Computer And Technologies

Computer And Technologies: Interesting
Showing posts with label Interesting. Show all posts
Showing posts with label Interesting. Show all posts

Tuesday, 10 November 2009

Ho will you detect SNMP crash or core dump ?

How will you detect or how to debug where the core dump occures?
Please follow the steps:-

GDB is the GNU debugger, which is a terminal-based debugger. DDD is a graphical (GUI) front end to GDB.

Normal invocation

The simplest way to run an application under GDB is like so:

$ gdb /usr/local/sbin/snmpd
(gdb) run -f -Lo

The '-f' is necessary to prevent snmpd from forking into the background, and '-Lo' tells snmpd to send log messages to STDOUT (i.e. print them in the GDB console window).

Libtool invocation

Net-SNMP uses libtool while building it's applications. This means that sometimes the applications in the source/build directory are not actually binaries, but shell scripts. The libtool script does some magic so that the applications will run using the shared libraries in the build directory, instead of any libraries installed on the system. To run an application with GDB, you have to run GDB through libtool, like so:

$ ./libtool gdb agent/snmpd
(gdb) run -f -Lo

Getting a backtrace (aka stack trace)

Once you have got an application running under GDB, you can easily get a backtrace, which will display the sequence of functions that were called to arrive at the point where the debugger is currently stopped.

(gdb) bt
#0 0x10153d78 in init_snmp(type=0x101bb140 "snmp") at snmp_api.c:854
#1 0x1000524c in main(argc=3, argv=0x7fe04636) at snmpd.c:910
If an application has crashed, often it will leave a core file. This core file can usually be loaded into GDB to get debugging information after the fact. Simply add the path to the core file after the path to the application when starting GDB.
$ gdb /usr/local/sbin/snmpd /tmp/core.70816

Often this will tell you why the application crashed (e.g. SIGSEGV, aka signal 11). You can then get a backtrace to send to one of the mailing lists for interpretation.

If testing snmpd (or another application) from within the source tree, you'll need to run gdb via libtool:

$ ./libtool gdb agent/snmpd /tmp/core.70816

Debugger "DGB" Part-1

Introduction

This is a very short introduction into using gdb. Target audience is a unix user which has a serious problem with some application and wants to help fixing the issue by giving detailed informations to the developer or maintainer of the application.

Debug information

Unix binaries can have debug informations attached. gdb can use the debug informations to provide more detailed informations (like function prototypes, source file names and line numbers, ...), thus it is generally a good idea to use a binary which has debug informations.

gcc has a command line switch (-g) which will make gcc write debug informations into object files and executables. It is common practice in the free software community to compile projects with debug info, but strip it off when installing with "make install". Thus you'll usually see a big file size difference between the executables within the source tree and the installed ones, and using the executables from the source tree with gdb gives better results.

Analyzing a segfault

The linux kernel is able to write a so called core dump if some application crashes. This core dump records the state of the process at the time of the crash. gdb can read such a core dump and get informations out of it.

Most distributions have core dumps disabled by default, thus you'll have to reenable them first. "ulimit -c unlimited" will do that for the current shell and all processes started from it. Check the bash manpage if you want to know more about the ulimit command.

The next time some application crashes with a segfault you'll see that the message "Segmentation fault" changed to "Segmentation fault (core dumped)" and you'll find a file named "core" or "core.pid" in the current directory. Note: You need also write access for the current directory, otherwise that isn't going to happen.

Now it is time to start gdb to see what exactly happened. The first argument for gdb should be the executable of the crashed application, the second the core dump written due to the crash. gdb will read alot of informations and will great you with a "(gdb)" prompt when it is done. The most useful piece of information for a developer is a so called stacktrace. Typing "bt" at the prompt asks gdb to print one (which you can mail to the developer). With "quit" you'll leave gdb.

