blocks|key|523014|text|Errno下的所有类都是SystemCallError的子类。并且SystemCallError的所有子类都是Errno下的类。这两组是相同的，所以只要拯救SystemCallError就可以了。这假设您使用的不是添加到一个库而不是另一个库的外部库。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|523015|验证两个集合的身份(使用active_support)：|523016|Errno.constants.map+{%7Cname%7C
++Errno.const_get(name)
}.select{%7Cconst%7C
++Class+===+const
}.uniq.map(&:to_s).sort+==
++++SystemCallError.subclasses.map(&:to_s).sort|code-block|syntax|javascript|523017|这将为我返回true。|offset|length|style|CODE|523018|因此，将其应用于您的示例：|523019|begin
++#+my+code
rescue+SystemCallError
++#+handle+exception
end|523020|entityMap^0|0|0|0|6|4|0|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|V|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|W|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|X|8|@$K|Y|L|Z|M|N]]|9|@]|A|$]]|$1|O|3|P|5|6|7|10|8|@]|9|@]|A|$]]|$1|Q|3|R|5|F|7|11|8|@]|9|@]|A|$G|H]]|$1|S|3|-4|5|6|7|12|8|@]|9|@]|A|$]]]|T|$]]

All classes under Errno are subclasses of SystemCallError. And all subclasses of SystemCallError are classes under Errno. The 2 sets are identical, so just rescue SystemCallError. This assumes that you're not using an external lib that adds to one and not the other.

Verify the identity of the 2 sets (using active_support):

<pre><code>Errno.constants.map {|name|
 Errno.const_get(name)
}.select{|const|
 Class === const
}.uniq.map(&amp;:to_s).sort ==
 SystemCallError.subclasses.map(&amp;:to_s).sort
</code></pre>

This returns <code>true</code> for me.

So, applied to your example:

<pre class="lang-rb prettyprint-override"><code>begin
 # my code
rescue SystemCallError
 # handle exception
end
</code></pre>

blocks|key|523080|text|这里是一个更通用的解决方案，在这种情况下，您想拯救一些Errno类型，而不是其他类型。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|523081|创建一个自定义模块，将其包含在我们想要挽救的所有错误类中|523082|module+MyErrnoModule;+end|code-block|syntax|javascript|523083|根据您的喜好自定义此数组，直到"each“调用。|523084|Errno.constants.map+{%7Cname%7C
++Errno.const_get(name)
}.select{%7Cconst%7C
++Class+===+const
}.uniq.each+{%7Cklass%7C
++klass.class_eval+{
++++include+MyErrnoModule
++}
}|523085|测试：|523086|begin
++raise+Errno::EPERM
rescue+MyErrnoModule
++p+"rescued+#{$!.inspect}"
end|523087|测试结果：|523088|"rescued+#<Errno::EPERM:+Operation+not+permitted>"|523089|我猜这比需要检查异常名称的解决方案性能稍好一些。|523090|entityMap^0|0|0|0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Y|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|Z|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|10|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|11|8|@]|9|@]|A|$]]|$1|K|3|L|5|F|7|12|8|@]|9|@]|A|$G|H]]|$1|M|3|N|5|6|7|13|8|@]|9|@]|A|$]]|$1|O|3|P|5|F|7|14|8|@]|9|@]|A|$G|H]]|$1|Q|3|R|5|6|7|15|8|@]|9|@]|A|$]]|$1|S|3|T|5|F|7|16|8|@]|9|@]|A|$G|H]]|$1|U|3|V|5|6|7|17|8|@]|9|@]|A|$]]|$1|W|3|-4|5|6|7|18|8|@]|9|@]|A|$]]]|X|$]]

Here is a more generic solution, in the case you wanted to rescue some Errno types and not others.

Create a custom module to be included by all the error classes we want to rescue

<pre><code>module MyErrnoModule; end
</code></pre>

Customize this array to your liking, up to the "each" call.

