Awesome timeline of Unix, Linux and Mac OSX

A beautifully constructed timeline of Unix which includes modern day Unix descendants such as Solaris and Mac OSX as well as Linux. This timeline is not very much unlike the mind map of Linux I had created a long time back. But this timeline also provides the year when the Unix/Linux flavor was born. [Via: Zwahlen Design blog]

Fig: Unix - Linux timeline

September to be one Ubuntu screencast per day month

September 2007 is going to be a special month for the Ubuntu enthusiasts and would be converts. In this month, you get to view videos of accomplishing various tasks in Ubuntu at the rate of one screencast per day.

Each screencast will be made available through the Ubuntu Screencast site in three sizes and two formats (OGG and Flash). The screencasts are licensed under the permissive Creative Commons Attribution-Share Alike 3.0 License, so you're free to modify, pass on, sell or otherwise distribute them so long as the attribution stays intact.

In fact, you do not have to wait for September to begin as the Ubunut screencast website already has a collection of videos which explain topics such as Samba file sharing, Printing in Ubuntu, Customizing Ubuntu desktop and many others as well.

So do check out the screencasts and bookmark the site as well for future reference.

Guess what this mystery character is used for ?

Today I came across an interesting blog post related to a mystery character. The character in question is the one shown below.

Fig: Picture of the mystery character.

Let's see what effect this mystery character has when it is cut and pasted in different text fields....

Fig: Firefox address bar

Fig: Pasted inside Gimp

As you can see, after this character is pasted, all the succeeding text is typed backwards from right to left. Really strange.

The closest valid explanation that was made was the following comment made by Charlie Halpern in the afore mentioned blog. And I quote ...

As noted about, the backwards type comes from the other characters, not from the circle of commas. The circle of commas (҉) is the Unicode character U+0489 COMBINING CYRILLIC MILLIONS SIGN. It actually is supposed to combine with the character before it, surrounding it with them crazy commas. It is a historic character that isn’t much in current use. See this pdf document for more details.

Note: For this unique magic to work, the program into which you paste this symbol should support unicode. For example, pasting this symbol in an 8-bit Ascii software such as Windows Notepad or Internet Explorer will display a series of gibberish.

Installing Solaris 10 on an under $300 machine

Solaris is perceived to be a heavy weight operating system in terms of the kind of resources (read hardware) that is required to install and use it. And when you hear the word Solaris, you at once visualize Sun Blades and Sun fire servers costing upwards of a few thousand dollars.

But it is possible to install Solaris 10 on a machine which costs under $300 if the machine is build with carefully chosen parts as shown by Christian Joaquin Cruz.

He selected parts with the following specifications to build his test machine :

• Motherboard - Intel D201GLY "Little Valley" Mini-ITX
• Hard drive - Maxtor 300GB PATA 16mb-buffer drive
• Memory - DDR 1GB pc6400 single-module 800MHz
• Optical drive - Sony DRU-170C
• Case - CoolerMaster Elite 340 mATX Case
• Power supply - RaidMaster 380w Power Supply
• Case fan - LD 80mm
  

And it cost him $279 before taxes. After installing Solaris 10 on this machine, he concludes ...

The machine, after installation of all the drivers, networking and apache configuration, was very functional and able to serve up web pages on my local network quite well. Secure Shell connections worked straight out-of-the-box, as did hot-plug-in detection of USB thumbdrives. The CD/DVD reader/burner was compatible with Solaris, but Sun has omitted the inclusion of a graphical CD/DVD burner application. The upshot of this is that you have to use the commands mkisofs and cdrw to use this functionality (or download a compatible GUI based application).

In most respects I am quite pleased at the results. It's quite a cool box for the very low amount of time and money invested.

Read the full findings of Christian Joaquin Cruz in taking his newly built under $300 Solaris box on a test drive. [Print version]

Tweak your host file to block ad generating web sites

Here is a cool tip to block ad generating websites from serving ads while you are browsing the web. The idea is to direct all the domains pointing to the ad serving sites to your localhost aka 127.0.0.1 . Now, the next time you visit a website and the website is serving an ad from a domain which you have directed to your localhost, you will see a blank space at the position where the ad was to be served.

This is done by inserting lines in your host file (/etc/hosts) on your Linux machine which are in the following format one domain per line :

FILE: /etc/hosts
127.0.0.1   localhost
127.0.0.1   ad.doubleclick.net
127.0.0.1   xx.adserver.xxx
...

... and so on.

