SafeYAML.rb

require 'psych'

module SafeYAML

  def self.dump obj, io = nil, options = {}
    visitor = Psych::Visitors::YAMLTree.new(options)
    visitor << obj
    ast = visitor.tree

    ast.grep(Psych::Nodes::Scalar).each do |node|
      node.style  = Psych::Nodes::Scalar::DOUBLE_QUOTED if
        node.value =~ /^0[xbod]+/i && node.plain && node.quoted
    end

    begin
      ast.yaml
    rescue
      # The `yaml` method was introduced in later versions, so fall back to
      # constructing a visitor
      Psych::Visitors::Emitter.new(io, options).accept ast
    end
  end
end

puts SafeYAML::dump(hash)