Ruby 异常处理：反向堆栈跟踪顺序

Posted 2023-02-19

【中文标题】Ruby 异常处理：反向堆栈跟踪顺序

【英文标题】：Ruby Exception Handling: reverse stack-trace order

【发布时间】：2013-07-31 05:25:57

【问题描述】：

当 ruby​​ 应用程序遇到异常时，无论框架如何，堆栈跟踪都会首先显示最重要的信息。通常很长，我发现自己向上滚动命令行以查找它的开始位置，而实际上我只需要阅读前一两行。

我想重新排列输出以反转堆栈跟踪的显示顺序。也许我的措辞不正确，但我无法通过快速搜索找到如何做到这一点。

有没有人有任何处理异常输出的经验，可以为我指明正确的方向？

例如：

$ rackup
/Users/Ascended/Ruby/sinatra/genye/app.rb:19:in `include': wrong argument type String (expected Module) (TypeError)
    from /Users/Ascended/Ruby/sinatra/genye/app.rb:19:in `block in <class:Application>'
    from /Users/Ascended/.rbenv/versions/2.0.0-p0/lib/ruby/gems/2.0.0/gems/sinatra-1.4.3/lib/sinatra/base.rb:1385:in `configure'
    from /Users/Ascended/Ruby/sinatra/genye/app.rb:17:in `<class:Application>'
    from /Users/Ascended/Ruby/sinatra/genye/app.rb:11:in `<top (required)>'
    from /Users/Ascended/.rbenv/versions/2.0.0-p0/lib/ruby/gems/2.0.0/gems/backports-3.3.3/lib/backports/tools.rb:328:in `require'
    from /Users/Ascended/.rbenv/versions/2.0.0-p0/lib/ruby/gems/2.0.0/gems/backports-3.3.3/lib/backports/tools.rb:328:in `require_with_backports'
    from /Users/Ascended/Ruby/sinatra/genye/config.ru:7:in `block in <main>'
    from /Users/Ascended/.rbenv/versions/2.0.0-p0/lib/ruby/gems/2.0.0/gems/rack-1.5.2/lib/rack/builder.rb:55:in `instance_eval'
    from /Users/Ascended/.rbenv/versions/2.0.0-p0/lib/ruby/gems/2.0.0/gems/rack-1.5.2/lib/rack/builder.rb:55:in `initialize'
    from /Users/Ascended/Ruby/sinatra/genye/config.ru:in `new'
    from /Users/Ascended/Ruby/sinatra/genye/config.ru:in `<main>'
    from /Users/Ascended/.rbenv/versions/2.0.0-p0/lib/ruby/gems/2.0.0/gems/rack-1.5.2/lib/rack/builder.rb:49:in `eval'
    from /Users/Ascended/.rbenv/versions/2.0.0-p0/lib/ruby/gems/2.0.0/gems/rack-1.5.2/lib/rack/builder.rb:49:in `new_from_string'
    from /Users/Ascended/.rbenv/versions/2.0.0-p0/lib/ruby/gems/2.0.0/gems/rack-1.5.2/lib/rack/builder.rb:40:in `parse_file'
    from /Users/Ascended/.rbenv/versions/2.0.0-p0/lib/ruby/gems/2.0.0/gems/rack-1.5.2/lib/rack/server.rb:277:in `build_app_and_options_from_config'
    from /Users/Ascended/.rbenv/versions/2.0.0-p0/lib/ruby/gems/2.0.0/gems/rack-1.5.2/lib/rack/server.rb:199:in `app'
    from /Users/Ascended/.rbenv/versions/2.0.0-p0/lib/ruby/gems/2.0.0/gems/rack-1.5.2/lib/rack/server.rb:314:in `wrapped_app'
    from /Users/Ascended/.rbenv/versions/2.0.0-p0/lib/ruby/gems/2.0.0/gems/rack-1.5.2/lib/rack/server.rb:250:in `start'
    from /Users/Ascended/.rbenv/versions/2.0.0-p0/lib/ruby/gems/2.0.0/gems/rack-1.5.2/lib/rack/server.rb:141:in `start'
    from /Users/Ascended/.rbenv/versions/2.0.0-p0/lib/ruby/gems/2.0.0/gems/rack-1.5.2/bin/rackup:4:in `<top (required)>'
    from /Users/Ascended/.rbenv/versions/2.0.0-p0/bin/rackup:23:in `load'
    from /Users/Ascended/.rbenv/versions/2.0.0-p0/bin/rackup:23:in `<main>'
$

我想看看这条线：

/Users/Ascended/Ruby/sinatra/genye/app.rb:19:in `include': wrong argument type String (expected Module) (TypeError)

在输出的末尾而不是开头，有效地颠倒了输出的顺序。

【问题讨论】：

异常可以在很多不同的地方打印出来——你在什么情况下试图完成这个？

谢谢丹，我已经用一个例子更新了我的问题，这些错误是我想要影响的。

【参考方案1】：

如果你发现异常，你可以尝试这样的事情：

begin
  bad_code
rescue Exception => e 
  puts e.backtrace.reverse
end

【讨论】：

嗯，所以从这个模式中，我可以更改 Ruby 的 Exception 类以在应用程序级别反转输出，但是如果运行像 rackup 这样的命令行函数，输出不会受到什么影响会在应用程序中以编程方式定义吗？