groman-me

To redirect stdout in bash, overwriting file
cmd > file.txt

To redirect stdout in bash, appending to file
cmd >> file.txt

To redirect both stdout and stderr, overwriting
cmd &> file.txt

To redirect both stdout and stderr appending to file

groman-me

# AR
ActiveRecord::Base.logger = Logger.new(STDOUT)

# Redis
$redis.client.logger = Rails.logger

groman-me

# Time.local returns time in Time zone of your machine:
Time.local(2012,8,31)
# => Fri Aug 31 00:00:00 +0400 2012 

# Time.zone.local returns time in Time zone of your application
Time.zone.local(2012,10,31)
# => Wed, 31 Oct 2012 00:00:00 EET +02:00 

groman-me

class User < ActiveRecord::Base
  after_save :queue_welcome_email, :on => :create

  private
  def queue_welcome_email
    Resque.enqueue(WelcomeEmailJob, Marshal.
      dump({ :email => self.email, :full_name => "#{self.first_name} #{self.last_name}" }))
  end
end

groman-me

SELECT create_time FROM INFORMATION_SCHEMA.TABLES WHERE table_schema = 'schema' AND table_name = 'name';
SHOW ENGINE INNODB STATUS;
SHOW CREATE TABLE foo;

groman-me

http://robots.thoughtbot.com/post/27985816073/the-hitchhikers-guide-to-riding-a-mountain-lion

REE
======
https://rvm.io/packages/iconv/
rvm pkg install iconv
export CPPFLAGS=-I/opt/X11/include
rvm reinstall ree --with-iconv-dir=$rvm_path/usr

gem uninstall nokogiri

groman-me

Order.paid.joins(:user).merge(User.blue_eye)

# => SELECT "orders".* FROM "orders" INNER JOIN "users" ON "users"."id" = "orders"."user_id" WHERE "orders"."status" = 3 AND "users"."eye_color" = 'blue' AND "users"."status" = 1

groman-me

def to_hash
  @reports.map(&:to_hash).reduce({}, :merge)
end

groman-me

http://stackoverflow.com/questions/341143/can-rails-routing-helpers-i-e-mymodel-pathmodel-be-used-in-models
In Rails 3:
Rails.application.routes.url_helpers

Rails 2
include ActionController::UrlWriter