June 03, 2009

Working with binary data in irb

Since I have been workign on a ruby port of a windows program that has a binary format, I find myself having to examine the memory contents in Visual Studio and try to reproduce the same output in ruby. Well, maybe it is years of pratice, but I find it much easier to read the hex output than the octal that ruby uses. This is something I normally want when working in IRB or as fixture data in my tests. So to make this a little easier I extended Integer and String. I wound up dumping this code into my .irbrc file so I could easily cut-n-paste the memory from windows.

class Integer
  def to_binary_s
    bits = self.to_s(2)
    prepend = (8 - bits.length % 8)
    bits = ('0' * prepend) + bits
    return [bits].pack('B*')
  end
end
class String
  def read_hex_s
    self.gsub(" ", "").hex.to_binary_s
  end
  def to_hex_s
    self.unpack("H*")[0]
  end
end