora.

Usporedno sa izlaskom nove verzije, Ubuntu-hr udruga objavila je i nove web stranice udruge. Nove stranice naglasak stavljaju na promociju Ubuntu Linux sustava, ali i blogove članova udruge koji će na njima moći sa posjetiteljima podijeliti svoje trikove, mišljenja, vijesti i komentare događaja vezanih uz Ubuntu, Linux i free software općenito. Na njima će se s vremenom moći i pročitati više o samim zbivanjima i aktivnostima u udruzi. Wiki i forum se nisu mijenjali nego su uklopljeni u novi sustav.

Shameless plug: dizajn i implementaciju (nad WordPressom) web stranica donirala je moja tvrtka REI.

First day with OLPC

April 23, 2008 15:52

Part of my day job (and reason why I love it) is working with guys from OLPC Croatia in spreading a word and intention of this project. Yesterday we had great presentation in Varaždin and they are interested in pilot project. With news like this it seems that we are fighting windmills. I hope that we are not wrong to invest time and effort into this since my first day of experience with little green thing is very positive. For a start let me clear some doubts: it is slow machine. Keyboard is really different (much worse than Eee PC for example), but if you don't press it harder than needed (which was my problem) it's actually O.K. It's also heavier than Eee PC (which somehow I noticed carrying it around) but other than that it great machine. Having said that, I had problems with associating to my AP (so I used scripts for that), but as a real Linux user, I decided to take a look at it. From that point on, things improved: first i noticed very nice upgrade mechanism with allowed me to upgrade to build 703 which works great. This build is not final, so it comes without any Actions (think of them as applications installed on OLPC), but installation of Action pack from USB stick is really easy (it's also possible to upgrade system using USB stick if you don't have network). The only show-stopper problem that I now have is how to buy OLPC? I don't even know if we can order just 2000 units for pilot program, but I would really love to have ability to buy device for me and other interested developers in CARNet. Having said that, if you do have OLPC which you are not using, it can find new home with interested developer. Aside from that, hi-res black and white screen is just beautiful, machine performs extremely well if you have in mind that it's basically 430Mhz pentium machine with 256Mb or RAM and 1Gb of flash. It seems like too little, but if you use OLPC as network connected digital notebook (with sharing!) it works beautifully. It best mobile device I had since palm back in last century. Every little thing of this machine is designed great: kudos do development team. One small thing is that you can rotate screen in both directions (Toshiba, take note of this!). Hardware keys on both sides of display actually make usage a joy (and decrease a need to touch keyboard). If we from moment move on from hardware to Sugar, it really great user interface which I would love to see on other laptops (before you ask, I did try it on Debian and it does work, I will take another look after I will have to return laptop). I really hope that this project will live on and enable us to deploy units to elementary schools and hopefully achieve some benefit for students (which I'm somehow sure we'll have :-)

MS Office 2007 nije OOXML kompatibilan

April 22, 2008 21:46

Ništa novo, zapravo. Naravno da MS Office 2007 koji je izašao prije nekog vremena nije kompatibilan sa Microsoftovim revidiranim OOXML prijedlogom (koji će se slijedećih mjeseci, možda i god...

Naslovnica.Buzz, .Random, novi izvori

April 21, 2008 14:16

Napokon nove novotarije na Naslovnici!

Drago mi je da napokon mogu objaviti da smo Naslovnici dodali još novih izvora (a određenim osobama se ovom prilikom ispričavam što su izvori toliko čekali da ugledaju svjetlo dana), i to Stvari.Net, 24sata, GameLand, Kosarka.hr, SportNet te Lider.

Osim toga, pokrenuli smo i dva nova podservisa, Naslovnica.Buzz i Naslovnica.Random.

Naslovnica.Buzz namjenjena je onima koje ne zanimaju sve vijesti dana nego samo žele pregled najbitnijih vijesti u danu, a Naslovnica.Random idealna je za ubit’ par minuta slobodnog vremena na Internetu, čitajući slučajno odabranu vijest iz zadnjih dan-dva.

Nadamo se da će vam nove mogućnosti Naslovnice biti korisne i zanimljive!

Thou shalt not change hardware

April 20, 2008 21:46

The reason I haven't posted the story about DORS/CLUC 2008 already is the fact that I dared to install new motherboard (Asus P5e) and new CPU (Q9450). Oh, and a new graphics card - an Asus 8800GTS TOP. I was a little bit sceptical about how my Windows partition would survive such a drastic change, but none the less, the reinstallation was long overdue. So I did it. At first, everything seemed well. Then, it happened. I couldn't find my Linux partitions. Everything has turned into a really, really Read more... (http://www.oddparity.org/index.php?option=com_content&task=view&id=46&Itemid=99999999)

Open source web analitika i još ponešto

April 20, 2008 18:04

Statistika je jedan od najvećih fetiša većine webmajstora. Takvi će s radošću isprobati svaki novi statistički alat, a još kad je isti open source… phpMyVisites je dogurao do 2.3 inačice i kraja razvojnog puta. Na temelju dosadašnjeg iskustva autori su odlučili napraviti novi i bolji alat te je nastao Piwik. Djeluje poprilično zanimljivo, dostupan je demo, a i blog donosi par zanimljivih postova i prezentaciju koja otkriva zašto je Piwik bolji od konkurencije. PHP developerima se otvara mogućnost zarade na razvijanju pluginova za Piwik.

