From: William James <w_a_x_man@...>
Date: 2005-12-11T23:42:37+09:00
Subject: Re: new to Ruby - pls help in translating this

Eric Hodel wrote:

> seen = {}
>
> ARGF.each do |elem|
>    print elem if seen.include? elem
>    seen[elem] = true
> end

seen = {}
while s = gets
  print s if seen.key? s
  seen[ s ] = nil
end

Or:

seen = Hash.new(0)
while s = gets
  print s if ( seen[s] += 1 ) > 1
end