ubuntu 下安装ruby 1.9.1

http://hi.baidu.com/%D5%D4%C8%D9/blog/item/0dbc800812fd31d862d986be.html

1.安装build工具
sudo apt-get install build-essential

2.安装readline zlib libncurses5
sudo apt-get install zlib1g-dev
sudo apt-get install libreadline5 libreadline5-dev

3.安装openssl
sudo apt-get install libopenssl-ruby1.8
sudo apt-get install openssl libssl-dev 

4.下载 ruby-1.9.1-p0.tar.gz
tar zxvf ruby-1.9.1-p0.tar.gz
cd ruby-1.9.1-p0
./configure --prefix=/usr/local/ruby-1.9.1
make
sudo make install

5.设置环境变量
sudo vim /etc/environment
PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/ruby-1.9.1/bin"
source /etc/environment
接着就可以使用ruby -v查看自己安装的ruby版本了
不过sudo ruby -v需要自己做软连接到/usr/bin下面去。(例如：sudo ln -s /usr/local/ruby-1.9.1/bin/ruby /usr/bin/ruby )
6.cd ruby-1.9.1-p0/ext/openssl

   1. ruby extconf.rb  
   2. make  
   3. sudo make install 

7.cd ruby-1.9.1-p0/ext/zlib

   1. ruby extconf.rb  
   2. make  
   3. sudo make install 

8.升级rubygems
$ sudo gem install rubygems-update
$ sudo update_rubygems

9.清空rubygems的cache，并更新源
sudo gem sources -c
sudo gem sources -u

10.sudo gem install rails
安装结束
rails -v
rails myapp
cd myapp
ruby script/server
打开浏览器http://localhost:3000出现rails欢迎页面