Compiz - Debian ; Up and running!

This is just a plain simple way to have Compiz installed on your system ( i use Debian Etch ).

install compiz:

$ sudo apt-get install compiz

now edit the xorg.conf file: /etc/X11/xorg.conf, add the following lines at the bottom
Section "Extensions"
Option "Composite" "Enable"
EndSection

create a .xinitrc in your home directoy i.e. ~/.xinitrc with following lines:
#!/bin/sh
gnome-terminal &
exec compiz

Now, kill your current X server session by pressing Ctrl-Alt-BackSpace .

login onto a ( virtual ) terminal using your username and password, then just fire the following command:

$ startx

And here you go! All the nice effects of wobble etc. at your desk and a terminal window on your screen.

this is really a light way, without putting too much of memory on useless applications running along with GNOME/KDE.

Whatever you really need to use, just start from the terminal.


References:
http://ubuntuforums.org/showthread.php?t=131267
http://xwinman.org/basics.php

Ruby - The Programming Language

Here a few links that are good as a first look while learning Ruby.

General:

http://blade.nagaokaut.ac.jp/ruby/ruby-talk/index.shtml
http://www.ruby-lang.org/
http://www.37signals.com/
http://www.ruby-doc.org
http://api.rubyonrails.com/
http://www.ruby-forum.com/
http://www.rubyforums.com/forumdisplay.php?f=1
http://www.sitepoint.com/forums/forumdisplay.php?f=227
http://railsforum.com/
http://www.rubyinside.com/
http://redhanded.hobix.com/
http://www.rubyist.net/~matz/
http://www.planetrubyonrails.com/

:symbols in Ruby

http://glu.ttono.us/articles/2005/08/19/understanding-ruby-symbols
http://onestepback.org/index.cgi/Tech/Ruby/SymbolsAreNotImmutableStrings.red

writing daemons

http://daemons.rubyforge.org/classes/Daemonize.html


more to come...

Finding duplicate files on your system?!

I ( and many others ) have a lot media files ( mp3, jpg, avi, etc. ) lying around in the system. I wondered that how shall I get the list of all the duplicate files lying in my computer. Writing a script in Ruby which identifies the duplicate files using the MD5 hash values of the files contents, was no difficult a task. Here is the script.

#!/usr/bin/ruby

## This file finds all the duplicate files form a directory given
## at the command line.
## Released under the GPLv2
## Copyright (C) tuxdna(at)gmail(dot)com

require 'digest/md5'

## novice use of exceptions
begin
  throw nil if ARGV.length == 0
rescue
 print "Usage: ", $0, " \n"
 exit 1
end

directory = ARGV[0]
print "Name of directory given is :", directory, "\n"

## do not proceed if it is not a directory
exit 1 if File.file?(directory)

puts "Getting the list recursively, for all the files and sub-directories."
filelist = Dir[directory+"/**/*"]

puts "Now scanning the files: "
puts "Determining file size and Filtering the directories:"

sizehash = Hash.new { |h,k| h[k] = [] }
filelist.each do |filename|
 if File.file?(filename)
  sizehash[File.size(filename)].push(filename)
 end
end

## prune those entries which do not have same size
sizehash.delete_if { |k,v| v.length<=1 }
duplicates_md5 = Hash.new { |h,k| h[k] = [] }
  sizehash.each do | size, files |
  files.each do |filename|
     md5sum = Digest::MD5.new( File.new(filename).read )
     ## Necessary to do this because md5sum is an object of class Digest::MD5
     ## and we need a string for a key!!
     md5sum = md5sum.to_s
     duplicates_md5[md5sum].push(filename)
  end
end

## prune those entries which do not have same md5 hash value 
duplicates_md5.delete_if { |k, v| v.length <= 1 }
## print the files if we find duplicates now!
duplicates_md5.each do |h, files|
  puts "Following files match: "
  files.each { |f| puts f }
  puts
end
exit 0