小编Mar*_*ing的帖子

当我在R中导入Stata数据集(使用外部包)时,导入有时包含无效的UTF-8字符.这本身就令人不愉快,但是一旦我尝试将对象转换为JSON(使用rjson包),它就会破坏所有内容.

您是否有想法,如何识别字符串中的无效UTF-8字符并在此之后将其删除？

运行后gem update,当我尝试启动rails时出现以下错误:

$ rails s
/usr/lib/ruby/1.9.1/rubygems.rb:238:in `activate': can't activate rack (~> 1.4.5, runtime)
for ["actionpack-3.2.12", "railties-3.2.12"], already activated rack-1.5.2 for ["rack-
ssl-1.3.3", "railties-3.2.12"] (Gem::LoadError)
    from /usr/lib/ruby/1.9.1/rubygems.rb:254:in `block in activate'
    from /usr/lib/ruby/1.9.1/rubygems.rb:253:in `each'
    from /usr/lib/ruby/1.9.1/rubygems.rb:253:in `activate'
    from /usr/lib/ruby/1.9.1/rubygems.rb:254:in `block in activate'
    from /usr/lib/ruby/1.9.1/rubygems.rb:253:in `each'
    from /usr/lib/ruby/1.9.1/rubygems.rb:253:in `activate'
    from /usr/lib/ruby/1.9.1/rubygems.rb:1065:in `gem'
    from /usr/local/bin/rails:18:in `<main>'

任何人都可以帮助我,这意味着什么以及如何解决问题？