Other ways to use gdb

You can start a application completely under gdb's control. To do that just type "gdb executable". At the gdb prompt type "run arguments" to start the application. If the application receives some signal gdb will give you a prompt asking for commands. You can also type Ctrl-C at any time to get a gdb prompt. The most useful gdb commands are:

bt
print a stacktrace (as mentioned above).
c
continue running the application.
print expression
print the value of the specified expression. Can be used to inspect the value of certain variables for example, simply specify the variable name as expression
quit
quit gdb.

It is also possibel to attach gdb to a already running process. This can be done with "gdb executable pid". gdb will attach to the process specified by the process id. That might be useful it some application seems to be stuck in a endless loop and you want to figure where exactly it hangs.

Advanced gdb debugging

If you start to do more things with gdb than just printing a stacktrace you likely notice some odd effects like not being able to inspect certain variables. That may happen due to compiler optimizations. If gcc decides to make a variable a register variable (i.e. never store it somewhere in memory) gdb will not see it. To avoid that rebuild the application you are going to debug without optimizations.

More common gdb commands are:

s
single step though the application.
break argument
set breakpoints, i.e. make the application stop (and gdb give you a prompt) once it reaches some specific point, some function for example.
watch expression
set a watchpoint, i.e. stop if expression has changed. Can be used to catch the line of code which modifies some variable for example.
up, down
walk up and down in the stack, to inspect variables in other places of the stack too, not just the current function.
help
gdb online help. Go read there all the details, the scope of this document ends just here :-)
BTW: a nice info manual for gdb is available too.

other useful debug tools

electric fence
malloc debugger, helps to catch typical memory management bugs like accessing already freed memory, buffer overflows, ...
Comes as library which can either explicitly linked against the application or loaded via LD_PRELOAD.
strace
print a log of all (or selected) system calls some application performes.
One common programming mistake is missing error handling, not checking the return value of system calls for example. Instead of notifying the user with a message like "opening file foo failed with error bar" applications simply assume that opening the file worked and just crash later if it didn't. That kind of bug often can easily be found with strace because you'll see the system call return values in the strace log.
Of course strace is useful for alot of other purposes too.

Doubt in C programme

Dear all,

I have small doubt can anybody guide me how it's working and why?

It's give O/P as same code.
Please find the bellow code for your review.


int main()

{

char *s = "int main() { char *s = %c%s%c; printf(s,34, s, 34); ";

printf(s,34, s, 34);

}


Thanks,

-Amaresh

www.eOdissa.com

Tuesday, 27 October 2009

Resize your Images Using ImageMagick @ deian linux

If you are using Linux and you need to resize a hundred images or so, you can certainly use Gimp, but that would be too much work. Consider ImageMagick set of graphic tools. You can install ImageMagick on Ubuntu by going to the Terminal and typing: “sudo apt-get install imagemagick.” Once the application is installed, all you need to do is go to your image directory and execute the following command:

mogrify -resize 900×600 *.jpg

This command will resize any image with a .jpg extension to a size of 900×600 pixels.

PS:- do backup before doing it.

Tuesday, 18 August 2009

Different Linux command @faced in Interview

>chage :-
chage (1) - change user password expiry information

amaresh@eOdissa-desktop:~$ chage -l amaresh
Last password change : Jul 08, 2009
Password expires : never
Password inactive : never
Account expires : never
Minimum number of days between password change : 0
Maximum number of days between password change : 99999
Number of days of warning before password expires : 7

>seq:-
seq (1) - print a sequence of numbers

amaresh@eOdissa-desktop:~$ seq 1 4
1
2
3
4
amaresh@eOdissa-desktop:~$ seq 1 2 6
1
3
5
amaresh@eOdissa-desktop:~$ seq 6
1
2
3
4
5
6
amaresh@eOdissa-desktop:~$ seq 1 3 9
1
4
7

>vmstat :-
vmstat (8) - Report virtual memory statistics

usage: vmstat [-V] [-n] [delay [count]]
-V prints version.
-n causes the headers not to be reprinted regularly.
-a print inactive/active page stats.
-d prints disk statistics
-D prints disk table
-p prints disk partition statistics
-s prints vm table
-m prints slabinfo
-S unit size
delay is the delay between updates in seconds.
unit size k:1000 K:1024 m:1000000 M:1048576 (default is K)
count is the number of updates.

