rake sh en otro directorio

Posted: July 17th, 2009 | Author: FreedomCoder | Filed under: Open Source, Programming, how-to, rake | Tags: , , , | No Comments »

Problema: Quiero ejecutar un comando desde otro directorio en rake (por ejemplo, ejecutar un makefile que está en un subdirectorio).
Solución: Agrego al rakefile la posibilidad de ejecutar comandos en otro directorio. Para eso, al principio de mi rakefile puse:


require 'fileutils'

def sh_in_dir( dirname, *args, &block )
  old_path = pwd
  FileUtils.chdir( dirname )
  sh( *args, &block )
  FileUtils.chdir( old_path )
end

Happy hacking,

Aureliano.

(Via aurelianito.) Original Link: rake sh en otro directorio


RubyInstaller: Getting Started with Rails and SQLite3

Posted: July 7th, 2009 | Author: FreedomCoder | Filed under: Rails, SQL, how-to | Tags: , , | 1 Comment »

A few folks asked this over the past weeks, and since I released preview1 version of RubyInstaller, wouldn’t be awesome I write a guide for it?

So, here we go

First, Getting Ruby

Please download from here one of the preview1 installers for Ruby.

For this demonstration, I’m going to use Ruby 1.9.1-p129. Downloaded, executed and installed to it’s default location C:\Ruby19

Now, start a Command prompt with Ruby (under start menu, inside Ruby 1.9.1-p129).

Command Prompt with Ruby

Getting SQLite3

As you may know, Windows do not came out of the box with libraries like SQLite3. For this, we are going to download it from Internet.

Going to SQLite downloads, under Precompiled binaries for Windows, download sqlitedll-3_6_16.zip and sqlite-3_6_16.zip. Those two packages contains the DLL (sqlite3.dll) and the command line executable for SQLite (sqlite3.exe).

Please extract those contents inside C:\Ruby19\bin

Now, let’s get the Ruby bindings for SQLite3

Getting SQLite3/Ruby bindings

As you may know, the preferred way to distribute Ruby libraries is using Gems. Users on other platforms usually compile themselves these components, using the mechanisms provided by the operating system distribution.

We are going to avoid the compilation process using pre-compiled binaries that has been cooked for us.

So, back to the Command Prompt with Ruby, let’s install the sqlite3 bindings:

gem install sqlite3-ruby --source http://gems.rubyinstaller.org

Adding --source help us indicate a non-standard location from where gems are going to be installed. RubyInstaller team has built and packaged special versions of these gems that we hope get published soon into RubyForge, the official place for gem distribution.

Once installed, you should see something like this at the screen:

Successfully installed sqlite3-ruby-1.2.4.1-x86-mingw32
1 gem installed

These special version of the gem are fat binaries, which means these can be safely installed on Ruby 1.8.6 or 1.9.1.

Getting Rails

Now it’s time to install and build a Rails application. First, let’s install the rails gem:

gem install rails

That command is going to take a bit, since is a 2MB or so download, and will install several of the Rails dependencies (ActiveRecord, ActionPack, ActiveSupport, etc). You should expect similar output to this:

Successfully installed activesupport-2.3.2
Successfully installed activerecord-2.3.2
Successfully installed actionpack-2.3.2
Successfully installed actionmailer-2.3.2
Successfully installed activeresource-2.3.2
Successfully installed rails-2.3.2
6 gems installed

Let’s build our application now.

Creating a Rails application.

Let’s call the application railsapp

rails railsapp

An excerpt of the output you should get:

      create
      create  app/controllers
      create  app/helpers
      create  app/models
      create  app/views/layouts
      create  config/environments
      create  config/initializers
      create  config/locales
      create  db
...

Rails 2.3.2 defaults it’s database format to SQLite3, so there is no need for us to tweak anything.

