ruby gem tips(转)

淘宝源：

https://ruby.taobao.org

升级ruby gem 

gem update --system

查看gem版本 

gem -v

查看gem版本，gems安装目录，remote sources等 

gem env

查看已经添加的remote sources 

gem sources

添加一个source 

gem sources -a 'https://rubygems.org'

删除一个source

gem sources --remove 'https://rubygems.org'

安装一个gem包 

gem install will_paginate

指定源位置 

gem install will_paginate --source 'http://rubygems.org'
gem install will_paginate -s 'http://rubygems.org'

指定版本 

gem install rails -v=2.3.5

查看已经安装的全部gem包 

gem list

或者 gem list -d 查看具体的信息，例如project的author，homepage，安装在系统中的路径 等信息，建议加上该参数… 
查看d开头的gem包 

gem list d

更详细的查看 

gem list will_paginate -d

卸载gem包 

gem uninstall rails

卸载指定版本 

gem uninstall rails -v=2.1.0

查找gem包 

gem search will_paginate --both (在local和remote源中search含有will_paginate关键字的)
gem list -r will_paginate
gem list -dr will_paginate (我常用这个)

查看gem包依赖其他的gem： 

gem dependency rails -v 2.3.5
Gem rails-2.3.5
  actionmailer (= 2.3.5, runtime)
  actionpack (= 2.3.5, runtime)
  activerecord (= 2.3.5, runtime)
  activeresource (= 2.3.5, runtime)
  activesupport (= 2.3.5, runtime)
  rake (>= 0.8.3, runtime)

查看gem包的rdoc帮助 

gem server (然后http://localhost:8808查看)

windows 平台上安装 

gem install hpricot --platform=mswin32 # 不指定在windows安装会报错

不安装ri 和 rdoc 

gem install hpricot --no-ri --no-rdoc

查看更多的gem帮助，可以 

gem -h

项目里常用gem命令 

rake -T gems:
(in /usr/local/system/entos/netposa_redmine)
rake gems:build                # Build any native extensions for unpacked gems
rake gems:build:force          # Force the build of all gems
rake gems:install              # Installs all required gems.
rake gems:refresh_specs        # Regenerate gem specifications in correct format.
rake gems:unpack               # Unpacks all required gems into vendor/gems.
rake gems:unpack:dependencies  # Unpacks all required gems and their dependencies into vendor/gems.

例如你enviroment.rb 中配置了paperclip gem 

config.gem 'paperclip', '2.3.5'

那么 

rake gems:install

将会安装paperclip 2.3.5 到你的ruby目录里, 

rake gems:unpack:dependencies

将会把依赖的gem包unpack 到vendor/gems 目录下, 
如果你是直接从gem包copy 到vendor/gems 目录下的话,需要执行 

rake gems:refresh_specs

来生成 .specifications 文件 

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gem安装mysql包

1.安装依赖：

yum install -y ruby-devel mysql mysql-devel gcc make

2.gem安装mysql包(国内建议替换gem源为淘宝源)

gem install mysql