Ping

This is just to check if this blog app really works.

[Random Image] Aparna Sarovar kids are skating

Microsoft IDC Academic Intern program questions

Microsoft with a team of 7 people came to our college for recruiting candidates for both Internship Program and Full-Time Employee(FTE) on 4th January, 2010. Good news, I am now somehow associated with the 9 lettered company 'Micro$oft' (Internship).
Lets get to the selection procedure. Selection consisted of 5 rounds (1 written and 4 interviews)

Written Round (1 hr):

1. Recursion question. You need to find the output (question was very lengthy)


2. Given an integer array, find the lowest n integers


3. Find successor and predecessor of a node in BST


4. There is a live streaming file, a program displays the last n lines of the file, you need to find the test cases for the program


5. Port a drawing and paint tool in Mobile phones

Interview Round:

1. Reverse an integer array, without using additional array


2. Given 2 linked list having integer values (0-9) in each node, you need to add the linked list assuming each linked list represent a number


3. Given an integer array with both +ve and -ve numbers, you need to find the highest sum of the sub array in O(n) time


4. Given a function which finds a given sub sting from a given mother string, give the Test Cases


5. Given a string with more than 1 space between words, compact the spaces without using additional array and in O(n) time. Example:
   Given: foo    bar  hello   world
   Output: foo bar hello world
   


6. Given a character matrix with random letter in each cell. Give a algo for finding if 'microsoft' is present in the matrix, there is no order in which the string exists, only given is each consecutive letter in present in the neighbouring cell of the previous letter.


7. Given an integer matrix mxn with random integers in each cell, print the matrix in spiral order


8. Given a string, you need to reverse each word in that string in O(n) time and without using additional string. Example:
   Given: Hello World
   Output: olleH dlroW


9. A game program was given, I won't be able to explain it here, but the task was to automate the moves of a player

In all it was less of interview and more of a conservation but fully technical. And the most important thing was there was always one interviewer for each candidate in each session.

Buzz Me..

This is just a dummy post to show you that I am not dead. Its been really long since I threw any update. I had quite a lot to rant but time and reluctance prevented me. In between :

• I was up to a self hosted Wordpress blog which I installed on maah gnutop. But then skipped the thought for no reason.


• Was the founding member and designer of our college's first full-fledged newsletter 'The Eminence' and it made me so proud.


• Built maah first Forum Application: Graph - Gaping Random Access Portal Host, totally from scratch.
  Member Credits
  • Rachit Gupta : For giving Graph its Name and Interface Design
  • Puneet Garg : For his work on Macromedia Flash and the Graph Banner
  
  Application Credits
  
  • Linux (Fedora) : Base operating system
  • Apache : Web Server
  • MySQL : DBMS Software
  • PHP : For SQL connectivity, front end and server side scripting
  • CSS : For interface upliftment
  • Javascript : For buttons
  
  


• Bid farewell to our Final Years (Bangla Meet 2009)


• blah.. blah.. blah..


• Ended up sophomoric stage of maah life

Hope to continue maah updates, and bring back the glory of Bright Edges..

P.S. : I missed the Indibloggers' Bhopal Meet, am really very sorry for that.

Rip Youtube the CLI way

There are many applications for extracting and downloading videos from youtube and other video hosts like web-based KeepVid or addons like VideoDownloader, and many others. There's also a very good technique of saving any streaming video by buffering it till 100%, navigate to the Cache folder and simply copy the video file (which is /tmp in case of linux).

But recently I got a python based CLI tool youtube-dl, which is a nifty yet a powerful must have tool. You can get it from your default repositories or for youtube-dl under Windows XP. Get it :

$ sudo yum install youtube-dl

Usage

• Simply download :

  $ youtube-dl http://www.youtube.com/watch?v=video_id



• Specify filename
  
  Manually specify :

  $ youtube-dl -o output.flv http://www.youtube.com/watch?v=video_id

  Use the original video title :

  $ youtube-dl -t http://www.youtube.com/watch?v=video_id

  Have a literal title :

  $ youtube-dl -l http://www.youtube.com/watch?v=video_id



• Download videos which requires your youtube account privileges and confirmation :

  $ youtube-dl -u username -p password http://www.youtube.com/watch?v=video_id

  
  Or read account details from .netrc file :

  $ youtube-dl -n http://www.youtube.com/watch?v=video_id

  Append this line to ~/.netrc file :
  

  machine youtube login username password password



• Simply print video URL instead of downloading :

  $ youtube-dl -g http://www.youtube.com/watch?v=video_id

  Or grab the Title :

  $ youtube-dl -2 http://www.youtube.com/watch?v=video_id



• Download in silent mode (like wget) :

  $ youtube-dl -q http://www.youtube.com/watch?v=video_id &



• Get Help :

  $ youtube-dl -h

Know more at the Official Page.