Checking if everything is ok, using script\about:

cd railsapp
ruby script\about

And the output should be something like this:

About your application's environment
Ruby version              1.9.1 (i386-mingw32)
RubyGems version          1.3.4
Rack version              1.0 bundled
Rails version             2.3.2
Active Record version     2.3.2
Action Pack version       2.3.2
Active Resource version   2.3.2
Action Mailer version     2.3.2
Active Support version    2.3.2
Application root          C:/Users/Luis/railsapp
Environment               development
Database adapter          sqlite3
Database schema version   0

Now, it’s up to you create your models, controllers and everything.

Some notes and considerations.

At the time of this writing, Mongrel has not been updated to build and install properly either on 1.9 or MinGW versions of Ruby.

As part of Mongrel development team, I’m going to work on a solution for this in the upcoming days.

If you find something wrong with the Ruby Installer, please report here, but issues with your code, Rails or other are not responsability of RubyInstaller.

The binary gems provided at gems.rubyinstaller.org are based on our forks of sqlite3-ruby, which can be cloned and explored here at GitHub.

Keep in mind that some gems would not work under Ruby 1.9, or you will need a compiler (DevKit) for it. See previous post with details how to get those from our download page.

(Via DEV_MEM.dump_to(:blog) – Multimedia systems blog.) Original Link: RubyInstaller: Getting Started with Rails and SQLite3


RubyInstaller: Getting Started with Rails and MySQL

Posted: July 7th, 2009 | Author: FreedomCoder | Filed under: Rails, SQL, how-to | Tags: , , | No Comments »

This is a follow up instruction set from previous post, but this time, using MySQL

Getting Ruby

These steps are the same for Ruby 1.9 or Ruby 1.8, please feel free to download the installer from here

For this guide I’m going to use Ruby 1.9.1-p129, since it the coolest new version that all the guys are playing with ;)

Now, start a Command prompt with Ruby (under start menu, inside Ruby 1.9.1-p129).

Command Prompt with Ruby 1.9

Getting the right MySQL version

While building the MySQL/Ruby bindings, we found that mixing versions of the bindings with different versions of MySQL installations ended on undesired results (abnormal program termination, weird errors, etc.)

For this guide, and because we are going to use binary gems, we are going to stick to MySQL version 5.0.83.

Now is time to download MySQL. For this guide, I’m going to install the essentials version, which contains only MySQL and command line tools, no Query Builder or any other administrative tool.

Please go to this page and download Windows Essentials (x86). Once downloaded you will end with mysql-essential-5.0.83-win32.msi file. Execute it and install with defaults.

Configure MySQL

If you’re an advanced and savvy MySQL user, you can skip the following steps. For the sake of this guide, I’m going to list the simple options you must follow when installing it.

Once you installed MySQL, the installer should have started the Configuration Wizard page.

Inside of it, please apply the following options:

Option/Screen Value
Configuration Type Detailed configuration
Server type Developer Machine
Database usage Transactional Database only
InnoDB datafile Your option or leave defaults
Number of connections Decision Support
Networking options Check Add firewall exceptions
Character set Best support for Multilingualism (UTF8)
Windows Options Add to PATH if you want mysql available on every prompt
Security Options Uncheck if you want root password be blank

Once done with all this, on the summary screen, please click Execute to complete the configuration of MySQL Server.

Under some system, starting of MySQL server will fail during this wizard, but don’t be afraid, most of the times, this can be safely ignored.

To check everything was properly installed, please go to the Start Menu, and inside MySQL Server 5.0, click on MySQL Command Line Client

If you changed the root password, or, like me, leaved it unchecked, you can simply press enter when asked for the password and see that the server is running!

MySQL Console Client

If you decided to add MySQL to the PATH, you will require to restart your computer so the PATH change is available to the system.

If you decided not to add MySQL to the PATH, please go, with Explorer to the location where you installed MySQL Server and copy libmySQL.dll into C:\Ruby19\bin

In my case, I found this file in C:\Program Files\MySQL\MySQL Server 5.0\bin

Now, it is time to install the bindings.

Getting MySQL/Ruby

For this version of Ruby, there is no official binary gems for both Ruby 1.8 and 1.9. So we are going to install the specially built version from RubyInstaller gems repository.