Dopadaju vam se Piwikovi grafikoni? Krivac za njih je još jedan open source proizvod: Open Flash Chart.

Nije vezan uz prethodna dva projekta, ali nalazim da je CodePress vrlo zanimljiv online editor s sintaksnim bojanjem i već znam gdje bi mogao naći svoju primjenu. Imam zanimljivu zamisao koja bi se mogla ostvariti u sklopu Django Dash natjecanja. Ima li zainteresiranih Django developera?

Ubuntu 8.04 and DELL PowerEdge 1650

April 20, 2008 13:30

Do not just upgrade to Hardy! A bug in PowerEdge's firmware could bite you.

Before you upgrade your Ubuntu 6.06 to 8.04, take a moment or two and check all devices firmware on your PowerEdge. If yours Perc (PowerEdge Adaptec based RAID controller) 3/Di didn't get firmware update for couple of years, go to the Dell support page and download update. Unfortunatly, you'll need Windows machine with a diskette unit and two diskettes. Update of PERC firmware is needed for getting anything out of your new Ubuntu 8.04. This is also true for all other distributions with newer kernels.

More details:

http://bugzilla.kernel.org/show_bug.cgi?id=9133

Brave New Web

April 19, 2008 15:44

Danas sam naletio na API Finder, katalog API-ja. Većinu njegovih eksponata čine razni web servisi, ali spominju da prihvaćaju API bilo kojeg tipa. Važno je samo da je negdje na Internetu službeno dokumentiran. Način prezentacije API Findera mi se baš ne dopada, podaci su prešturi, ako vas zanima ta problematika onda je bolje da posjetite Programmable Web koji pruža bolje i potpunije informacije. A ako baš nemate što raditi, skloni ste programiranju, možete zaviriti i u Programming Contest Guide.

Što je zajedničko API-jima i naslovu ovog posta? Vjerujem da su oni srž slijedećeg velikog web potresa kojeg bi netko mogao nazvati i web 3.0. Samo što bi njihov utjecaj na cjelokupni IT mogao biti puno veći nego što je to bio slučaj s web 2.0 balončićima.

Sve više različitih uređaja s različitim mogućnostima prikaza i obrada informacija pristupa Internetu. Prilagođavanje web stranica svima njima je nemoguća misija. Jednostavnije je izložiti API i napraviti prilagođene klijente. Odlični primjeri takvih klijenata su Facebook for BlackBerry i Yahoo! Go.

Čak se i u bankovnim časopisima može pročitati da će 2008. godina biti RIA godina. Web API-ji su idealni za vezu s RIA klijentima. Tržišni udio nijednog od njih nije dovoljan da bi mogli igrati samo na jednu kartu. Bolje je igrati na sigurno, na poslužitelju univerzalni API, a RIA klijenta odaberete prema potrebama.

Preglednika (po naški browser) bi mogao zamijeniti potrošač (API Consumer). Neki budući RAD alat mogao bi se bazirati na analizi API-ja i odabiru uobičajenih obrazaca obrade onoga što oni nude. U tu igru još ubacimo mikroformate (znate kakvi su to podaci i što bi mogli napraviti s njima) i već se obrisi nekog budućeg vrlog weba mogu naslutiti.

Piracy is Good?

April 18, 2008 14:28

Kad već embeddam filmove, evo još jedan koji mi se čini vrlo zanimljivim. Poprilično je dug (nešto preko sat vremena), ali vrijedan pažnje (IMHO), a govori o (video) piratstvu, BitTorrentu, i što to znači za televizijske mreže i producente TV sadržaja.

Za razliku od tipičnih polariziranih “Sloboda (tevea) narodu!” vs. “Piratstvo je zločin!” argumenata, Mark cijelom problemu pristupa sa shvaćanjem da distribucija TV sadržaja preko Interneta sigurno neće nestati, te kako se TV industrija može prilagoditi tome i iskoristiti novu situaciju za zaraditi još više para.

Prezentacija je prilično stara, gotovo 2 godine, a ono što je zanimljivo je da su se neke stvari već kod nas obistilnile, kao što je dilanje serija na DVDovima uz časopise, te korištenje social networka za preporuku što gledati ili slušati. A ako uzmemo u obzir da Hrvatska uvijek kaska par godina za ostatkom svijeta, stavovi u prezentaciji su taman aktualni za naše trenutno stanje.