One thing worth noting is that once you have collected (almost) all the ad serving sites domains, the resulting host file will be really huge as there are an ever growing collection of companies which make a living serving ads on publishing sites. More over, after some time it gets a bit tedious to update the /etc/hosts file on a regular basis.

LittleUbuntu has a nice writeup about implementing this feature in Ubuntu as well as a link to the original article.

Howto: Build an selinux policy the Red Hat enterprise way

Red Hat / Fedora has now got GUI tools to help edit and create SElinux policy files. And it is much more simpler to create a custom selinux policy in Red Hat Enterprise Linux.

In this detailed article, Dan Walsh gently walks you through the policy module creation process.

A lot of people think that building a new SELinux policy is magic, but magic tricks never seem quite as difficult once you know how they’re done. This article explains how to build a policy module and gives you the step-by-step process for using the tools to build your own.

Read more on a step by step guide to creating an selinux policy module explained by Dan Walsh.

Update: Also check out this PDF presentation on Managing Red Hat Enterprise Linux 5 which also contain information on SELinux.

Set up an Apache web server cluster in 5 easy steps

A server cluster is a group of independent servers that are managed as a single system for higher availability, easier manageability, and greater scalability.

In a Web server environment, server clusters can be defined in two basic ways:

Active/Active

• There are multiple independent, redundant servers
• The load is distributed through round-robin DNS
• The load is balanced by a load-balancing solution
  

Active/Passive

• Multiple servers are configured to provide a service
• Only a single server provides the service at any given time
• Other servers serve as hot-spares in case of a server (service) problem or a site hosted on the servers suddenly start getting load spikes such as when being slashdotted.
  

Now a days, many shared web hosting providers are turning to a web server cluster solution over managing individual web servers on independent machines. Clustering is said to provide some respite to the performance issues.

Eli M. Dow and Frank LeFevre, both, Software Engineers at IBM have written this insightful albeit rather technical article which explains how to setup an Apache web server cluster in 5 easy steps.

From the article ...

Spreading a workload across multiple processors, coupled with various software recovery techniques, provides a highly available environment and enhances overall RAS (Reliability, Availability, and Serviceability) of the environment. Benefits include faster recovery from unplanned outages, as well as minimal effects of planned outages on the end user.

To get the most out of this article, you should be familiar with Linux and basic networking, and you should have Apache servers already configured. Our examples are based on standard SUSE Linux Enterprise Server 10 (SLES10) installations, but savvy users of other distributions should be able to adapt the methods shown here.

Learn how to set up an Apache web server cluster in 5 easy steps.

Image Retargeting - A new technology to display images on the web

Displaying images on the web is always a case of walking the fine line between optimizing the image for the web and making sure the image doesn't lose its clarity or its intended purpose. There are two ways of resizing an image which is popularly used by web masters and lay persons alike. They are cropping an image and scaling an image to the desired size. The former method will most possibly end with the image losing its fine details where as using the latter method will reduce the image's clarity.

Now it seems a new method of resizing an image has been demonstrated by two Israeli professors, Shai Avidan and Ariel Shamir which ensures that the image retains both its functionality as well as its clarity. This method is called re-targeting. The idea is to algorithmically determine which areas of the image are important and then delete other areas retaining those which are important.

Fig: Re-targeted vs cropped vs scaled image

At present none of the graphics suites including Photoshop and Gimp provide tools to re-target an image. Perhaps if this new algorithm (or method) is released under an open license, we could see this functionality being incorporated in Gimp in the future. You can read more about this new method here (PDF document). It is popularly known as 'Seam Carving for Content-Aware Image Resizing'.

For now watch this Youtube video which explains this interesting process in more detail.

A list of new features expected in Ubuntu Gutsy Gibbon

Ubuntu is on a roll to create the best Linux distribution targeted at the lay person ever. And a number of user friendly features are expected to be included in the yet to be released Gutsy Gibbon (stable version) which is expected some time in October this year.

Some of the new features are as follows :

1. Latest version of Gnome - It is well known that Ubuntu is a Gnome centric Linux distribution. True, they have Kubuntu for the KDE users among us. But in my honest opinion, Ubuntu is much more polished than Kubuntu. Not surprisingly, Gutsy Gibbon will ship with Gnome ver 2.19.90.
2. Graphical configuration tool for X - I do not have any problem editing the xorg.conf file using a text editor. It is well commented and is easy to understand. But there are numerous people who would prefer a GUI tool to edit this file and are more at home with the point and click method. Gutsy Gibbon is expected to include a GUI tool for these set of users thus making Ubuntu even more user friendly.
3. Firefox extension is to be apt-enabled - That is right and while you are reading this make sure to call it Ubufox because that is the name given to Firefox in Ubuntu. While it is quite easy to visit addons.mozilla.org and install all your favorite extensions, having another way to install and keep track of all your Firefox (aka Ubufox) extensions is really nice.
4. Creates a virtual PDF printer by default - Now I find this a very good step to user friendliness. Consider this, from now on, you will be able to create PDF documents from within almost any applications, be they Gimp, text editors, word processors or even a web browser. More over, printers are now automatically, fully configured by merely plugging them in and turning them on.
   