At the Command Prompt with Ruby, please enter the following command:

gem install mysql --source http://gems.rubyinstaller.org
  

This is going to install the special version of MySQL bindings. This version works with Ruby 1.8 and 1.9, since bundles fat binaries. You should expect a similar output like this:

Successfully installed mysql-2.8.1.1-x86-mingw32
1 gem installed

Getting Rails

Now is time to install Rails and build our application. At the same command prompt, please enter the following command:

gem install rails

This is going to take a bit, since Rails and it’s dependencies takes around 2MB or so, and need to be downloaded and installed.

Once done, expect see at the screen something like this:

Successfully installed activesupport-2.3.2
Successfully installed activerecord-2.3.2
Successfully installed actionpack-2.3.2
Successfully installed actionmailer-2.3.2
Successfully installed activeresource-2.3.2
Successfully installed rails-2.3.2
6 gems installed

Creating a Rails application

Let’s name our application mysqlapp

rails mysqlapp --database=mysql

The --database option indicates to Rails that we want to use MySQL instead of the default database adapter (SQLite3).

Rails will output a lot of lines when creating your application structure, just an excerpt of what to see:

...
      create  config/database.yml
      create  config/routes.rb
      create  config/locales/en.yml
      create  config/initializers/backtrace_silencers.rb
      create  config/initializers/inflections.rb
      create  config/initializers/mime_types.rb
      create  config/initializers/new_rails_defaults.rb
      create  config/initializers/session_store.rb
      create  config/environment.rb
...

Configuring our Database

Now Rails have configured for us the name of the database we want to use, and you can verify it in config\database.yml

Rails will try to connect to mysqlapp_development, but that database do not exist in our fresh new MySQL server.

So, let’s create it:

cd mysqlapp
rake db:create

Just that, simple db:create is going to connect to our MySQL server, and create the database for us.

Keep in mind that if you changed root password or want to use other MySQL user to connect to the database, you need to edit database.yml to reflect those changes.

Let’s verify that everything is in place, using the following command:

About your application's environment
Ruby version              1.9.1 (i386-mingw32)
RubyGems version          1.3.4
Rack version              1.0 bundled
Rails version             2.3.2
Active Record version     2.3.2
Action Pack version       2.3.2
Active Resource version   2.3.2
Action Mailer version     2.3.2
Active Support version    2.3.2
Application root          C:/Users/Luis/mysqlapp
Environment               development
Database adapter          mysql
Database schema version   0

Now is up to you to create your models, controllers and views!

Some notes and considerations

On other post I’m going to guide you with steps on building the bindings against MySQL 5.1.36, since you will need to install the Ruby Development Kit and the development headers for MySQL.

If you find something wrong with the Ruby Installer, please report it here, but issues with your code, Rails or other are not responsability of RubyInstaller.

The binary gems provided at gems.rubyinstaller.org are based on our forks of mysql bindings, which can be cloned and explored here at GitHub.

Keep in mind that some gems would not work under Ruby 1.9, or you will need a compiler (DevKit) for it. See previous post with details how to get those from our download page.

(Via DEV_MEM.dump_to(:blog) – Multimedia systems blog.) Original Link: RubyInstaller: Getting Started with Rails and MySQL


I’m back with some Code …

Posted: July 6th, 2009 | Author: FreedomCoder | Filed under: Open Source, Programming, github, how-to | Tags: , , , | No Comments »

Well, hello again, long time since the last post. I went on vacations, work a lot and did some programming. Let’s talk abount the programming part, since it is the most interesting one. ;)

I created a small library called “Esearchy” capable of searching the internet for email addresses. Currently, we the supported search methods are engines such as Google, Bing, Yahoo, PGP servers, GoogleGroups, etc , but I intend to add many more.
Also, the library searches inside .pdf and .txt files for emails addresses and adds them to the list of found accounts.

