str.split(//).each {|e|print (e.unpack('H*').to_s + "\n")}
#irb
# 52
# 75
# 62
# 79
# =>["R", "u", "b", "y"]
使用_itoa()char *_itoa( int value, char *string, int radix )
value → 欲转换的数值
string → 存放转换结果的字串
radix → 进制
int number = 12345
char string[25]
itoa(number, string, 10) //按十进制转换
printf("integer = %d string = %s\n", number, string)
integer = 12345 string = 12345 －－说明12345的十进制表示就是12345