Custom Search Tool in Firefox

There are search engines which you visit/use frequently and are not listed in Firefox plugin page, so what you will do? Create your own simple :

I will making a Google Linux search tool :

• Open any text editor and paste this code :

  <search 
   name="Google Linux"
   method="GET"
   action="http://www.google.co.in/linux"
   queryCharset="utf-8"
  > 
    <input name="q" user>
  </search>



• You can add more parameters other than query like "Search within a domain".
  Add

  <input name="sitesearch" value="gnu.org">

  below

  <input name="q" user>

  Just carefully observe the URL after you hit a search for the parameter name/value and keep adding for a filtered search.


• Save the file as filename.src (I am using glinux.src) to ~/.mozilla/firefox/<profile>/searchplugins/
  
  TIP : To display icon next to your search engine create a 16X16 PNG or GIF image and save it in the same folder as glinux.src and name it glinux.png or glinux.gif as per your file format


• Restart Firefox, your source will be compiled and converted into a .XML file automatically and what next! use your engine

Also check : Mycroft Project

Attached few of my favorites : search.tar.gz

IP address from NetBIOS name

I will use ping command for knowing the IP address, but for a default *nix system we cannot ping a node using its NetBIOS name. So with a minor edit we can do it all. Here's the process :

• Edit /etc/nsswitch.conf :

  $ vim /etc/nsswitch.conf

  Or use any other editor of your choice


• Search for something similar to this :

  hosts:          files mdns4_minimal [NOTFOUND=return] dns mdns4

  and add wins at the end of the line

  hosts:          files mdns4_minimal [NOTFOUND=return] dns mdns4 wins

  Save the file and exit


• Now use ping command :

  $ ping xyz

  You will get a output something like this :

  PING xyz (192.168.2.1) 56(84) bytes of data.

  Here 192.168.2.1 is the required IP

There may be different ways but I find this one quite simple.

Source(s) : Samba HOWTO

Maah! Desktop

With GNU/Linux systems you can have a highly customizable desktop with no bounds to possibilities. I have discussed few techniques for a nerdy looking environment in my Feeling Geeky... post earlier. Well this one is just a snapshot preview kinda thing... concentrating mainly on the eye candy stuffs..


Distro : Ubuntu Hardy Heron 8.04
Desktop Environment : GNOME
Window Manager : Metacity/Compiz-Fusion/Fluxbox

Neat		Dirty

I have used Mac4Lin Themes/Skins by Anirudh


Compiz Fusion :

Cube Effect		Window Decoration		Shift Switcher

Random Shots:

Emulators		Gimp
Python Programming		Fluxbox

Build your own desktop, use this links :

http://www.gnome-look.org/
http://www.kde-look.org/
http://www.xfce-look.org/
http://compiz-themes.org/
http://www.fluxbox.org/

(wget = DM) != GUI

Wget the default download manager in *nix systems is a very versatile tool. I will be focusing on some of its very important features useful to a end user. So here we begin :

1. Simply downloading a file :

   $ wget <URL>

   Or better :

   $ wget -c <URL>

   -c or --continue lets you resume your incomplete download done using wget or a different program


2. Downloading a file silently (a very imp. feature in wget, to work in background) :

   $ wget -q <URL> &

3. Taking a log of all messages :

   $ wget <URL> -o filename

4. Downloading files from a Queue :

   $ wget -i filename

   Strore all download links in a file separated by Return key and link it with wget
5. Set your no. of retries and timeout seconds :

   $ wget -t <no. to tries> -T <duration> <URL>

6. Displaying the content of a file rather than saving it on Hard Disk :

   $ wget -O - <URL>

7. Retrieving all file with a particular extension from a web directory :

   $ wget -r -l1 -np -A.<extension> <directory>

   Example for http://www.abc.com/def/*.jpg

   $ wget -r -l1 -np -A.jpg http://www.abd.com/def/

8. Downloading an entire Web Site :

   $ wget -c -r -nc -p -D <domain> -k <URL>

   For this I have written a script for easy downloading :