For now, there are two main ways of performing a search, “the ruby way”

  1. Esearchy.create "domain.com" do |domain|
  2.    domain.maxhits = 500
  3.    domain.search
  4.    domain.clean {|e| e =~ /<|>/ }
  5.    domain.save_to_file "~/emails.txt"
  6.  end

and the more classic way in which users can create an Esearchy objetc and work on it

  1.  domain = Esearchy.new :query => "domain.com", :maxhits => 500
  2.   domain.search
  3.   domain.save_to_file "~/emails.txt"

For now , that’s it for now , but keep on tuned for more shitty code ajjajaa

(Via 自由編碼人.) Original Link: I’m back with some Code …


Patch en Regexp para poder usarlas como clave en un Hash

Posted: July 6th, 2009 | Author: FreedomCoder | Filed under: Open Source, Programming, how-to | Tags: , , , | No Comments »

Siguiendo mi proyecto de hacer mi wiki en Ruby, encontré un comportamiento muy raro.
Generé un hash (que se llama @rules) que no tiene un elemento que tiene. O sea, @rules[@rules.keys[2]] da nil, pero @rules.values[2] devuelve el objeto asociado a la clave @rules.keys[2]. Como este hash tiene como claves un montón de expresiones regulares, me imaginé que había un problema con el hash y el eql? de Regexp, así que los implementé de nuevo y monkeypatchié.
Este es el código:

class Regexp
 alias_method  :o ld_rapidito_inspect, :inspect

 def inspect
   @inspect = old_rapidito_inspect if @inspect.nil?
   @inspect
 end

 def eql?( other )
   false if other.class != Regexp
   self.inspect == other.inspect
 end

 alias_method :"==", :eql?

 def hash
   self.inspect.hash
 end
end

Esta corrección me anduvo con la siguiente versión de ruby:

$ ruby --version
ruby 1.8.7 (2008-08-11 patchlevel 72) [i486-linux]

Espero que les sirva.
Happy hacking,
Aureliano.

(Via aurelianito.) Original Link: Patch en Regexp para poder usarlas como clave en un Hash


Más rapidito

Posted: July 1st, 2009 | Author: FreedomCoder | Filed under: Open Source, Programming, how-to | Tags: , , , | No Comments »

Como les estuve contando, sigo escribiendo mi wiki. Ya parsea un subconjunto interesante del lenguaje definido por trac.
Siguiendo la tradición, les cuento como está avanzando el tokenizer. Al tokenizer lo simplifiqué para que devuelva la expresión regular que matcheo junto con el match (en vez del “tipo”). Esto hizo que la interfase para definir las reglas para tokenizar sea más simple. Si no hay ninguna regla que matchee sigue devolviendo ["string", :text].
Sin más, acá el código:

module Rapidito
  class Tokenizer

    def initialize( *delimiters )
      @delimiter_list = delimiters +  [/\z/]
      @match_cache = nil
    end

    def source
      valid_cache? ? @match_cache[0].to_s + @source : @source
    end

    def source=(s)
      @match_cache = nil
      @source = s
    end

    def has_next?
      !@source.empty? || valid_cache?
    end

    def valid_cache?
      (!@match_cache.nil?) && (@match_cache[0].to_s.length > 0)
    end

    def next_match
      @delimiter_list.map {|regex| [regex.match(@source),regex]}.reject {|p| p[0].nil?}.inject do
        |better,new|
        better_pos = better[0].pre_match.length
        new_pos = new[0].pre_match.length

        if better_pos < new_pos
          better
        elsif new_pos < better_pos
          new
        elsif better[0].to_s.length > new[0].to_s.length
          better
        else
          new
        end
      end
    end

    def next_token
      if @match_cache #cached delimiter
        rv = @match_cache
        @match_cache = nil
        return rv
      end

      match = next_match
      p = match[0].pre_match.length
      @source = @source[p + match[0].to_s.length, @source.length]

      if p == 0 #delimiter
        match
      else #text
        @match_cache = match
        [match[0].pre_match, :text]
      end
    end

    def all_tokens
      tokens = []
      while has_next?
        tokens << next_token
      end
      tokens
    end
  end
end

