bef = IO.read(__FILE__)
aft = $<.read(bef.bytesize-1)
bef.chars.zip(aft.chars).each_with_index do |cc,i|
    if cc[0] != cc[1]
        p i
        puts '"'+cc[0]+'"'
        puts '"'+cc[1]+'"'
        STDOUT.flush
        exit
    end
end
abort "RE: bef.len=#{bef.bytesize}, aft.len=#{aft.bytesize}"