Mark Pesce - Piracy is Good? :

Nagovorilo me da pređem na Vistu

April 17, 2008 23:30

Ovako nečemu stvarno ne možete odoljeti:

(via TechCrunch)

First Croatian Perl Workshop

April 15, 2008 23:07

First of all, we had first ever Croatian perl workshop. Thanks to all the people who showed up, we had attendance of about ten. Organizing a workshop event turned out to be much more work then I anticipated, and various other tasks stopped me from preparing for it as good as I should. Also, small number of people force me to re-consider my lectures about perl. On one hand, I really, really, tried to spread perl (and had good fortune of being at right place at right time to get Zagreb.pm off the ground), but with such low attendance, I must conclude that perl is used only by about 20 people in Zagreb. This seems somehow disturbing. Comparing size of Zagreb with Moscow turned out to show about same proportion, so I was just overly optimistic. I also gave half an hour presentation about Jifty, based on Building a Jifty app in a jiffy by Kevin Falcone and showed some examples of my jifty apps (I actually didn't talk about last one, just mentioned it as integration of external javascript -- CodePress in this example). I also have to thank to Andrew Shitov from Moscow.pm who have managed to prepare several very interesting topics which, in my opinion, made this event worthwhile. If it wasn't free I would ask my money back :-\

Upgrading to 8.04

April 15, 2008 16:23

In last 3-4 days I've upgraded 10 servers (i386 and amd64) and couple of desktops from 6.06 and/or 7.10 to 8.04, something that makes system administrators sweat :). These were upgrades of not so important machines, but whole procedure was a test case for upgrades of important machines.

I taught there'll be plenty to write about, but all upgrades went without big or even medium sized problems. Biggest problem was waiting for all packages to configure :) For desktop upgrades, I've used 'update-manager -d', and for server upgrades all upgrading was done by do-release-upgrade program (from update-manager-core package). So, what could you expect during upgrade?

If you had NFS exports configured as:

/path 192.168.0.*(ro)

after upgrade, your clients won't be able to connect. I'm still not sure if that was correct way of specifying allowed clients, but it worked in 6.06. FWIW, now this works:

/path 192.168.0.0/255.255.255.0(ro)

That's it. That's the only thing that I had to fix after upgrades. Services upgraded on machines include: dovecot, postfix, nfs-kernel-server, samba, netatalk, chillispot, dhcp3-server, apache, squid, mdadm, hylafax, freeradius, rp-pppoe, fetchmail, sshd, no-ip, vsftpd, cupsd, openvpn, pptpd, mysql-server, ntop, ntpd...

Most of the custom scripts and oracle database 9.2 worked without any intervention. Very few scripts and configuration required adjustments.

If you have custom compiled applications (including PHP or Apache modules), don't forget to compile them again.

Before this week comes to an end, I'm planing to do a test upgrade of servers running redhat-cluster-suite (right, on Ubuntu!) and couple of mysql replications.

One can't say more than 'Great job everybody! Ubuntu server upgrade is easier than an upgrade of a Nokia mobile phone software :)'

Dent game: an example of nonexistant security

April 13, 2008 19:58

In Norway, there's a commercial campaign (ending 15.4.) for Dent candies; you're invited to play a game (www.dent.no), and the best scores win some prizes (the coolest prize is a free cinema-ticket for two valid for 1 year). Since the prizes are attractive, I was wondering what kind of security they implemented. Surprisingly (or not; Norwegian companies have a bad track record with security issues), the answer is none!

Before submitting my result, together with my data (email address and phone number), I fired up wireshark and found out the following:

They first connect to stats.indexstats.com to report some basic statistics (a cookie with base-64 url, among other stuff, is sent and an empty GIF is returned).

Then a simple POST request is sent with the score and entered data about the user. Everything through ordinary HTTP, and everything in cleartext! Some binary data is returned, but I haven't bothered to figure out what it is.

So it's trivial to record the traffic into a file, change the score, and resubmit the better score by e.g. netcat. (No, I haven't done it myself -- the hardest part seems to be guessing high enough to win, but still plausible score.)

What could have been done differently? It's impossible to secure an application 100% when the user has full control over the computer, but I think that just AES-encrypting the sent data with a key preshared between the client and the server would have risen the hacking bar significantly. You'd have to download the raw flash file, try to find the encryption key inside it, guess the encryption algorithm, etc. If the encryption key is not stored contiguosly in the file, then you'd also have to reverse-engineer the flash code to see what's going on.

In any case, very badly done web application.

