问题
I am working on unpacking a binary file for the first time in Ruby. Already found the unpack method which works pretty nice. Which according to the docs works perfect for 8(1 byte),16(2 byte),32(4 byte) and 64 bit(8 byte).
But now I have to unpack 5 bytes. How do I do this?
Thx in advance!
回答1:
To literally unpack five bytes: str.unpack 'C5'
That gives you five byte values as unsigned ints. The question is how to reinterpret those ints as a single data type. Pack/unpack only recognize the standard power of two sizes, so you'll have to do that part manually.
For example, to get a little endian unsigned 40-bit int
bytes = str.unpack 'C5'
int = bytes.map.with_index { |byte, i| byte << (i * 8) }.reduce(:+)
If you need to do something more sophisticated like a signed type or a float... good luck.
来源：https://stackoverflow.com/questions/55125275/ruby-unpack-binary