Fig: Print to PDF dialog box

You can download an alpha release of Ubuntu Gutsy Gibbon tribe 5 and give it a trial run.

SSH tutorial for Linux

SSH stands for Secure SHell. This is similar to telnet but with the difference that while telnet sends all your data including your password as plain text across the network, SSH sends everything in encrypted format. This means that it is well impossible to snoop at your data or passwords while it is in transit across the Internet or network.

Over a period of time, I have written a couple of articles on this blog related to SSH. Today I came across a very well written tutorial on using SSH by Mark Krenz. He explains the concept of SSH, generating public private encryption keys, forwarding an X11 session on top of SSH, TCP forwarding, SOCKS5 proxying and so on. A very good article worth spending ones time to read.

Related articles:

• How to setup SSH keys and why ?
• SSH - Secure SHell explained
• Integrating SSH in GNU/Linux

How to find out if your Linux machine has been hacked ?

It is very rare that your Linux PC which you use as a Desktop will get compromised especially if you do not run any services like a web server, mail server and so on. More over many modern Linux distributions like for example Ubuntu, targeted at the end user ship with all the ports closed by default. And others like PCLinuxOS bundles with it a robust firewall. So it makes the job of an intruder all the more harder to crack into your machine.

But suppose after all the precautions you take, some resourceful cracker succeeds in finding a loophole and hacks into your machine, how do you detect that your machine has been compromised in the first place?

Lars has written a step-by-step process by which he ascertains that a Linux server run by his friend has been compromised by an intruder. His findings throw light on what you can expect and the steps to take when you are suspicious of getting your machine rooted.

The server was running a fairly updated Ubuntu 6.06 LTS. He goes on to conclude that the compromise could have been caused by :

1. An exploit unknown to the public.
2. A user accessing this server from an already compromised host. The attacker could then sniff the the password.
   

Read this very interesting article which throws some light on the actions of a hacker.

Download YouTube videos - A list of online file conversion tools

In the last couple of years, Flash has fast risen to the top as a very popular form of sharing video, audio and data content online. But creating Flash content has a big drawback which is that the end users need to install a proprietary closed source software stub (Adobe Flash Player) to view the content. To be honest, Adobe has already released a native Flash player for Linux and the Linux version is updated in tandem with the Windows and Mac version so it is a good thing. More over Adobe has been consistently improving and adding new features to its Flash player.

But those who do not like to have Adobe Flash player installed in Linux or those using other Operating systems such as the BSD's can make use of online resources to convert the Flash video files to a number of formats. Some of them which I have found useful are as follows :

1. ConvertTube.com - This online service converts YouTube videos to a variety of compatible file formats and provides a link for download.
2. Media-Convert.com - 100% Free online file conversion which includes images, audio, video and documents.
3. Vixy.net - This service allows you convert a Flash Video / FLV file (YouTube's videos,etc) to MPEG4 (AVI/MOV/MP4/MP3/3GP) file online. It is using a compressed domain transcoder technology (outline in Japanese). It converts FLV to MPEG4 faster and less lossy than a typical transcoder.
4. Flv2Mp3.com - This online service converts Flash audio files to Mp3 format.
5. Zamzar.com - Use this online service to save and convert YouTube videos and Flash videos from numerous other sites.
6. Viloader.net - This is another online service which allows you to convert media files from one format to another.
7. Hey! Watch - Hey!Watch is a simple and robust encoding platform for both individuals (B2C) and companies (B2B). It allows conversion of videos to a variety of formats. But you need to register with them first to start using their service.

Flash player version 9 release gets H.264 support

The recent news from the Adobe camp is that the now ubiquitous flash player version 9 (Update 3 Beta 2) currently has H.264 standard video support. The H.264 is a standard which is deployed in Blu-Ray and HD-DVD high definition video players.

What this translates for the lay person is better quality of video and audio in flash players. H.264 is also an open standard. It is currently believed that the penetration of the Adobe Flash player is just over 98% making it the most used media player [Courtesy: ReadWriteWeb].

You can download the latest version of Adobe Flash player (version 9) from the official Adobe labs website.