Y si miran los tests de unidad, van a ver que también quedaron más lindos:

require 'test/unit'
require 'rapidito/tokenizer'

include Rapidito

class TokenizerTest < Test::Unit::TestCase

  def test_no_token
    tok = Tokenizer.new
    tok.source = "aaaa"
    assert_equal true, tok.has_next?
    assert_equal ["aaaa", :text], tok.next_token
    assert_equal false, tok.has_next?
  end

  def assert_all_tokens( expected, tokenizer )
    assert_equal expected,
      tokenizer.all_tokens.map { |token, kind| [token.to_s, kind] }
  end

  def test_two_delimiters
    tok = Tokenizer.new(
      /\|/, /;;/
    )

    tok.source = "aa|bbb;;;;cccc"
    assert_all_tokens \
      [ ["aa", :text], ["|", /\|/], ["bbb", :text],
        [";;", /;;/], [";;", /;;/], ["cccc", :text] ],
      tok

    tok.source = "aa;;bbb||cccc"
    assert_all_tokens \
      [ ["aa", :text], [";;", /;;/], ["bbb", :text],
        ["|", /\|/], ["|", /\|/], ["cccc", :text] ],
      tok
  end

  def test_choose_longest_match
    tok = Tokenizer.new(
      /aa/, /aaa/
    )
    tok.source = "aaaa"
    assert_all_tokens [ ["aaa", /aaa/], ["a", :text ] ], tok
  end

  def test_reset_precache
    tok = Tokenizer.new(
      /\|/, /,/
    )
    tok.source = "original start|original end"
    tok.next_token
    tok.source = "new start,new end"
    assert_equal ["new start", :text], tok.next_token
  end

  def test_almost_finished
    tok = Tokenizer.new( /!/ )
    tok.source = "bang!"
    tok.next_token
    assert_equal true, tok.has_next?
    tok.next_token
    assert_equal false, tok.has_next?
  end

  def test_carriage_return_ending
    tok = Tokenizer.new( /!/ )
    tok.source = "bang!\n"
    tok.next_token
    assert_equal true, tok.has_next?
    tok.next_token
    assert_equal true, tok.has_next?
    assert_equal "\n", tok.next_token[0].to_s
    assert_equal false, tok.has_next?
  end

  def test_transparent_caching
    tok = Tokenizer.new( /!/ )
    tok.source = "bang!pum"
    tok.next_token

    assert_equal "!pum", tok.source
  end

  def test_match_klass
    tok = Tokenizer.new( /!/ )
    tok.source = "!bang!pum"

    assert_equal \
      [MatchData, String, MatchData, String],
      tok.all_tokens.map { |tok, kind| tok.class }
  end
end

Happy hacking,
Aureliano.

(Via aurelianito.) Original Link: Más rapidito


Pequeñas delicias de las expresiones regulares

Posted: June 13th, 2009 | Author: FreedomCoder | Filed under: Open Source, Programming, how-to | Tags: , , , | No Comments »

Como les conté acáacá, estoy escribiendo un tokenizador para un wiki que estoy programando. Y hoy me encontré con una cosa muy extraña de las expresiones regulares.
En ruby la función match sirve para buscar el primer match de una regex dentro de un string. Por ejemplo (usando el irb):

irb(main):001:0> m = /a/.match "babab"
=> #<MatchData "a">
irb(main):002:0> m.pre_match
=> "b"
irb(main):003:0> m[0]
=> "a"

En particular, el pre_match es lo que está antes del match en el string. También según había entendido (mal) /\Z/ matchea con el final del string. Por ejemplo:

irb(main):004:0> m = /\Z/.match "hola"
=> #<MatchData "">
irb(main):005:0> m.pre_match
=> "hola"
Pero, /\Z/ tiene un comportamiento muy extraño, aunque documentado, cuando el último caracter antes del final es un \n. Lo que pasa es que el pre_match queda ¡sin el\n del final!. Lo muestro en el irb:
irb(main):006:0> m = /\Z/.match "\n"
=> #<MatchData "">
irb(main):007:0> m.pre_match
=> ""

