From: Tim Hunter <cyclists@...>
Date: 2004-09-26T04:34:37+09:00
Subject: Re: Nuby: How do I find out what exception was thrown?

Roy Pardee wrote:

> If I try to run this while the file in question is opened by another
> process I get this output:
> 
> ------------------------------------------
> F:\>ruby KillOwnerLok.rb
> \\blackula\Profiles\Laurel\Application Data\Qualcomm\Eudora\owner.lok
> found!
> KillOwnerLok.rb:9:in `delete': Permission denied -
> \\blackula\Profiles\Laurel\Ap
> plication Data\Qualcomm\Eudora\owner.lok (Errno::EACCES)
>         from KillOwnerLok.rb:9
> ------------------------------------------
> 
> I'd like to print my "Could not delete..." message in a rescue
> section, but I don't know how to translate the error message from the
> output into something 'rescuable'.  How do I do that?

Ruby's telling you: Errno::EACCES

rescue Errno::EACCES => exp
   puts "Caught an exception: #{exp.message}"
end

But you probably want to catch other Errno's, too. You can catch them all by
rescuing StandardError. If you need to know exactly which exception was
thrown you can call `exp.class' in your rescue clause.