   #!/bin/bash
   
   # Bash Script for Web Site downloading by GNUger
   # Syntax : $ sitesdwn [URL]
   
   command="wget -c -r -p -k"
   domain=$(echo $1 | cut -d/ -f3 | cut --complement -d. -f1)
   
   echo
   read -p "Download within $domain only (y/n) : " opinion
   if [[ $opinion == 'y' ]] ; then
    command="$command -D $domain"
   fi
   read -p "Disable overwriting existing files (y/n) : " opinion
   if [[ $opinion == 'y' ]] ; then
    command="$command -nc"
   fi
   read -p "Download outside the current directory (y/n) : " opinion
   if [[ $opinion == 'n' ]] ; then
         command="$command -np"
   fi
   read -p "Save as HTML extension (y/n) : " opinion
   if [[ $opinion == 'y' ]] ; then
         command="$command -E"
   fi
   read -p "Enable compatibility with Windows (y/n) : " opinion
   if [[ $opinion == 'y' ]] ; then
         command="$command --restrict-file-names=windows"
   fi
   echo "Downloading ... "
   echo
   $command $1
   echo
   echo "End"
   exit 1
   fi

   Or download the script from here. Syntax :

   ./sitedwn.sh <URL>

This is not it.. there's hell lot more but beyond the scope of this post. So just read the Manuals (worth reading specially the Examples part). There are GUI version for wget :

• GWget - For Gnome
• Kget - For KDE

But they does not provide you so many options and manual customizations as wget (CLI) does.

References : man pages of wget, Linux Journal

DC++ and Linux

Particularly in colleges where media sharing is very popular among students (like in ours) DC++ can be used to inter-connect different hostels and enable fast file-sharing. DC++ is a free and open-source, peer-to-peer file-sharing client that can be used to connect to the Direct Connect network. It has private messaging features or one can globally chat in a Hub Room. It also indexes files, so you just search for a file with specified characteristics. Many more handy features more you try to explore more you know. But alas! this program is not for Linux and designed specially for Windows. But should we worry... naah! We have LinuxDC++, whose interface is rewritten in GTK+ toolkit but the core code is that of DC++ and it works/behave exactly in the same manner.

Some very initial steps you should follow to trigger your DC++ engine :

1. Open LinuxDC++
2. Navigate to File > Preferences > Personal. There fill the form ( 'Nick' field is compulsory )
3. Navigate to File > Preferences > Sharing. There add the folders you want to share.
   NOTE: In DC++ each hub has its minimum sharing limit below which a user cannot join it, so create your share accordingly
4. Navigate to File > Quick Connect and enter the hub's IP address.
   

One minus point I would like to share is we cannot preview a file, its like download and use. But it hardly matters when you are in a local hub and have ample disk space. Happy Sharing!!


ADDED (18th Oct 2008) :

Digit Magazine, Oct 2008

Audio Boost using MPlayer

I often felt pissed off when my friends used VLC and others programs for software level volume amplification, so I searched for a similar kind in mplayer and guess what! It was already there in mplayer since ages. You just need to RTFM.

Syntax :

mplayer -af volume=20:0 mediafile

Would amplify the sound by 20dB and hard-clip if the sound level is too high

Reference ( man pages of mplayer ) :

AUDIO FILTERS
Audio  filters allow you to modify the audio stream and its properties. The syntax is:

       -af <filter1[=parameter1:parameter2:...],filter2,...>
              Setup a chain of audio filters.

