编写一个Rubygem， 如何在gem 被Install之前运行一段程序？

答案很简单：不能。

我搜了以下， RubyGem中提供了一个API，叫Gem.pre_install。 但是经过研究后， 发现这个API跟他的名字完全不相符， 为此我给rubygems提交了一个Bug, 原文这么写地：


 

Gem.pre_install does not working as it named

October 28, 2010 @ 08:18 PM via web

I write a gem called 'gem-fast', I used curl , so I want to make sure 'curl' is installed before user install this gem.

I found that Gem.pre_installs only contains pre_install hooks of gems that already installed. It does not contains the current installing gem

I write my 'rubygems_plugin.rb' like this:

Gem.pre_install do
if curl not installed

raise Gem::InstallError, "Your should install curl before install this gem!"

end end

So I use Gem.pre_install to do this. But It doesn't work as I expected! the hook not run brefore the gem installed!

I check the code Of rubygems, found that the design of pre_install, post_install was not right.

 

 

 

不过你可以单独写一个make文件， 在里面作类似的编译检查。这么搞显然大题小作了。

rubygem应该在.gemspec中提供一个类似的字段。 而不是放到rubygems_plugin.rb中

 

最终能像这样：

 

 

Gem::Specification.new do |s|

  s.pre_install =  Proc.new{

#add your pre_install_hook here

}

end

 

 

posted @ 2010-10-29 09:42  dazuiba  阅读(329)  评论(0)  编辑  收藏  举报