print hex dump of a string

hex_dump.rb

# hex_dump.rb
# print hex dump of a string
module HexDump
  module_function
  def hex_dump(str)
    cs = str.unpack 'C*'
    puts "[#{cs.size} bytes]"
    addr = 0
    loop do
      cs16 = cs.shift 16
      break if cs16.empty?
      hexs = cs16.map{|x| "%02x" % x}.join ' '
      chrs = cs16.map{|x| (31 < x && x < 127) ? x.chr : '.'}.join
      puts "%08x %-47s %s" % [addr, hexs, chrs]
      addr += 16
    end
  end
end

if $0 == __FILE__
  HexDump.hex_dump File.read __FILE__
end