如何从 ruby 脚本中安装 rubygem 并在之后需要此 gem？

Question

我想做这样的事情：

begin
  require 'progressbar'
rescue LoadError => e
  puts "exception .. installing with gem"
  h = system 'gem install progressbar'
  puts "gem installed #{h}"
  require 'progressbar'
end
pbar = ProgressBar.new("test", 100)
100.times {sleep(0.1); pbar.inc}; pbar.finish

但显然，如果您运行此代码段，则进度条 gem 不可用。

Answer 1

我找到了这个讨论：https://www.ruby-forum.com/topic/131346 显然调用 Gem.clear_paths 解决了这个问题。总计：

begin
  require 'progressbar'
rescue LoadError => e
  puts "exception .. installing gem"
  h = system 'gem install progressbar'
  puts "gem installed #{h}"
  Gem.clear_paths
  require 'progressbar'
end
pbar = ProgressBar.new("test", 100)
100.times {sleep(0.1); pbar.inc}; pbar.finish

如何从 ruby 脚本中安装 rubygem 并在之后需要此 gem？

How to install a rubygem from inside a ruby script and require this gem afterwards?

ruby

gem

rubygems