Incidentally, you might also find this quite detailed article by Tinic Uro who explain all the new features of the latest release of Adobe Flash player ver 9 an interesting read.

A talk by Richard M Stallman - Youtube video

This is a very interesting concise talk (or rather, answers to a set of questions) by Richard.M.Stallman the father of GNU movement. The video was shot by Arturo Di Corinto for Candida TV. This is one of the best video clips of talk by RMS I have come across in recent times.

Linus Torvalds speaks on the future of Linux

Linus Torvalds, creator of the Linux kernel, has, along with others like Richard Stallman, literally changed the world of software forever.

Linux-based distributions seem to pop up every day, while more and more devices now run Linux at their core, from mobile phones to inflight entertainment systems, to the world's mission critical server infrastructures.

The development of the kernel has changed, and Linux is just getting better and better. However, with a community as large and fractured as the Linux community, it can sometimes be hard to get a big picture overview of where Linux is going: what's happening with kernel version 2.6? Will there be a version 3.0? What has Linus been up to lately? What does he get up to in his spare time?

APC Interviewer James Buchanan who is an Australian programmer, writer and cartoonist chats with Linus Torvalds and quizes him about what the future holds for the Linux kernel and in what direction it is being steered. Read the full interview.

Installing Vmware on Ubuntu Using the Canonical Repository

This is a step by step howto to install and setup a Vmware server on a machine running a server version of Ubuntu. The idea is to install a linux server to run a Vmware Server and host the virtual machines without installing X windows and all the associated bloat. This ensures that the maximum amount of memory on the server machine is made available for the virtual machines.

Check out this well illustrated howto by Matthew Browne to learn how to achieve this.

ClamAV gets acquired by Sourcefire

Remember ClamAV the free anti-virus solution released under a GPL licence ? A long time back, I had written an article on how to install and use ClamAV anti-virus software in Linux which you might find interesting.

Well, ClamAV just got acquired by Sourcefire. Sourcefire claim themselves to be world leaders in intrusion prevention and their flagship product is Snort which is an open source tool which is used by many thousands for detection of intruders on ones servers or rather keeping them at bay.

• The bottom line of the acquisition is that all the members of the core developer team of ClamAV will now be working as the employees of Sourcefire.
• The ClamAV engine and CVD will remain under GPL.
• Sourcefire now owns the ClamAV project and related trademarks, as well as the source code copyrights held by the five principal members of the ClamAV team. Sourcefire will also assume control of the ClamAV project including: the ClamAV.org domain, web site and web site content; and the ClamAV Sourceforge project page.
• As far as end users are concerned, the company claims nothing much has changed.
  

Read the official announcement here.

A talk with Opera CEO Jon Von Tetzchner

Ask me which web browser I use the most and I won't even pause before telling you that Opera is one of the web browsers of my choice. I have always had a soft corner for Opera web browser going even way back when it was an ad supported one. There was this thin non-intrusive bar on the top of the browser which showed a couple of ads when you were browsing the net. But now it is a totally ad-free free web browser which is famed for its innovative features and relatively small memory footprint.

And Jon Von Tetzchner is the CEO of Opera which is a Norwegean web pioneer. The main income for Opera comes from operator deals with search engines such as Google, Yahoo and telephony providers T-Mobile, Vodafone, Telfonica and so on. This means that the end users get to use the world class products of Opera such as the desktop web browser and Opera mini - the web browser for mobile phones, for free while still making money for the company.

Read this exciting interview with Opera CEO Jon Von Tetzchner by Andrew Orlowski.

Book Project

I am compiling the information from the web site into a book. If you would like to be a technical reviewer for the book, please let me know, and I will send you a copy of the current draft. People who provide me with comments will be thanked on the acknowledgment page; I'm afraid I'm not in a position to offer anything more than that.

You can contact me through the email address listed for this blog, or by adding a comment to this blog posting. The folks at Princeton are not involved in this project, so please don't direct any inquiries there.

--Scott

Compact disc turns 25

The compact disc was first manufactured in August 17 1982. Since its first appearance, it has been a very good run for the compact disc (CD). And last friday August 17, the now ubiquitous CD celebrated its 25th anniversary.

The CDs are engraved with a spiral of tiny pits that are scanned by a laser - the equivalent of a record player's needle. Because the pits are covered with plastic and the laser's light doesn't wear them down, the CD never loses sound quality. And because of this endurable quality of a CD, it became an instant hit with the music lovers around the world. Even to this date, go to any music store and you are sure to find aisles stacked with rows and rows of music CDs.

