a___zsh_output

$ ./loader.rb input.rb 
hi
true
$ 

input.rb

puts 'hi'
'lololol'

loader.rb

#!/usr/bin/env ruby

require 'stringio'

file = ARGV[0]

exit 1 if ARGV.length == 0

$stdout = $stderr = StringIO.new

ret = begin
  load file
rescue Exception => e
  "#{e.class}: #{e.message}"
end

out = $stdout.string

$stdout = STDOUT
$stderr = STDERR

puts out
puts ret