require 'libcrc' strz = "\0" * 70 11.times { |li| 3.times { |oi| str = strz.dup str[li] = (1 << oi) puts "0x%.8x" % CRC.calc_crc(str, 70, 0xffffffff) } } puts "z 0x%.8x" % CRC.calc_crc(strz, 70, 0xffffffff)