#!/usr/bin/env ruby

#Author: Eric Stratmann
#Date: 2006-12-01
#Description: Takes a ruby file as input and outputs a modified file
#             with a new method quine which returns the source code
#             of the modified file

abort("Usage: quineit.rb INFILE [OUTFILE]") if ARGV.length < 1 or ARGV.length > 2
input = ARGV[0]


bang = String.new
file = File.readlines(input) #Read file into an array
bang = file[0] + "\n" if file[0] =~ /#!/ #We can't put anything before #!/usr/...
escaped = file.map{|line| line.inspect[1...-1]}.flatten
file.flatten!

start = "def quine\n\ts = " #Beginning of string, so we can test length
loc = start.length + bang.length - 1 #Everything up to "s = " in the string 

out = ARGV[1] ? File.open(ARGV[1], "w") : STDOUT #Writing to file or stdout?

out.print bang
out.print "#{start}\"#{bang.inspect[1...-1]}def quine\\n\\ts = \\n\\t"
out.puts "s[0..#{loc}] + s.inspect + s[#{loc + 1}..-1]\\nend\\n\\n#{escaped}\""
out.puts "\ts[0..#{loc}] + s.inspect + s[#{loc + 1}..-1]"
out.puts "end"
out.puts
out.puts file