Assuming I have two binary files A and B, how can I subtract the bytes of file B from the bytes of file A and store the result in file C. I would like to perform this operation using only tools defined in the POSIX spec such as dd (Or failing that something which is likely to be found on most systems). My plan is to generate a new file (file C) in such a way that I can later add the bytes of this new file to the bytes of file B and restore the original file A.
The operation does not necessarily need to be subtraction so long as file C represents the difference in a way which is completely reversible. The solution can assume that file A will always be larger than file B.
question from:
https://stackoverflow.com/questions/65928160/posix-subtract-bytes-of-file-b-from-file-a 与恶龙缠斗过久,自身亦成为恶龙；凝视深渊过久,深渊将回以凝视…