Para que no se manduque el \n, hay que usar /\z/ (¡en minúscula!):

irb(main):008:0> m = /\z/.match "\n"
=> #<MatchData "">
irb(main):009:0> m.pre_match
=> "\n"

Por lo tanto tuve que tocar el tokenizer, ahora la función de initialize quedó así (miren el cambio de la "Z" a "z"):

    def initialize( delimiters )
      @delimiter_list = [[/\z/, :finish]] +
        delimiters.to_a.map { |k,arr| arr.map { |re| [re, k] } }.inject([]) { |ac,ps| ac + ps }
      @match_cache = nil
    end

Y el test que captura el problema que genera usar \Z en vez de \z quedó así:

  def test_carriage_return_ending
    tok = Tokenizer.new( :a_kind => [/!/] )
    tok.source = "bang!\n"
    tok.next_token
    assert_equal true, tok.has_next?
    tok.next_token
    assert_equal true, tok.has_next?
    assert_equal "\n", tok.next_token[0].to_s
    assert_equal false, tok.has_next?
  end

Happy hacking,

Aureliano.

(Via aurelianito.) Original Link: Pequeñas delicias de las expresiones regulares


RubyInstaller: One-Clicks need a new home, can you help him?

Posted: May 19th, 2009 | Author: FreedomCoder | Filed under: Programming, Windows, how-to | Tags: , , | No Comments »

I must say that my skills to ask for something are really lacking, and my design skills are even worse.

So, I’m bringing this topic to the table, seeking for ideas on how to improve the Ruby on Windows image beyond just code.

I’m willing to offer money to pay for it, since I’m quite aware that Open Source and contributions don’t put food on the table.

Of course, I’m not rich, so the balance needs to be found :D

So, what is the idea:

  • Build the website with Radiant or a simple CMS over Ruby
  • Design needs to be simple and provide access to:
    1. News feed (small articles)
    2. Download info and links
    3. Getting Started Resources (info and links)
    4. Contribute (RubyForge and GitHub info)
    5. Support (access to mailing list and forums of interest)
  • Initial artwork (logo and iso) already exist
  • Application icons can be highly improved :D

For the record: there is no need to be a Windows user or designer, so people on Linux and OSX are welcome ;)

If there is more interest, maybe a Bounty can be opened, but time, feedback and community response will tell.

Please, comment and pass the message!

(Via DEV_MEM.dump_to(:blog) – Multimedia systems blog.) Original Link: RubyInstaller: One-Clicks need a new home, can you help him?


Pure-Ruby Readline: Released 0.1.2

Posted: May 19th, 2009 | Author: FreedomCoder | Filed under: Open Source, Programming, github, how-to | Tags: , , , | No Comments »

Well, well, less than 24 hours since my last blog post, I have more updates for you!

Thanks to GitHub, rb-readline, the Pure-Ruby Readline project I’ve mentioned earlier, have now two forks and 3 bugs fixed!

Thanks to Roger Pack and Jugyo !!!

Now, there is no gem for rb-readline, mainly because readline needs to be available even if RubyGems is not loaded (like on IRB).

So, to install the updated package:

  • Download rb-readline-0.1.2.zip
  • Extract to a folder and open a command prompt there
  • Execute ruby setup.rb

That should update the installed RbReadline, but just to verify:

ruby -rreadline -e 'puts Readline::RB_READLINE_VERSION'

The output should say 0.1.2

That’s all! Enjoy!

(Via DEV_MEM.dump_to(:blog) – Multimedia systems blog.) Original Link: Pure-Ruby Readline: Released 0.1.2


Instalando Mod_Ruby

Posted: April 22nd, 2009 | Author: FreedomCoder | Filed under: Open Source, Programming, how-to | Tags: , , , , | No Comments »

Bueno dada la escasa y fea documentación que mod_ruby tiene me decidí a escribir un pequeño tutorial de instalación del mismo en debian, que paso a detallar:

Primero instalamos el modulo de apache para ruby (mod_ruby)

apt-get install libapache2-mod-ruby

Luego debemos crear el siguiente archivo:
vi /etc/apache2/mods-available/ruby.conf

y ponemos lo siguiente:

<IfModule mod_ruby.c>
  RubyRequire apache/ruby-run

  <Files *.rbx>
  SetHandler ruby-object
  RubyHandler Apache::RubyRun.instance
  </Files>
</IfModule>

Entre otras cosas le decimos que debe tratar los archivos .rbx como
archivos de ruby.