Google App Engine

April 08, 2008 07:19

Najava javne dostupnosti njihove BigTable tehnologije nije me mogla natjerati da zbog toga otresem prašinu s tipkovnice i napišem post. Da, to je Google i dovoljno je da se pomakne pa svi zuje, ali konkurencija je već reagirala prva…Apache CouchDB, Amazon SimpleDB, Microsoft SSDS…

Jučer najavljeni Google App Engine je nešto sasvim drugo, kompletna razvojna okolina s kojom nećete imati problem kod skaliranja. Meni je najzanimljivija činjenica da se GAE temelji na Pythonu i trenutno je to jedini jezik kojeg možete koristiti za razvoj na toj platformi (najavljeni i drugi). Već se prijavilo predviđenih 10000 developera pa trenutno nije moguće odmah isprobati taj servis, ali moguće je skinuti SDK i započeti razvoj/testiranje. Moguće je korištenje skoro svih Python web okruženja za razvoj, a za Django postoje i posebne upute. Od priloženih apija zanimljiv je Datastore API i Users API koji omogućava integraciju s Google korisničkim računima.

Radeon HD 3850 Power consumption/Linux

April 05, 2008 18:24

I had the opportunity to test a Radeon HD 3850 card recently and I've tested my two favorite hardware properties: Performance and power consumption. I won't go into too many details about the performance, it's sufficient to say that Crysis is playable with max details under 1024x768 with a Core 2 E8200 CPU. Of course Crysis won't work under Linux, at least not yet.

About the power consumption though:

I've recently bought a Kill-a-watt equivalent for the European market, an Art. Nr. 002580 from REV (description available from in the German language page).

So I've measured the consumption of a complete system. 460W power supply from Coolermaster, P35-DS3P rev 2.0 motherboard from Gigabyte, 2 GB of Corsair CL5 RAM, and our subject the Sapphire Radeon HD 3850 Ultimate.

When the graphics driver was still not loaded (in the BIOS, during post, in the boot loader, and during the OS load) the machine was using 119 W. When Windows loaded power consumption under idle went down to 81 W. Under Linux idle consumption with the latest fglrx driver was 87 W, so somewhat higher. When I switched the VT to text mode, it went up to arround 119 W again. When the graphics driver under Linux does a LeaveVT, it usually restores the state of the registers to the one found before the driver is loaded. That leads me to a conclusion that the video BIOS of the card doesn't do anything to save the power, and we must wait for the driver to load for the PowerSaving features to be enabled. Regarding the open source "radeon" driver for Xorg, Alex Deucher just recently added DynamicClocks support, so that should help. I'll test it later and make an update to this post to let you know how it works out.

Here are some more values for the system if you're curious.

Crysis 1024x768 all details high: 153 W
3DMark 2001SE under Linux/Wine, Fill rate test, single texturing: 165-172 W (this is the champion)
3DMark 2001SE under Linux/Wine, High poly count: 123-128 W
glxgears Linux: 140 W

2x burnP6 (this test just exercizes the CPU): 116 W

As a contrast the Thinkpad X60s that I'm writing this post on uses 38 W under maximum load, and 17-19 W when idle, and around 22 W under typical use. Internal LCD panel consumption included in the figure of course. When on battery it uses about 10-11 W. (Panel brightnes lowered, wireless turned off).

dv capturing pod linux-om

April 05, 2008 10:18

Za one koji ne znaju o čemu se ovdje radi, kratko objašnjenje:

Imate DV kazetu na kojoj je neki zapis

Posjedujete kameru koja ima ulaz za DV kazete.

Kompjuter vam ima firewire ulaz i posjedujete firewire kabel.

Sve to spojite i uz pomoc nekog programa imate zaspis sa DV kazete na svom kompjuteru.

Ja osobno koristim Kino. Pokrenete Kino. i odete na “Capture”.
Mene osobno svaki put doceka poruka:
WARNING: raw1394 kernel module not loaded or failure to read/write /dev/raw1394!

I sve sto treba napraviti je:
sudo chmod 777 /dev/rav1394

I poslje toga sve radi savrseno.
Ono sto mi je bilo zanimljivo za primjetiti je zauzece procesora.
Na istom kompjuteru kada bih to radio u windowsima(naravno ne sa kinom), bilo je oko 80%, dok na ubuntu oko 30%.

Update on tha XAA/EXA saga

April 05, 2008 07:59

If you're using newer Xorg/mesa/intel driver, you will find that XAA doesn't work anymore. My machine tends to have a hard lockup. XAA probably broke because of the changes in the DRI/DRM 3D part of the driver.

Switching back to EXA makes it work, but with the same old performance problems. Still it's possible to make it go faster with a

Option "MigrationHeuristic" "greedy"

in the "Device" section of your xorg.conf

The mandatory sysprof of Firefox 3 doing business.hr test:

The exa manual page says this about the option:

Option "MigrationHeuristic" "anystr": Chooses an alternate pixmap migration heuristic, for debugging purposes. The default is intended to be the best performing one for general use, though others may help with specific use cases. Available options include "always", "greedy", and "smart". Default: always.

