backslash.rb

irb(main):001:0> s = 92.chr
=> "\\"
irb(main):002:0> s.size
=> 1
irb(main):003:0> puts s
\
=> nil
irb(main):004:0> s2 = s + s
=> "\\\\"
irb(main):005:0> s2.size
=> 2
irb(main):006:0> puts s2
\\
=> nil