       NOTE: To get a full list of available audio filters, see -af help.

            volume[=v[:sc]]
              Implements  software  volume control.  Use this filter with cau‐
              tion since it can reduce the signal to noise ratio of the sound.
              In  most  cases it is best to set the level for the PCM sound to
              max, leave this filter out and control the output level to  your
              speakers  with  the master volume control of the mixer.  In case
              your sound card has a digital PCM mixer  instead  of  an  analog
              one,  and you hear distortion, use the MASTER mixer instead.  If
              there is an external amplifier connected to the  computer  (this
              is  almost always the case), the noise level can be minimized by
              adjusting the master level and the volume knob on the  amplifier
              until the hissing noise in the background is gone.
              This  filter has a second feature: It measures the overall maxi‐
              mum sound level and prints out that level  when  MPlayer  exits.
              This  volume estimate can be used for setting the sound level in
              MEncoder such that the maximum dynamic range is utilized.
              NOTE: This filter is not reentrant and can therefore only be en‐
              abled once for every audio stream.
                 <v>
                      Sets  the  desired  gain  in  dB for all channels in the
                      stream from -200dB to  +60dB,  where  -200dB  mutes  the
                      sound  completely  and  +60dB equals a gain of 1000 (de‐
                      fault: 0).
                 <sc>
                      Turns soft clipping on (1) or  off  (0).   Soft-clipping
                      can  make the sound more smooth if very high volume lev‐
                      els are used.  Enable this option if the  dynamic  range
                      of the loudspeakers is very low.
                      WARNING:  This  feature creates distortion and should be
                      considered a last resort.

Enjoy your home theater ... :)

Ubuntu getting slow....

The day I installed Ubuntu and the day after few upgrades.. I noticed drastic decrease in speed. I thought the problem was with my user, so I deleted the configuration files within my ~/ folder many times but never got a preferred result. Nautilus took 10-20 sec to just open, furthermore my gnutop went indiscoverable in my Hostel's LAN Server and I was receiving error messages after login. The symptom which took me towards the solution to this problem was, I got this message everytime I used sudo :

sudo: unable to resolve host HOSTNAME

After a bit of googling I found that it was already reported : Bug #195308.

Here is the solution (if it ever happens to you):

• Open Terminal
• Edit your /etc/hosts file

  sudo vim /etc/hosts



• There replace :

  127.0.1.1 hostname.domainname

  with

  127.0.1.1 hostname

  
  Example in my case:
  Hostname : gnutop
  Domainname: workgroup


• Save and Exit

This worked for me as a charm and thought of removing Ubuntu remained a thought.. now Ubuntu is as fast as ever.

Grab your IP

Often you need to know your IP, particularly when your are connected by DCHP kinda connection. So here are some handy tips :

CLI

• Displaying the current config for all NIC's :
  

  $ ifconfig



• Displaying the current config for a particular device :
  

  $ ifconfig device

  Example:

  $ ifconfig ppp0



• For knowing your IP via which you are accessing WWW:

  $ ifconfig  | grep 'P-t-P' | cut -d: -f2 | awk {'print $1'}

  OR

  $ wget -q -O- http://www.whatismyip.com/automation/n09230945.asp

  Here we are taking the help of http://www.whatismyip.com/


• Additional Jobs:
  
  Display the kernel’s IPv4 network neighbour cache:
  

  $ arp

  
  Display the kernel’s IP routing tables

  $ route

  
  Pinging:

  $ ping IP addr

  Example:

  $ ping 192.169.25.15

There are many more tools for advanced usage like nmap and others, but these are the basics.

SOURCE

LAN Messenger

Today I was searching for a LAN messaging client on my Ubuntu box, so after a bit of googling I turned to Pidgin. I searched if it was possible to configure Pidgin as a LAN Messenger and out of my surprise it was simpler than I ever thought of. Here's how:

1> Open Pidgin

2> Then Navigate to Accounts > Manage > Add

3> Select Bonjour

4> Fill the other details as per your choice.

5> Do the same setting in other nodes and enjoying offline chat

Pidgin is a Crossplatform Mutliprotocol Instant Messaging client, so it doesn't matters if you are in Windows or Linux. The only thing that may matter is it comes preloaded in most of the present Linux Distros where as you have to install it in Windows.

Battey Stats

There are ready made panel applets available for viewing your battery remaining, current state and others.. Well here I give you more geekier an efficient way of doing that .. CLI ofcourse :

1. Know your battery's specification :

   $ cat /proc/acpi/battery/BAT0/info



2. Know your current battery status :

   $ cat /proc/acpi/battery/BAT0/state

   NOTE: BAT0 may differ as per your Laptop model, look for what you have got in /proc/acpi/battery directory.

