bxor

Chandrashekhar Mullaparthi <>
Wed Feb 19 18:47:39 CET 2003


You could convert them to integers, bxor them and then convert the result to
a binary again.

bin_bxor(Bin1, Bin2) ->
    Sz1 = size(Bin1)*8,
    Sz2 = size(Bin2)*8,
    <<Int1:Sz1>> = Bin1,
    <<Int2:Sz2>> = Bin2,
    Int3 = Int1 bxor Int2,
    Sz3 = max(Sz1, Sz2),
    <<Int3:Sz3>>.

max(Int1, Int2) when Int1 >= Int2 -> Int1;
max(Int1, Int2) when Int1 < Int2 -> Int2.

cheers
Chandru

-----Original Message-----
From: Dan Melomedman [mailto:]
Sent: 19 February 2003 17:29
To: 
Subject: Re: bxor


Matthias Lang wrote:
> 
> Dan Melomedman writes:
>  > Hi. I need to bxor other datatypes than integers. What's the
>  > recommended way of doing something like this? Thanks.
> 
> It depends on what you want to do and how fast you want to do it and
> how long you want to spend programming it. 

It doesn't need to be fast, and I don't want to spend too much time
programming just to be able to XOR. So I am hoping there's an easy way.

> A simple byte-wise approach to XOR-ing the binary Bin with a constant is:
> 
>   list_to_binary( [X bxor 123 || X <- binary_to_list(Bin)] )

I think initially I'd like to be able to XOR two binaries. Or two lists.
What if the sizes of the two binaries differ? Will I need to pad one of
them to the size of the other? Thanks much.



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