Q:What command do you use to get the information about disk statistics?
Ans:- vmstat -d

amaresh@eOdissa-desktop:~$ vmstat -d
disk- ------------reads------------ ------------writes----------- -----IO------
total merged sectors ms total merged sectors ms cur sec
ram0 0 0 0 0 0 0 0 0 0 0
ram1 0 0 0 0 0 0 0 0 0 0
ram2 0 0 0 0 0 0 0 0 0 0
ram3 0 0 0 0 0 0 0 0 0 0
ram4 0 0 0 0 0 0 0 0 0 0
ram5 0 0 0 0 0 0 0 0 0 0
ram6 0 0 0 0 0 0 0 0 0 0
ram7 0 0 0 0 0 0 0 0 0 0
ram8 0 0 0 0 0 0 0 0 0 0
ram9 0 0 0 0 0 0 0 0 0 0
ram10 0 0 0 0 0 0 0 0 0 0
ram11 0 0 0 0 0 0 0 0 0 0
ram12 0 0 0 0 0 0 0 0 0 0
ram13 0 0 0 0 0 0 0 0 0 0
ram14 0 0 0 0 0 0 0 0 0 0
ram15 0 0 0 0 0 0 0 0 0 0
sr0 0 0 0 0 0 0 0 0 0 0
sda 129824 12599 1675591 430108 108073 14333 979288 2993424 0 36


Q:What command do you use to get the information about disk table?
Ans:-vmstat -D

amaresh@eOdissa-desktop:~$ vmstat -D
18 disks
5 partitions
129824 total reads
12599 merged reads
1675591 read sectors
430108 milli reading
107383 writes
13450 merged writes
966704 written sectors
2990880 milli writing
0 inprogress IO
366 milli spent IO

Q:What command do you use to get the information about no of forking ?
Ans:- vmstat -f

amaresh@eOdissa-desktop:~$ vmstat -f
11008 forks


>What command do you use to create swap space?

Monday, 10 August 2009

Some Network Linux Commands...

How will you get only TCP protocol status in a network?

Ans:- # netstat -t
O/P:-
root@eOdissa-desktop:/home/amaresh/Documents/Testing# netstat -t
Active Internet connections (w/o servers)
Proto Recv-Q Send-Q Local Address Foreign Address State
tcp 0 0 eOdissa-desktop.l:59156 www-sf2p-a.facebook:www ESTABLISHED
tcp 0 0 eOdissa-desktop.l:59175 www-sf2p-a.facebook:www ESTABLISHED
tcp 0 0 eOdissa-desktop.l:57170 px-in-f83.google.co:www ESTABLISHED
tcp 0 0 eOdissa-desktop.l:45271 pv-in-f100.google.c:www ESTABLISHED
tcp 0 0 eOdissa-desktop.l:41356 a96-17-8-64.deploy.:www ESTABLISHED
tcp 0 0 eOdissa-desktop.l:52631 a96-17-8-48.deploy.:www ESTABLISHED
tcp 0 0 eOdissa-desktop.l:41932 ord-qs2-n24.panther:www ESTABLISHED
tcp 0 0 eOdissa-desktop.l:54438 px-in-f154.google.c:www ESTABLISHED
tcp 0 0 eOdissa-desktop.l:54442 px-in-f154.google.c:www ESTABLISHED
tcp 0 0 eOdissa-desktop.l:56950 a96-17-69-27.deploy:www ESTABLISHED
tcp 0 0 eOdissa-desktop.l:56949 a96-17-69-27.deploy:www ESTABLISHED
tcp 0 0 eOdissa-desktop.l:56948 a96-17-69-27.deploy:www ESTABLISHED
tcp 0 0 eOdissa-desktop.l:56947 a96-17-69-27.deploy:www ESTABLISHED
tcp 0 0 eOdissa-desktop.l:53859 221x247x49x219.ap:34580 ESTABLISHED

