紅寶石，二進制字符串XOR隨機字節

Question

我有一串二進制數據，並希望選擇一個字符，並^它由0xff。有沒有簡單的方法來做到這一點？例如：

x = "test\223\434t" 
r = rand(x.length) 
c = x[r].unpack("H*")^0xff # This doesnt work 
# Re concat the string 

Answer 1

bytes = x.bytes.to_a 
# => [116, 101, 115, 116, 147, 28, 116] 
bytes[rand(bytes.length)]^0xff 
# => 139