AIR Linux

April 03, 2008 21:10

Dok nisam bolovao od kroničnog nedostatka vremena nije mi se to događalo. Alfa inačica AIR-a za Linux već je vani nekoliko dana, a ja sam je tek večeras uspio isprobati. Instalacija je brza, onih nekoliko aplikacija za primjer radi pristojno. Od dječjih bolesti uglavnom se javlja problem s encodingom, na Ubuntuu (Gnome) skoro svaka novo instalirana aplikacija dodaje novu, istoimenu stavku u glavni izbornik umjesto da se sve utabore u jednom. Za jednu alfa inačicu sve radi pristojno dobro. AIR se instalira u /opt direktorij, a korisničke podatke i postavke sprema u ~/.adobe direktorij. Osim navedenih primjera isprobao sam i nekoliko drugih AIR aplikacija i sve su radile ok. Uključujući i snippely, zgodan alat za spremanje korisnih komadića koda. Snippely bi mogao biti puno korisniji kad bi postojala mogućnost integracije s online servisima kao što je Django snippets.

Oni koje zanima AIR za Linux najvjerojatnije će razvijati html aplikacije u njemu, a za takav tip AIR aplikacija sve više developera koristi Ext JS. To je i logično jer je Ext jedan od najboljih JavaScript biblioteka za razvoj korisničkog sučelja, a u sklopu AIR okruženja poništavaju se neki njegovi nedostaci (veličina, sporost). AIR je prisutan na Ext forumu, u primjerima…

Inkscape

April 02, 2008 19:29

I've been looking for a long time for some visio-like vector drawing program for Linux. Well, I've recently tried Inkscape, and, while still not a Visio replacement, it does its job pretty well even for technical diagrams.

ODF accepted as Croatian national standard

April 01, 2008 20:17

Today, after a four hour meeting, Croatian CSI accepted ODF as a national standard. I have rather few and incomplete information from the meeting (formal press release will be made by CSI in a few days, I hope), but as it seems, there were mostly political and not much technical objections regarding ODF (that were risen by Microsoft earlier on), but at the end of the day ODF was accepted. It is worth noting that Microsoft requested that their statement pro ODF be officialy noted. That is a fair move Read more... (http://www.oddparity.org/index.php?option=com_content&task=view&id=45&Itemid=99999999)

ODF prihvaćen kao nacionalna norma

Tue, 01 Apr 2008 19:00:04 +0200

Danas je, nakon četverosatne rasprave, prihvaćen ODF kao hrvatska nacionalna norma. Službeno će ta vijest biti objavljena u glasniku HZN-a. Nužno je napomenuti da norme nisu obvezujuće, pa t...

Update na Naslovnici - Patka.Ekskluziv

March 31, 2008 23:29

S konačnim dolaskom proljeća vrijeme je i za nove proljetne radove i svježe ideje.

Jedna od novosti vezana je i uz Naslovnicu. Za sve one kojima je dosta stalno istih vijesti koje
se prenose od medija do medija uz tek minorne izmjene, predstavljamo novi pod-servis,
Patka.Ekskluziv

Patka.Ekskluziv ne prati vijesti, već ih stvara! Umjetna inteligencija već godinama
marljivo upija sve znanje o vijestima iz zemlje i svijeta, te je već dosegnula točku gdje
je dovoljno pametna da zna što se u svijetu događa, ili će se tek dogoditi, ili bi se
trebalo dogoditi, te tu vijesti, samo za Vaše oči, ekskluzivno, servira.

Stoga ne časite ni časka, nego pohitajte na Patku!

OOXML: Croatia isn't going to change vote after the BRM

March 28, 2008 23:54

Croatia's initial position regarding fast-tracking OOXML was "Yes, with no comments". After the BRM resolution, NB's were given time to reconsider their vote in the light of new circumstances (namely, changes to original proposition). The second round of voting was initiated by some Croatian NB members asking for the second round, mainly because there are many changes between initial proposition and the post-BRM changes. However, that was strongly disputed by Microsoft Croatia, who argued that there's no need for a second round, because it Read more... (http://www.oddparity.org/index.php?option=com_content&task=view&id=44&Itemid=99999999)

Document Freedom Day in Croatia

March 28, 2008 22:00

Document Freedom Day was celebrated in Croatia, and what a nice little show it was! To be honest, the timing of the whole event was just way too short to thoroughly prepare an event, so we had to improvize a little bit - and the fact that we have sent an event notification to the media didn't help much, as it was done the evening before the event. However, it turned out to be quite a success. Our idea was to get our penguin mascot out, giving away Read more... (http://www.oddparity.org/index.php?option=com_content&task=view&id=42&Itemid=99999999)

HULK-ovo pismo ravnatelju HZN-a

March 27, 2008 20:55

Pingvin je tako na Document Freedom Day prošetao ispred HZN-a, pokušao uručiti ravnatelju protestnu notu HULK-a, ali nije uspio jer su zaštitari smatrali da pingvinima nije mjesto u važnoj i...

Python decorators demystified

March 26, 2008 19:29

One of the things you may have noticed if you took a look at some of the newer Python programs is extensive use of decorators. Decorators are relatively new concept in Python world, and they first appeared in version 2.4. Decorators can help you to avoid unnecessary code duplication and to write elegant code in many situations which could otherwise lead to ugly code. Decorators are way to do metaprogramming in Python, ie. to enhance functionality of an existing (decorated) function without modifying it's body.

What precisely is a decorator? Let's first give a more or less formal definition in context of Python programming. Decorator is an object that acts as syntactic glue and is used to modify behavior of a method or a function. You can recognize a decorator by the following syntax:

@<decorator_name>
def <function_name>:
   <function_body>

What Python interpreter actually does under the hood is translation of previous code to:

<function_name> = <decorator_name>(<function_name>)

Here decorator acts simply as a wrapper for an existing function, but as we will show later, it can add a new functionality to that function.

Although previous syntax indicates that a function may have only one decorator, that is not true - a function may have more that one decorator. By using the multiple decorators, code is translated from this syntax:

@<decorator1>
@<decorator2>
def <function_name>:
   <function_body>

to this:

<function_name> = <decorator1>(<decorator2>(<function_name>))

In all of the examples we have assumed that decorators are already defined, but in your programs you will have to write a decorator before you can use it.

Let's start with the most basic example. We will modify a function that makes a sum of two integers so it will return a result in hexadecimal notation instead of default decimal notation.

def sum(a, b):
   return a + b

Instead of modifying the function itself, we write a decorator function. Decorator function takes a function as an argument and it returns a new function which will replace the old one.

def hex(fn):
 def new_fn(*args):
    return "%x" % fn(*args)
 return new_fn

In the body of decorator, we have defined a new function that reads all arguments into a tupple (*args syntax), and then uses a decorated function (fn) to calculate result. The result is then returned in hexadecimal. At the end of decorator body, new function is returned. Now, we can simply modify any function that returns a single integer with this decorator. Just add "@hex" in front of function definition, and it will do it's job.

>>> @hex
... def sum(a, b):
...     return a + b
...
>>> sum(10,5)
'f'

Decorators, like everything else in Python, are objects, so we can do more interesting things with them. For example we can pass arguments inside decorator to specify our output more precisely.

What are the possible real world situations where you might use decorators? Let's suppose you're developing a multithreaded application and you need an elegant way to mutually exclude the execution of some functions that run in separate threads. What you want to achieve is basically serialization of two or more functions, i.e. we must prevent starting of other functions when any other is already running. To accomplish this, you can use Python's built in reentrant lock object (threading.RLock) inside of decorator to prevent concurrent execution.and queue object (collections.Queue) to remember what functions (or transactions) must be executed after lock is released.

Good starting point to learn more about decorators is PEP 318.

VRač - virtualno računalo

March 23, 2008 12:51

Really funny name of post, isn't it? It should mean something to people who understand Croatian: it's virtual computer. This fun toy begin it's existence as Orao emulator. In the process, I wrote 6502 and Z80 emulator (actually only perl xs bindings for existing cpu emulators) and implemented Orao, Galaksija and Galeb using it. Various machines are in different stage of usability. Orao emulation is working (without tape support), Galaksija is too slow to be useful (also doesn't have tape) and Galeb doesn't have keyboard or tape support. I would be very grateful for hardware information about those machines if you can spare some time writing them. I'm somewhat hope that source code of this emulators might serve as historic reference how this machines where constructed. Lately, I have also found mess project, but soon after that I also noticed that I need about six times as much to implement changes in it. C is just not my language, so actually only hope for preservation of those computers is good documentation (which is something mess community is striving also). On the other hand, currently CPU emulation library is not license compatible with GPL so I won't probably push this to CPAN any time soon but I would love to find another implementation (PowerPC anyone?) and basically create thin layer of perl code which can express different architectures. Having written all that now it's time to show you how to compile dam thing!

svn co svn://svn.rot13.org/VRac/
cd VRac
perl Makefile.PL
make
make orao

And you will have working Orao emulator in a second. You can also try make galaksija or make galeb. This post was originally written on 2007-09-05 when I wanted to announce this project after playing with it over the summer. Since I never finished emulation of Galaksija or Galeb, I left it in draft mode for too long. Now that first Croatian Perl Workshop is coming along I will talk about this project, so it's just fair to announce it, so you can have preview about what my lecture will be.

MIPS CPU simulator, CMake

March 22, 2008 16:40

Today I've published the first version of a MIPS CPU simulator; you can read more about it here. Even though the version number is 0.9, the program is not in any case beta: it is quite stable, CPU torture tests pass in 32-bit and 64-bit environments, and there seems to be no open security holes, though error "reporting" is sometimes unfriendly: the simulator shall call abort() if the simulated program tries to access memory outside of its allocated range.. but I think that's still way better than doing random stuff to random memory. Work on better error handling is the top priority right now.

I'm also using this opportunity to learn about the CMake build system.

