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

但很明显，如果您运行此代码段，则无法使用进度条宝石。

Answer 1

我发现了这个讨论：https://www.ruby-forum.com/topic/131346 显然，调用Gem.clear_paths可以解决问题。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并在之后需要这个gem？

1 个答案: