Less Code: 2009

Thursday, May 28, 2009

FTP with backslash in username or passwd

If you have a backslash in username or passwd, you need to do a special character to escape backslash.

For example: ftp\username

export ftpusername='ftp\\username'

If you put a double quote around export ftpusername, it doesn't work. Or if you try to add "/" like "ftp/\username" doesn't work either. Imagine how syntax could get your way.

Saturday, May 9, 2009

Ubuntu useful commands

To install .deb package.

sudo dpkg -i package_file.deb

When using vi editor in Awn gnome-terminal, ESC does not work, but Ctrl+[. It's hard to use vi in Awn, but it's still work.

-- searching virtualbox in the system

sudo aptitude search virtualbox

-- install virtual box

sudo apt-get virtualbox-ose

-- get new updates

sudo apt-get update

-- install updates

sudo apt-get upgrade

-- How to change files/folders ownership

sudo chown username /location_of_files_or_folders

-- If you want to change ownership of all containing files and folders recursively, use the -R option like this:

sudo chown -R username /location_of_files_or_folders

-- How to change files/folders group ownership

sudo chgrp groupname /location_of_files_or_folders

-- If you want to change group ownership of all containing files and folders recursively, use the -R option like this:

sudo chgrp -R username /location_of_files_or_folders

yakuake drop-down terminal emulator

This is my favorite terminal emulator.

Yakuake is a drop-down terminal emulator based on KDE Konsole technology.

http://yakuake.kde.org/

You can install on Ubuntu:

sudo apt-get install yakuake

VPN client on Ubuntu 9.04

VPN client on Ubuntu 9.04 is getting easier:

1. sudo apt-get install network-manager-pptp
2. click network-manager icon in panel-->VPN connections-->Configure VPN…
3. click Add button to add your vpn.server.com, username and passwd

Friday, April 24, 2009

Generate Power Ball numbers


class Lottery
  attr_reader :lotteryArray, :maxNumber, :powerBall, :maxPB
  #attr_writer :maxNumber
  
  def initialize(arraySize, maxNumber, powerBall, maxPB)
    @lotteryArray = Array.new(arraySize)
    @maxNumber  = maxNumber
    @powerBall     = powerBall
    @maxPB         = maxPB
  end
  
  def getUniqueLottery
    loop do
      checkDuplicate = 0
      numRand = getRandomNumber(@maxNumber)
      
      for i in 0...@lotteryArray.length
        if numRand == @lotteryArray[i] || numRand == 0
                checkDuplicate = 1
                break
        end
      end
      
      if checkDuplicate == 0 
        return numRand
      end
      
    end # end of loop
  end # getUniqueLottery
  
  def buildLottery
    for i in 0...@lotteryArray.length
      @lotteryArray[i] = getUniqueLottery
    end
  end # buildLottery
  
  def sortLottery
    return @lotteryArray.sort
  end
  
  def printLottery
    a = sortLottery
    a.each do |num|
      printf "%2s ", num
    end     
    
    if @powerBall == "Y"
      printf "\tPB: %2s \n", getPowerBall
    end 
  end # printLottery
   
  def getRandomNumber(number)
    randNum =  rand(number)
  end # getRandomNumber
  
  def getPowerBall
    randNum = 0
    until randNum  > 0
      randNum = getRandomNumber(@maxPB)
    end
    return randNum
  end # getPowerBall
end

# To run program
#
# ruby -w lottery.rb 5
#
# where TotalTickets is number of tickets that generates

# start program 
  lotto = Lottery.new(5, 56, "Y", 43)
  
  #for i in 1..$TotalTickets.to_i
  for i in 0...ARGV[0].to_i
    lotto.buildLottery
    lotto.printLottery
  end

Thursday, April 23, 2009

Syntax Color Highlight

After many tries, finally I got it to work. This is a ruby code to print out a string.
I am using coderay to do color highlighting.

To install coderay

sudo gem install coderay

To generate html type:

coderay -ruby -page < yourRubyProgram.rb > yourRubyProgram.rb.html

puts "To seek elegance rather than luxury"

Thursday, April 16, 2009

Install Oracle 11g on Ubuntu 8.10

Follow this link to install Oracle 11g on Ubuntu 8.10

Parsing US Census Data

The goal is to get State, State Code, Place FIPS code, City Name, Lat, and Lon from places2k.txt.
http://www.census.gov/geo/www/gazetteer/gazette.html

Here is the layout of place2k.txt

Columns 1-2: United States Postal Service State Abbreviation
* Columns 3-4: State Federal Information Processing Standard (FIPS) code
* Columns 5-9: Place FIPS Code
* Columns 10-73: Name
...
* Columns 144-153: Latitude (decimal degrees) First character is blank or "-" denoting North or South latitude respectively
* Columns 154-164: Longitude (decimal degrees) First character is blank or "-" denoting East or West longitude respectively

luan@luan-desktop:~/app/software/census_data$ head -5 places2k.txt
AL0100124Abbeville city 2987 1353 40301945 120383 15.560669 0.046480 31.566367 -85.251300
AL0100460Adamsville city 4965 2042 50779330 14126 19.606010 0.005454 33.590411 -86.949166
AL0100484Addison town 723 339 9101325 0 3.514041 0.000000 34.200042 -87.177851
AL0100676Akron town 521 239 1436797 0 0.554750 0.000000 32.876425 -87.740978
AL0100820Alabaster city 22619 8594 53023800 141711 20.472605 0.054715 33.231162 -86.823829

luan@luan-desktop:~/app/software/census_data$ cut -c -2,3-4,5-9,10-73,144-153,154-164 --output-delimiter="|" places2k.txt | head -5
AL|01|00124|Abbeville city | 31.566367| -85.251300
AL|01|00460|Adamsville city | 33.590411| -86.949166
AL|01|00484|Addison town | 34.200042| -87.177851
AL|01|00676|Akron town | 32.876425| -87.740978
AL|01|00820|Alabaster city | 33.231162| -86.823829

You can write C or Java to parse the above data, but it would take more time to write code for it.
If cut command does not serve your need, you should look at awk programming language before jump into C or Java.

Install ruby 1.9 on Ubuntu 9.04

First, remove any ruby version on the system:

sudo apt-get remove --purge ruby1.8 ruby1.9

-- package build dependencies (ruby)

sudo apt-get build-dep ruby1.9

-- get ruby 1.9 source
-- if you can't get it, try to download from
-- http://www.ruby-lang.org/en/

wget -c ftp://ftp.ruby-lang.org/pub/ruby/1.9/ruby-1.9.1-p0.tar.gz

-- extract ruby source using tar

tar -xvzf ruby-1.9.1-p0.tar.gz

-- go to extracted ruby code dir

cd ruby-1.9.1-p0/

-- execute configure
./configure --prefix=/opt/ruby-1.9.1-p0 --enable-pthread --enable-shared

-- execute make command
make

-- install process
sudo make install

Then I add the following line to the bottom of $HOME/.bash_profile

luan@luan-desktop:~$ cat .bash_profile
export OC4J_HOME=/opt/oc4j

export JAVA_HOME=/opt/java
export ECLIPSE_HOME=/opt/eclipse
export GROOVY_HOME=/opt/groovy

export GRAILS_HOME=/opt/grails
export TNS_ADMIN=/opt/oracle
export ORACLE_HOME=/u01/app/oracle/product/11.1.0/db_1
export RUBY_HOME=/opt/ruby

export NLS_LANG=AMERICAN_AMERICA.UTF8
export PATH=$ORACLE_HOME/bin:$RUBY_HOME/bin:$JAVA_HOME/bin:$OC4J_HOME/bin:$ECLIPSE_HOME:$GROOVY_HOME/bin:$GRAILS_HOME/bin:$PATH

export AWT_TOOLKIT=MToolkit

Create a link:

luan@luan-desktop:/opt$ ln -s /opt/ruby-1.9.1-p0 /opt/ruby

luan@luan-desktop:/$ cd

luan@luan-desktop:/$ source .bash_profile

luan@luan-desktop:/$ ruby -v
ruby 1.9.1p0 (2009-01-30 revision 21907) [i686-linux]

If you are using ruby gem, you need to type:
sudo /opt/ruby/bin/gem

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