Kako najviše zbuniti korisnike?

March 22, 2008 12:08

Pročitavši vijest na IZ-infoNEWS portalu o prvom javnom e-mail servisu, koji je potpuna novost na hrvatskom Internetu, bijah zbunjen. Izgleda da sam živio u zabludi da u .hr već dugo postoje javni e-mail servisi. Moje prve e-mail adrese bile su na domaćim javnim e-mail servisima. U najavi su podebljane riječi svaka osoba ili firma i adresa prema vlastitoj želji ime@prezime.com. Zbunjola.

Posjet navedenoj stranici nije otkloni zbunjenost. Prvo primjećujem usability zajeb, linkovi O usluzi, Česta pitanja i Uvjeti korištenja u sebi skrivaju JavaScript kod koji otvaraju novi prozor. U njima ima nekoliko osnovnih informacija, ali i dalje prosječan korisnik ne može shvatiti u čemu je kvaka. Molim bez komentara da je u vratima. Brzi uvid u kod otkriva da funkcionalnost stranice jako ovisi o pomalo staromodno pisanom JavaScriptu, za što nema previše opravdanja.

Igranje s pretraživanjem daje naslutiti o čemu se radi. Korisnik odabire korisničko ime i naziv domene, Posta.com.hr registrira navedenu domenu (ako je slobodna), doda MX zapis (ako ne znate što je to potražite MX zapis na DNS KAKO stranici) za nju koji pokazuje na njihov server i otvori korisnički račun. Pretpostavljam da je Posta.com.hr vlasnik te domene? U uputama stoji da svatko može naručiti neograničen broj adresa, ali nije jasno da li to sve ide pod onih 10 kn mjesečno, ili svaku adresu plaćate posebno? Da li i drugi korisnici mogu imati e-mail adresu na toj domeni?

Posta.com.hr bi na prvoj stranici trebala imati jednostavno objašnjenje, po mogućnosti ilustrirano i u točkama, iz kojega bi bilo odmah jasno kakvu to uslugu oni nude i o čemu se zapravo radi. Većina korisnika će otići s njihove stranice ako im odmah nije jasno što je to.

Post@ pred sobom ima trnovit put, kad korisnik i shvati što oni nude treba pobijediti mentalitet domaćeg surfera koji je naučen da je sve na Internetu besplatno. Ako se korisnik i odluči na korištenje onda je slijedeća stepenica predugu razdoblje od plaćanja do početka korištenja usluge. U današnje vrijeme korisnici su naučeni da par trenutaka nakon plaćanja mogu koristiti uslugu.

Post@ nema nikakav trial ili demo inačicu, korisnik kupuje mačka u vreći. Za početak su trebali organizirati marketinšku akciju u kojoj bi određen broj korisničkih računa (ne manje od 100) nudili besplatno. Ali ne po principu tko prvi, njemu e-mail, jer bi u tom slučaju dobili masu korisnika koje zapravo ne zanima usluga već grabe sve što je besplatno. Mogli bi iskoristiti foru s pozivnicama poslanih na odabrane adrese, mogli su odabrati hrpu blogera koji bi pisali o servisu i stvorili buzz, mogli su…ali nisu.

Nova pravila za glasovanje o OOXML-u

March 20, 2008 22:09

Ako neće brdo Muhamedu, Muhamed će brdu. ISO je promjenio pravila za slanje glasova o OOXML prijedlogu. Podsjetimo se, države imaju vremena do 28.3. eventualno promjeniti svoj glas kojeg su ...

ODF vs. OOXML - konzistentnost predstavljanja podatka

March 20, 2008 10:47

U prošlom blogu spomenuti Rob Weir osvrnuo se i na konzistentnost u predstavljanju podatka o boji i poravnanju teksta, usporedivši u tablici način na koji to prikazuju ODF i OOXML. Bacite ok...

Jeste li vi gospodin Dejanović?

March 19, 2008 23:23

HEP ima krasnu opciju - omogućuje korisnicima komunikaciju e-mailom. Koristio sam ju u par navrata i zadovoljan sam uslugom. Nije najsavršenija, ali je sasvim Ok, brza, efikasna, uljudna. I, tako sam ja prije par dana poslao e-mail sa očitanjem brojila. Pritom sam, kako sam kasnije shvatio (kad je već bilo kasno), pogreškom unio dvije šestice umjesto jedne. Mea culpa. No, jučer ujutro, mojoj sestrični zvoni telefon... sestrična: "Molim?" glas: "Dobar dan, ovdje X.Y. iz HEP-a. Pa znate li vi koliko sam ja vremena potrošila da nađem vaš broj Read more... (http://www.oddparity.org/index.php?option=com_content&task=view&id=41&Itemid=99999999)

Tražite greške u OOXML specifikaciji!

