From: Daniel Finnie <danfinnie@...>
Date: 2006-12-17T12:04:32+09:00
Subject: Re: Trapping error not caught by rescue Exception -- How to?

Ruby doesn't hang when I run that code.

This is the output:
daniel@daniel-desktop:~$ ruby /tmp/tmp.rb
expr=5**2, expr.class=String
eval(expr)=25
expr=date, expr.class=String
ERROR: undefined local variable or method `date' for main:Object
ERROR: undefined method `strip!' for nil:NilClass
expr=y, expr.class=String
ERROR: undefined local variable or method `y' for main:Object
expr=`date`, expr.class=String
eval(expr)=Sat Dec 16 22:01:37 EST 2006

Richard wrote:
> Hi,
> 
> The fourth data line in the program below hangs rather than submitting
> to the rescue clause.  How can I trap that kind of error?
> 
> I'm running WinXP-Pro/SP2, Ruby 1.8.2-15, Rails  1.1.6, MySQL
> 5.0.15-nt, SciTE 1.59
> 
> TIA,
> Richard
> 
> === code start ===
> begin
> 	DATA.each do |line|
> 		var, expr, excess = line.chomp.split(/=/, 3)
> 		var.strip!; expr.strip!
> 		puts	"expr=" + expr +  ", expr.class=" +expr.class.to_s
> 		puts	"eval(expr)="  + eval(expr).to_s
> 	end
> rescue Exception => eMsg
> 	puts "ERROR: " + eMsg
> 	retry
> end
> 
> __END__
> a = 5**2	=# 25
> b =date	        =# undefined local variable or method `date' for
> main:Object
> c = y		 =# undefined local variable or method `y' for main:Object
> c =`date`	=# (ruby hangs;  Ctrl-C kills it)
> === code end ===
> 
> 
>