serialized replace

gistfile1.rb

    def serialized_replace!(source_field, dest_field)
      length_delta = source_field.length - dest_field.length

      sql_content.gsub!(/s:(\d+):([\\'"]+)(.*?)\2;/) do |match|
        length = $1.to_i
        delimiter = $2
        string = $3

        string.gsub!(/#{Regexp.escape(source_field)}/) do |match|
          length -= length_delta
          dest_field
        end

        %(s:#{length}:#{delimiter}#{string}#{delimiter};)
      end
    end