How will you get only UDP protocol status in a network ?
Ans:- # netstat -u
O/P:-
root@eOdissa-desktop:/home/amaresh/Documents/Testing# netstat -u
Active Internet connections (w/o servers)
Proto Recv-Q Send-Q Local Address Foreign Address State

How will you find only listening socket information?
Ans:- #netstat -l
O/P:-
root@eOdissa-desktop:/home/amaresh/Documents/Testing# netstat -r
Kernel IP routing table
Destination Gateway Genmask Flags MSS Window irtt Iface
192.168.152.128 * 255.255.255.128 U 0 0 0 tap0
192.168.1.0 * 255.255.255.0 U 0 0 0 eth0
link-local * 255.255.0.0 U 0 0 0 eth0
192.168.0.0 192.168.152.129 255.255.0.0 UG 0 0 0 tap0
172.16.0.0 192.168.152.129 255.240.0.0 UG 0 0 0 tap0
default 192.168.1.1 0.0.0.0 UG 0 0 0 eth0

How will you get the class of any IP ?
Ans:- ipcals ( install apt-get install ipcalc in debian linux)

O/P:-
root@eOdissa-desktop:/home/amaresh/Documents/Testing# ipcalc 192.168.1.143
Address: 192.168.1.143 11000000.10101000.00000001. 10001111
Netmask: 255.255.255.0 = 24 11111111.11111111.11111111. 00000000
Wildcard: 0.0.0.255 00000000.00000000.00000000. 11111111
=>
Network: 192.168.1.0/24 11000000.10101000.00000001. 00000000
HostMin: 192.168.1.1 11000000.10101000.00000001. 00000001
HostMax: 192.168.1.254 11000000.10101000.00000001. 11111110
Broadcast: 192.168.1.255 11000000.10101000.00000001. 11111111
Hosts/Net: 254 Class C, Private Internet

root@eOdissa-desktop:/home/amaresh/Documents/Testing#ipcalc 192.168.0.1 255.255.128.0 255.255.192.0
Address: 192.168.0.1 11000000.10101000.0 0000000.00000001
Netmask: 255.255.128.0 = 17 11111111.11111111.1 0000000.00000000
Wildcard: 0.0.127.255 00000000.00000000.0 1111111.11111111
=>
Network: 192.168.0.0/17 11000000.10101000.0 0000000.00000000
HostMin: 192.168.0.1 11000000.10101000.0 0000000.00000001
HostMax: 192.168.127.254 11000000.10101000.0 1111111.11111110
Broadcast: 192.168.127.255 11000000.10101000.0 1111111.11111111
Hosts/Net: 32766 Class C, Private Internet

Subnets after transition from /17 to /18

Netmask: 255.255.192.0 = 18 11111111.11111111.11 000000.00000000
Wildcard: 0.0.63.255 00000000.00000000.00 111111.11111111

1.
Network: 192.168.0.0/18 11000000.10101000.00 000000.00000000
HostMin: 192.168.0.1 11000000.10101000.00 000000.00000001
HostMax: 192.168.63.254 11000000.10101000.00 111111.11111110
Broadcast: 192.168.63.255 11000000.10101000.00 111111.11111111
Hosts/Net: 16382 Class C, Private Internet

2.
Network: 192.168.64.0/18 11000000.10101000.01 000000.00000000
HostMin: 192.168.64.1 11000000.10101000.01 000000.00000001
HostMax: 192.168.127.254 11000000.10101000.01 111111.11111110
Broadcast: 192.168.127.255 11000000.10101000.01 111111.11111111
Hosts/Net: 16382 Class C, Private Internet


Subnets: 2
Hosts: 32764

How will you monitor your LAN IP?
Ans:- iptraf (use apt-get install iptraf in debian linux)

How will you get your bandwidth usages of your interface by host ?
Ans:- iftop

Monday, 8 June 2009

17 People Who Changed the Internet Forever!!!

From its birth in the labs of Tim Berners-Lee back in 1992, to its interaction with the Napster in 1999, and its 2004 induction of Wikipedia: the Internet as we know it, has evolved drastically, been around the world literally, and changed the way humans live permanently.

