Monday, September 29, 2008

Firefox: "Secure connection Failed"

Visiting websites with secure connection enabled can sometimes lead to problems in Firefox. Websites just link their https certificate to whatever sub-domain they want or they redirect to another website without registering it properly. Mozilla Firefox 3 detects that "glitch" and adds an extra protection layer by stating the following error:
Page load error
Secure connection Failed

*site* uses an invalid security certificate
The certificate is only valid for *another site*
(Error code: ssl_error_bad_cert_domain)

There's an easy way to resolve this, if you click on "Or you can add an exception" → "Add exception" → "Get certificate" → Read the reason it was invalid and if you're OK with the reason → "Confirm security exception".

Tuesday, September 23, 2008

How to install Folding@home in Ubuntu using origami

This is a quick "how to" tutorial in order to provide some of your CPU time for a good cause, which is called Folding@home. As they explain it at the F@h website:
Folding@home is a distributed computing project -- people from throughout the world download and run software to band together to make one of the largest supercomputers in the world. Every computer takes the project closer to our goals. Folding@home uses novel computational methods coupled to distributed computing, to simulate problems millions of times more challenging than previously achieved.

There are other projects out there, like BOINC. In that case, I suggest to install boinc-manager (menu Applications → Add/Remove) and check out Rosetta.

Now let's get down to business. You need to pick a name, which can be anything you like, as long as it's not taken - you can also pick a team, but that's optional. You do not need a password for a username, but you need one in order to create your own team.
Tip #1: A person is called a "Donor" in F@h.

Next is the application. Ubuntu is based on GNU/Linux, and the (good? :P) people of Stanford have created a console client. Despite the fact that we are left without a graphical interface, we can still get the client program and use it.

It's time to visit our good ol' friend, the Terminal (or Konsole for KDE users). Once you start terminal (menu Applications → Accessories → Terminal) we will install the origami package:
sudo apt-get install origami
Tip #2: Type in your password and press enter if you are asked to do so

The following step is to download and install the f@h client program.
The origami manual has several examples:
origami install -u Joe -t 45104
This example will install the Folding @ Home client to the local
machine, reporting data as the Joe user as part of the 45104
(TeamUbuntu) Team.

origami install -u Joe -t 45104 -c1
This example will install the Folding @ home client to the local
machine, reporting data as the Joe user as part of the 45104
(TeamUbuntu) Team, using the i386 Folding @ Home client and
toggling the cron option to auto-stop between the hours of 8:00am
and 5:00pm.

origami install -u Joe -t 45104 -p amd64
This example will install the Folding @ home client to the local
machine, reporting data as the Joe user as part of the 45104
(TeamUbuntu) Team, using the amd64 Folding @ Home client and
toggling the cron option to auto-stop between the hours of 8:00am
and 5:00pm.

Tip: If you are on your own and don't have a team, I urge you to join TeamUbuntu ( 45104 ) or UbuntuForums ( 45399 ).

Tip #3: Don't know whether you have a 32-bit or 64-bit operating system (OS)? If you're not sure, execute this:
uname -m
It shows whether you have 32-bit (x86/i386) or 64-bit (x86_64/amd64) OS. 64-bit users will want to fully use their processors, so they need to use the -p amd64 argument.

In short, the recommended command for 32-bit is:
sudo origami install -u YourName -t 45104 -c1
..and for 64-bit is:
sudo origami install -u YourName -t 45104 -c1

Tip #4: origami installs a crontab if you use -c1 in its own system user 'origami'. If you want to edit the hours it starts/stops (after you install it), execute: sudo crontab -u origami -e

Once your f@h client is installed, you have finished the installation! You can see how your folding process goes:
sudo origami status

Tip #5: Your origami configuration files are found in the /var/lib/origami/ folder. For example, my current CPU #1 configuration file is /var/lib/origami/foldingathome/CPU1/client.cfg

Tip #6: You can give a small boost to your folding process by making it use really low CPU instead of running when it's just idle. Execute:
sudo origami 
Wait for it to stop, then run your text editor to edit the configuration file:
gksu gedit /var/lib/origami/foldingathome/CPU1/client.cfg
Add the following at the bottom of the file:
[core]
priority=96
Save and close your text editor, and restart origami:
sudo origami start

Enjoy folding proteins folks! :) You'll actually be helping out various medical fields, such as Alzheimer's and Huntington's disease researching.

Finally, take a look at these sites:
http://en.wikipedia.org/wiki/List_of_distributed_computing_projects
http://www.gridrepublic.org/
http://game.bakerlab.org/portal/

Saturday, September 13, 2008

Free rice!

