ruby de dupe

gistfile1.rb

# dedupe.rb
# Sean Stephenson
# 2009-10-20


#################################
#                               #
#  takes one file as input.     #
#  reads a line and writes      #
#  this line to output file     #
#  if and only if that line     #
#  is unique (i.e. the line     #
#  exists nowhere else in       #
#  the input file.)             #
#                               #
#################################


h  = Hash.new
in = File.new('in.txt')

while (str = in.gets)
  str.chomp!
  h[str]!=nil ? h[str]+=1 : h.merge!({str => 0})
end


out = File.new('out.txt', 'w+')

h.each do |key, value|
  out.puts "#{key}" if value == 0
end