def raise_exception
  raise Exception, 'You wanted me to raise an exception, so...'
end
begin
  raise_exception
rescue Exception => e
  puts "Backtrace of the exception:\n #{e.backtrace.join("\n ")}"
end

Backtrace of the exception:
(irb):2:in `raise_exception'
(irb):5:in `irb_binding'
/usr/lib/ruby/1.8/irb/workspace.rb:52:in `irb_binding'
:0

Backtrace of the exception:
 (irb):2:in `raise_exception'
 (irb):5:in `irb_binding'
 /usr/lib/ruby/1.8/irb/workspace.rb:52:in `irb_binding'
 /usr/lib/ruby/1.8/irb/workspace.rb:52

CALLER_RE = /(.*):([0-9]+)(:in \`(.*)')?/
def parse_caller(l)
  l.collect do |c|
    captures = CALLER_RE.match(c)
    [captures[1], captures[2], captures[4]]
  end
end
begin
  raise_exception
rescue Exception => e
  puts "Exception history:"
  first = true
  parse_caller(e.backtrace).each do |file, line, method|
    puts %{ #{first ? "L" : "because l"}ine #{line} in "#{file}"} +
         %{ called "#{method}" }
    first = false
  end
end

Exception history:
Line 2 in "(irb)" called "raise_exception"
because line 24 in "(irb)" called "irb_binding"
because line 52 in "/usr/lib/ruby/1.8/irb/workspace.rb" called "irb_binding"
because line 0 in "" called ""

Exception history:
 Line 2 in "(irb)" called "raise_exception" 
 because line 17 in "(irb)" called "irb_binding" 
 because line 52 in "/usr/lib/ruby/1.8/irb/workspace.rb" called "irb_binding" 
 because line 52 in "/usr/lib/ruby/1.8/irb/workspace.rb" called ""