I have made a small script for Battery Status :

#!/bin/bash
# Battery Status by GNUger

current=`grep remaining /proc/acpi/battery/BAT0/state | awk {'print $3'}`
total=`grep "design capacity:" /proc/acpi/battery/BAT0/info | awk {'print $3'}`

percent=$[100*$current/$total]

echo `grep charging /proc/acpi/battery/BAT0/state | awk {'print $3'}`  $percent%

Attached the script file here

TIP: You can add this script in conkyrc file

Ctrl + Alt + Del

Sometimes users get annoyed with not having their favorite Windows key combination "Ctrl + Alt + Del" working on Linux Box. Well here's how to view your process manager for "Ctrl + Alt + Del" :

GNOME :

1. Start gconf-editor via terminal / Alt+F2 & navigate to : apps > metacity > global_keybindings


2. Double click on run_command_1 and change its value to <Control><Alt>Delete


3. The navigate to : apps > metacity > keybinding_commands


4. Double click on command_1 and change its value to gnome-system-monitor

Fluxbox

1. With any text editor edit you ~/.fluxbox/keys file, Example:

   $ vim ~/.fluxbox/keys



2. Append this at the end of the file:

   Control Mod1 Delete :ExecCommand xterm -e top

   You can use gnome-system-monitor instead of xterm -e top, but I have used it to retain Fluxbox's spirit of minimalism

Relogin to check its effect...

Cyber-shot DSC-S650

Specifications :

• Brand : SONY, S-Series Cyber-shot camera
  
• Mega pixels : 7.2 Mega pixels
• Zooming : 3x Optical Zoom
• 2 inch. LCD Monitor
• Media Type : Memory Stick Duo, Memory Stick PRO Duo
• High Sensitivity ISO 1000
• Spot Metering, Scene Selection Modes
  
• Looks : Cool and Sleek
• Accessories : Sony Original 1GB Memory Stick
• Recommended goodies : Original Sony Nickel-Metal Hydride, Rechargeable Batteries, Sony CycleEnergy Battery Charger, Sony Carrying Case LCS-BDA.

"It is easy to use and likely to appeal to anyone looking for a less expensive camera from one of the leading brands" by http://www.cameras.co.uk/
I myself use this Camera and simply cannot resist myself in adoring its high picture quality and a option for lot of custom settings for professional quality snapshots.

For More Info. & do check out the Pictures/Videos taken from DSC-S650

File transfer to/from Mobile Phone

With new distros its very simple to do file transfer using bluetooth. Just a matter of few clicks :

1. Insert your Bluetooth Dongle, and a bluetooth icon will appear in the notification area, otherwise start your bluetooth service by executing : bluetooth-applet


2. Right click on that icon and Browse Device > Select your Mobile > Connect


3. If your device is not paired up, it will pop up pairing up menu on your phone and then on your PC. Then it will mount your phone's directory on your computer which you can browse using a Nautilus.

Else there is a geekier way too using CLI based obexftp :

1. Discover your mobile's MAC address and its channel for Object Push

   $ obexftp -b



2. Browse your phone's directory

   obexftp -b mac address -B channel -l

   You can also change the current directory to browse its content

   $ obexftp -b mac address -B channel -c directory -l

   NOTE: Replace mac address, channel & directory with your own value


3. Now upload file :

   $ obexftp -b mac add -B channel -c phone directory -p file

   And retrieve file :

   $ obexftp -b mac add -B channel -c phone directory -g file

For more on Bluetooth check this page

Mario, Contra, Ice Climber play them all

I remember the days when I was addicted to TV video games, so thought of bringing them back. After a bit of googling I got a open source NES emulator named Nestopia, but was unable to download it because the links for Linux download were dead. Then I turned to NTSC and PAL Famicom/NES emulator called FCE Ultra whose packages are easily available in Ubuntu Repositories.



Install it :

$ sudo apt-get install gfceu

Start the Emulator from Menu > Games > GFCE Ultra NES Emulator
Configure the keys : GFCE Window > Input > Gamepad 1 then press keys on your keyboard as per your convenience.
Execute a game : GFCE Window > Main > Browse then locate your .nes file.

For more documentation : FCE Ultra: General Documentation

Download the game files from NES Rom

Feeling Geeky...

Fed up with GNOME/KDE resource hogging Desktop Environment, but do not want to loose GUI! So now its time when you turn to fluxbox. Call this page "HowTo forge a simple geeky environment"..