March 19, 2008 23:01

Sve je, zapravo, počelo kao eksperiment Roba Weira. Čovjek se upitao koliko grešaka može naći ako izabere 200 slučajnih stranica dijela OOXML specifikacije (XML specifikacije, preciznije) ko...

jQuery JavaScript toolkit - korisni linkovi

March 19, 2008 22:57

Moj JavaScript weapon of choice je odnedavna jQuery. Malen je (barem što se tiče API-ja, nisam uspoređivao veličine datoteka), način razmišljanja mi se totalno sviđa (razdvojenost HTML-a, CSS-a i JS-a, korištenje standardnih CSS selektora za dohvaćanje DOM elemenata), a CSS selektori i chainanje filtera i naredbi su premoćni. Ako već niste upoznati s jQueryem, preporučam da pogledate tutorial te prošvrljate i ostatkom dokumentacije koja je prilično iscrpna.

Osim glavne stranice projekta, naišao i sam na još hrpu korisnih stvari vezanih uz jQuery. Moj osobni izbor:

jQuery in Action knjiga. Nedavno pročitao, odličan uvod, dobro objašnjavanje osnovnih koncepata, standardnih trikova i naprednijih stvari tipa pisanja vlastitog plugina.
Learning jQuery blog. Korisni tips’n'tricks, da se svašta naučiti.
jQuery UI, set standardnih, kvalitetnih i prilagodljivih UI pluginova.
jQuery Enchant, hrpa zgodnih i nenameljivih (većinom) efekata i animacija.
AJAX Form plugin, skroz jednostavno ajaxiziranje formi.
facebox plugin, simpatičan Facebook-lookalike Lightbox klon koji za razliku od originala ne ubije Firefox2 na Linux platformi.
rudimentarni rich text editor plugin - less is more, ovih par featureva koje podržava su mi dovoljni u 90% slučajeva (za ostatak je tu TinyMCE)
UI datepicker - uvijek dobro dođe
SuperFish, jQuery Deluxe verzija čuvenog AListApartovog SuckerFish dropdown sustava

Nikad nije kasno za dobre linkove

March 18, 2008 20:46

Nekoliko izrezanih virtualnih papirića s linkovima povlači se po mojem virtualnom stolu, a šteta ih je baciti. I zato, nikad nije kasno za dobre linkove…

Uvijek volim pogledati kad netko napravi inventuru i popiše najbolje stvari koje koristi ili siteove koje posjećuje. Ako mi je tematika srodna rijetko nađem nešto novo i zanimljivo, ali uvijek se nadam…Takav je slučaj bio i s postom 20 Websites That Made Me A Better Web Developer. Jedini novi, meni nepoznati site, s te liste bio je Web Design from Scratch. Site pokriva skoro sve procese u razvoju web stranica i preporučam ga kao obavezno štivo za sve webmajstore koji su s webom još na Vi.

Damien Katz je podigao dosta prašine svojim postom Signs You’re a Crappy Programmer (and don’t know it). O nekim stavkama bi se dalo diskutirati, ali ukoliko Damiena ne shvatite potpuno doslovno onda se morate složiti s njim. Jedan od komentatora je to lijepo definirao: Another sign you are a crappy programmer:
You disagree with this article. Oni hitrog oka će zacijelo upucati poznato ime među komentatorima.

7. travnja u Zagrebu će se održati predavanje pod nazivom Webscale Computing. Najavu i još poneku korisnu pojedinost možete pročitati na web stranici udruge Initium. Predavač Mike Culver je evangelist za Amazon Web Services platformu, a o čemu bi on mogao govoriti pročitajte u intervjuu za Avangate.

FreeBSD je osvanuo u svojoj 7.0 inačici, a OS news donosi link na zanimljivu prezentaciju FreeBSD 7.0 and beyond u kojoj je težište na višeprocesorskoj podršci i performansama MySQL-a i PostgreSQL-a u takvom okruženju. Napravljena je i usporedba s Linuxom, NetBSD-om i Dragonfly BSD-om, a zanimljivi su i komentari na 18. stranici. Dobro je imati konkurenciju.

O startupovima se puno piše, svi nude recepte, puteve kako doći do uspjeha. A najčešće pravilo je da nema pravila ni točno određenog recepta. How to make your startup successful je jedan od startup postova, a ono što bih želio izdvojiti i naglasiti je…

There is no secret formula or obvious path to success. Just one common trait…an indomitable desire to succeed against all adversity and doubt. Very few people have this drive and the leadership ability to attract great people to their cause. This drive is indefinable but we know it when we see it. It is sometimes misdiagnosed as being delusional and fanatical. The difference in diagnosis is success or failure. Succeed and you are a brilliant visionary. Fail and you are a delusional loser. The line between them is very fine.

OOXML u brojevima

March 17, 2008 20:31

Zahvaljujem Valentu Turkoviću koji se potrudio nabaciti informaciju...Ovdje ćete pronaći duhovitu stranicu koja kratko sumarizira OOXML standard i BRM u brojevima. Ima i šarene sličice, za o...