Nothing can replace it, nothing is like it, and it has no alternative. The internet is like a diamond mine for the people who wish to acquire wealth, a profound lake of information for those who have an insatiable appetite for knowledge, and an eternal form of entertainment for those wish to amuse themselves.

With the passage of time, people from amongst us have emerged with the craziest of ideas to test and enhance the potential of this God’s gift to mankind. And it is due to the efforts of these noble souls, that we have the entire world at the simple tap of our fingers.

In no particular order, Skidzopedia provides you with a list of those people who have influenced the Internet greatly.

Larry Page and Sergey Brin - Google Inc.

Larry Page and Sergey Brin

Two PhDs from Stanford University started work in the garage of a friend’s. And they were defiantly not building steam engines!

They were, however, creating the internet’s most powerful search engine. Sergey Brin and Larry Page are arguably the world’s most successful Internet entrepreneurs and developers in history. This enabled them to earn billions, while assisting everyone from high school students to particle physicists have an easy time searching for information over the internet.

Google was first launched on Stanford’s website (google.stanford.edu) and then finally on Google.com in 1997. It is estimated that GOOGLE is worth about a staggering $25 billion dollars.

David Filo and Jerry Yang - Yahoo! Inc.

David Filo and Jerry Yang

Yahoo! too is the creation of two Stanford University’s Electrical Engineer graduates, called Jerry Yang and David Filo. Yang started by listing web pages on the Internet and named it “Jerry’s Guide to the World Wide Web”. Then, he decided to switch it to Yahoo! and the initial URL was at akebono.stanford.edu/yahoo

In December 1994, that particular website had already received over a million hits. Realizing its potential, David Filo and Jerry Yang got serious and diversified Yahoo! as a web portal.

David Filo’s net worth is $2.9 billion dollars and Jerry Yang’s is $2.3 billion dollars.

Bill Gates - Microsoft

bill-gates

William Henry “Bill” Gates III, is an American business magnate, philanthropist, the world’s third richest person (as of February 8, 2008), and chairman of Microsoft, the software company he founded with Paul Allen.

Gates is one of the best-known entrepreneurs of the personal computer revolution. In the later stages of his career, Gates has pursued a number of philanthropic endeavors, donating large amounts of money to various charitable organizations and scientific research programs through the Bill & Melinda Gates Foundation, established in 2000.

Gates also holds the record of being the Richest Person in the world for 15 consecutive years.

Steven Paul Jobs - Apple Inc.

steven-paul-jobs

Steven Paul Jobs is the co-founder, Chairman, and CEO of Apple Inc. and former CEO of Pixar Animation Studios.

In the late 1970s, Jobs, with Apple co-founder Steve Wozniak, created one of the first commercially successful personal computers. In the early 1980s, Jobs was among the first to see the commercial potential of the mouse-driven GUI (Graphical User Interface)

After losing a power struggle with the board of directors in 1985, Jobs resigned from Apple and founded NeXT, a computer platform development company specializing in the higher education and business markets.

Jobs is currently the Walt Disney Company’s largest individual shareholder and a member of its Board of Directors. He is considered a leading figure in both the computer and industries.

Mark Zuckerberg - Facebook

mark-zuckerberg

One of the most admired and successful youngster of the 21st century is a 24 years old Harvard graduate - the world’s youngest billionaire, with an estimated net worth of $1.5 billion

He founded Facebook, the online social networking website. Zuckerberg launched The Facebook (FaceMatch) from his Harvard dorm room in 2004 and started promoting it to all Ivy League schools and some Boston institutions.

