From: Carlos <angus@...>
Date: 2005-03-23T04:20:19+09:00
Subject: Re: Reading and writing a binary file

[Chris G�nther <cg_@gmx.de>, 2005-03-22 12.29 CET]
> Thanks Robert,
> 
> you are absolutely right with your remarks using a block. The code I 
> posted was just a small copied fraction of the real code, in which I 
> cannor use a block because the same fd will be stored in a hash for 
> later usage by another method.
> Anyway, meanwhile I found the cause of this problem (again you are 
> right, it was not in the code I posted) , but now I have another related 
> problem that tricks my mind. I am trying to patch binary data in a file.
> Unfortunately the data I am patching is not the data I get when reading 
> it back from the patched binary file.
> Any ideas??

All your problems come from the fact that your are opening the file for
appending ("ab+") instead of for reading ("r+b"). With "ab+", you can set fd.pos=0,
if you want, but it will always write at the end of file.