Do pay a visit at http://www.freerice.com - It's an amazing concept where the sponsors will donate 20 grains of rice for each right answer you provide! If you can't give financially, give by testing your knowledge.
There are various subjects to choose for answering! I took 10 minutes of my free time and summed 3000 grains of rice :)

Friday, September 12, 2008

Ranting developer

I recently stumbled upon an old thread about linux users searching for someone to create an autoit-like application for linux. Starting from this post the ranting begins, it's really fun, I went through the whole 5 pages laughing :)
Sometimes people don't understand "No", that's why developers head to the aggressive "Let me say it again: No you idiot!"

Nevertheless, if you're looking to automatize some of your basic daily work, you should be looking to learn bash scripting or even an advanced programming language such as perl or python - if you're still looking for something that handles windows and gui interface, try gambas or python-dogtail (or here).

Saturday, September 06, 2008

The sign language

I was watching a video clip the other day, Edo Maajka - To Što Se Traži (YouTube). I was astonished by the fact that the rap song was actually interpreted correctly using the same fluidity as if it was spoken.
People are always in need to communicate with someone in case something happens to them. And here kick in the various languages. Since programming languages aren't something that could actually help me communicate with another human being, I've been always fond of the sign language and I thought that the least I could do is to start learning simple phrases, such as "Are you OK?" or "Do you feel pain?".
The really intriguing part is that this kind of language is very plain, yet so complicated - combining orientation and movement of parts of your body (hands or arms), facial expressions or even hand shapes to fluidly express yourself. It's almost like learning how to grammatically speak right. It is also pretty cool to be able to understand what is someone trying to explain to you.
The bad thing is that, as spoken language, each region has its own established "jargon", it takes time to adapt to several expressions, depending on the region you're living in. Also, most regions or countries have their own sign language, which can get pretty messy if you, for example, try learning the sign language in english and head to live in Japan.
Despite the above fact, it can be useful for communication with babies, like this video shows a mother communicating with her 1-year-old daughter - it's really amazing, kind of makes me wonder what are the limitations of teaching a child at such young age!
Searching around using Google, I was able to get some information that might be a good starting place for anyone having the desire to learn this language. The best resource that I can recommend is the American Sign Language (ASL) Browser. Do try it out!

Monday, September 01, 2008

Keeping your Ubuntu clean

GNU/Linux is said to be one of the most stable operating systems in the market, which is why a lot of people prefer it as their server solution. But as a desktop, Linux and especially Ubuntu with GNOME, can get easily oversized without the proper care and before you know it, you end up with 1% free disk size of your root (or "/") partition; and taking up stress-relieve medicaments just doesn't seem right...

Here's a list of things I tend to do when such crisis strikes:
  1. Clear your Recent documents using the menu Places → Recent Documents → Clear Recent Documents
  2. If you use chat (IRC or Instant messaging), clear your log files.
    The following list contains client applications and their default folder log location:
    I strongly recommend closing your applications before removing any log files!!

    irssi$HOME/irclogs
    xchat$HOME/.xchat2/xchatlogs/
    pidgin$HOME/.purple/logs/

  3. After constantly installing and removing software, some leftover information might be just clogging your disk space for no apparent reason. The apt-based package management has two commands when you remove packages: remove and purge. The difference is that purge actually deletes the configuration files that are deliberately left there when you used remove, in case you want to install it again.
    a) But which packages have their configuration files left over? Run Terminal (head to menu Applications → Accessories → Terminal) and execute the following command:
    dpkg -l | grep -i '^rc' | tr -s ' ' | cut -d ' ' -f 2
    Another way to find these out it to head to System → Administration → Synaptic Package Manager → Click "Status" (lower left corner) → Select "Not Installed (residual config)"
    Now in the package list, right-click on the package that you wish to completely remove (aka purge) and select "Mark for Complete Removal". Then you press "Apply" and let it flow.
    Tip: Press SHIFT+A to select them all.

    b) Leftover package dependencies that were installed with your applications might still be around. You can clear them all out by executing the following in terminal:
    sudo apt-get autoremove --purge

    c) Ubuntu packages are cached in the folder /var/cache/apt/archives/, which can also get clogged up by numerous packages that are either updated or not used anymore. You can solve that by executing in terminal:
    sudo apt-get autoclean
    sudo apt-get update
    If you really want to clear all the packages archived:
    sudo apt-get clean
    sudo apt-get update
    

    d) To remove obsolete packages go to System → Administration → Synaptic Package Manager → Click "Status" → Installed (local or obsolete) → Mark the packages you wished to be completely removed (or preferably removed).
    Warning: These section includes packages that have been manually installed by third-party packages (not from ubuntu repositories), if you need them, don't remove them!
  4. A lot of linux kernel versions in your GRUB boot menu? Time to get rid of them! Use step 3(d), and mark packages that begin with linux- for complete removal
    Warning: These section includes packages that have been manually installed by third-party packages (not from ubuntu repositories), if you need them, don't remove them!

