From: Rick DeNatale <rick.denatale@...>
Date: 2006-09-01T12:16:02+09:00
Subject: Re: Rescuing a 'require'

On 8/31/06, Garance A Drosehn <drosihn@gmail.com> wrote:
> I wanted to use Socket.gethostname to get the current hostname
> without executing a unix command.  So:
>
> require 'socket'
> $this_host = Socket.gethostname
>
> I have to run this code on several platforms, and it turned out that
> some of them do not have 'socket'.  So, my first idea was change
> it to:
>
> begin
>    require 'socket'
>    $this_host = Socket.gethostname
> rescue
>     $this_host = `hostname`.chomp
> end
>
> but the require still caused the script to terminate on the platforms
> which didn't have 'socket'.  I already have an alternate solution for
> this specific case, but I'm wondering if there was something that I
> missed.  Is there any way to catch errors from a require command?

irb(main):006:0> begin
irb(main):007:1*   require 'foo'
irb(main):008:1> rescue LoadError
irb(main):009:1>   puts "caught it"
irb(main):010:1> end
caught it
=> nil

rescue without a specific exception or exceptions only catches
subclasses of StandardError.  LoadError is a subclass of ScriptError
which in turn is a subclass of Exception.
-- 
Rick DeNatale

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