Soon, he bought over Facebook.com domain name. Facebook is now a household name with people of all ages, groups and interests, interacting with each other. Its business and pleasure at the same time!

Kevin Rose - Digg

kevin-rose1

You all know Kevin, don’t you? Perhaps one of the most respected internet idealist and TV show host, Kevin Rose has definitely placed a huge impacts among all Digg users.

He became well known as an on-air talent and later as a co-host working on TechTV’s popular show The Screen Savers (which later became Attack of the Show! ) until his departure from the network on May 2005.

He also co-founded Pownce and Revision3 besides his popular Digg.com, social-bookmarking website. He created Digg in 2004 by hiring a freelance programmer who Kevin Rose paid $12 per hour through eLance.

Kevin Rose later bought Digg.com domain name for $1,200 and then went on to buy larger server space. Digg received an ultra boost of capitals when they received $2.8 million of venture capital from Omidyar Network, Netscape co-founder Marc Andreessen and Greylock Partners.

Bram Cohen - BitTorrent

bram-cohen

Best known as the developer, co-founder and author behind peer-to-peer sharing, Bram Cohen is the inventor of BitTorrent. The other day a cousin of mine said “Bit Torrent has made life easier!” That’s how easily we can sum up the achievements of this man.

Bram Cohen is also the co-founder of CodeCon and co-author of Codeville. In 2001, he quit his job at MojoNation to work in BitTorrent. He firstly revealed his ideas in a CodeCon conference and started luring beta testers by collecting free pornography.

He then spent some time working with Valve, but quit his job later to work in BitTorrent Inc. with his brother and business partner Mike Morhaime - Blizzard Entertainment

Mike Morhaime - Blizzard Entertainment

mike-morhaime

Mike Morhaime is the president and a co-founder of Blizzard Entertainment, a video game developer located in Irvine, California and currently owned by Activision Blizzard.

He is best know for his creation of a popular online gaming fantasy, World of Warcraft (WoW). It has over 10 million online gamers, raking Morhaime at least $1.5 billion every year.

Jimmy Wales - Wikipedia

jimmy-wales

Jimmy Wales is the co-founder of Wikipedia: a free and open content encyclopedia launched in 2001. He is also the co-founder of Wikia, a privately own web hosting company set up in 2004.

Jimmy Wales at first started a peer-reviewed, open-content encyclopedia which is Nupedia. He then utilized the ideas of Nupedia with his “wiki” software to form today’s Wikipedia.

His work with Wikipedia, which has become the world’s largest encyclopedia, prompted Time magazine to name him in its 2006 list of the world’s most influential people.

Chad Hurley and Steve Chen - YouTube

chad-hurley-and-steve-chen

Chad Hurley (aged 28) and Steve Chen (aged 27) became the founders of the popular San Bruno, California-based video sharing website YouTube, one of the biggest providers of videos on the Internet.

Chad Hurley used to work for eBay’s PayPal in the designing department where he designed their logo. Together with PayPal colleagues, Jared Karim and Steve Chen, Chad founded YouTube in 2005.

Google later acquired YouTube at $1.65 billion dollars.

Jeff Preston Bezos - Amazon

Jeff Bezos is the founder, chairman of board, president and the chief executive officer of Amazon.com, a major e-commerce company that sells goods through the Internet. His net worth is currently at $8.2 billion dollars.

He was named Time magazine Person of the Year in 1999.

Shawn Fanning - Napster, Rupture

shawn-fanning1

Inventor of Napster, the first popular peer-to-peer file sharing platform, Shawn Fanning is a computer programmer who developed Napster when he was still pursuing his studies in Northeastern University, Boston.

Soon after, however, Napster was the target of several music industry-backed lawsuits, which ultimately ended up causing the cessation of the service.

In December 2006, Fanning developed Rupture, a social networking tool that facilitates profiles and communications of online gamers in World of Warcraft.