It is a truism that for all things related to technology, there is always an end in sight. And this is applicable for the CD too. For instance, it is claimed that the CD sales are on the decline. Mainly because nowadays there are portable devices such as iPods and flash memory sticks which have gigabytes of storage and which are smaller than the size of a CD which makes it the preferred medium to store and transport data. Then you have the internet boom which has made data transfer itself a non-issue for those who have access to the internet. Then there are the DVDs and HDVDs which store many times more data than what is possible in a CD. So in all respects the CD is on its way out. Nevertheless it has been a very honorable run for the CD. So here is hoping it will continue to celebrate its birthday for just a few more years ....

Introducing the Interactive Linux kernel map

Linux kernel contains well over 5 million lines of code spread over 100's of files. And it should be a real chore to keep track of specific functions in the different files.

Enter the Interactive Linux kernel map. This map is unique in the sense that all the main functions which play an important part in the functioning of various aspects of Linux kernel are listed in a pictorial format. What is more, the picture can be moved around in the page using the mouse pointer and also zoomed to various levels just by moving the mouse wheel (if your mouse has one).

Navigation using the mouse is done as follows :

• Wheel - zoOM
• Drag - Move
• Keywords, which are links which you can click and be taken to the respective pages.
  

Fig: Interactive Linux kernel map.

Let's say I want to find out more about the function sys_open(). I know that it belongs to the user space interfaces and in the storage section. Using the interactive Linux kernel map, I can easily navigate to the sys_open() link and voila! I am taken to another page which lists the name of all the files where this function can be found. Clicking on any link on this page takes one to the file and location in the file this function is used. Really cool. Even if you are not a programmer, you will find this tool really useful to troubleshoot or atleast pinpoint the problem if you have a better understanding of some of the functions used in the Linux kernel. SO without much ado, check out the Interactive Linux kernel map.

XOrg version 7.3 blueprint for Ubuntu

Ubuntu is fast on its way to achieving full XOrg ver 7.3 integration in its next major release - Gusty Gibbon. Some of the features that one can look forward to in Ubuntu when XOrg 7.3 is fully merged can be put in a nutshell as follows :

• One of the key features of Xorg 7.3 is better monitor autodetection. In integrating 7.3, the Ubuntu team will attempt to leverage this capability for as many graphics cards as possible. For those cards that lack drivers with xrandr support, they will retain the current system.
• Output hotplug, as well as on-the-fly output reconfiguration and mode switching.
• Input hotplug allows hotplugging of input devices, and also adds enhanced support for touchscreens and tablets provided xserver 1.4 is included.
• Better support for multiple input devices.
• A new intel driver replacing i810 and other intel drivers.

Then there is the prospect of a full featured GUI which allows one to edit and change the configuration of the XOrg server. At present if you want to change any aspect of xorg X server, you have to edit the /etc/X11/xorg.conf file by hand. You can check out the blueprint for the merger of XOrg 7.3 in Ubuntu here.

More details of the xorg GUI including screenshots can be viewed here.

Fig: Dependency tree of XOrg 7.3

Ubuntu sources.list online generator

I have faced a number of times the prospect of entering the web address of the online repositories just because I some how tampered the contents of the sources.list file which is residing in /etc/apt/ location. Agreed, it is not difficult to fire up ones favorite editor and enter a bunch of lines by hand. But then it would be nice to have a tool which creates the code to be entered in your sources.list file automatically.

More specifically if the tool resides online, you can access it anywhere. Enter the Ubuntu sources.list online generator. The USP of this unique online tool is that you can create your own custom sources.list from various available sources and it takes only two simple steps.

So next time you are faced with re-building your sources.list file in Ubuntu, visit the Ubuntu sources.list generator and populate your sources.list file.

Related articles :
Using netselect-apt - Tip to select the fastest Debian mirror.
A Concise apt-get / dpkg primer - For new Debian users.
A list of Ubuntu/Kubuntu repositories

Installing Fedora - a video tour

Are you thinking of installing Fedora 7 on your machine ? If you are, then you should take a look at the Fedora 7 installation screenshots I had posted previously.

But if you need something even better such as a video of the installation steps then you should check out the three part video put together at linux.com.

Roblimo Miller the chief editor at OSTG has put together a series of three videos demonstrating all the steps needed to get up and running in Fedora 7. The videos explain the full installation of Fedora 7 from start to finish, First boot after the install and lastly Adding and removing software in Fedora 7.

The videos are made available in two formats ie. Flash and Ogg files and have been released under Creative Commons Attribution-Noncommercial-Share Alike 3.0 License. So you are free to download and share the videos with anybody.

