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Re: distributing data across a structure (new to c please help)

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On Mon, 2012-08-20, Dennis Yurichev wrote:
> nwdpil <mkeput@gmail.com> writes:
>
>> the ulimate goal is to read the MZ header from a binary windows pe
>> file, which is simple enough. anyway the theory goes (and this is the
>> bit i dont understand im new to c programming) i memcpy the data from
>> the file ACROSS a struct. is this possible?
...
>> typedef struct _test {
>> 	char b[8];
>> 	char bb[8];
>> }; test, *ptest;
>
> Also, do not forget about C compiler may align all struct members by 4
> bytes on x86 and 8 bytes on Win64. 
> Since Windows PE file fields are all differently sized and this is very
> important, please consult "pack" pragma:
> http://msdn.microsoft.com/en-us/library/2e70t5y1(v=vs.80).aspx

Or skip the "map binary data to a struct" strategy and stick to
portable C, reading the MZ header octet by octet from an uint8_t
array.  I find this much easier in the long run. For example, you
avoid endianness issues.

/Jorgen

-- 
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\X/     snipabacken.se>   O  o   .
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distributing data across a structure (new to c please help) nwdpil <mkeput@gmail.com> - 2012-08-09 20:32 -0500
  Re: distributing data across a structure (new to c please help) James Kuyper <jameskuyper@verizon.net> - 2012-08-10 00:43 -0500
  Re: distributing data across a structure (new to c please help) Dennis Yurichev <dennis_mailing_lists@conus.info> - 2012-08-20 14:17 -0500
    Re: distributing data across a structure (new to c please help) Keith Thompson <kst-u@mib.org> - 2012-08-20 22:10 -0500
    Re: distributing data across a structure (new to c please help) Jorgen Grahn <grahn+nntp@snipabacken.se> - 2012-08-20 22:11 -0500

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