  5. Clear the temporary files created with gedit - to do this, you have to search for them.
    Go to menu Places → Search → Click "Select more options".
    Now select "Show hidden and backup files" and click "Add".
    Also add the "Name matches regular expression". Next to this last one you will type ~$, which will find all filenames that end with "~" character and most of them are temporarily created by gedit (gnome's text editor). Press "Find".
    Now you can select the files you want to delete and right-click → Move to trash.

    Warning: Some files are temporary application files that are deleted when you end the application. It might be best not to mess around a lot with this one.

Update:
6. Clear your temporary flash-related cached files found in .macromedia folder by executing this command in terminal:
rm -rf $HOME/.macromedia/
(thanks Simon!)

Social life and recreational drugs: Smoking

  As modern humans, or homo sapiens sapiens, we have evolved greatly in a lot of areas - from creating ways of verbal and signal communication to the rapid development of economy, trading and science, as well as technology. While this exponential progression was successful so far, something has gone wrong the past century. In this errata belongs the use of recreational drugs.
  Drugs of this kind haven't been banned yet and people have a free choice of using them or not (most countries have an age-limit). Tobacco smoking, alcohol and caffeine are now three of the most powerful profit-making industries of the 21st century.


Smoking
  By the mid-17th century, most major civilizations had been introduced to tobacco and recreational smoking; We should probably forgive the past generations for using them in neglect of the consequences of this type of drug use, but nowadays a lot of studies have shown the nasty effects of these indelicate habits, is there really a reason to use them? I'm surely not referring to medical patients which have a couple of years to live and seek to live it pain-free and pass away peacefully.
  Despite the way tobacco is taken, smoked, snuffed or chewed, the effects in a human being are devastating after prolonged usage, lung cancer and cardiovascular disease have boosted over the years and despite these facts, tobacco consumption is still increasing.
In the false belief that nicotine "calms down", humans intake large amounts of this drug in small dosage. This brilliant way of  taking up poison without even realizing it has enormous negative effects just after several years of constant smoking. You first start small; either as a need for relaxation, a window out of dullness or to become accepted in the "cool" or audacious sect of a social group. You continue the uptake in normal dosages every now and then. But, just like the body adapts to high or low temperatures in a number of days or your nose to an awful smell in a matter of 5 minutes, the same exact way your body becomes accustomed to tobacco as a normal intake.
  Taking it down slowly, you may think you can control it, but you find yourself in need to "relax" after an attempt to break the habit for several days. A parasite of your own free will has taken over your wallet, your pocket money, and your years to live. People cannot understand this and keep taking nicotine.
  A lot of people believe that smoking can calm you or provide you with extra alertness and concentration (increase of a substance called acetylcholine), that it can drop the level of anxiety (due to the release of beta-endorphins), that you can afterwards endure large psychological stress, which is not always true. As mentioned earlier, after several years of using tobacco, you become a slave to a regular dosage that tends to increase day by day, while you grow up and face the world's problems. Arousal? Probably the first couple of years. But what could happen in several years later is to reach a state of sexual disfunction (genital haemodynamic disruption).
  Finally, most people don't understand the cost of the cigarettes, since they dosage is small and for. An accustomed male or female might smoke one pack of cigarettes per day. Multiply the cost of the pack by 30 for a month. Suppose they cost 3 €, you would save 60 or 90 € per month for this nasty habit, which could be used for two nights at a lovely appartment outside town.

  All in all, the "great" or "pleasing" effects of nicotine only apply for a short timeline usage, longterm usage comes with great negative effects and therefore problems, may these be financial or health related. Your body doesn't need to relax every day, your body is a temple made of hard stone and marble, that can re-enstate itself back to normal after a good sleep of just one hour. Outdoor activity can prove much helpful to decrease anxiety, since you stress out yourself in exercise - this way you get a sexy body, ladies/men to want you and keep it healthy. I dare you to compare that to a "sitting-eating-mcdonalds-and-smoking" syndrome that an obese person's lifestyle might include.

  Recreational drugs of such sort can be controlled by seeking professional/medical help - don't let yourself reach a stage where you need such help.

To be continued...

Movie codec information - the gspot alternative

To be clear, no, I'm not talking about the ladies' G spot :) But if you're looking for GSpot Codec Information Appliance alternative tool for GNU/Linux, you're definetely looking for a tool like themonospot!
The monospot is written in C sharp (C#) using the MONO Framework and GTK#, licensed under GNU GPL, and it's a tool to extract information about various movie formats and reveals valuable information such as:
  • Video codec used
  • Frame size
  • Average video bitrate
  • File size
  • Total time
  • Frame rate
  • Total frames
  • Info data
  • Packet Bitstream
  • User data (in MOVI chunk)
  • Audio codec used
  • Average audio bitrate
  • Audio channels
This could definitely help you dig out the codec used for a specific movie you're trying to view. There various packages available for download, among them Ubuntu, Opensuse, Fedora, Windows and many more!