Packages Recommended :

• Window Manager : fluxbox
• File manager : pcmanfm
• Web Browser : epiphany
  
• ImageMagick software suite
• Mplayer + Codecs

Other light-weight applications as per your requirement, there are many pages on it just Google.

Install them :

 # yum install fluxbox pcmanfm imagemagick mplayer epiphany

Start Fluxbox :
After finishing off with installation just log out and select fluxbox in the Session Type and Login.

Start Configuring :

• Generate a perfect menu, it will take some time

  $ fluxbox-generate_menu -kgB -is -ds -t xterm -b epiphany

  You can also add custom items to your menu : Editing Menu


• Set Wallpaper :

  $ fbsetbg /path/to/wallpaper

  Now edit you ~/.fluxbox/init file with any editor and search for session.screen0.rootCommand: and add fbsetbg -l beside it.


• Binding your ~/Desktop folder with your desktop, use PCMan FM :
  Start your pcmanfm file manager and navigate to Edit>Preference>Desktop and mark "Show files on Desktop", "Wallpaper" and "Allow window manager to decide right click". Edit you ~/.fluxbox/init file with any editor and search for session.screen0.rootCommand: and add pcmanfm beside it (replace fbsetbg -l).


• Use a animated wallpaper instead!
  You can use your screen-saver as a wallpaper. Edit your ~/.fluxbox/init file with any editor and search for session.screen0.rootCommand: and add /usr/lib/xscreensaver/gears -root beside it (you can use other screen-savers too). Actually you have to choose between normal wallpaper, desktop with icons or animated desktop.
  For having icons on desktop check this : Idesk


• System Monitor widget : install conky, get its readymade configuration files (conkyc) here


• Choose your default applications :
  Image Files : display
  Media Files (Audio/Video) : xterm -e mplayer

Further keep experimenting with the CLI commands, it makes you make proficient with Linux platform and do check this link (Linux Command Line).

Webcam and MPlayer

Ubuntu really shocked me today when it recognized my integrated webcam automatically, which I discovered via Ekiga application.. Ok so drivers set, what I need now is record videos and take snapshots.. Mplayer as the title indicates does this all, the versatile player which can load video devices too. Lets begin with our task :


Viewing :


Fireup this command to bring up your video streamer:

$ mplayer -fps 15 tv:// -tv  driver=v4l2:device=/dev/video0

You can replace your video fps(frames per second), device and driver value as per your convenience.

Specify the video dimensions :

$ mplayer -fps 15 tv:// -tv driver=v4l2:width=640:height=480:device=/dev/video0

Horizontally inverse the stream i.e. mirror effect :

$ mplayer -vf mirror -fps 15 tv:// -tv  driver=v4l2:device=/dev/video0

View Fullscreen :

$ mplayer -aspect 16:10 -fps 15 tv:// -tv  driver=v4l2:device=/dev/video0
$ mplayer -aspect 16:10 -vf mirror -fps 15 tv:// -tv  driver=v4l2:device=/dev/video0

Then press 'f' key to enter Fullscreen. NOTE: Enter aspect value as per your screen resolution ratio eg. 4:3, 16:9, 1:1


Snapshots:


Take snapshots while streaming by pressing 's' :

$ mplayer -vf screenshot -fps 15 tv:// -tv  driver=v4l2:device=/dev/video0

Mirrored :

$ mplayer -vf mirror,screenshot -fps 15 tv:// -tv  driver=v4l2:device=/dev/video0

The files will be saved in your current directory with name "shot####.png", where #### is for index number.


Video Capturing:


For video capturing you will need a companion of mplayer named "mencoder", install it if you don't have one. So here is the way you start your recording:

Without sound:

$ mencoder tv:// -tv driver=v4l2:width=640:height=480:device=/dev/video0 -nosound -ovc lavc -o filename.avi

With sound:

$ mencoder tv:// -tv driver=v4l2:width=640:height=480:device=/dev/video0:forceaudio:adevice=/dev/dsp -ovc lavc -oac mp3lame -lameopts cbr:br=64:mode=3 -o filename.avi

You can combine other subtags like vf, aspect, fps to enhance your video.

This is all, you can try a different short program too for video/photo capturing : VideoView.

This post took from me a lot of manual reading and googling but am happy to present it before you. Here are the major sources : Gentoo Wiki, Mencoder -vf and mplayer manuals.