Luego de esto ya tenemos los dos archivos necesarios para habilitar el módulo en apache:

ruby.load (que secopia al instalar el módulo) y ruby.conf generado por nosotros. Ahora cómo mod_ruby ejecuta los scrips de ruby como CGI necesitamos poner la directiva Options +ExecCGI en el folder dónde vamos a poner nuestros scripts, en mi caso particular necesito que todos los usuarios del sistema puedan ejecutar sus scripts desde su ~/public_html entonces para lograr esto tenemos que editar la configuración del módulo user_dir, editamos el archivo

vi /etc/apache2/mods-available/userdir.conf
y agregamos lo siguiente:
 <IfModule mod_userdir.c>
        UserDir public_html
        UserDir disabled root

        <Directory /home/*/public_html>
                AllowOverride FileInfo AuthConfig Limit Indexes
                Options MultiViews Indexes SymLinksIfOwnerMatch IncludesNoExec
                # Para poder ejecutar scripts en ruby agregamos la linea de abajo
                Options +ExecCGI
                <Limit GET POST OPTIONS>
                        Order allow,deny
                        Allow from all
                </Limit>
                <LimitExcept GET POST OPTIONS>
                        Order deny,allow
                        Deny from all
                </LimitExcept>
        </Directory>
</IfModule>

No sé si esto muy seguro o tiene alguna consecuencia no deseada, si es así comenten!
Bueno ahora sólo necesitamos habilitar el móludo para esto ejecutamos el siguiente comando:

a2enmod ruby

y hacemos un reload del apache

/etc/init.d apache2 reload

despues de esto para probarlo ponemos un archivo en nuestro home

vi /home/gaston/test-ruby.rb

con un simple:

puts 'hello world'

vamos al navegador a la siguiente url:

http://aca-va-la-url-de-tuserver/~gaston/test-ruby.rb

y vamos a ver un hermoso ‘hello world’ si todo salió bien.

Bueno, con mod_ruby solo para escribir una página web dinámica vamos a tener que hacer algo cómo esto:

puts ‘<h1>Mi Título</h1>’

lo cual es muy molesto, para hacer las cosas un póco más lindas y más fácil debemos usar eruby que nos permite ejecutar código ruby dentro de archivos de text (como por ejémplo un arhivo html)

Entonces comencemos por instalar eruby:

apt-get install eruby

y luego tenemos que modificar nuevamente el archivo /etc/apache2/mods-available/ruby.conf de esta manera:

<IfModule mod_ruby.c>
  RubyRequire apache/ruby-run
  RubyRequire apache/eruby-run

  <Files *.rbx>
  SetHandler ruby-object
  RubyHandler Apache::RubyRun.instance
  </Files>

 <Files *.rhtml>
  SetHandler ruby-object
  RubyHandler Apache::ERubyRun.instance
 </Files>

</IfModule>

Y luego debemos agregar la siguiente directiva al archivo de configuración de apache /etc/apache2/apache2.conf

AddType text/html .rhtml

Con esto recargamos el apache y ya podemos escribir nuestros .rhtml
y poner código ruby entre los tags <%= %>

Links útiles:

http://en.wikipedia.org/wiki/ERuby
http://wiki.modruby.net/ja/?InstallGuide
http://modruby.net/
http://ubuntuforums.org/archive/index.php/t-356350.html
http://www.ruby-doc.org/docs/ProgrammingRuby/html/web.html

(Via Gastón Ramos – Ruby, Rails….) Original Link: Instalando Mod_Ruby