<pre><code>Errno.constants.map {|name|
 Errno.const_get(name)
}.select{|const|
 Class === const
}.uniq.each {|klass|
 klass.class_eval {
 include MyErrnoModule
 }
}
</code></pre>

Test:

<pre><code>begin
 raise Errno::EPERM
rescue MyErrnoModule
 p "rescued #{$!.inspect}"
end
</code></pre>

Test result:

<pre><code>"rescued #&lt;Errno::EPERM: Operation not permitted&gt;"
</code></pre>

I would guess this performs slightly better than a solution that needs to check the name of the exception.

blocks|key|306388|text|这是另一个有趣的alternative。可以适应你想要的东西。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|306389|粘贴最有趣的部分：|306390|def+match_message(regexp)
++lambda{+%7Cerror%7C+regexp+===+error.message+}
end

begin
++raise+StandardError,+"Error+message+about+a+socket."
rescue+match_message(/socket/)+=>+error
++puts+"Error+#{error}+matches+/socket/;+ignored."
end|code-block|syntax|javascript|306391|参见ruby+1.8.7解决方案的原始站点。|306392|结果是lambda不接受我最近的ruby版本。似乎选择是使用在1.8.7中起作用的东西，但这是IM较慢(在所有比较中创建一个新类。所以我不推荐使用它，甚至还没有尝试过：|306393|def+exceptions_matching(&block)
++Class.new+do
++++def+self.===(other)
++++++@block.call(other)
++++end
++end.tap+do+%7Cc%7C
++++c.instance_variable_set(:@block,+block)
++end
end

begin
++raise+"FOOBAR:+We're+all+doomed!"
rescue+exceptions_matching+{+%7Ce%7C+e.message+=~+/%5EFOOBAR/+}
++puts+"rescued!"
end|306394|如果有人知道ruby在rescue中删除了对lambda的支持，请发表评论。|style|CODE|306395|entityMap|0|LINK|mutability|MUTABLE|url|http://ablogaboutcode.com/2011/09/21/dynamic-rescue-clause-in-ruby/^0|8|B|0|0|0|0|0|0|0|B|6|0^^$0|@$1|2|3|4|5|6|7|12|8|@]|9|@$A|13|B|14|1|15]]|C|$]]|$1|D|3|E|5|6|7|16|8|@]|9|@]|C|$]]|$1|F|3|G|5|H|7|17|8|@]|9|@]|C|$I|J]]|$1|K|3|L|5|6|7|18|8|@]|9|@]|C|$]]|$1|M|3|N|5|6|7|19|8|@]|9|@]|C|$]]|$1|O|3|P|5|H|7|1A|8|@]|9|@]|C|$I|J]]|$1|Q|3|R|5|6|7|1B|8|@$A|1C|B|1D|S|T]]|9|@]|C|$]]|$1|U|3|-4|5|6|7|1E|8|@]|9|@]|C|$]]]|V|$W|$5|X|Y|Z|C|$10|11]]]]

Here is another interesting <a href="http://ablogaboutcode.com/2011/09/21/dynamic-rescue-clause-in-ruby/" rel="nofollow">alternative</a>. Can be adapted to what you want.

Pasting most interesting part:

<pre><code>def match_message(regexp)
 lambda{ |error| regexp === error.message }
end

begin
 raise StandardError, "Error message about a socket."
rescue match_message(/socket/) =&gt; error
 puts "Error #{error} matches /socket/; ignored."
end
</code></pre>

See the original site for ruby 1.8.7 solution.

It turns out lambda not accepted my more recent ruby versions. It seems the option is to use what worked in 1.8.7 but that's IM slower (to create a new class in all comparisons. So I don't recommend using it and have not even tried it:

<pre><code>def exceptions_matching(&amp;block)
 Class.new do
 def self.===(other)
 @block.call(other)
 end
 end.tap do |c|
 c.instance_variable_set(:@block, block)
 end
end

begin
 raise "FOOBAR: We're all doomed!"
rescue exceptions_matching { |e| e.message =~ /^FOOBAR/ }
 puts "rescued!"
end
</code></pre>

If somebody knows when ruby removed lambda support in <code>rescue</code> please comment.

Is there a way to rescue all exceptions under a certain namespace?

For example, I want to rescue all of the Errno::* exceptions (Errno::ECONNRESET, Errno::ETIMEDOUT). I can go ahead and list them all out on my exception line, but I was wondering if I can do something like.

<pre><code>begin
 # my code
rescue Errno
 # handle exception
end
</code></pre>

The above idea doesn't seem to work, thus is there something similar that can work?

How to rescue all exceptions under a certain namespace?

有没有办法挽救某个名称空间下的所有异常？例如，我想拯救所有的Errno::*异常(Errno::ECONNRESET，Errno::ETIMEDOUT)。我可以继续在我的异常行中列出它们，但我想知道我是否可以这样做。begin  # my coderescue Errno  # handle exceptionend上...

问如何抢救某个命名空间下的所有异常？
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