I found all three videos to be clear, precise and to the point in explaining and showing each tasks. In short a must watch for all Linux neophytes interested in installing Fedora 7.

You can view the Fedora 7 video tour here. On a different note, I also found the Kubuntu 7.04 video tour equally interesting.

Poll - Which Window manager or desktop do you use the most ?

Nowadays, a majority of Linux users make use of a Desktop or a Window manager while working in Linux, irrespective of the flavor of Linux distribution. Some of us are more comfortable when using KDE while many others swear by Gnome. Again, lots of people use alternatives to the big two - Gnome and KDE for their own personal and practical reasons.

This new poll asks you which Window manager or Desktop you use the most while working in GNU/Linux or any other Unix.

One thing which I would like to highlight is that there is a slight difference between a Window manager and a Desktop. For instance, all Desktops can be considered to be window managers but not all window managers can be categorized as desktops. But for this poll, you can use the two words interchangeably.

So which window manager or desktop do you use the most ? You can cast your answer by participating in the poll. Like last time, the poll will be open for voting just over two weeks ie, till 31st of August 2007.

The future of C++ as seen by Dr. Bjarne Stroustrup

Dr. Bjarne Stroustrup is credited with creating the ever popular C++ programming language. While there are pure object oriented programming languages such as 'smalltalk' for instance, it was C++ which shot the object oriented programming paradigm to popularity.

In this video interview, Dr. Bjarne Stroustrup answers a number of questions such as the following ....

• Do you think you'll ever design a new language from scratch?
• How long after the standard is out do you expect to see a production compiler?
• Is it possible to do garbage collection cleanly and efficiently in C++?
• How soon after you created C++ did you see it start to take over the industry?
• Is there any particular naming convention you subscribe to?
• What's your opinion about the Microsoft implementation of C++?
  

Very interesting questions indeed... which ask for equally interesting answers from Dr Bjarne Stroustrup. Watch the video.

Free Software Sticker Book - free download

Are you looking for that exact sticker to stick on your machine, on your car's windshield or anywhere you fancy, in order to proclaim to the world that you support GNU Free software ? Then look no further because a group of three people have compiled a book featuring hundreds of stickers of various hues and shapes and which is made available for free download as a PDF document.

So all you have to do is to download the book and print out your favorite sticker from the lot. And then you are ready to advertise your personal preferences as far as computing is concerned. For all you know, you might even be able to persuade people close to you to try out the Free software in the process. Here is a screenshot of a subset of the collection of stickers you will find in this very beautifully compiled book.

Fig: A sample of the variety of stickers you will find in this book.

You can download the book of stickers from the following link.

Tip: Download Accelerator for Linux

There are different ways of downloading files from remote locations. While all web browsers support downloading files via http or ftp, I have found that in the case of Firefox (at least), it doesn't support resuming downloads. While this is not a problem for files of small size, when it comes to downloading huge files such as ISO images of Linux distributions, this lack of support for resuming downloads from where you had left off earlier would mean you have to start downloading the file again from the beginning.

The most common and fail safe method of downloading huge files in Linux is to use the wget tool. By using the -c option, you can resume the download of the file at a later stage in the event the downloading fails due to connection time out.

I usually use the following wget command to download Linux distributions.

$ wget -c full_path_to_the_linux_iso

Using Curl to speed up your downloads

But here is a nice tip to speed up your download of files by a significant factor. This tip is applicable for people who have a large bandwidth internet connection in the lines of 4 MBps and above. Usually different mirrors have different speeds. A Linux distribution mirror in say Japan may have a 100MBps connection but another mirror in a different location will be connected only to a 10 MBps pipe. More over these mirrors throttle the bandwidth made available for each individual connection thus providing a upper limit of download speeds.

What you can do is split the file (in our case the ISO image) you are downloading into a number of pieces and download each piece from a different mirror simultaneously. At the end of the download, you can combine all the pieces together to get your file in one piece. This is known as download acceleration where the software connects to more than one location simultaneously and splits the downloads among the locations. This feature is commonly found in many download managers for Windows but is hard to find in those available for Linux.

You can get the same feature in Linux too by using the program curl to download your files. Let's say I want to download the Ubuntu ISO image of size 700MB. I split the download into 4 parts as follows :

$ curl --range 0-199999999 -o ubuntu-iso.part1 $url1 &
$ curl --range 200000000-399999999 -o ubuntu-iso.part2 $url2 &
$ curl --range 400000000-599999999 -o ubuntu-iso.part3 $url3 &
$ curl --range 600000000- -o ubuntu-iso.part4 $url4 &

Where url1, url2, url3 and url4 are as follows ...

url1=http://ubuntu.intergenia.de/releases/feisty/ubuntu-7.04-desktop-i386.iso
url2=http://ubuntu.virginmedia.com/releases/7.04/ubuntu-7.04-desktop-i386.iso
url3=http://es.releases.ubuntu.com/7.04/ubuntu-7.04-desktop-i386.iso
url4=http://ftp-mirror.internap.com/pub/ubuntu-releases/7.04/ubuntu-7.04-desktop-i386.iso

This creates four background download processes, each transferring a different part of the ISO image from a different server. The --range option specifies a subrange of bytes to extract from the ISO file. The -o option provides the name of the file to which the data is to be saved. So once all the four curl processes finish their download, you will have four files namely ubuntu-iso.part1, ubuntu-iso.part2, ubuntu-iso.part3 and ubuntu-iso.part4 in your current directory.

To get the original Ubuntu ISO file, I just combine the files using the cat command as follows :

$ cat ubuntu-iso.part? > ubuntu-7.04-desktop-i386.iso

As I said earlier, if you have a high speed Internet connection then this method will considerably shorten the time taken to download huge files.

As an aside, I have entered all the commands in a file as follows :

#FILE NAME : da.sh (Download accelerator)
#!/bin/sh

url1=http://ubuntu.intergenia.de/releases/feisty/ubuntu-7.04-desktop-i386.iso
url2=http://ubuntu.virginmedia.com/releases/7.04/ubuntu-7.04-desktop-i386.iso
url3=http://es.releases.ubuntu.com/7.04/ubuntu-7.04-desktop-i386.iso
url4=http://ftp-mirror.internap.com/pub/ubuntu-releases/7.04/ubuntu-7.04-desktop-i386.iso

curl --range 0-199999999 -o ubuntu-iso.part1 $url1 &
curl --range 200000000-399999999 -o ubuntu-iso.part2 $url2 &
curl --range 400000000-599999999 -o ubuntu-iso.part3 $url3 &
curl --range 600000000- -o ubuntu-iso.part4 $url4 &

... set the executable bit of the file and then I run it.

$ chmod u+x da.sh
$ ./da.sh

inittab update

I updated the inittab page to correct the error that Todd pointed out. Thanks for the help! Please let me know if you find other errors or pages that need better explanation.

The LOPSA conference in Cherry Hill was great! If you didn't make it this year, make sure to put it on your calendars for next year.

--Scott

Oxygen wallpaper contest

Oxygen is the team behind the beautiful icon sets you will get to experience in KDE 4.0 when it is released sometime this year. The goal of Oxygen icon set is to create a set of icons for use on the desktop which are beautiful, support usability and accessibility and in a way, better fulfill the needs of the users.

The Oxygen team has announced a contest. Put your creativity to task and create a wallpaper. The wallpaper can be of jpg jpeg bmp gif png svg svgz formats. The theme for the wallpaper you create can be any of 3D art, vectors, photos, and pixmaps and it can be of any standard wallpaper dimension but bigger the better.

Fig: A sample set of Oxygen Icons

Once you have created the wallpaper, upload it to their website. If you are lucky and your wallpaper is selected, it will be included in the wallpapers that will ship as default set in KDE 4. More details here.

Google phone based on Linux in the making ?

After getting tired of all the iPhone hype one saw in diverse media, now the rumor is that Google is planning to roll out its own branded Phone. And one can find sneak peaks at a prototype (See photo below). No details of the specification of the phone are yet available.

The phone is supposed to be an ad-supported phone which means the consumers ie the end users can look for a free lunch by way of heavily subsidised call rates which cost next to nothing (again a rumor). And Wallstreet Journal is reporting that Google has invested hundreds of millions of dollars in its cell phone project and is courting U.S. and European mobile operators.

And most obviously the Google phone (for now nicknamed GPhone) will be powered by Linux. Check out this prototype of a GPhone which is floating on the net.

Fig: A prototype of GPhone [Courtesy: VOIP blog]

Runes of Avalon - an enjoyable game for Linux

In my teens I was addicted to playing computer games. We all are at some point of our lives. And I have played a wide variety of games from arcade to RPG and simulations. But the most enjoyable ones were games which had simple controls. Some of the classic games of yore I have immensely enjoyed are Pacman, MS-Pac, Dig Dug, Snake and so on. More recently, I enjoyed playing the two games Fizzball and Prof Fizzwizzle and the molten mystery which the regular readers of this blog would have already read a review of.