Pierre Omidyar - eBay

pierre-omidyar1

Pierre Omidyar is the founder of eBay, an online auctioning marketplace that connects buyers and sellers. With a net worth of about $7.7 billion dollars, Omidyar and his wife Pam, are one of those entrepreneurs that go beyond doing profits, which is by contributing to non-profits organizations and aiding start-ups.

He wrote the source code of eBay when he was 28 years old in 1995. Initially, he decided to name his auction site after his consulting firm, Echo Bay but unfortunately, echobay.com was already taken. To save up his Internet service provider cost, he registered eBay.com.

Jack Ma - Alibaba

jack-ma1

A similar site like ebay, was founded by Jack Ma, in 1999. It is basically a China-based business marketplace site that serves international businesses.

Alibaba Group then founded TaoBao.com, which is an online auction website that is pretty much similar to eBay and instead of paying through PayPal, TaoBao’s currency is AliPay. Yahoo Inc. then acquires 40% stocks worth over $1 billion dollars.

Craig Newmark - Craigslist

craig-newmark1

Craig Newmark is an Internet entrepreneur that invented the Craigslist, with over 14.1 million page-views a month, Craigslist.org is one of the most visited website on the Internet.

Craigslist is a centralized network of communities, featuring free advertisements and forums on various topics.

Matt Mullenweg - WordPress

If it weren’t for Matt Mullenweg creating WordPress, I would not have been here writing at this blog and you all wouldn’t have been reading this article.

At the age of 19, he invented the core of Wordpress, and later on when he turned 24, quit his job at CNET to fully focus on developing WordPress - a blogging platform.

He is also the founder of Automattic, the business behind WordPress as well as famous spam fighter, Akismet.

Sir Tim Berners-Lee - World Wide Web

sir-tim-berners-lee

Sir Tim Berners-Lee; the father of World Wide Web. On 25 December 1990 he implemented the first successful communication between an HTTP client and server via the Internet with the help of Robert Cailliau and a young student staff at CERN.

Sir Tim Berners-Lee is also the founder of World Wide Web Consortium (W3C) at Massachusetts Institute of Technology which comprises of companies that are willing to create standards and improvements of the Web.

From my point of view, if it wasn’t for him, none of the above mentioned personalities existed.

UPDATE (24/11/08)

Thomas Anderson - MySpace

thomas-anderson
Thomas “Tom” Anderson is the President of the social networking website, MySpace. He is one of the people identified as a founder of the site, along with CEO Chris DeWolfe.

Since newly created MySpace accounts include Tom as a default “friend,” he has become known as the face of MySpace. As of November 20, 2008, Tom has over 250 million “friends”, a number which is constantly increasing due to new MySpace accounts being created.

In 2003, working for eUniverse under the preview of Brad Greenspan he and a few other eUniverse employs set up the first pages of MySpace and the site grew from there. It is currently the most popular social networking website in the United States, and is the most popular website for teenagers as well.

Interesting Fact: According to several sources, in 1985 then 14-year-old San Pasqual High School (Escondido, California) student Tom Anderson was a computer hacker operating under the alias Lord Flathead“.

He was known for leading a team that broke into Chase Manhattan Bank computers, altered records and left a message saying that unless he was given free use of the system he would destroy records. He was never charged.

Garrett Camp - StumbleUpon

garrett-camp

Garrett Camp is the co-founder as well as the chief architect of Stumbleupon, a social bookmarking site that lets you discover and share new websites from all over the world. StumbleUpon took-off in November 2001, and continued, until late 2005 when it was moved to San Francisco.

To be more precise, StumbleUpon was founded by Garrett Camp, Geoff Smith, Justin LaFrance, and Eric Boyd during Garrett’s time in post-graduate school (in Calgary, Alberta, Canada).

The popularity of the software attracted Silicon Valley investor Brad O’Neill to take notice of the company and assist with a move to San Francisco. Garrett Camp and Geoff Smith now reside in San Francisco, where StumbleUpon is headquartered.

According to its About page, Stumble Upon has over 6,443,266 users.The majority of which are between the ages of 18 and 45 (in English-speaking countries). Half in the United States, half abroad, and the majority using Firefox.

