From: Eric Hodel <drbrain@...7.net>
Date: 2011-02-03T09:28:42+09:00
Subject: Re: How to know the exit status within at_exit() block?

On Feb 2, 2011, at 02:46, Iņaki Baz Castillo wrote:
> 2011/2/1 Eric Hodel <drbrain@segment7.net>:
>>> Hi, my program invokes "exit true" or "exit false" and I want to catch
>>> such return code into at_exit() block, but I don't know how to do
>>> that.
>> 
>> ruby -e 'at_exit { p $!.status }; exit 1'
> 
> Really interesting. However, it fails if exit() is called outside of the scope:
> 
> irb> at_exit { p "$!.inspect = #{$!.inspect}" }
> #<Proc:0x000000019f99c0@(irb):1>
> irb> exit 1
> "$!.inspect = nil"
> 
> So $! is nil and I cannot get $!.status.

It is irb's fault:

$ cat t.rb
def x
  at_exit { p $!.status }
end

def y
  exit 2
end

x
y
$ ruby t.rb
2