From: Robert Klemme <bob.news@...>
Date: 2004-07-02T23:32:47+09:00
Subject: Re: Exceptions list - Unix ENOENT not the name of the exception - what is?


"Austin Ziegler" <halostatue@gmail.com> schrieb im Newsbeitrag
news:9e7db91104070206039eee67a@mail.gmail.com...
> On Fri, 2 Jul 2004 21:48:45 +0900, Dick Davies
> <rasputnik@hellooperator.net> wrote:
>
> > Out of interest, is there anyway of knowing what exceptions a given
> > class can raise?
> >
> > I'd expect not, but I've been wrong before (as any regulars on this
list
> > will know).
>
> As far as I know, no. However, I have also read that the "promised"
> list of exceptions (cf Java) is more problematic than useful (ISTR
> something on Joel on Software about it). However, using the classtree
> method (http://www.rubygarden.org/ruby?ASCIIClassHierarchyGenerator),
> you can call:
>
>   class_tree(Exception, false, false)
>
> And get a tree of possible exceptions. That's where I found
Errno::ENOENT.

In this case catching Exception should have helped, too.  Or am I missing
something?

begin
  File.open("not possibly found here")
rescue Exception => e
  p e
  puts e.class
end

Yields this in IRB:

irb(main):001:0> begin
irb(main):002:1*   File.open("not possibly found here")
irb(main):003:1> rescue Exception => e
irb(main):004:1>   p e
irb(main):005:1>   puts e.class
irb(main):006:1> end
#<Errno::ENOENT: No such file or directory - not possibly found here>
Errno::ENOENT
=> nil

Regards

    robert