readline有什么问题？

Question

我使用不同的操作系统和Rails 3和4设置了三次Rails环境.它顺利进行,直到我打开一个控制台来输入一些Ruby,或用rails console或检查我的数据库rails dbconsole.我得到类似的东西:

$ rails console
/home/tobias/.rvm/rubies/ruby-1.9.2-p180/lib/ruby/1.9.1/irb/completion.rb:9:in       `require': no such file to load -- readline (LoadError)
from /home/tobias/.rvm/rubies/ruby-1.9.2-p18080/lib/ruby/1.9.1/irb/completion.rb:9:in `<top (required)>'
from /home/tobias/.rvm/gems/ruby-1.9.2-p180/gems/railties-3.0.9/lib/rails/commands/console.rb:3:in `require'
from /home/tobias/.rvm/gems/ruby-1.9.2-p180/gemsems/railties-3.0.9/lib/rails/commands/console.rb:3:in `<top (required)>'
from /home/tobias/.rvm/gems/ruby-1.9.2-p180/gems/railties-3.0.9/lib/rails/commands.commandsrb:20:in `require'
from /home/tobias/.rvm/gems/ruby-1.9.2-p180/gems/railsilties-3.0.9/lib/rails/commands.rb:20:in `<top (required)>'
from scriptt/rails:6:in `require'
from script/rails:6:in `<main>'

这来自" 修复Ruby on Rails控制台的readline ".这解决了我的问题两次.

现在我使用的是Rails 4和Ruby 2,它运行良好,直到:

mto@mto-mint-vm ~/src/rpg $ rails console
/home/mto/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/irb/completion.rb:9:in `require': /usr/local/lib/libreadline.so.6: undefined symbol: UP - /home/mto/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/site_ruby/2.0.0/x86_64-linux/readline.so (LoadError)
    from /home/mto/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/irb/completion.rb:9:in `<top (required)>'
    from /home/mto/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/gems/2.0.0/gems/railties-4.0.0/lib/rails/commands/console.rb:3:in `require'
    from /home/mto/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/gems/2.0.0/gems/railties-4.0.0/lib/rails/commands/console.rb:3:in `<top (required)>'
    from /home/mto/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/gems/2.0.0/gems/railties-4.0.0/lib/rails/commands.rb:53:in `require'
    from /home/mto/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/gems/2.0.0/gems/railties-4.0.0/lib/rails/commands.rb:53:in `<top (required)>'
    from bin/rails:4:in `require'
    from bin/rails:4:in `<main>'

这次博客没有帮助我.Stackoverflow有相关问题:

• 尝试启动rails控制台时,为什么会出现Readline错误？
• 如何为rails控制台安装"readline"

最后一个建议添加gem 'rb-readline'到我的gemfile.我添加了这条线,跑了bundle install,得到了这个:

mto@mto-mint-vm ~/src/rpg $ rails console
Loading development environment (Rails 4.0.0)
/home/mto/.rvm/scripts/irbrc.rb:30:in `block in <top (required)>': uninitialized constant Readline (NameError)
/home/mto/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/irb/input-method.rb:150:in `gets': uninitialized constant IRB::ReadlineInputMethod::Readline (NameError)
    from /home/mto/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/irb.rb:472:in `block (2 levels) in eval_input'
    from /home/mto/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/irb.rb:624:in `signal_status'
    from /home/mto/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/irb.rb:471:in `block in eval_input'
    from /home/mto/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/irb/ruby-lex.rb:190:in `call'
    from /home/mto/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/irb/ruby-lex.rb:190:in `buf_input'
    from /home/mto/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/irb/ruby-lex.rb:105:in `getc'
    from /home/mto/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/irb/slex.rb:206:in `match_io'
    from /home/mto/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/irb/slex.rb:76:in `match'
    from /home/mto/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/irb/ruby-lex.rb:290:in `token'
    from /home/mto/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/irb/ruby-lex.rb:266:in `lex'
    from /home/mto/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/irb/ruby-lex.rb:237:in `block (2 levels) in each_top_level_statement'
    from /home/mto/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/irb/ruby-lex.rb:233:in `loop'
    from /home/mto/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/irb/ruby-lex.rb:233:in `block in each_top_level_statement'
    from /home/mto/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/irb/ruby-lex.rb:232:in `catch'
    from /home/mto/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/irb/ruby-lex.rb:232:in `each_top_level_statement'
    from /home/mto/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/irb.rb:488:in `eval_input'
    from /home/mto/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/irb.rb:397:in `block in start'
    from /home/mto/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/irb.rb:396:in `catch'
    from /home/mto/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/irb.rb:396:in `start'
    from /home/mto/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/gems/2.0.0/gems/railties-4.0.0/lib/rails/commands/console.rb:90:in `start'
    from /home/mto/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/gems/2.0.0/gems/railties-4.0.0/lib/rails/commands/console.rb:9:in `start'
    from /home/mto/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/gems/2.0.0/gems/railties-4.0.0/lib/rails/commands.rb:64:in `<top (required)>'
    from bin/rails:4:in `require'
    from bin/rails:4:in `<main>'

" Rails 3:Heroku中未初始化的常量IRB :: ReadlineInputMethod :: Readline(NameError) "通过将gem绑定到版本0.4.2解决了这个问题.我有0.5.0.

为什么一个简单的库,在Rails中有这样一个中心位置,在Ruby中也是如此,我想,会导致如此多的痛苦？有什么办法让这更容易吗？

这只是一个从控制台读取线路的库,对吗？上面的例子在哪里出错了？我想知道为什么而不是什么以及如何.

Answer 1

你可以这样做,它对我有用:

gem install rb-readline

并将以下行添加到项目的Gemfile中:

gem 'rb-readline', '~> 0.4.2'

我将gem锁定到此版本,因为更新版本会出现一些错误.