Two weeks back I had the opportunity to try out another very interesting game called "Runes of Avalon". This game is the brain child of Roman Budzowski the founder of Anawiki Games - a professional game developing firm based in Poland. "Runes of Avalon" game has been released for the Linux platform apart from that for Windows and MacOSX.

The game is played entirely with the aid of the mouse and the objective of the game is to clear out runes which are nothing but small tablets of varied colors with inscriptions on it. On first glance the game has some semblance with a tetris game in that you have to match three or more tablets (runes) of similar colors to make them disappear from the board. You can rotate the runes by clicking the right mouse button. And the runes come in different combinations so some mixing and matching is in order. But the similarity to tetris ends there.

Fig: Play Quest mode main page

Fig: Game play in progress

The game has three modes of play. Them being "Play Quest", "Time attack" - where you have just one minute to clear the board of runes and "Endless play".

There are a total of 105 different levels in the "Play Quest" mode. In this mode each time you bring together three or more runes of same color together to form combinations, it gets recorded in a beautiful energy meter on the top left corner of the game board (See figure below). And once the specified quota of energy for each color of rune is met, the level is completed.

Fig: Different stages of the energy meter and timer

This very entertaining game also has a bonus game called "Gallery" where you have to put together jumbled images and make them whole again.

Fig: Completing this level provides you with additional spells or power-ups

It might be said that there are numerous games of these sort with similar game play. To some extent it is true but if you ask me, what makes a game a success and a joy to play is a combination of factors - them being ease of control, superior graphical effects and an entertaining game play. I found "Runes of Avalon" game to sport all these qualities.

It is also commendable that the game developers decided to release a Linux version of their game albeit a non-free game, which in my mind is a big thing in itself because as they all say, an Operating system is as useful as the applications which run on it. And as more and more game developers roll out games for Linux platform it will have a trickle effect in the rise in popularity of Linux.

Pros of Runes of Avalon

• Very entertaining game play
• Ease of control - You play the game entirely using the mouse.
• Beautiful graphics.
• More than one person can play the game simultaneously by managing multiple profiles and the game keeps track of individual scores.
• Automatic saving of ones play levels so you can come back and continue playing where you left off.
• Value for money
• Has over 105 different levels in the "Play Quest" mode, with other modes containing more levels.
• Can download additional levels from the net for free.
  

Any drawbacks ?

This game makes use of OpenGL libraries. So if you have an NVIDIA or ATI graphics card, you won't be able to play the game properly using their open source drivers bundled with all Linux distributions. You will have to download and install the proprietary drivers from the respective websites before you can play the game.

If you are using a Linux distribution such as PCLinuxOS or Ubuntu, downloading and installing the proprietary graphics drivers is a piece of cake and can be done using Synaptic. I tested this game in PCLinuxOS 2007 and the game played flawlessly.

What really makes me happy is that professional game developers are eyeing the Linux platform with increasing interest. The OpenGL framework on which many games could be based upon shows a lot of promise. The Beryl and Compiz project is proof of what could be achieved with OpenGL and that, is just the tip of the iceberg.

The game - Runes of Avalon - is nominally priced at $19.99 and you can download a time limited demo version of the game which is fully playable and test it out before making the jump to buy it. The simplicity of this game makes it an ideal one for kids and adults alike and provide hours of fun in the process.

Poll shows majority favor Vi as their editor of choice

Two weeks back, this blog had run a poll which asked which was your favourite editor. The poll was open for voting roughly for a period of two weeks or 14 days. And nearly 750 people participated in the poll.

Guess what ? Over 50% of the people that is well over 375 people said their favourite editor is Vi or its equivalent such as Vim, GVim and so on. And I find this a pleasant surprise because I am myself an avid Vi user.

Fig: Pie chart representation of usage of the editors

The second place goes to GEdit - the default text editor in Gnome followed closely by Kate and Emacs. One thing worth noting is that perhaps the people who participated in the poll might have a programming or system administration background which could be why Vi editor fared so well over the notepad equivalent editors such as Gedit.

Or it could be that most Linux and Unix users are predominantly hard core techies who do programming or system administration for a living and who have already mastered the fine art of editing using Vi to appreciate its true power.

While GEdit is a far second in the poll having garnered just 13% of the votes, I suspect that it is quite popular with non-techies who use Linux since it is the default editor in Gnome. Many times I myself have reverted to Gedit when I couldn't find GVim on a Linux machine.

Finally, while I listed some of the most widely known editors, I forgot to include an 'Other' option in the poll and so the poll fails to indicate the percentage of Linux/Unix users who favor an editor not in the list.