Linus Torvalds - Linux

linus-torvalds

Linus Benedict Torvalds is a Finnish software engineer best known for having initiated the development of the Linux kernel. He later became the chief architect of the Linux kernel, and now acts as the project’s coordinator.

Initially Torvalds wanted to call the kernel he developed “Freax” - a combination of “free”, “freak”, and the letter X to indicate that it is a Unix-like system, but his friend Ari Lemmke, who administered the FTP server where the kernel was first hosted for downloading, named Torvalds’ directory linux.

Since Linux has had thousands of contributors, such a percentage represents a significant personal contribution to the overall amount of code. Torvalds remains the ultimate authority on what new code is incorporated into the standard Linux kernel.

UPDATE (25/11/08)

Jon Postel - Internet Pioneer

jon-postel1

Jonathan Bruce Postel made many significant contributions to the development of the Internet, particularly in the area of standards. He is principally known for being the Editor of the Request for Comment (RFC) document series, and for administering the Internet Assigned Numbers Authority until his death.

The Internet Society’s Postel Award is named in his honor, as is the Postel Center at Information Sciences Institute. His obituary was written by Vint Cerf and published as RFC 2468 in remembrance of Postel and his work.

In its infancy, Jon worked on its development, from its early protocols, to the creation of TCP/IP. Documenter and co-developer many of the key Internet standards, including TCP/IP (basic Internet protocols), SMTP (email transfer), and DNS (name servers).

Jon’s influence is felt throughout the Internet, in its protocols, in their documentation, in the DNS names we use and the ‘dot’ we use to separate them, and, in no small way, in the ‘good engineering’ that helped the Internet thrive from its inception in 1969 to today.

Caterina Fake - Flickr

Fake is best known as the co-founder, with her husband Stewart Butterfield, of Flickr, a photo-sharing service developed by Ludicorp in Vancouver and acquired by Yahoo! in 2005.

Flickr ushered in the so-called Web 2.0 integrating features such as social networking, community open APIs, tagging, and algorithms that surfaced the best, or more interesting content. Prior to founding Ludicorp she was Art Director at Salon.com and heavily involved in the development of online community, social software and personal publishing. She joined the board of directors of Creative Commons in August of 2008.

Stewart Butterfield

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General Manager of Flickr In 2005. Butterfield was named one of Businessweek’s Top 50 Leaders in the entrepreneur category and was awarded a TR35 award as one of 35 top innovators under the age of 35 by MIT’s Technology Review. On 2006 he was named to the Time 100, Time Magazine’s list of the 100 most influential people in the world.

Marc Andreessen - Netscape

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Marc Andreessen is known as an entrepreneur, investor, startup coach, blogger, and a multi-millionaire software engineer best known as co-author of Mosaic, the first widely-used web browser, and founder of Netscape Communications Corporation.

He was the chair of Opsware, a software company he founded originally as Loudcloud, when it was acquired by Hewlett-Packard. He is also a co-founder of Ning, a company which provides a platform for social-networking websites.

As of June 30, 2008, he is said to be joining the Board of Directors of Facebook. On September 30, 2008, it was announced that he had joined the Board of Directors of eBay.

Jack Dorsey - Twitter

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Jack Dorsey is an American software architect and businessperson best known as the creator of Twitter - a free social networking and micro-blogging service. BusinessWeek called him one of technology’s best and brightest. MIT’s Technology Review named him to the TR35, an outstanding innovator under the age of 35.

Dorsey, Stone and Williams co-founded Obvious which then spun off Twitter Inc. As chief executive officer, Dorsey saw the startup through two rounds of funding by the venture capitalists who back the company. In October 2008 Williams took over the role of CEO, and Dorsey became chairman of the board.

As the service grew in popularity, Dorsey had to choose improving uptime as top priority— even over creating revenue, which as of 2008, Twitter was not designed to earn.


Source:--www.stubleupon.com