aghyad

If you have a packaged ruby / rails / rvm / rbenv etc installed, get rid of them all, eg:

$ ruby --version
ruby 1.8.7 (2011-06-30 patchlevel 352) [x86_64-linux]

$ sudo apt-get remove ruby

if that didn't work, you can do:
$ aptitude purge ruby

aghyad

To be able to utilize more than one key in your github environment on one computer, and assuming we have the 2 following keys:
~/.ssh/id_rsa_personal_key
~/.ssh/id_rsa_company_key

Create the file ~/.ssh/config with the follwoing content:

### Default (Personal) GitHub
Host github.com
  HostName github.com
  User git

aghyad

alias glog="git log --color --graph --pretty=format:'%Cred%h%Creset -%C(yellow)%d%Creset %s %Cgreen(%cr) %C(bold blue)<%an>%Creset' --abbrev-commit"

alias mycukes= 'RAILS_ENV="development" bundle exec cucumber'
alias myspecs= 'RAILS_ENV="development" bundle exec rspec spec'

alias vim='vim +NERDTree'
alias rspecc='clear && bundle exec rspec'
alias drspecc='clear && RAILS_ENV=development bundle exec rspec'

alias mygit='git config --global user.name "SOME-NAME-HERE" && git config --global user.email SOME-EMAIL-HERE && echo "************" && echo "switched git user name to:" && git config user.name && echo "and git user email to:" && git config user.email && echo "************"'

aghyad

require 'resolv' 

def validate_email_domain(email)
  domain = email.match(/\@(.+)/)[1]
  Resolv::DNS.open do |dns|
    @mx = dns.getresources(domain, Resolv::DNS::Resource::IN::MX) + dns.getresources(domain, Resolv::DNS::Resource::IN::A)
  end
  @mx.size > 0 ? true : errors.add(:email, "Invalid email id")
end

aghyad

When installing passenger, Nginx, Ruby and Rails on Ubuntu 12.04 (without RVM/without rbenv):

First: installing Ruby (without RVM):

	sudo apt-get update

	sudo apt-get install ruby1.9.1 ruby1.9.1-dev \
	  rubygems1.9.1 irb1.9.1 ri1.9.1 rdoc1.9.1 \
	  build-essential libopenssl-ruby1.9.1 libssl-dev zlib1g-dev
	

aghyad

Experimenting with Ruby 2.0 and DTrace scripts

I was very excited when I heard about the new Ruby 2.0 features. I am not going to delve into Ruby 2.0 features here, but I will talk about one feature I consider the best of Ruby 2: integration of DTrace.

I've never used DTrace before, much less I thought it can be used efficiently with Ruby the same way debugger is being used with ruby on rails.

DTrace has been for years the most famous tracing framework and now it's time to start using it with Ruby 2. So, after readings about DTrace, I tried to put it in action. I will be using Mac OS X 10.7.

Installing Ruby 2.0

aghyad

module BinaryTree
  class Node
    attr_reader :word, :count, :left, :right

    include Enumerable

    def initialize(word)
      @word, @count = word, 1
    end

aghyad

class Array

  def aghyad_counting_sort
    count = []
    a = self
    puts a.inspect

    m = a.first
    a.each do |x|
      m = x if m < x

aghyad

class Array

  def aghyad_radix_sort
    round = 0
    bucket = [[],[],[],[],[],[],[],[],[],[]] #bucket of 10 sub-arrays
    self.each do |x|
      bucket[x.to_s.split('')[-1*(round+1)].to_i] << x
    end

    a = bucket.flatten

aghyad

class Array                                                                                                                                                                                                                 

  def aghyad_quick_sort                                                                                                                                                                                                            
    return self if length <= 1                                                                                                                                                                                              
    pivot = self[length/2]                                                                                                                                                                                                  
    return find_all { |i| i < pivot }.quick_sort + find_all { |i| i == pivot } + find_all { |i| i > pivot }.quick_sort