What the heck is up with BINARY file i/o?

[Zack]

I want to make a program, very basic, that will XOR the first byte in a file with a code, and replace that byte with the new character.

Code:

dim as string infile
input "infile: ",infile
dim as ubyte code
input "code:",code
open infile for binary as #1
dim as ubyte temp,c
get #1,1,temp
c=temp xor code
put #1,1,temp xor code
close #1

It simply doesn't work. It ruins the file, adding extra characters and changing the size of the file. Any insight?

[DrV]

The expression 'temp xor code' that you are using in the PUT statement is evaluated in a full 32-bit integer.  Cast to a UByte or do it in a temporary variable to get the right results.

[Zack]

Thanks, it works. Funny, I tried that with the c=... line, but I forgot to use c instead in the PUT statement.