有机会再试一试Rails了，仅仅是原来接触的是2，如今已然变成了4，似乎如今的安装比原来会快些。。

Rails 4 安装

针对于安装了RVM

gem install rails

没有的话应该主

sudo gem install rails

安装RVM能够用

\curl -L https://get.rvm.io | bash -s stable

查看rails版本号

rails -v

Rails 4.0.3

似乎这就是当前的最新版本号

Ruby版本号

We recommend Ruby 2.1.0 for use with Rails. We stopped supporting Ruby 1.8.x after Rails 3.2. Ruby 1.9.2+ will be supported until Rails 5.

官方推荐用2.1.0. 也就是最新版本号

安装SQLite

似乎这就是诸如Django、Rails这类对于轻量级站点的数据库要求。

假设是mac os

brew install sqlite3

其它能够看情况安装，如openSUSE

sudo zypper install sqlite3

Rails 4 Hello,World

能够直接用rails生成

$rails new hello

于是就有了

create  create  README.rdoc  create  Rakefile  create  config.ru  create  .gitignore  create  Gemfile  create  app  create  app/assets/javascripts/application.js  create  app/assets/stylesheets/application.css  create  app/controllers/application_controller.rb  create  app/helpers/application_helper.rb  create  app/views/layouts/application.html.erb  create  app/assets/images/.keep  create  app/mailers/.keep  create  app/models/.keep  create  app/controllers/concerns/.keep  create  app/models/concerns/.keep  create  bin  create  bin/bundle  create  bin/rails  create  bin/rake  create  config  create  config/routes.rb  create  config/application.rb  create  config/environment.rb  create  config/environments  create  config/environments/development.rb  create  config/environments/production.rb  create  config/environments/test.rb  create  config/initializers  create  config/initializers/backtrace_silencers.rb  create  config/initializers/filter_parameter_logging.rb  create  config/initializers/inflections.rb  create  config/initializers/mime_types.rb  create  config/initializers/secret_token.rb  create  config/initializers/session_store.rb  create  config/initializers/wrap_parameters.rb  create  config/locales  create  config/locales/en.yml  create  config/boot.rb  create  config/database.yml  create  db  create  db/seeds.rb  create  lib  create  lib/tasks  create  lib/tasks/.keep  create  lib/assets  create  lib/assets/.keep  create  log  create  log/.keep  create  public  create  public/404.html  create  public/422.html  create  public/500.html  create  public/favicon.ico  create  public/robots.txt  create  test/fixtures  create  test/fixtures/.keep  create  test/controllers  create  test/controllers/.keep  create  test/mailers  create  test/mailers/.keep  create  test/models  create  test/models/.keep  create  test/helpers  create  test/helpers/.keep  create  test/integration  create  test/integration/.keep  create  test/test_helper.rb  create  tmp/cache  create  tmp/cache/assets  create  vendor/assets/javascripts  create  vendor/assets/javascripts/.keep  create  vendor/assets/stylesheets  create  vendor/assets/stylesheets/.keep     run  bundle install

接着会安装包依赖

Fetching gem metadata from https://rubygems.org/..........  Fetching additional metadata from https://rubygems.org/..  Resolving dependencies...  Using rake (10.3.1)  Using i18n (0.6.9)  Using minitest (4.7.5)  Using multi_json (1.9.2)  Using thread_safe (0.3.3)  Using tzinfo (0.3.39)  Using activesupport (4.0.3)  Using builder (3.1.4)  Using erubis (2.7.0)  Using rack (1.5.2)  Using rack-test (0.6.2)  Using actionpack (4.0.3)  Using mime-types (1.25.1)  Using polyglot (0.3.4)  Using treetop (1.4.15)  Using mail (2.5.4)  Using actionmailer (4.0.3)  Using activemodel (4.0.3)  Using activerecord-deprecated_finders (1.0.3)  Using arel (4.0.2)  Using activerecord (4.0.3)  Using bundler (1.5.3)  Using coffee-script-source (1.7.0)  Using execjs (2.0.2)  Using coffee-script (2.2.0)  Using thor (0.19.1)  Using railties (4.0.3)  Using coffee-rails (4.0.1)  Using hike (1.2.3)  Using jbuilder (1.5.3)  Using jquery-rails (3.1.0)  Using json (1.8.1)  Using tilt (1.4.1)  Using sprockets (2.11.0)  Using sprockets-rails (2.0.1)  Using rails (4.0.3)  Using rdoc (4.1.1)  Using sass (3.2.19)  Using sass-rails (4.0.3)  Using sdoc (0.4.0)  Using sqlite3 (1.3.9)  Using turbolinks (2.2.2)  Using uglifier (2.5.0)  Your bundle is complete!  Use `bundle show [gemname]` to see where a bundled gem is installed.

执行Rails

$rails server

这种话打开  就能够看到,Rails的欢迎界面Welcome aboard，有点类似于Django-CMS的小马哥~~

创建controller

如官方指南所说

运行命令

$rails generate controller welcome index

就会创建以下这些文件()

create  app/controllers/welcome_controller.rb   route  get "welcome/index"  invoke  erb  create    app/views/welcome  create    app/views/welcome/index.html.erb  invoke  test_unit  create    test/controllers/welcome_controller_test.rb  invoke  helper  create    app/helpers/welcome_helper.rb  invoke    test_unit  create      test/helpers/welcome_helper_test.rb  invoke  assets  invoke    coffee  create      app/assets/javascripts/welcome.js.coffee  invoke    scss  create      app/assets/stylesheets/welcome.css.scss

在config/routes.rb加入�默认页面

root 'welcome#index'

再执行

rails server

就会出现

Welcome#indexFind me in app/views/welcome/index.html.erb

一切来得非常快，非常突然